检索结果-南通市图书馆

High-speed GeSn resonance cavity enhanced photodetectors for a 50 Gbps Si-based 2 μm band communication system

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

Photonics Research 2024年第4期12卷 767-773页

作者： JINLAI CUI JUN ZHENG YUPENG ZHU XIANGQUAN LIU YIyang WU QINXING HUANG yazhou yang ZHIPENG LIU ZHI LIU YUHUA ZUO BUWEN CHENG Key Laboratory of Optoelectronic Materials and Devices Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

Expanding the optical communication band is one of the most effective methods of overcoming the nonlinear Shannon capacity limit of single *** this study,GeSn resonance cavity enhanced(RCE)photodetectors(PDs)with an active layer Sn component of 9%–10.8%were designed and fabricated on an SOI *** GeSn RCE PDs present a responsivity of 0.49 A/W at 2μm and a 3-dB bandwidth of approximately 40 GHz at 2μ***,Si-based 2μm band optical communication with a transmission rate of 50 Gbps was demonstrated by using a GeSn RCE *** work demonstrates the considerable potential of the Si-based 2μm band photonics in future high-speed and high-capacity optical communication.

关键词： resonance system approximate

在线全文

学校读者我要写书评

暂无评论

铲齿-双滚筒组合式花生捡拾装置研制

农业工程学报 2024年第12期40卷 13-22页

作者：高连兴梁港平蔡依琳冯伟志杨亚洲刘娟杨建刚吉林农业大学工程技术学院长春130118 济南吉美乐电源技术有限公司济南250100 河南省农业科学院花生研究所郑州450002 郑州市双丰机械制造有限公司登封452400

两段收获是国内花生机械化收获主要方式。大中型花生捡拾收获机所配置的弹齿滚筒式捡拾装置结构复杂且易损坏,捡拾过程中不仅存在植株抛起、壅堆、漏捡和掉果等问题,弹齿弹出地面时也会造成扬尘,严重制约了花生收获作业效率、增加花生损... 详细信息

两段收获是国内花生机械化收获主要方式。大中型花生捡拾收获机所配置的弹齿滚筒式捡拾装置结构复杂且易损坏,捡拾过程中不仅存在植株抛起、壅堆、漏捡和掉果等问题,弹齿弹出地面时也会造成扬尘,严重制约了花生收获作业效率、增加花生损失,加剧环境污染。针对上述问题,该研究在分析弹齿滚筒捡拾花生过程基础上,提出了由铲齿、拨秧滚和捡拾滚(简称双滚筒)构成的花生捡拾机构,研制出相应的捡拾装置样机并进行田间性能试验;基于Box-Behnken中心组合设计原理,以植株捡拾率和荚果落果率为试验指标以机组前进速度,捡拾速比和铲齿半径为试验因素进行了正交试验,并对试验因素进行优化。试验结果表明,铲齿-双滚筒组合式花生捡拾装置作业中不存在植株抛起、壅堆和弹齿扬尘等问题;在田间试验条件下,作业速度为1.2 m/s、捡拾速比为1.2、铲齿半径为498 mm时,花生植株捡拾率均值为99.22%,落果率均值为1.84%,均优于花生捡拾作业标准要求。铲齿-双滚筒研究结果对解决国内花生捡拾收获机存在的捡拾问题具有重要意义。

关键词：农业机械收获机花生捡拾装置

行星科学研究中热发射光谱的实验测量与定标方法

在线全文

学校读者我要写书评

暂无评论

空间科学学报 2024年第2期44卷 270-286页

作者：杨亚洲 MILLIKEN Ralph E BRAMBLE Michael S PATTERSON William R 邹永廖刘洋中国科学院国家空间科学中心空间天气学国家重点实验室北京100190 布朗大学地球环境与行星科学学院普罗维登斯02912

准确的物质组成信息是解译行星体形成与演化历史的关键,可见–近红外遥感光谱探测一直是获取行星表面成分的主要技术手段.在热红外谱段光谱特征更为丰富,因此随着探测技术的发展,其在行星探测中得到越来越多的应用.尤其是在目前已经实... 详细信息

准确的物质组成信息是解译行星体形成与演化历史的关键,可见–近红外遥感光谱探测一直是获取行星表面成分的主要技术手段.在热红外谱段光谱特征更为丰富,因此随着探测技术的发展,其在行星探测中得到越来越多的应用.尤其是在目前已经实施与立项的国内外小行星探测任务中,都将热发射光谱仪作为核心载荷之一.为了更好地对将来获取的热发射光谱数据进行解译,建立科学合理的数据处理与定标方案是必不可少的.本文对用于行星科学研究的热发射光谱测量装置的设计、测量及数据处理方法进行了系统分析.针对低温、真空条件下热发射测量过程中样品辐射信号与仪器辐射信号难以分离的问题,提出并论证了基于傅里叶变换红外光谱仪原始测量信号–干涉图的数据处理方法.该方法可以更为有效地分离出样品实际辐射信号,从而获得更为准确的发射率光谱数据.研究结果可为国内相关热发射测量装置的设计与搭建以及未来天问二号等探测数据的处理与科学解译提供参考.

关键词：行星探测热发射光谱实验室测量定标

新疆准噶尔盆地西北缘克拉玛依-乌尔禾断裂带推覆体上盘构造样式及影响因素

在线全文

学校读者我要写书评

暂无评论

地质通报 2024年第5期43卷 802-811页

作者：张磊白雨李梦瑶王涛马银山杨亚洲中国石油新疆油田分公司/勘探开发研究院新疆克拉玛依834000 中国地质科学院北京100037

准噶尔盆地西北缘克拉玛依-乌尔禾断裂带(克-乌断裂带)及其周缘发现了大量的油气藏,尤其是推覆体上盘伴随着勘探程度及地质认识不断深化,已呈现出“百里油区”的态势。然而,受多期构造活动及断裂带内部复杂的岩性组合影响,石炭系内幕地... 详细信息

准噶尔盆地西北缘克拉玛依-乌尔禾断裂带(克-乌断裂带)及其周缘发现了大量的油气藏,尤其是推覆体上盘伴随着勘探程度及地质认识不断深化,已呈现出“百里油区”的态势。然而,受多期构造活动及断裂带内部复杂的岩性组合影响,石炭系内幕地层构造样式展现出多种类型及复杂的空间展布样式,因此需要对构造样式及成因进一步探讨。综合地震和钻井资料,结合区域构造格局,梳理了准噶尔盆地西北缘克-乌断裂带上盘构造变形特征与影响因素;根据构造样式与推覆体内的岩性组合类型,将克-乌断裂带推覆体上盘划分出南段、中段和北段3个变形单元;明确了上盘石炭系5期主要构造阶段,分段恢复了推覆体上盘构造演化期次及样式。综合上述研究,认为克-乌断裂带上、下盘原始岩性组合关系是造成上盘石炭系内幕地层原始形变差异的主要因素,上盘石炭系内幕地层岩性组合差异是造成原生构造保存的主要因素。上述因素共同造成了圈闭条件沿克-乌断裂带自南向北变化。该研究为克-乌断裂带上盘油气勘探提供指导,同时也为类似条件地区的油气勘探提供借鉴。

关键词：准噶尔盆地克-乌断裂带构造样式构造演化石炭系油气勘探

Data-driven Methods to Predict the Burst Strength of Corroded Line Pipelines Subjected to Internal Pressure

在线全文

学校读者我要写书评

暂无评论

Journal of Marine Science and Application 2022年第2期21卷 115-132页

作者： Jie Cai Xiaoli Jiang yazhou yang Gabriel Lodewijks Minchang Wang Department of Technology and Innovation University of Southern DenmarkCampusvej 55-5230 OdenseDenmark Department of Maritime and Transport Technology Delft University of Technology2628 CD Delftthe Netherlands College of Advanced Interdisciplinary Studies National University of Defence TechnologyChangsha410073P.R.China School of Engineering University of NewcastleNSW2308Australia Hangzhou Silan Microelectronics Co.Ltd. HangzhouZhejiang310008P.R.China.

A corrosion defect is recognized as one of the most severe phenomena for high-pressure pipelines,especially those served for a long ***-element method and empirical formulas are thereby used for the strength prediction of such pipes with ***,it is time-consuming for finite-element method and there is a limited application range by using empirical *** order to improve the prediction of strength,this paper investigates the burst pressure of line pipelines with a single corrosion defect subjected to internal pressure based on data-driven *** supervised ML(machine learning)algorithms,including the ANN(artificial neural network),the SVM(support vector machine)and the LR(linear regression),are deployed to train models based on experimental *** analysis is first conducted to determine proper pipe features for *** tuning to control the learning process is then performed to fit the best strength models for corroded *** all the proposed data-driven models,the ANN model with three neural layers has the highest training accuracy,but also presents the largest *** SVM model provides both high training accuracy and high validation *** LR model has the best performance in terms of generalization *** models can be served as surrogate models by transfer learning with new coming data in future research,facilitating a sustainable and intelligent decision-making of corroded pipelines.

关键词： Pipelines Corrosion Burst strength Internal pressure Data-driven method Machine learning

Epigenetic and transcriptional landscapes during cerebral cortex development in a microcephaly mouse model

在线全文

学校读者我要写书评

暂无评论

Journal of Genetics and Genomics 2024年第4期51卷 419-432页

作者： Qing yang Qiang Cao Yue Yu Xianxin Lai Jiahao Feng Xinjie Li Yinan Jiang yazhou Sun Zhong-Wei Zhou Xin Li School of Medicine Shenzhen Campus of Sun Yat-sen UniversityShenzhenGuangdong 518107China Academy of Medical Engineering and Translational Medicine Tianjin UniversityTianjin 300072China Scientific Research Center The Seventh Affiliated Hospital of Sun Yat-sen UniversityShenzhenGuangdong 518107China Guangdong Provincial Key Laboratory of Digestive Cancer Research The Seventh Affiliated Hospital of Sun Yat-sen UniversityShenzhenGuangdong 518107China

The cerebral cortex is a pivotal structure integral to advanced brain functions within the mammalian central nervous *** methylation and hydroxymethylation play important roles in regulating cerebral cortex ***,it remains unclear whether abnormal cerebral cortex development,such as microcephaly,could rescale the epigenetic landscape,potentially contributing to dysregulated gene expression during brain *** this study,we characterize and compare the DNA methylome/hydroxymethylome and transcriptome profiles of the cerebral cortex across several developmental stages in wild-type(WT)mice and Mcph1 knockout(Mcph1-del)mice with severe ***,we discover a global reduction of 5′-hydroxymethylcytosine(5hmC)level,primarily in TET1-binding regions,in Mcph1-del mice compared to WT mice during juvenile and adult ***,genes exhibiting diminished 5hmC levels and concurrently decreased expression are essential for neurodevelopment and brain ***,genes displaying a delayed accumulation of 5hmC in Mcph1-del mice are significantly associated with the establishment and maintenance of the nervous system during the adult *** findings reveal that aberrant cerebral cortex development in the early stages profoundly alters the epigenetic regulation program,which provides unique insights into the molecular mechanisms underpinning diseases related to cerebral cortex development.

关键词： Microcephaly Epigeneticmodification Tet1 Cerebral cortexdevelopment DNA hydroxymethylome Transcriptome

不同栽培措施对豫东地区春播花生农艺性状与生理特性的影响

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

贵州农业科学 2024年第3期52卷 15-24页

作者：雷亚柯张建航展世杰邓陈威王伟杰张俊杨亚洲马振威贾朝阳周口市农业科学院河南周口466001 河南省农业科学院经济作物研究所河南郑州450002

【目的】探明豫东地区春播花生适宜的人工播种和机械播种模式,为提升豫东地区花生种植效益、推动花生产业高质量发展提供参考。【方法】采用L8(4×24)正交试验方法,研究播种密度、每穴种子数、包衣剂用量、起垄高度和底肥用量5个因素对... 详细信息

【目的】探明豫东地区春播花生适宜的人工播种和机械播种模式,为提升豫东地区花生种植效益、推动花生产业高质量发展提供参考。【方法】采用L8(4×24)正交试验方法,研究播种密度、每穴种子数、包衣剂用量、起垄高度和底肥用量5个因素对花生株高、总分枝数、倒伏率、单株无效果针数、单株饱果数、单株秕果数、单株饱果率、单株果重、百果重、百仁重、出仁率、荚果产量和叶片SPAD值等方面的影响,并分析不同栽培因素与荚果产量的相关性。【结果】增加花生播种密度可显著促进株高,加重倒伏,显著降低总分枝数、单株饱果数、单株秕果数和单株果重;荚果产量随着种植密度增加呈先升后降趋势,最佳播种密度为21万穴/hm^(2)。与每穴种子数1粒相比,2粒可显著提升株高和荚果产量,但显著降低总分枝数、无效果针数、单株饱果数、单株秕果数、单株果重和百果重。种子包衣可显著提高荚果产量和单株果重。起垄种植可显著提高单株果重和百仁重,但显著降低株高。适当减少底肥用量对花生各农艺性状均无显著影响。每穴种子数、包衣剂用量、种植密度和底肥用量均与荚果产量正相关,其中,每穴种子数与荚果产量的相关性达显著水平;起垄高度与荚果产量呈负相关,未达显著水平。8种种植模式(P1~P8)在株高、总分枝数、无效果针数、单株饱果数、单株秕果数、单株果重、百果重和荚果产量方面存在极显著差异,在倒伏率、百仁重、出仁率和生长后期叶片SPAD值方面存在显著差异。人工播种模式下P4处理和机械播种模式下P5处理的荚果产量均最高,分别达5401.65 kg/hm^(2)和5024.40 kg/hm^(2)。【结论】综合考虑花生产量和投入成本,豫东地区春播花生最佳种植模式:人工播种为密度18万穴/hm^(2),2粒/穴,种子包衣,起垄,底肥复合肥料硫酸钾用量102.0 kg/hm^(2);机器播种为密度21万穴/hm^(2),1粒/穴,种子包衣,起垄,底肥复合肥料硫酸钾用量102.0 kg/hm^(2)。

关键词：花生农艺性状生理特性春种栽培模式豫东地区

Sex-specific facilitation and reproduction of the gynodioecious cushion plant Arenaria polytrichoides on the Himalaya-Hengduan mountains,SW China

在线全文

学校读者我要写书评

暂无评论

Plant Diversity 2024年第2期46卷 247-255页

作者： Xufang Chen yazhou Zhang Lishen Qian Renyu Zhou Hang Sun Jianguo Chen State Key Laboratory of Plant Diversity and Specialty Crops Kunming Institute of BotanyChinese Academy of SciencesKunmingYunnanChina Yunnan Key Laboratory of Plateau Wetland Conservation Restoration and Ecological ServicesSouthwest Forestry UniversityKunmingYunnanChina

When benefiting other beneficiaries,cushion plants may reciprocally receive feedback *** feedback effects on different sex morphs,however,remains *** this study,taking the gynodioecious Arenaria polytrichiodes as a model species,we aimed to assess the sex-specific facilitation intensity of cushion plant by measuring the beneficiary cover ratio,and to assess the potential costs in cushion reproductive functions by measuring the flower and fruit cover *** total beneficiary cover ratio was similar between females and *** produced much less flowers but more fruits than *** results suggested that females and hermaphrodites possess similar facilitation intensity,and female cushion *** may allocate more resources saved from pollen production to seed production,while hermaphrodites possibly allocate more resources to pollen production hence reducing seed *** surface areas covered by beneficiaries produced less flowers and fruits than areas without *** addition,strong negative correlations between beneficiary cover and flower cover were detected for both females and hermaphrodites,but the correlation strength were similar for these two sex ***,the correlation between beneficiary cover and fruit cover was only significantly negative for females,suggesting that beneficiary plants negatively affect fruit reproduction of females while have neutral effects on *** the results suggest that to facilitate other beneficiaries can induce reproductive costs on cushion ***,with females possibly suffering greater cost than *** differentiation in reproductive costs between sex morphs,in long-term perspective,may imply sex imbalance in population dynamics.

关键词： Facilitation intensity Feedback effect Sex-specific facilitation Nurse plant Population dynamics Reproductive function

Multi-scale modeling for prediction of mechanical performance in brazed GH99 thin-walled structure

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第7期37卷 550-563页

作者： yazhou LIU Shengpeng HU Yanyu SONG Wei FU Xiaoguo SONG Ning GUO Weimin LONG State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China Shandong Institute of Shipbuilding Technology Weihai 264209China China Machinery Intelligent Equipment Innovation Research Institute(Ningbo)Co. Ltd.Ningbo 315700China

Superalloy thin-walled structures are achieved mainly by brazing,but the deformation process of brazed joints is non-uniform,making it a challenging research *** paper records a thorough investigation of the effect of brazing parameters on the microstructure of joints and its mechanical properties,which mainly inquires into the deformation and fracture mechanisms in the shearing process of GH99/BNi-5a/GH99 *** macroscopic-microscopic deformation mechanism of the brazing interface during shearing was studied by Crystal Plasticity(CP)and Molecular Dynamics(MD)on the basis of the optimal brazing *** experimental results show that the brazing interface is mainly formed by(Ni,Cr,Co)(s,s)and possesses a shear strength of approximately 546 *** shearing fracture of the brazed joint occurs along the brazing seam,displaying the characteristics of intergranular *** simulations show that dislocations disassociate and transform into fine twinning with increased *** simulated the shear deformation process of the brazed *** multiscale simulation results are consistent with the experimental *** mechanical properties of thin-walled materials for brazing are predicted using MD and CP methods.

关键词： Multi-scale modeling Brazing Shear mechanisms Crystal plasticity GH99 superalloy