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Scalable and reproducible sub-5 nm manufacturing for next-generation devices 认领 引用
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作者 Lijuan Chen Sihai Luo +11 位作者 Dongxu Yang Qi Yuan Yingfang Zhang Bai Sun Jian Lv Xiaoliang Chen Hongmiao Tian Xiangming Li Fenggang Ren Yi Lv Stefan A Maier Jinyou Shao 《International Journal of Extreme Manufacturing》 SCIE EI CAS CSCD 2026年第2期352-390,共39页
The capability to consistently manufacture structures with sub-5 nm features has greatly accelerated scientific advancements in nanoscience and nanotechnology.However,most current methods are serial processes that are... The capability to consistently manufacture structures with sub-5 nm features has greatly accelerated scientific advancements in nanoscience and nanotechnology.However,most current methods are serial processes that are time-consuming and impractical for large-scale manufacturing at the sub-5 nm level.The challenge of achieving scalable and reproducible production of sub-5 nm structures poses a significant hurdle for both fundamental research and commercial implementations.In this review,we explore some representative sub-5 nm fabrication strategies,focusing on approaches that facilitate scalable and reproducible manufacturing.We highlight the most promising techniques such as extreme ultraviolet lithography,electron beam lithography,directed self-assembly and atomic layer lithography that hold potential breakthroughs in both research and industry,based on criteria such as resolution,scalability,reproducibility and their applicability in photonics such as surface-enhanced spectroscopies,terahertz science,and nonlinear optics,as well as in electronics such as quantum devices,molecular devices and memory devices.The evolution of scalable and reproducible sub-5 nm manufacturing methods will ultimately revolutionize next-generation devices,encompassing quantum technologies,neuromorphic computing chips,and the mass production of integrated circuits. 展开更多
关键词 sub-5 nm lithography devices nanofabrication nanostructures
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Tailoring sub-5 nm Fe-doped CeO2nanocrystals within confined spaces to boost photocatalytic hydrogen evolution under visible light 认领 引用 被引量：1
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作者 Giuseppina Iervolino Olimpia Tammaro +4 位作者 Marco Fontana Bruno Masenelli Anne D.Lamirand Vincenzo Vaiano Serena Esposito 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2025年第2期263-277,I0007,共15页
This work aimed to study the efficiency of the reverse micelle(RM)preparation route in the syntheses of sub-5 nm Fe-doped CeO2nanocrystals for boosting the visible-light-driven photocatalytic hydrogen production fr... This work aimed to study the efficiency of the reverse micelle(RM)preparation route in the syntheses of sub-5 nm Fe-doped CeO2nanocrystals for boosting the visible-light-driven photocatalytic hydrogen production from methanol aqueous solutions.The effectiveness of confining precipitation reactions within micellar cages was evaluated through extensive physicochemical cha racterization.In particula r,the nominal composition(0-5 mol%Fe)was preserved as ascertained by ICP-MS analysis,and the absence of separate iron-containing crystalline phases was supported by X-ray diffraction.The effective aliovalent doping and modulation of the optical properties were investigated using UV-Vis,Raman,and photoluminescence spectroscopies.2.5 mol%iron was found to be an optimal content to achieve a significant decrease in the band gap,enhance the concentration of oxygen vacancy defects,and increase the charge carrier lifetime.The photocatalytic activity of Fe-doped CeO2prepared at different Fe contents with RM preparation was studied and compared with undoped CeO2.The optimal iron load was identified to be2.5 mol%,achieving the highest hydrogen production(7566μmol L-1after 240 min under visible light).Moreover,for comparison,the conventional precipitation(P)method was adopted to prepare iron containing CeO2at the optimal content(2.5 mol%Fe).The Fe-doped CeO2catalyst prepared by RM showed a significantly higher hydrogen production than that obtained with the sample prepared by the P method.The optimal Fe-doped CeO2,prepared by the RM method,was stable for six reuse cycles.Moreover,the role of water in the mechanism of photocatalytic hydrogen evolution under visible light was studied through the test in the presence of D2O.The obtained results evidenced that hydrogen was produced from the reduction of H+by the electrons promoted in the conduction band,while methanol was preferentially oxidized by the photogenerated positive holes. 展开更多
关键词 Sub-5nm Fe-doped CeO2 Hydrogen evolution Photocatalysis Visible light Reverse micelles Mesoporous CeO2
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鄂尔多斯盆地东北部奥陶系马五5亚段岩相古地理特征 认领 引用
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作者 石磊 鲁慧丽 +2 位作者 李雪娇 周铭子 李欣阳 《地质科学》 CAS CSCD 北大核心 2026年第1期59-67,共9页
鄂尔多斯盆地东北部奥陶系马五5亚段是天然气勘探的重要目的层系之一,但对该亚段沉积特征认识还不够清楚,制约了下一步勘探部署。为此,综合钻井、岩心和薄片等资料,对盆地东北部奥陶系马五5亚段岩相古地理开展了系统研究,并预测... 鄂尔多斯盆地东北部奥陶系马五5亚段是天然气勘探的重要目的层系之一,但对该亚段沉积特征认识还不够清楚,制约了下一步勘探部署。为此,综合钻井、岩心和薄片等资料,对盆地东北部奥陶系马五5亚段岩相古地理开展了系统研究,并预测了有利储集层分布区。研究结果表明:1)盆地东北部奥陶系马五5亚段发育颗粒滩、微生物丘、云质潟湖和灰质潟湖微相;2)隆坳相间古地理格局控制了奥陶系马五5亚段沉积分异,颗粒滩环中央古隆起成环带分布,微生物丘和云质潟湖沿盆地东部古地貌高部位分布,灰质潟湖主要分布于坳陷区;3)颗粒滩和微生物丘因颗粒堆积或微生物格架而发育先存孔隙,云质潟湖因生物扰动作用和早期白云石化作用而发育孔隙,3类微相是奥陶系马五5亚段有利储集相带。结论认为,乌审旗—吴起地区、米脂地区是盆地东北部奥陶系马五5亚段有利储层分布区,值得进一步探索。 展开更多
关键词 鄂尔多斯盆地东北部 奥陶系 马五5亚段 岩相古地理 丘滩体 云质潟湖
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氟硅嵌段共聚物自组装创制亚5 nm特征微域 认领 引用
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作者 郑立新 肖龙强 侯琳熙 《精细化工》 EI CAS CSCD 北大核心 2026年第3期603-610,670,共8页
通过阴离子聚合(LAP)与端基修饰合成了聚三氟丙基甲基硅氧烷链转移剂(PMTFPS-CTA),结合可逆加成-断裂链转移(RAFT)分别与侧链含苄基(BzMA)、萘甲基(1NpMMA)和蒽甲基(AnMMA)的甲基丙烯酸酯单体聚合,得到了无机/有机杂化嵌段共聚物PMTFPS-... 通过阴离子聚合(LAP)与端基修饰合成了聚三氟丙基甲基硅氧烷链转移剂(PMTFPS-CTA),结合可逆加成-断裂链转移(RAFT)分别与侧链含苄基(BzMA)、萘甲基(1NpMMA)和蒽甲基(AnMMA)的甲基丙烯酸酯单体聚合,得到了无机/有机杂化嵌段共聚物PMTFPS-b-PBzMA、PMTFPS-b-P1NpMMA和PMTFPSb-PAnMMA。通过1HNMR和FTIR表征确定了嵌段共聚物的结构。采用GPC、DSC、TGA、小角X射线散射(SAXS)对其性能进行了测试。结果表明,制得的嵌段共聚物具有较窄的相对分子量分布(Đ<1.5)。3种嵌段共聚物的玻璃化转变温度(50、79、154℃)与失重3%时的温度(即初始热分解温度,275、255、253℃)均适配热退火工艺条件。PMTFPS-b-PBzMA系列材料在80~110℃退火后即可形成层状相,最小特征尺寸为4.9 nm,且域间距(d)与聚合度(N)标度关系满足d∝N0.62,证实了该嵌段共聚物具有强微相分离特性;此外,PMTFPS的高硅含量赋予材料内在刻蚀对比度,为导向自组装光刻提供了兼具分辨率与刻蚀性能的新材料。 展开更多
关键词 嵌段共聚物 聚三氟丙基甲基硅氧烷 聚甲基丙烯酸苄基酯 自组装 亚5 nm 电子化学品
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鄂尔多斯盆地桃7区块马家沟组马五1-5亚段高频层序划分及控储效应 认领 引用
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作者 郭健 刘桂珍 李霖葳 《沉积学报》 CAS CSCD 北大核心 2026年第1期339-354,共16页
【目的】探讨碳酸盐岩地层中高频层序划分及高频沉积旋回的控储效应。【方法】选取鄂尔多斯盆地桃7区块马家沟组马五1-5亚段,以自然伽马能谱测井中Th/U比值曲线为指示曲线,频谱分析结合Fischer图解和岩性组合序列,定量划分高频层序。【... 【目的】探讨碳酸盐岩地层中高频层序划分及高频沉积旋回的控储效应。【方法】选取鄂尔多斯盆地桃7区块马家沟组马五1-5亚段,以自然伽马能谱测井中Th/U比值曲线为指示曲线,频谱分析结合Fischer图解和岩性组合序列,定量划分高频层序。【结果】碳酸盐岩地层中,自然伽马能谱测井中Th/U比值能够作为天文轨道间接替代指标,通过频谱分析结合Fischer图解、岩性岩相分析等定量加定性的分析方法可以有效划分高频层序。桃7区块马五1-5亚段可划分1个三级层序、6个四级层序,20个五级层序,经估算马五1-5亚段纵向上平均沉积速率约束为5.03 cm/kyr,沉积时限约为2.43 Ma。潮坪相向上变浅的高频沉积旋回顶部,即潮间带上部含膏粉晶白云岩,是储层发育的优势相带;四级高频层序界面附近是储集层发育有利层段。海平面频繁变化引起的早期岩溶作用,是马五1-4亚段溶模孔形成的主要动力,为后期表生期岩溶奠定了基础。【结论】碳酸盐岩地层中高频层序定量识别和划分对储集层预测具有重要指导意义。 展开更多
关键词 高频层序 碳酸盐岩 马五1-5亚段 鄂尔多斯盆地
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Diagnosis Delay and Assessment of the Quality of Life of Patients with Endometriosis Using the Endometriosis Health Profile 5 Questionnaire in a Sub-Saharan Population 认领 引用
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作者 Monzango Sibo Mboloko Esimo +16 位作者 Mputu Lobota Itewa Monka Kitenge Kia Kayembe Tambola Grace Samba Kevine Maesheka Patrick Ntanga Kabuya Amba Naomie Maxime Fastrez Buka Ikoko Ndjukendi Ally Sangana Georges Barhayiga Berthe Mbanzulu Pita Longo Mbenza Clément Ferrier Emile Darai 《Open Journal of Obstetrics and Gynecology》 2023年第5期907-917,共11页
Context: Endometriosis is a pathology that directly affects the daily lives of women with frequent impairment of their quality of life. In our environment, medical, socio-cultural, financial factors and factors relate... Context: Endometriosis is a pathology that directly affects the daily lives of women with frequent impairment of their quality of life. In our environment, medical, socio-cultural, financial factors and factors related to the organization of the health care system greatly delay its diagnosis. The objectives of the present study were to determine the diagnosis delay and to assess the quality of life before surgery of women with endometriosis using the specific Endometriosis Health Profile 5 (EHP-5) questionnaire. Methods: We carried out a descriptive, observational, retrospective study in 8 medical centers in the City of Kinshasa, from January 2019 to October 2022. A total of 80 women with endometriosis confirmed by laparoscopy (16 diagnostic and 64 operative laparoscopies) and histopathology were interviewed. We used the revised American Society for Reproductive Medicine (rASMR) classification, the Endometriosis Fertility Index (EFI) score was calculated for infertile women and the EHP-5 questionnaire to assess quality of life. Our data was entered and analyzed using Statistical Analysis Software 16.1 (STATA 16.1). Results: Diagnosis delay of endometriosis was on average 12 ± 4.3 years. The overall mean EHP-5 score of all patients showed a severe deterioration in quality of life (604 ± 235). A negative relationship was observed between the age of the patient, the diagnostic delay, and the alteration of the quality of life in patients over 36 years old and those with about 11 years of diagnostic delay presenting the slight alteration. Patients with a high social level had very severe quality impairment. Women on hormonal treatment, those with a history of pregnancy, childbirth, miscarriage and abortion had a slight and significant deterioration in quality of life (p 0.05). Conclusion: Despite some limitations, our preliminary study highlights that in sub-Saharan Africa, the diagnosis of endometriosis is delayed and associated with a severe alteration in quality of life. Moreover, diagnosis of endometriosis seems to be restricted to women with high social levels. Therefore, further efforts are required to develop a health policy to decrease delay for diagnosis with potential benefits on symptoms, quality of life, fertility while limiting stigma and psychological effects of this debilitating pathology. 展开更多
关键词 Diagnosis Delay EHP-5 Endometriosis Quality of Life Sub-Saharan
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新冠病毒“奥密克戎亚变体BA.5”的最新研究进展 认领 引用 被引量：11
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作者 王彩红 姚晓文 +4 位作者 王蓉 周玉霞 李斌 于晓辉 张久聪 《海南医学院学报》 CAS 2022年第20期1521-1525,共5页
自2019年新型冠状病毒肺炎爆发以来,新型冠状病毒基因组仍在不断地变异,形成多种传播力强的变异株,致使全球范围内疫情蔓延,给人们的身心健康带来严重威胁,也对全球公共卫生构成重大挑战。而奥密克戎(Omicron)仍是全球多起疫情的主要变... 自2019年新型冠状病毒肺炎爆发以来,新型冠状病毒基因组仍在不断地变异,形成多种传播力强的变异株,致使全球范围内疫情蔓延,给人们的身心健康带来严重威胁,也对全球公共卫生构成重大挑战。而奥密克戎(Omicron)仍是全球多起疫情的主要变异株,约占全球基因序列的99%。近日,世界卫生组织公布已在全球100多个国家和地区发现Omicron亚变体BA.5,变异株致使全球疫情反弹。但目前关于亚变体BA.5的报道较少。本文就Omicron亚变体BA.5的流行病学、传染性、致病性、疫苗及单克隆抗体对其保护效力等方面的最新研究进展进行综述,以期为Omicron亚变体BA.5的科学防控提供参考。 展开更多
关键词 新冠病毒 奥密克戎变异株 BA.5亚变体 进展
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拟南芥Argonaute1/2/4/5序列分歧以及与特定miRNA的协同表达(英文) 认领 引用 被引量：1
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作者 赵文文 韩颖颖 +1 位作者 刘宝林 王志翠 《中国生物化学与分子生物学报》 CAS CSCD 北大核心 2015年第1期47-54,共8页
Argonaute(Ago)是RNA诱导的基因沉默复合体(RISC)中的一个重要组成部分,在RNA沉默通路中结合小RNA发挥着关键的作用.本文对12个物种的85个Ago/Ago-like基因序列进行了系统发育进化分析.结果表明,植物Ago可被分为3大分支,且基因在物种产... Argonaute(Ago)是RNA诱导的基因沉默复合体(RISC)中的一个重要组成部分,在RNA沉默通路中结合小RNA发挥着关键的作用.本文对12个物种的85个Ago/Ago-like基因序列进行了系统发育进化分析.结果表明,植物Ago可被分为3大分支,且基因在物种产生分歧之前就已经发生了重复.3个分支之间高同义和非同义突变频率揭示了Ago蛋白家族功能的高度保守性.采用实时荧光定量PCR对拟南芥Ago1/2/4/5在不同发育阶段和胁迫条件下的表达情况进行了分析.结果显示,Ago1在拟南芥幼苗和成熟组织中表达显著;与23℃(最适温度)相比,16℃(亚适温度)条件下,Ago1表达量显著下调,Ago5表达量则显著上调;在脱水胁迫下,Ago5表达量下调,Ago4表达量上调.另外,根据5'端碱基类型不同,188 954个幼苗miRNAs和2 047 843个成熟组织miRNAs被分类.结果显示,5'端为U的miRNAs在植物中的含量最多,这与Ago1表达量最高是协同的;16℃条件下,5'端为C的miRNAs和Ago5表达协同上调.这些结果都表明,Ago蛋白及其偏好的miRNAs是协同表达的. 展开更多
关键词 系统发育分析 argonaute miRNA的5'端碱基类型 亚适温度 脱水胁迫 协同表达
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基于SPOT-5遥感影像的小班区划探讨 认领 引用 被引量：10
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作者 张艮龙 冯益明 +2 位作者 贾建华 武红敢 李增元 《浙江林学院学报》 北大核心 2010年第2期299-303,共5页
森林资源调查小班区划主要是在现地进行对坡勾绘,这种方法存在人为主观性,不够科学客观等问题,因此,常产生误判。而地球遥感卫星SPOT-5遥感数据具有高空间分辨率和多光谱分辨率,可提供丰富、可靠、高精度的基础数据,且能节约成本,提高... 森林资源调查小班区划主要是在现地进行对坡勾绘,这种方法存在人为主观性,不够科学客观等问题,因此,常产生误判。而地球遥感卫星SPOT-5遥感数据具有高空间分辨率和多光谱分辨率,可提供丰富、可靠、高精度的基础数据,且能节约成本,提高效率。提出了适用于森林资源区划的SPOT-5遥感数据处理和目视解译方法,即建立SPOT-5影像解译标识、野外核实与补测等。最后对计算机自动解译SPOT-5影像进行森林区划进行了讨论,研究可为森林区划提供指导与借鉴。 展开更多
关键词 森林经理学 SPOT-5遥感数据 森林资源调查 小班区划
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Ulcerative Colitis in Sub-Saharan Africa: Analysis of 24 Cases in Dakar (Senegal) 认领 引用
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作者 Mamadou Ngoné Gueye Sokhna Niang Diop +7 位作者 Salamata Diallo Gnagna Diouf Cheikh Ahmadou Bamba Cissé Marème Polèle Fall Mame Aissé Thioubou Marie Louise Bassène Daouda Dia Mouhamadou Mbengue 《Open Journal of Gastroenterology》 CAS 2020年第6期128-136,共9页
Introduction: The aim of our study was to determine the socio-demographic, diagnostic and therapeutic aspects of ulcerative colitis (UC) in one of the largest gastroenterology departments in Senegal. Patients and Meth... Introduction: The aim of our study was to determine the socio-demographic, diagnostic and therapeutic aspects of ulcerative colitis (UC) in one of the largest gastroenterology departments in Senegal. Patients and Method: This was a retrospective and descriptive study based on the analysis of the records of patients hospitalized in the Hepato-Gastroenterology Department of the Grand Yoff General Hospital (Dakar, Senegal) between January 2013 and December 2019. All cases of UC were collected. Clinical, biological, endoscopic and histological data were collected, as well as treatment options. Results: We observed 24 cases, representing a prevalence of 0.87% of inpatients. The mean age of patients was 36 (ranged 18 to 73) and sex ratio 0.9 (13 females). The mean diagnostic delay was 1.6 years (ranged 4 months to 5 years). The clinical symptomatology was dominated by diarrhea with blood and mucus (18 cases). The Litchiger score on admission averaged 8 and 5 patients (20.8%) had severe acute colitis. Colonoscopy showed pancolonic involvement (Montreal E3) in 11 cases (45.8%) and severe endoscopic lesions (stage 3 of the Mayo endoscopic subscore) in 10 cases (41.6%). Therapeutically, 17 patients (70.8%) were initially treated with corticosteroids. Background therapy was 5-ASA in 17 patients (70.8%) and azathioprine in 7 patients (29.2%). Two cases of death (8.3%) were observed following colectasia with colonic perforations before emergency surgery could be performed. Conclusion: UC in our study was primarily among young adults with a slight female predominance. Diagnosis is often late. The lack of biotherapy requires close collaboration with surgeons for the management of severe forms. 展开更多
关键词 Ulcerative Colitis Sub-Saharan Africa Toxic Megacolon 5 ASA Azathioprine
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一种基于GaAs pHEMT工艺的高效率E类功率放大器设计 认领 引用 被引量：1
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作者 刘柯 曾琳淇 +2 位作者 叶志聪 张志浩 章国豪 《广东工业大学学报》 CAS 2025年第6期18-26,共9页
针对5G Sub-6 GHz通信系统对S波段(2~4 GHz)射频功率放大器(Power Amplifier,PA)在高效率、高线性度及宽带性能方面的迫切需求,本文提出了一种基于砷化镓赝配高电子迁移率晶体管(Gallium Arsenide Pseudomorphic High Electron Mobility... 针对5G Sub-6 GHz通信系统对S波段(2~4 GHz)射频功率放大器(Power Amplifier,PA)在高效率、高线性度及宽带性能方面的迫切需求,本文提出了一种基于砷化镓赝配高电子迁移率晶体管(Gallium Arsenide Pseudomorphic High Electron Mobility Transistor,GaAs pHEMT)工艺的创新设计。传统硅基CMOS工艺在高频场景中受限于击穿电压与寄生效应,而氮化镓(GaN)工艺因成本与集成度问题难以广泛应用。因此,研究聚焦于GaAs pHEMT工艺的潜力,旨在通过优化谐波抑制与阻抗匹配网络,突破S波段PA在效率、带宽及谐波抑制方面的技术瓶颈,同时探索其在射频前端模组中的集成应用。研究采用混合π型谐波匹配网络与电抗补偿技术,通过单级拓扑结构集成阻抗变换、谐波抑制及寄生参数动态补偿功能,解决了传统多级LC网络带宽受限(<10%)与面积冗余的难题。设计结合片外分立LC补偿模块,优化高频寄生效应,并采用两级级联架构(驱动级与功率级)提升增益与功率输出。通过精确调谐栅极(0.38 V/0.45 V)与漏极(6 V)偏置电压,结合版图对称布局与电磁仿真优化,显著降低非线性失真与直流功耗。实验结果表明,所设计的E类功率放大器在2.45~2.85 GHz频段内实现15%的相对带宽,二次谐波抑制比优于20 dB(5.3 GHz处),负载阻抗优化至50Ω。实测功率附加效率(Power Added Efficiency,PAE)在中心频率2.65 GHz时达到56.4%,输出功率为26.2 dBm,增益为26 dB,综合性能优于同类研究。 展开更多
关键词 砷化镓赝配高电子迁移率晶体管 E类功率放大器 并联π型谐波匹配网络 电抗补偿技术 5G Sub-6 GHz通信系统
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单层SnS场效应晶体管的第一性原理研究 认领 引用 被引量：2
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作者 郭颖 潘峰 +2 位作者 姚彬彬 孟豪 吕劲 《物理学报》 SCIE EI CAS CSCD 北大核心 2024年第20期266-276,共11页
基于硅基材料的逻辑器件由于其短沟道效应,使摩尔定律失效,二维半导体材料被认为是继续缩小晶体管尺寸以生产更多摩尔电子器件的潜在沟道材料.最近在实验上突破了技术瓶颈的限制,实现了二维场效应晶体管突破亚1 nm沟道极限,并且表现出... 基于硅基材料的逻辑器件由于其短沟道效应,使摩尔定律失效,二维半导体材料被认为是继续缩小晶体管尺寸以生产更多摩尔电子器件的潜在沟道材料.最近在实验上突破了技术瓶颈的限制,实现了二维场效应晶体管突破亚1 nm沟道极限,并且表现出优异的器件性能.这极大地鼓舞了在理论上进一步探索二维器件的性能.二维SnS具有较高的载流子迁移率和各向异性的电子性能,且材料性能环境稳定.本文应用第一性原理研究了亚5 nm SnS场效应晶体管的量子输运特性,鉴于SnS的各向异性,本文将器件沿单层SnS的armchair和zigzag两个方向进行构造,发现p型zigzag方向的器件性能优于其他类型(包括n型、p型的armchair方向和n型的zigzag方向).p型zigzag方向器件的开态电流在栅长缩短到1 nm也能满足国际半导体技术路线图的高性能(HP)器件要求,其值高达1934μA/μm.这在目前报道的1 nm栅长上的器件材料性能方面处于领先. 展开更多
关键词 量子输运模拟 单层SnS 亚5nm场效应管 开态电流
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外源ALA促进亚低温胁迫下番茄幼苗营养元素积累与分配 认领 引用 被引量：6
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作者 康珍 袁路乔 +3 位作者 贾媛婕 张政达 薛建康 胡晓辉 《东北农业大学学报》 CAS CSCD 北大核心 2022年第4期9-16,共8页
为探究亚低温胁迫下番茄幼苗元素利用规律,明确外源5-氨基乙酰丙酸(ALA)对亚低温下植株元素积累与分配的影响,以低温敏感型番茄‘金棚一号’为试验材料,研究叶面预喷施ALA对亚低温(8~18℃/8~12℃昼/夜)下番茄幼苗各器官(根、茎、上位叶... 为探究亚低温胁迫下番茄幼苗元素利用规律,明确外源5-氨基乙酰丙酸(ALA)对亚低温下植株元素积累与分配的影响,以低温敏感型番茄‘金棚一号’为试验材料,研究叶面预喷施ALA对亚低温(8~18℃/8~12℃昼/夜)下番茄幼苗各器官(根、茎、上位叶和下位叶)干鲜重和全氮、全磷、全钾、全钙、全镁、全铁积累量及叶片叶绿素含量的影响。结果表明,外源预喷施25 mg·L-1 ALA缓解亚低温造成的番茄幼苗氮、磷、钾、钙、镁、铁元素吸收障碍,且存在器官差异性。外源ALA通过促进亚低温胁迫下番茄整株幼苗对氮、磷、钾、钙、镁、铁元素的吸收和根系钾元素、茎中磷钾元素及叶片氮、磷、钙、镁、铁元素的积累,同时显著缓解氮元素在根系的积滞并增加其在上位叶和下位叶的分配率,促进氮元素由根向叶片、铁元素由下位叶向上位叶转运,减弱亚低温造成的番茄幼苗叶片叶绿素含量下降,缓解亚低温对植株营养生长的抑制。 展开更多
关键词 亚低温胁迫 5-氨基乙酰丙酸 番茄 元素积累与分配
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模块化多电平逆变器的改进型PS-SPWM研究 认领 引用 被引量：1
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作者 王辉 张宁敏 《控制工程》 CSCD 北大核心 2014年第6期797-801,共5页
模块化多电平换流器(MMC)具有级联型多电平换流器"模块化"的优点,输出电压中的谐波含量少,在高压直流输电中具有巨大的应用潜力。介绍MMC的数学模型和工作原理,分析传统载波移相调制策略,针对其存在的缺点提出一种改进型载波... 模块化多电平换流器(MMC)具有级联型多电平换流器"模块化"的优点,输出电压中的谐波含量少,在高压直流输电中具有巨大的应用潜力。介绍MMC的数学模型和工作原理,分析传统载波移相调制策略,针对其存在的缺点提出一种改进型载波移相PS-SPWM调制算法,即载波三角波移相-开关频率优化PWM法(PS-SFO-PWM),并与载波移相SPWM调制算法进行比较;针对MMC中特有的三相之间的环流问题,通过对其进行PI调节,使环流抑制在一定的范围内,利于功率的有效传输。最后,在Matlab/Simulink7.0环境下搭建了基于载波三角波移相-开关频率优化PWM法的5电平逆变器的仿真模型,仿真结果验证了所提方法具有直流电压利用率高、开关频率小等优点。 展开更多
关键词 模块化多电平换流器 子模块 PS-SFOPWM 5电平逆变器
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致密碳酸盐岩储层矿物组分计算模型建立——以鄂尔多斯盆地东部马五X亚段储层为例 认领 引用 被引量：3
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作者 俞保财 牟瑜 +3 位作者 任小锋 蔡芳 姚海林 罗丹婷 《石油地质与工程》 CAS 2020年第4期36-41,共6页
鄂尔多斯盆地东部马五X亚段碳酸盐岩储层主要发育岩溶残丘型气藏,方解石、泥质等填充程度较高,岩性致密,储层基质孔隙度和渗透率低。为了实现利用常规测井资料较为精确地计算各类矿物组分的体积含量,从而为储层岩性识别、储层划分及其... 鄂尔多斯盆地东部马五X亚段碳酸盐岩储层主要发育岩溶残丘型气藏,方解石、泥质等填充程度较高,岩性致密,储层基质孔隙度和渗透率低。为了实现利用常规测井资料较为精确地计算各类矿物组分的体积含量,从而为储层岩性识别、储层划分及其有效性评价提供依据,开展了PE法、复杂矿物组分分析法(包括CNL-DEN图版法和CNL-AC图版法)及组合参数回归模型3种方法建立矿物组分含量计算模型及计算精度分析对比。结果表明,基于复杂矿物组分分析法的CNL-DEN图版法精度最高,对马五X亚段储层矿物组分计算具有较好的适用性,该方法可为后期储层识别、划分及有效性评价提供准确依据。 展开更多
关键词 鄂尔多斯盆地 马五X亚段 碳酸盐岩储层 CNL-DEN图版法 矿物组分
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内蒙古草原植被覆盖度遥感估算 认领 引用 被引量：17
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作者 朱敬芳 邢白灵 +2 位作者 居为民 朱高龙 柳艺博 《植物生态学报》 CAS CSCD 北大核心 2011年第6期615-622,共8页
以内蒙古锡林浩特市南部中国科学院草原生态系统定位研究站周围的草场为研究对象,分析比较了统计模型和亚像元分解模型进行草地植被覆盖度(vegetation coverage,VC)遥感估算的适用性。结果表明,根据Landsat-5TM影像数据计算的比值植被指... 以内蒙古锡林浩特市南部中国科学院草原生态系统定位研究站周围的草场为研究对象,分析比较了统计模型和亚像元分解模型进行草地植被覆盖度(vegetation coverage,VC)遥感估算的适用性。结果表明,根据Landsat-5TM影像数据计算的比值植被指数(simple ratio vegetation index,SR)与观测的VC的相关性最高(R2=0.761);统计模型和亚像元分解模型生成的VC空间分布特征相似,但亚像元分解模型得到的VC平均值比统计模型的结果高0.091;在VC的低值和高值区,两种方法得到的VC结果相似;但在VC的中值区,亚像元模型得到的结果较统计模型的结果偏高。 展开更多
关键词 内蒙古白音锡勒草原 草地植被覆盖度 Landsat-5TM影像 统计模型 亚像元分解模型
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基于电容箝位五电平H桥的逆变器应用 认领 引用 被引量：2
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作者 胡书举 李建林 许洪华 《高电压技术》 EI CAS 北大核心 2008年第9期1932-1936,共5页
为研究基于电容箝位五电平H桥逆变器的应用,以电容箝位5电平H桥构成三相逆变器,结合电容箝位3电平和常规H桥电路的优点,并采用消谐波PWM和载波相移PWM相结合的调制策略,对所采用的逆变器拓扑及其控制策略的有效性进行了仿真和实验验证... 为研究基于电容箝位五电平H桥逆变器的应用,以电容箝位5电平H桥构成三相逆变器,结合电容箝位3电平和常规H桥电路的优点,并采用消谐波PWM和载波相移PWM相结合的调制策略,对所采用的逆变器拓扑及其控制策略的有效性进行了仿真和实验验证。结果表明:所采用的逆变器拓扑可以方便地得到5电平输出,提高了输出电压和功率等级;所采用的控制策略能够有效提高等效载波频率,降低滤波器的体积和容量;两种调制方法的结合可发挥各自的优势,使控制灵活、实现简单。 展开更多
关键词 多电平变换器 电容箝位 五电平H桥 消谐波PWM 载波相移PWM 逆变器
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鄂尔多斯盆地大牛地气田马五6~10亚段沉积相高频演化特征 认领 引用 被引量：2
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作者 刘兆恒 吴冬 +5 位作者 邓虎成 伏美燕 曹凯旋 胥旺 刘慧 李可赛 《科学技术与工程》 北大核心 2024年第9期3554-3566,共13页
鄂尔多斯盆地大牛地气田马五6~10亚段沉积微相高频变化,分布特征尚不明确,严重制约了天然气勘探与开发。综合利用岩心、薄片、测井及野外露头等资料,详细分析了该地区马五6~10亚段碳酸盐岩岩石类型及测井响应特征,划分了4种沉积微... 鄂尔多斯盆地大牛地气田马五6~10亚段沉积微相高频变化,分布特征尚不明确,严重制约了天然气勘探与开发。综合利用岩心、薄片、测井及野外露头等资料,详细分析了该地区马五6~10亚段碳酸盐岩岩石类型及测井响应特征,划分了4种沉积微相,进一步分析了该地区马五6~10亚段高频沉积相演化特征。研究表明,马五期海平面整体呈下降趋势,发育局限台地亚相,云坪、膏云坪、灰云坪微相在空间上彼此相邻,纵向上相互叠置,随海平面的涨落沉积微相在膏云坪、云坪和云坪、灰云坪、云灰坪之间频繁转化。马五10、马五8、马五72、马五61亚段主要发育膏云坪和云坪微相,马五9亚段主要发育云坪和灰云坪微相,马五71、马五62亚段主要发育膏云坪、云坪及灰云坪微相,马五63亚段则由西向东依次发育膏云坪、云坪、灰云坪、云灰坪微相。研究区海平面升降控制了沉积亚相的演化,更为高频的次级海平面变化控制着沉积微相快速变化。鄂尔多斯盆地大牛地气田马五6~10亚段沉积相高频演化特征研究,将有力支撑大牛地气田马家沟组深部天然气资源的开发动用,同时为大牛地气田马家沟组沉积模式研究提供依据。 展开更多
关键词 鄂尔多斯盆地 大牛地气田 碳酸盐岩 马五6~10亚段 沉积微相
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Morphological Diversity and Nomenclature of Swertia chirayita (Gentianaceae)—Recovery of Endangered Medicinal Plant Population in North Eastern Himalaya 认领 引用
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作者 Soumendra Chakraborty Dhiman Mukherjee Sibdas Baskey 《American Journal of Plant Sciences》 CAS 2016年第6期741-755,共15页
Swertia chirayita is a highly endangered and very well known medicinal plant enlisted in the IUCN list of endangered plants in the world. The plant is currently having a very low population in eastern Himalayan region... Swertia chirayita is a highly endangered and very well known medicinal plant enlisted in the IUCN list of endangered plants in the world. The plant is currently having a very low population in eastern Himalayan region due to its very low germinability in its own natural habitat. The plant population was found to have a range of diversity in morphological observations and some of the morphovariants were found to be very low among the variant populations which created a concern due to its diminishing range of genetic base in this region. A basic group of 5 morphovariants and 24 sub variants were identified and separately maintained. It is a pluriannual plant and reproductive or flowering stage was observed after completion of two years of vegetative stage from the time of seed germination. A range of morphovariant diversity was observed in the populations of Neora Valley and Lava region of eastern Himalaya in our investigation. Diversity was critically observed in some of the parameters of different morphovariants in the population. Conservation practices were generally done by not making groups or sub groups of this endangered plant while we proposed the way of conservation by making groups for proper conservation of this vulnerable plant. 展开更多
关键词 A Conservation Model Endangered Plant Morphovariants 5 Groups 24 Sub-Groups
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Headaches and Erectile Dysfunction Medications at UTH-Kara (Togo) 认领 引用
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作者 Léhleng Agba Nyinèvi K. Anayo +6 位作者 Hola K. Sikpa Mensah K. Guinhouya Tchilabalo M. Kpatcha Vinyo K. Kumako Damelan Kombate Komi Assogba Agnon A. Balogou 《World Journal of Neuroscience》 CAS 2023年第4期228-235,共8页
Introduction: Headaches are a common symptom affecting individuals worldwide, including in the tropical zone, and have been extensively studied in Togo. Phosphodiesterase-5 inhibitors, commonly prescribed for erectile... Introduction: Headaches are a common symptom affecting individuals worldwide, including in the tropical zone, and have been extensively studied in Togo. Phosphodiesterase-5 inhibitors, commonly prescribed for erectile dysfunction, are known to induce headaches, yet there is a lack of research on this topic in sub-Saharan Africa and Togo. Methods: A cross-sectional study conducted from February 1st to June 30th, 2023, including adult patients seeking erectile dysfunction treatment and prescribed PDE-5 inhibitors. Results: A total of 28 patients were included in the study, with an average age of 34.46 ± 7.5 years. The age group of 30 - 39 years was the most represented (53.57%). Among the participants, 67.86% had a history of chronic headaches. During the intake of PDE-5 inhibitors, 71.43% reported the onset of headaches. Among the 19 patients with chronic headaches, 68.42% developed headaches following PDE-5 inhibitor use (RR = 0.88, 95% CI: 0.55 - 1.40, p = 0.484). The characteristics of the induced headaches were similar to the patients’ pre-existing headaches in 78.95% of cases. Additional symptoms included nasal congestion (36.84%) and an urge to have a bowel movement (26.32%). Sildenafil (75.00%) and Tadalafil (25.00%) were the primarily prescribed PDE-5 inhibitors. The incidence of headaches did not significantly differ between the two groups (RR = 1.33, 95% CI: 0.67 - 2.64, p = 0.306). Treatment for the induced headaches involved self-medication with paracetamol (65.00%) and nonsteroidal anti-inflammatory drugs (NSAIDs) (35.00%). Conclusion: Headaches induced by PDE-5 inhibitors are a well-established reality, emphasizing the need for caution and warning in patients with pre-existing headache conditions, while individualized approaches are necessary to address the potential interplay between migraine medications and erectile dysfunction treatments. 展开更多
关键词 Headache Phosphodiesterase-5 Inhibitors Erectile Dysfunction Togo Sub-Saharan Africa
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