检索结果-南通市图书馆

Sertoli cell and spermatogonial development in pigs

Journal of Animal Science and Biotechnology 2022年第4期13卷 1028-1044页

作者： Yi Zheng Qiang Gao Tianjiao Li Ruifang Liu zechao cheng Ming Guo Jinhong Xiao De Wu Wenxian Zeng Key Laboratory for Animal Genetics Breeding and Reproduction of Shaanxi ProvinceCollege of Animal Science and TechnologyNorthwest A&F UniversityYangling 712100ShaanxiChina Zhumei Porcine Breeding Corporation ZhengzhouHenanChina Key Laboratory for Animal Disease Resistance Nutrition of the Ministry of Education of China Institute of Animal NutritionSichuan Agricultural UniversityChengdu 611100SichuanChina.

Background:Spermatogenesis is an intricate developmental process during which undifferentiated spermatogonia,containing spermatogonial stem cells(SSCs),undergo self-renewal and differentiation to generate eventually mature *** occurs in seminiferous tubules within the testis,and the seminiferous tubules harbor Sertoli and germ *** cells are an essential somatic cell type within the microenvironment that support and steer male germ cell development,whereas spermatogonia are the primitive male germ cells at the onset of *** the developmental progression of Sertoli cells and spermatogonia has been well established in mice,much less is known in other mammalian species including ***:To acquire knowledge of Sertoli cell and spermatogonial development in pigs,here we collected as many as nine ages of Duroc porcine testes from the neonate to sexual maturity,i.e.,testes from 7-,30-,50-,70-,90-,110-,130-,150-and 210-day-old boars,and performed histological and immunohistochemical analyses on testis *** first examined the development of spermatogenic cells and seminiferous tubules in porcine ***,by immunofluorescence staining for marker proteins(AMH,SOX9,DBA,UCHL1,VASA,KIT,Ki67 and/or PCNA),we delved into the proliferative activity and development of Sertoli cells and of spermatogonial subtypes(pro-,undifferentiated and differentiating spermatogonia).Besides,by immunostaining forβ-catenin and ZO-1,we studied the establishment of the blood-testis barrier in porcine ***:In this longitudinal study,we have systematically investigated the elaborate Sertoli cell and spermatogonial developmental patterns in pigs from the neonate to sexual maturity that have so far remained largely *** findings not only extend the knowledge about spermatogenesis and testicular development in pigs,but also lay the theoretical groundwork for porcine breeding and rearing.

关键词： Pig Sertoli cell Spermatogenesis Spermatogonia Testis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

基于形态学构建尺度空间与谱峭度的轴承故障诊断方法

引用

轴承 2025年第1期 95-101页

作者：杨旭刘鹏飞程伟欣许增兵刘泽潮石家庄铁道大学机械工程学院石家庄050043 石家庄铁道大学省部共建交通工程力学行为与系统安全国家重点实验室石家庄050043

针对高速列车轴箱轴承服役环境恶劣,故障特征难以提取的问题,提出了基于形态学构建尺度空间表征的经验小波变换(EWT)故障诊断方法。首先,提出基于形态学的尺度空间表征方法,实现共振频带边界的自适应识别;其次,将基于形态学构建的尺度... 详细信息

针对高速列车轴箱轴承服役环境恶劣,故障特征难以提取的问题,提出了基于形态学构建尺度空间表征的经验小波变换(EWT)故障诊断方法。首先,提出基于形态学的尺度空间表征方法,实现共振频带边界的自适应识别;其次,将基于形态学构建的尺度空间表征与谱峭度相结合,识别出共振频带;然后,根据所识别的频带边界构造滤波器组,对信号进行自适应分解;最后,对分解信号进行包络谱分析,识别故障特征频率,实现轴承故障的诊断。高速列车轴箱轴承振动试验结果表明,该方法能够有效提高频带划分的准确性以及计算效率,准确诊断轴承故障。

关键词：滚动轴承故障诊断小波变换形态学尺度空间峭度

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Moirésuperlattice engineering of two-dimensional materials for electrocatalytic hydrogen evolution reaction

引用

Nano Research 2023年第7期16卷 8712-8728页

作者： Yang Li Yuqi Hua Ning Sun Shijie Liu Hengxu Li cheng Wang Xinyu Yang zechao Zhuang Longlu Wang College of Electronic and Optical Engineering&College of Flexible Electronics(Future Technology) Nanjing University of Posts and Telecommunications(NJUPT)Nanjing 210023China Department of Chemistry Tsinghua UniversityBeijing 100084China

Vertically stacking two-dimensional(2D)materials with small azimuthal deviation or lattice mismatch generate distinctive global structural periodicity and symmetry,revealed as the moirésuperlattices(MSLs).Manipulating the interlayer twist angle enables the modification of the electronic structure of 2D materials to explore the advanced *** extraordinary progress has been achieved in the unique structure and emergent properties of MSLs,the investigation of the catalytic applications of MSLs materials is still in its *** is therefore very urgent to summarize the advanced development of MSLs in the field of *** this review,we firstly summarize the advanced fabrication and high-resolution characterization techniques of the MSLs materials,as well as their novel properties related to catalysis represented by electrocatalytic hydrogen evolution reaction(HER).Then,all the MSLs materials such as MoS_(2),WS_(2),and Ru serving as electrocatalysts for HER are further reviewed in ***,we outline the current challenges as well as the experimental and theoretical strategies to advance the development of function-oriented MSLs materials for *** review aims to provide profound insight into the wide applications of this novel material platform in catalytic field.

关键词： moirésuperlattices two-dimensional(2D)materials fabrication characterization properties hydrogen evolution reaction(HER)

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Stabilizing effects of atomic Ti doping on high-voltage high-nickel layered oxide cathode for lithium-ion rechargeable batteries

引用

Nano Research 2022年第5期15卷 4091-4099页

作者： Yong cheng Yan Sun Changting Chu Limin Chang Zhaomin Wang Dongyu Zhang Wanqiang Liu zechao Zhuang Limin Wang Key Laboratory of Preparation and Applications of Environmental Friendly Materials(Ministry of Education) Jilin Normal UniversityChangchun 130103China State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of materials science and engineering Changchun University of Science and TechnologyChangchun 130022China Department of Chemistry Tsinghua UniversityBeijing 100084China

High-voltage high-nickel lithium layered oxide cathodes show great application prospects to meet the ever-increasing demand for further improvement of the energy density of rechargeable lithium-ion batteries(LIBs)mainly due to their high output ***,severe bulk structural degradation and undesired electrode-electrolyte interface reactions seriously endanger the cycle life and safety of the ***,2 mol%Ti atom is used as modified material doping into LiNi_(0.8)Co_(0.2)Mn_(0.2O2)(NCM)to reform LiNi_(0.6)Co_(0.2)Mn_(0.18)Ti_(0.02)O_(2)(NCM-Ti)and address the long-standing inherent *** a high cut-off voltage of 4.5 V,NCM-Ti delivers a higher capacity retention ratio(91.8%vs.82.9%)after 150 cycles and a superior rate capacity(118 vs.105 mAh·g^(-1))at the high current density of 10 C than the pristine *** designed high-voltage full battery with graphite as anode and NCM-Ti as cathode also exhibits high energy density(240 Wh·kg^(-1))and excellent electrochemical *** superior electrochemical behavior can be attributed to the improved stability of the bulk structure and the electrode-electrolyte interface owing to the strong Ti-O bond and no unpaired *** in-situ X-ray diffraction analysis demonstrates that Ti-doping inhibits the undesired H2-H3 phase transition,minimizing the mechanical *** ex-situ TEM and X-ray photoelectron spectroscopy reveal that Ti-doping suppresses the release of interfacial oxygen,reducing undesired interfacial *** work provides a valuable strategic guideline for the application of high-voltage high-nickel cathodes in LIBs.

关键词： lithium-ion battery high-voltage high-nickel cathode Ti-doping structural stability interface stability

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Amorphous molybdenum sulfide and its Mo-S motifs:Structural characteristics,synthetic strategies,and comprehensive applications

引用

Nano Research 2022年第9期15卷 8613-8635页

作者： cheng Chang Longlu Wang Lingbin Xie Weiwei Zhao Shujuan Liu zechao Zhuang Shijie Liu Jianmin Li Xia Liu Qiang Zhao College of Electronic and Optical Engineering&College of Flexible Electronics(Future Technology) Nanjing University of Posts&Telecommunications(NJUPT)Nanjing 210023China Key Laboratory for Organic Electronics and Information Displays&Jiangsu Key Laboratory for Biosensors Institute of Advanced Materials(LAM)&Institute of Flexible Electronics(Future Technology)Nanjing University of Posts&TelecommunicationsNanjing 210023China College of Chemistry and Chemical Engineering Qingdao UniversityQingdao 266071China Department of Chemistry Tsinghua UniversityBeijing 100084China

Amorphous materials are one kind of nonequilibrium materials and have become one of the most active research *** with crystalline solids,the theory of amorphous materials is still in infancy because their characteristic of atomic arrangement is more like liquid and has no long-range ***,as the representative of amorphous materials,amorphous molybdenum sulfide(a-MoS_(x))with unique physical and chemical properties has been studied ***,considerable debate surrounds the structure–property relationships of a-MoS_(x)owing to its diverse Mo-S ***,we summarize recent discoveries and research results regarding a-MoS_(x),whose structural characteristics,synthetic strategies,formation criteria,and comprehensive applications are discussed in ***,this review is ended with our personal insights and critical outlooks over the development of a-MoS_(x).

关键词： amorphous molybdenum sulfide Mo-S motifs structural characterization synthetic strategies comprehensive applications

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Correlating the electronic structure of perovskite La_(1-x)SrxCoO_(3) with activity for the oxygen evolution reaction:The critical role of Co 3d hole state

引用

Journal of Energy Chemistry 2022年第2期31卷 637-645页

作者： zechao Shen Mei Qu Jueli Shi Freddy E.Oropeza Victor A.de la Peña O’Shea Giulio Gorni C.M.Tian Jan P.Hofmann Jun cheng Jun Li Kelvin H.L.Zhang State Key Laboratory of Physical Chemistry of Solid Surfaces College of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005FujianChina Photoactivated Processes Unit IMDEA Energy InstituteParque Tecnológico de MóstolesAvda.Ramón de la Sagra 328935 MóstolesMadridSpain CELLS-ALBA Synchrotron Carrer de la Llum 2-2608290 Cerdanyola del VallèsSpain Surface Science Laboratory Department of Materials and Earth SciencesTechnical University of Darmstadt Otto-Berndt-Strasse 364287 DarmstadtGermany

Perovskite LaCoO_(3) is being increasingly explored as an effective low-cost electrocatalyst for the oxygen evolution reaction(OER).Sr doping in LaCoO_(3)(La1-xSrxCoO_(3))has been found to substantially increase its catalytic *** this work,we report a detailed study on the evolution of the electronic structure of La1-xSrxCoO_(3) with 0≤x≤1 and its correlation with electrocatalytic activity for the OER.A combination of X-ray photoemission spectroscopy(XPS)and X-ray absorption spectroscopy(XAS)was used to unravel the electronic density of states(DOS)near the Fermi level(EF),which provide insights into the key electronic structure features for the enhanced OER catalytic *** analysis on the Co L-edge XAS suggest that LaCoO_(3) has a low spin state with t_(2g)^(6) e_(g)^(0) configuration at room *** implies that the high OER catalytic activity of LaCoO_(3) should not be rationalized by the occupancy of eg=1 *** Sr^(2+) for La^(3+) in LaCoO_(3) induces Co4+oxidation states and effectively dopes hole states into the top of valence band.A semiconductor-to-metal transition is observed for x>0.2,due to the holeinduced electronic DOS at the EF and increased hybridization between Co 3 d and O 2 *** an electronic modulation enhances the surface adsorption of the*OH intermediate and reduces the energy barrier for interfacial charge transfer,thus improving the OER catalytic activity in La_(1-x)Sr_(x)CoO_(3).In addition,we found that the La_(1-x)Sr_(x)CoO_(3) surface undergoes amorphization after certain period of OER measurement,leading to a partial deactivation of the *** Sr doping levels accelerated the amorphization process.

关键词： Perovskite oxide Oxygen evolution Cobalt Electronic structure

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

基于Fresnel透镜的激光车灯的设计与加工

引用

红外与激光工程 2020年第3期49卷 328-334页

作者：程颖王泽超谢小兵卢永斌常文爽天津科技大学机械工程学院天津市轻工与食品工程机械装备集成设计与在线监控重点实验室天津300222 天津大学天津微纳制造技术工程中心天津300072 天津中德应用技术大学天津300350

激光车灯对比于LED车灯,具有能耗小、体积小、亮度高等优点,是汽车车灯发展的新方向。提出了一种激光车灯的完整的设计思路。光源采用激光二极管激发荧光片得到白光。通过搭建光学检测平台研究激光驱动白光光源的光学特性,通过机器视觉... 详细信息

激光车灯对比于LED车灯,具有能耗小、体积小、亮度高等优点,是汽车车灯发展的新方向。提出了一种激光车灯的完整的设计思路。光源采用激光二极管激发荧光片得到白光。通过搭建光学检测平台研究激光驱动白光光源的光学特性,通过机器视觉的方法研究荧光片前后光斑的形状和尺寸的变化,从而精确地建立光源的仿真模型,为后续的光学设计提供理论依据。通过非成像光学设计方法,设计了Fresnel透镜实现了对激光的整形,并利用超精密车削实现透镜的加工。完成了车灯的设计和组装,并通过光学仿真和光学实验验证了设计的正确性。

关键词：非成像光学 Fresnel透镜几何构造法激光驱动白光光源

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

基于非球面透镜激光车灯的设计与加工

引用

光学技术 2020年第6期46卷 650-653页

作者：程颖谢小兵王泽超卢永斌天津科技大学机械工程学院天津市轻工与食品工程机械装备集成设计与在线监控重点实验室天津300222 沂普光电(天津)有限公司天津300457

激光车灯对比于LED车灯,具有能耗小、体积小、亮度高等优点,是汽车车灯发展的新方向。基于此提出了一种低功耗、高亮度的激光车灯的光学系统结构。通过搭建光学测试平台研究激光二极管经过荧光片变为白光光源的特征参数,如光源的尺寸、... 详细信息

激光车灯对比于LED车灯,具有能耗小、体积小、亮度高等优点,是汽车车灯发展的新方向。基于此提出了一种低功耗、高亮度的激光车灯的光学系统结构。通过搭建光学测试平台研究激光二极管经过荧光片变为白光光源的特征参数,如光源的尺寸、光通量等,从而建立光源模型。由点光源和接收面能量的映射关系,求解激光车灯透镜的初始面型。根据所建立的光源模型对透镜初始面型进行优化设计,得到最终结果。所设计的非球面透镜利用超精密加工实现,并对激光车灯进行了组装和测试,12.16W电功率驱动下,25m处的照度约为106lux。

关键词：非成像光学非球面激光驱动白光光源激光车灯

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

EDFA的频率响应测试

引用

光通信技术 2023年第5期47卷 88-90页

作者：张泽超程雯潘庆雯武汉邮电科学研究院武汉430074

掺铒光纤放大器(EDFA)对相同波长、不同频率的信号放大时,因频率响应不同导致信号失真。为了提高通信质量,介绍了一种EDFA频率响应测试方法,并编写了一套基于Python的数据处理系统。实验结果表明:该测试方法能够完成频率响应测试任务,... 详细信息

掺铒光纤放大器(EDFA)对相同波长、不同频率的信号放大时,因频率响应不同导致信号失真。为了提高通信质量,介绍了一种EDFA频率响应测试方法,并编写了一套基于Python的数据处理系统。实验结果表明:该测试方法能够完成频率响应测试任务,且能够快速准确地处理数据并实现数据可视化,提高了测试效率。

关键词：掺铒光纤放大器频率响应数据处理

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

海上油田小井眼注聚井分层测调技术研究及应用

引用

仪器仪表用户 2022年第4期29卷 41-44页

作者：黄泽超沙吉乐罗昌华郑春峰牛贵锋薛德栋刘铁明黄铖中海油能源发展股份有限公司工程技术分公司天津300452

针对海上油田小井眼注聚井分层测调困难、配注效率低、粘度损失高的问题,开发了小井眼分层测调注聚技术,设计研发小尺寸分层保粘注聚工具、配套井下测调仪器和地面控制设备。小尺寸分层保粘注聚工具设计大通径中心过流通道、桥式注入通... 详细信息

针对海上油田小井眼注聚井分层测调困难、配注效率低、粘度损失高的问题,开发了小井眼分层测调注聚技术,设计研发小尺寸分层保粘注聚工具、配套井下测调仪器和地面控制设备。小尺寸分层保粘注聚工具设计大通径中心过流通道、桥式注入通道和高保粘注入通道,实现小井眼注聚井的大排量、多层段、高保粘分层注聚。井下测调仪器和地面控制器可地面监测井下注入流量、压力等地层参数,在线精确调节各层注聚量,测调一体。现场应用试验表明:小井眼注聚工艺管柱简洁,可实现多层段大排量注入,保粘率>86%,配注效率高,测调仪器通讯、测调性能可靠,测调一体,测试精度≤3%,调配精度≤5%,解决小井眼注聚井分层测调注聚难题,提高了注聚效率和测调效率,降低了管柱作业强度和测调作业成本,为海上油田注聚、调驱工艺的发展提供强有力的技术支持,具有较高的应用推广价值。

关键词：海上油田小井眼注聚井大排量分层注聚测调一体

来源：

维普期刊数据库博看期刊

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：