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Attosecond electron bunch compression scheme based on transverse gradient undulator 认领 引用
1
作者 Liu Yinghan Gu Duan 《强激光与粒子束》 CAS CSCD 北大核心 2026年第6期131-138,共8页
[Background]Sub-femtosecond electron beams offer enormous promise for furthering ultrafast research,including ultrafast electron diffraction and free-electron lasers.However,traditional compression techniques are esse... [Background]Sub-femtosecond electron beams offer enormous promise for furthering ultrafast research,including ultrafast electron diffraction and free-electron lasers.However,traditional compression techniques are essentially constrained by slice energy spread and cannot stably produce sub-femtosecond electron beams.[Purpose]This work proposes a unique compression strategy based on a transverse gradient undulator(TGU).The slice energy spread is actively reduced by taking advantage of the link between transverse position and energy modulation in the TGU,hence breaking the compression limit.[Methods]Theoretical proof has been provided for the suppression effect of TGU on slice energy spread,with confirmation of the relevant parameters influencing this effect.A complete compression beamline has been designed,and numerical simulations have been conducted.[Results]Numerical simulations show that the proposed approach may compress the electron beam from 50 fs to less than 1 fs,with a compression factor over 52.09.Although phase jitter in the electron gun’s electric field affects the final compression pulse length,adjusting the modulation laser parameters of the TGU can effectively improve the compression results.[Conclusions]This study confirms that the TGU with flexible tunability and suppression of slice energy dispersion can be explored for application in ultrafast science research. 展开更多
关键词 attosecond electron bunch bunch compression transverse gradient undulator slice energy spread ultrafast electron diffraction
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Calculation algorithm for the space charge force of a train with infinite bunches 认领 引用 被引量：1
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作者 San-Hai Ren Hong-Yu Li +5 位作者 Jia-Ru Shi Hao Zha Wei-Hang Gu Qiang Gao Qian Tan Huai-Bi Chen 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2025年第6期13-25,共13页
Industrial linear accelerators often contain many bunches when their pulse widths are extended to microseconds.As they typically operate at low electron energies and high currents,the interactions among bunches cannot... Industrial linear accelerators often contain many bunches when their pulse widths are extended to microseconds.As they typically operate at low electron energies and high currents,the interactions among bunches cannot be neglected.In this study,an algorithm is introduced for calculating the space charge force of a train with infinite bunches.By utilizing the ring charge model and the particle-in-cell(PIC)method and combining analytical and numerical methods,the proposed algorithm efficiently calculates the space charge force of infinite bunches,enabling the accurate design of accelerator parameters and a comprehensive understanding of the space charge force.This is a significant improvement on existing simulation software such as ASTRA and PARMELA that can only handle a single bunch or a small number of bunches.The PIC algorithm is validated in long drift space transport by comparing it with existing models,such as the infinite-bunch,ASTRA single-bunch,and PARMELA several-bunch algorithms.The space charge force calculation results for the external acceleration field are also verified.The reliability of the proposed algorithm provides a foundation for the design and optimization of industrial accelerators. 展开更多
关键词 Particle-in-cell method Space charge force Algorithm Infinite bunches
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Influence of Ash from Oil Mill Boiler Emptying on Oil Palm Bunches Production 认领 引用
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作者 Bini Yao Christophe Adou Kouassi Quevin Yao +2 位作者 Eric Francis Soumahin Dolou Charlotte Tonessia Tonoh Hilaire Kouakou 《Journal of Agricultural Chemistry and Environment》 2025年第1期121-131,共11页
The use of organic fertilizers is less expensive and advantageous for both the development of the plant and the sanitation of the environment. This is why this investigation aims to promote the ash from emptying of oi... The use of organic fertilizers is less expensive and advantageous for both the development of the plant and the sanitation of the environment. This is why this investigation aims to promote the ash from emptying of oil mill boilers as a source of organic fertilization in the production of palm bunches. To do this, different doses of oil mill boiler emptying ash were tested on oil palms in production. The results showed that the oil palms responded favorably regardless of the dose of oil mill boiler emptying ash. Thus, the comparison of the different doses Tv1 (1 kg), Tv2 (1.5 kg), Tv3 (2 kg), Tv4 (3 kg), Tv5 (4 kg), Tv6 (5 kg) and Tv7 (7 kg) showed that the high doses led to an increase in the weight of the bunches. Better still, the Tv6 treatment at a dose of 5 kgree proved to be optimal for good production of palm bunches with a gain of 73.9% compared to the treatment without oil mill boiler emptying ash (absolute control). 展开更多
关键词 Ash Bunch Incinerated Oil Palm Bunch Roundups Oil Palm Côte d’Ivoire
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Synthesis and Application of Activated Charcoal from Indonesian Sugar Palm Bunches (Arenga longipes) as a Potential Absorbent for Heavy Metals 认领 引用
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作者 Luthfi Hakim Yunida Syafriani Lubis +7 位作者 ApriHeri Iswanto Harisyah Manurung Jayusman Widya Fatriasari Petar Antov Tomasz Rogozi′nski Lee Seng Hua Nur Izyan Wan Azelee 《Journal of Renewable Materials》 EI CAS 2025年第12期2354-2373,共20页
Activated charcoals were synthesized from sugar palm bunches(SPB)of the native tree of Arenga longipes in Indonesia.The synthesized activated charcoal(AC)was characterized,and utilized as an absorbent for heavy metals... Activated charcoals were synthesized from sugar palm bunches(SPB)of the native tree of Arenga longipes in Indonesia.The synthesized activated charcoal(AC)was characterized,and utilized as an absorbent for heavy metals(lead/Pb and copper/Cu)through thermal activation.The synthesis of AC was accomplished through furnace activation at temperatures of 500℃,600℃,700℃,and 800℃.Acid chlorides were blended with the SPB-AC samples at 5%impregnation level and subsequently subjected to washing for activation,resulting in the elimination of volatile substances and ash content,which facilitates the development of a porous structure in the activated charcoal.The proximate analysis results indicated a reduction in weight and moisture content with an increase in activation temperature.The C-O,C=C,O-H stretching chains were not visible in the SPB-AC,indicating that the chains were broken after activation.The treatments at 600℃ and 700℃ exhibited superior thermal stability relative to the others.Moreover,there was a notable reduction in the signal strength of low-crystallinity amorphous carbon,indicating that the high-temperature treatment substantially altered the structural characteristics of the crystal.The SPB-AC produced at 700℃ exhibited a primarily microporous architecture,characterized by a maximal surface area,reduced total pore volume,and small particle size.In conclusion,elevating the activation temperature to 700℃ leads to notable improvement in the adsorption of Pb(91.61%)and Cu(95.19%)metals. 展开更多
关键词 Absorbent activated charcoal Arenga longipes heavy metal sugar palm bunch
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Charcoal Briquette Manufactured from Indonesian Sugar Palm Bunches(Arenga longipes Mogea)as Biomass-Based New Renewable Energy 认领 引用
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作者 Luthfi Hakim Apri Heri Iswanto +10 位作者 Yunida Syafriani Lubis Adam Jagwani Wirawan Ridwanti Batubara Nam Hum Kim Petar Antov Tomasz Rogozinski Lee Seng Hua Lum Wei Chen Rangabhashiyam Selvasembian Jayusman Jajang Sutiawan 《Journal of Renewable Materials》 EI CAS 2025年第3期639-652,共14页
The utilisation of sugar palm bunches-charcoal briquettes(SPB-CB)represents a significant advancement in biomass energy.This study aimed to analyse the properties of charcoal briquettes produced from SPB(Arenga longip... The utilisation of sugar palm bunches-charcoal briquettes(SPB-CB)represents a significant advancement in biomass energy.This study aimed to analyse the properties of charcoal briquettes produced from SPB(Arenga longipes).The experiment involved categorising the dimensions of charcoal powder into three specific particle sizes:20-40 mesh,40-60 mesh,and particles that could pass through a 60-mesh screen.The charcoal powder will be combined with tapioca as a binding agent at three specific concentrations:11%,13%,and 15%.The research findings indicate that the samples underwent 60 mesh passes achieved the maximum briquette density,with an average value of 0.58 g/cm3.The highest attainable compressive strength sample value was 27.52 kgf/cm2,which was attained by employing 60 mesh size and 15%adhesive concentration.The calorimetric investigation showed that SPB-charcoal had the highest calorific value of 25.88 MJ/kg,while the SPB-CB had a little lower caloric value of 24.64 MJ/kg.The ash content and volatile matter values showed that the briquettes with the lowest ash content had values of 10.49%and 32.65%,respectively.Furthermore,the carbon fixation values varied between 16.65%and 52.36%.Thermogravimetric analysis indicates that charcoal derived from SPB exhibits superior thermal characteristics compared to charcoal briquettes.However,thermal properties of SPB charcoal do not show significant differences when compared to charcoal briquettes that have been processed with a mesh size of 20-40 and include 11%adhesive.According to this research,it may be inferred that charcoal briquettes made from sugar palm bunches meet the requirements specified in SNI 01-6235-2000. 展开更多
关键词 Arenga longipes sugar palm bunch charcoal briquettes calorific value
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Characteristics of Food Packaging Bioplastics with Nanocrystalline Cellulose (NCC) from Oil Palm Empty Fruit Bunches (OPEFB) as Reinforcement 认领 引用
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作者 Maryam Rahayu Puji +5 位作者 Luthfi Muhammad Zulfikar Ikhsandy Ferry Nadiyah Khairun Hidayat Ilyas Rushdan Ahmad Syafri Edi 《Journal of Renewable Materials》 EI CAS 2025年第12期2431-2451,共21页
The development of the bioplastics industry addresses critical issues such as environmental pollution and food safety concerns.However,the industrialization of bioplastics remains underdeveloped due to challenges such... The development of the bioplastics industry addresses critical issues such as environmental pollution and food safety concerns.However,the industrialization of bioplastics remains underdeveloped due to challenges such as high production costs and suboptimal material characteristics.To enhance these characteristics,this study investigates bioplastics reinforced with Nanocrystalline Cellulose(NCC)derived from Oil Palm Empty Fruit Bunches(OPEFB),incorporating dispersing agents.The research employs a Central Composite Design from the Response SurfaceMethodology(RSM)with two factors:the type of dispersing agent(KCl and NaCl)and the NCC concentration fromOPEFB(1%-5%),along with the dispersing agent concentration(0.5%-3%).The objective of this study is to analyze the characteristics of food packaging bioplastics composed of a sago starch matrix,NCC from OPEFB,and dispersing agents.The novelty of this research lies in the development of food packaging bioplastics using sago starch reinforced withNCC fromOPEFB and the addition of dispersing agents(KCl andNaCl).The results indicate that incorporating NCC from OPEFB and dispersing agents significantly enhances the bioplastic’s properties,meeting the JIS 2-1707 standards for food packaging plastic films.The bioplastic was tested as packaging for gelamai(a traditional food from West Sumatra)through an organoleptic evaluation.Consumer acceptance in terms of taste,smell,and color remained satisfactory up to the 14th day.Further research is required to scale up production using the optimal formulation identified in this study.Additionally,this bioplastic is recommended for use as packaging for various food products. 展开更多
关键词 Oil Palm Empty Fruit Bunches nanocrystalline cellulose bioplastics food packaging
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Direct observation of bunching of elementary steps on protein crystals under forced flow conditions 认领 引用
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作者 Gen Sazaki Guoliang Dai 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2015年第4期173-176,共4页
Bunching of elementary steps by solution flow is still not yet clarified for protein crystals. Hence, in this study, we observed elementary steps on crystal surfaces of model protein hen egg-white lysozyme （HEWL） un... Bunching of elementary steps by solution flow is still not yet clarified for protein crystals. Hence, in this study, we observed elementary steps on crystal surfaces of model protein hen egg-white lysozyme （HEWL） under forced flow conditions, by our advanced optical microscopy. We found that in the case of a HEWL solution of 99.99% purity, forced flow changed bunched steps into elementary ones （debunching） on tetragonal HEWL crystals. In contrast, in the case of a HEWL solution of 98.5% purity, forced flow significantly induced bunching of elementary steps. These results indicate that in the case of HEWL crystals, the mass transfer of impurities is more significantly enhanced by forced solution flow than that of solute HEWL molecules. We also showed that forced flow induced the incorporation of microcrystals into a mother crystal and the subsequent formation of screw dislocations and spiral growth hillocks. 展开更多
关键词 In situ observation Step bunching Step debunching Elementary steps Forced flow Protein crystal
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Statistical optimization of adsorption processes for removal of 2,4-dichlorophenol by activated carbon derived from oil palm empty fruit bunches 认领 引用 被引量：14
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作者 Md.Zahangir ALAM Suleyman A.MUYIBI Juria TORAMAE 《Journal of Environmental Sciences》 SCIE EI CAS 2007年第6期674-677,共4页
The adsorption capacity of activated carbon produced from oil palm empty fruit bunches through removal of 2,4-dichlorophenol from aqueous solution was carried out in the laboratory. The activated carbon was produced b... The adsorption capacity of activated carbon produced from oil palm empty fruit bunches through removal of 2,4-dichlorophenol from aqueous solution was carried out in the laboratory. The activated carbon was produced by thermal activation of activation time with 30 min at 800℃. The adsorption process conditions were determined with the statistical optimization followed by central composite design. A developed polynomial model for operating conditions of adsorption process indicated that the optimum conditions for maximum adsorption of phenolic compound were： agitation rate of 100 r/min, contact time of 8 h, initial adsorbate concentration of 250 mg/L and pH 4. Adsorption isotherms were conducted to evaluate biosorption process. Langmuir isotherm was more favorable （R^2=0.93） for removal of 2,4-dichlorophenol by the activated carbon rather than Freundlich isotherm （R^2=0.88）. 展开更多
关键词 activated carbon adsorption oil palm empty fruit bunches 2,4-dichlorophenol
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Preliminary study on detection and cleaning of parasitic bunches 认领 引用 被引量：8
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作者 Jun He Yan-Feng Sui +7 位作者 Yan-Hua Lu Di Yin Zhe Duan Sai-Ke Tian De-Chong Zhu Ying Zhao Jun-Hui Yue Jian-She Cao 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2021年第10期1-11,共11页
To establish a nuclear resonant scattering beamline at the High Energy Photon Source(HEPS),it is essential to develop tools for detection and cleaning of parasitic bunches,for meeting the stringent demands on bunch pu... To establish a nuclear resonant scattering beamline at the High Energy Photon Source(HEPS),it is essential to develop tools for detection and cleaning of parasitic bunches,for meeting the stringent demands on bunch purity.To this end,a novel time-correlated single-photon counting system was implemented at the electron storage ring of the Beijing Electron–Positron Collider II(BEPCII).The purity deterioration process over a week-long operation was recorded by the system.In this study,the mechanism of impurity growth was analyzed by numerical methods and validated on measurements.The agreement between the experimental results and the cal-culation was fairly good.Two main sources of parasitic bunches,pre-accelerators and the Touschek scattering were confirmed.A bunch-cleaning technique,based on a sinu-soidal signal mixed with a pseudo-square wave,was also developed and implemented,and its capability to improve the bunch purity to the level of 10–7 was experimentally demonstrated.We present the experimental setup,princi-ple,and measurement results of a system for detection and cleaning of parasitic bunches. 展开更多
关键词 Parasitic bunches Impurity growth High energy photon source(HEPS)
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Activated carbons derived from oil palm empty-fruit bunches: Application to environmental problems 认领 引用 被引量：3
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作者 Md. Zahangir ALAM Suleyman A. MUYIBI +1 位作者 Mariatul F. MANSOR Radziah WAHID 《Journal of Environmental Sciences》 SCIE EI CAS 2007年第1期103-108,共6页
Activated carbons derived from oil palm empty fruit bunches （EFB） were investigated to find the suitability of its application for removal of phenol in aqueous solution through adsorption process, Two types of activ... Activated carbons derived from oil palm empty fruit bunches （EFB） were investigated to find the suitability of its application for removal of phenol in aqueous solution through adsorption process, Two types of activation namely; thermal activation at 300, 500 and 800℃and physical activation at 150℃ （boiling treatment） were used for the production of the activated carbons. A control （untreated EFB） was used to compare the adsorption capacity of the activated carbons produced from these processes. The results indicated that the activated carbon derived at the temperature of 800℃ showed maximum absorption capacity in the aqueous solution of phenol. Batch adsorption studies showed an equilibrium time of 6 h for the activated carbon at 800℃. It was observed that the adsorption capacity was higher at lower values of pH （2-3） and higher value of initial concentration of phenol （200-300 mg/L）. The equilibrium data fitted better with the Freundlich adsorption isotherm compared to the Langmuir. Kinetic studies of phenol adsorption onto activated carbons were also studied to evaluate the adsorption rate. The estimated cost for production of activated carbon from EFB was shown in lower price （USD 0.50/kg of activated carbon） compared the activated carbon from other sources and processes. 展开更多
关键词 activated carbon adsorption lignocellulosic empty fruit bunches phenolic compound solid waste management
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High-brightness photo-injector with standing-wave buncher-based ballistic bunching scheme for inverse Compton scattering light source 认领 引用 被引量：4
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作者 Jian-Xin Wang Kui Zhou +7 位作者 Peng Li De-Xin Xiao Li-Jun Shan Xu-Ming Shen Yu Liu Zheng Zhou Han-Bin Wang Dai Wu 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2022年第4期51-61,共11页
We report our recent progress in the design and simulation of a high-brightness S-band photo-injector with a ballistic bunching scheme aimed at driving an inverse Compton scattering(ICS)X-ray source.By adding a short ... We report our recent progress in the design and simulation of a high-brightness S-band photo-injector with a ballistic bunching scheme aimed at driving an inverse Compton scattering(ICS)X-ray source.By adding a short standing-wave buncher between the RF gun and first booster in a conventional S-band photo-injector,electron bunches with a 500 pC charge can be compressed to the sub-picosecond level with very limited input RF power and an unchanged basic layout of the photo-injector.Beam dynamics analysis indicates that fine tuning of the focusing strength of the gun and linac solenoid can well balance additional focusing provided by the standing wave buncher and generate a well-compensated transverse emittance.Thorough bunching dynamics simulations with different operating conditions of the buncher show that a buncher with more cells and a moderate gradient is suitable for simultaneously obtaining a short bunch duration and low emittance.In a typical case of a 9-cell buncher with a 38 MV/m gradient,an ultrashort bunch duration of 0.5 ps(corresponding to a compression ratio of>5)and a low emittance of<1 mm mrad can be readily obtained for a 500 pC electron pulse.This feasible ballistic bunching scheme will facilitate the implementation of an ultrashort pulse mode inverse Compton scattering X-ray source on most existing S-band photo-injectors. 展开更多
关键词 Beam brightness Ballistic bunching Emittance compensation Compton scattering X-ray source
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Baseline recovery method to measure bunch charge under low-current mode of SSRF 认领 引用 被引量：3
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作者 CHEN Zhichu LENG Yongbin +2 位作者 ZOU Yi YAN Yingbin ZHOU Weimin 《Nuclear Science and Techniques》 SCIE CAS CSCD 2011年第5期261-264,共4页
The top-up injection mode of Shanghai Synchrotron Radiation Facility(SSRF)needs precise measurement of the beam bunch charges.This is performed by an integration current transformer,but the beam current is too low to ... The top-up injection mode of Shanghai Synchrotron Radiation Facility(SSRF)needs precise measurement of the beam bunch charges.This is performed by an integration current transformer,but the beam current is too low to neglect the background noise.In order to wipe out the noise coming from the ground loops,the adaptable polynomial fitting method is used to extract the baseline,instead of using the constant background or the linear background model.Test results show that the system resolution can be improved to<3%. 展开更多
关键词 Beam diagnostics ICT Bunch charge monitor Top-up SSRF
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Characteristics of terahertz coherent transition radiation generated from picosecond ultrashort electron bunches 认领 引用 被引量：6
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作者 刘文鑫 唐传祥 黄文会 《Chinese Physics B》 SCIE EI CAS 2010年第6期221-230,共10页
This paper presents a method of generating terahertz （THz） coherent transition radiation （CTR） from picosecond ultrashort electron bunches including single and train bunches, which are produced by a photocathode r... This paper presents a method of generating terahertz （THz） coherent transition radiation （CTR） from picosecond ultrashort electron bunches including single and train bunches, which are produced by a photocathode radio frequency gun. The radiation characteristics of THz CTR including formation factor and energy spectrum are analysed in detail. With the help of a 2-dimensional particle-in-cell simulation, the radiation characteristics including power, energy and magnetic field are analysed. The results show that the radiation frequency can be adjusted by tuning the repetition frequency of the train bunch and the energy can be enhanced with the train bunches. 展开更多
关键词 coherent transition radiation photocathode radio-frequency gun ultrashort electron bunches particle-in-cell
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Terahertz coherent transition radiation based on an ultrashort electron bunching beam 认领 引用 被引量：3
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作者 刘文鑫 黄文会 +3 位作者 杜应超 颜立新 吴岱 唐传祥 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第7期165-171,共7页
The experimental result of terahertz （THz） coherent transition radiation generated from an ultrashort electron bunching beam is reported. During this experiment, the window for THz transmission from ultrahigh vacuum... The experimental result of terahertz （THz） coherent transition radiation generated from an ultrashort electron bunching beam is reported. During this experiment, the window for THz transmission from ultrahigh vacuum to free air is tested. The compact measurement system which can simultaneously test the THz wave power and frequency is built and proofed. With the help of improved Martin-Puplett interferometer and Kramers-Krong transform, the longitudinal bunch length is measured. The results show that the peak power of THz radiation wave is more than 80 kW, and its radiation frequency is from 0.1 THz to 1.5 THz. 展开更多
关键词 coherent transition radiation ultrashort electron bunching beam Martin-Puplett interferometer compact measurement system
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Low specific contact resistance on epitaxial p-type 4H-SiC with a step-bunching surface 认领 引用 被引量：2
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作者 韩超 张玉明 +4 位作者 宋庆文 汤晓燕 张义门 郭辉 王悦湖 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第11期452-459,共8页
This paper reports the performances of Ti/Al based ohmic contacts fabricated on highly doped p-type 4H-SiC epitaxial layer which has a severe step-bunching surface. Different contact schemes are investigated based on ... This paper reports the performances of Ti/Al based ohmic contacts fabricated on highly doped p-type 4H-SiC epitaxial layer which has a severe step-bunching surface. Different contact schemes are investigated based on the AI：Ti composition with no more than 50 at.% Al. The specific contact resistance （SCR） is obtained to be as low as 2.6 × 10-6Ωcm2 for the bilayered Ti（100 nm）/Al（100 nm） contact treated with 3 rain rapid thermal annealing （RTA） at 1000 ℃. The microstructure analyses examined by physical and chemical characterization techniques reveal an alloy-assisted ohmic contact formation mechanism, i.e., a high degree of alloying plays a decisive role in forming the interfacial ternary Ti3SiC2 dominating the ohmic behavior of the Ti/Al based contact. Furthermore, a globally covered Ti3 SiC2 layer with （0001）-oriented texture can be formed, regardless of the surface step bunching as well as its structural evolution during the metallization annealing. 展开更多
关键词 4H-SiC p-type ohmic contact alloying step bunching
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Monitoring the charge bunch-by-bunch for the SSRF storage ring:Development and application 认领 引用 被引量：2
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作者 LENG Yongbin YAN Yingbin +3 位作者 YU Luyang YUAN Renxian CHEN Zhichu ZHOU Wcimin 《Nuclear Science and Techniques》 SCIE CAS 2010年第4期193-196,共4页
Bunch charge uniformity controlling is very important for top-up operation of the storage ring.In order to monitor filling pattern and measure the bunch charge precisely,a PXI waveform digitizer-based data acquisition... Bunch charge uniformity controlling is very important for top-up operation of the storage ring.In order to monitor filling pattern and measure the bunch charge precisely,a PXI waveform digitizer-based data acquisition system has been developed to retrieve bunch charge information from BPM pickup signals.An effective sampling rate is extended to 400 GHz by waveform rebuilding technology,which overlays multi-turn data into single turn with real time sampling rate of 8 GHz.An on-line evaluation indicates that resolution and linearity of the charge measurement are better than 0.5%at input range of 0.5-12nC. 展开更多
关键词 Beam diagnostics Bunch charge monitor Filling pattern Top-up SSRF
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A discrete-event model to simulate the effect of truck bunching due to payload variance on cycle time, hauled mine materials and fuel consumption 认领 引用 被引量：2
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作者 A.Soofastaei S.M.Aminossadati +1 位作者 M.S.Kizil P.Knights 《International Journal of Mining Science and Technology》 EI CAS CSCD 2016年第5期745-752,共8页
Data collected from truck payload management systems at various surface mines shows that the payload variance is significant and must be considered in analysing the mine productivity,energy consumption,greenhouse gas ... Data collected from truck payload management systems at various surface mines shows that the payload variance is significant and must be considered in analysing the mine productivity,energy consumption,greenhouse gas emissions and associated cost.Payload variance causes significant differences in gross vehicle weights.Heavily loaded trucks travel slower up ramps than lightly loaded trucks.Faster trucks are slowed by the presence of slower trucks,resulting in‘bunching’,production losses and increasing fuel consumptions.This paper simulates the truck bunching phenomena in large surface mines to improve truck and shovel systems’efficiency and minimise fuel consumption.The study concentrated on completing a practical simulation model based on a discrete event method which is most commonly used in this field of research in other industries.The simulation model has been validated by a dataset collected from a large surface mine in Arizona state,USA.The results have shown that there is a good agreement between the actual and estimated values of investigated parameters. 展开更多
关键词 Discrete-event model Simulation Truck bunching Payload variance Cycle time Fuel consumption
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Electron Acceleration and Bunch Generation by Intense Femtosecond Laser Pulse in Preplasma of a Target 认领 引用 被引量：1
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作者 刘明萍 汪庆年 +2 位作者 邓素辉 刘三秋 谢柏松 《Communications in Theoretical Physics》 SCIE CAS 2010年第8期359-364,共6页
We present analytical studies of electron acceleration in the low-density preplasma of a thin solid target byan intense femtosecond laser pulse.Electrons in the preplasma are trapped and accelerated by the ponderomoti... We present analytical studies of electron acceleration in the low-density preplasma of a thin solid target byan intense femtosecond laser pulse.Electrons in the preplasma are trapped and accelerated by the ponderomotive forceas well as the wake field.Two-dimensional particle-in-cell simulations show that when the laser pulse is stopped by thetarget,electrons trapped in the laser pules can be extracted and move forward inertially.The energetic electron bunchin the bubble is unaffected by the reflected pulse and passes through the target with small energy spread and emittance.There is an optimal preplasma density for the generation of the monoenergetic electron bunch if a laser pulse is given.The maximum electron energy is inverse proportion to the preplasma density. 展开更多
关键词 femtosecond laser-plasma interaction electron acceleration monoenergetic electron bunch PIC simulation
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Stress arch bunch and its formation mechanism in blocky stratified rock masses 认领 引用 被引量：3
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作者 Xin Huang Zixin Zhang 《Journal of Rock Mechanics and Geotechnical Engineering》 2012年第1期19-27,共9页
Stress arch is a common phenomenon occurring in continuous materials and has also l:een proved to have great influences on the self-stabilization of soils or rock masses after excavation. In this paper, based on UDEC ... Stress arch is a common phenomenon occurring in continuous materials and has also l:een proved to have great influences on the self-stabilization of soils or rock masses after excavation. In this paper, based on UDEC simulation, stress redistribution after excavation is investigated for a kind of special discontinuous material, i.e. blocky stratified rock mass. A layered stress arch system is observed with each stress arch lying over another. This special phenomenon is defined herein as "stress arch bunch". Effects of dip angle of bedding plane, lateral pressure and joint offset on this stress arch bunch are studied. Its formation mechanism is also discussed based on voussoir beam theory. 展开更多
关键词 blocky stratified rock mass UDEC stress arch bunch voussoir beam
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Space Charge Effect of Bunched Beam With Gaussian Distribution 认领 引用 被引量：1
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作者 Chen, Yinbao Fu, Shinian +1 位作者 Huang, Zhibin Zhang, Zhenhai 《Chinese journal of nuclear physics》 EI 1995年第2期174-178,共5页
The nonlinear space charge effect of a bunched beam with Gaussian distribu-tion in the longitudinal direction is discussed.Some useful formulae are derived for cal-culating the potential induced by a cylinder model of... The nonlinear space charge effect of a bunched beam with Gaussian distribu-tion in the longitudinal direction is discussed.Some useful formulae are derived for cal-culating the potential induced by a cylinder model of space charge in the waveguide of alinac with different combinations of density distribution:Gaussian distribution in thelongitudinal direction versus Kapchinskij Vladimirskij,waterbag,parabolic andGaussian distribution in the transverse direction,rcspectively. 展开更多
关键词 Gaussian distribution in the longitudinal direction Space charge effect Bunched beam
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