检索结果-南通市图书馆

Improved electrochemical hydrogen storage capacity of Ti45Zr38Ni17 quasicrystal by addition of ZrH2

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2018年第6期34卷 995-998页

作者： jianxun zhao Xiaojie Zhai Xing Tao Zhe Li Qingshuang Wang Wanqiang Liu Limin Wang School of Materials Science and Engineering Changchun University of Science and Technology Changchun 130022 China State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied Chemistry CAS Changchun 130022 China

Ti45Zr38Ni37 ＋ xZrH2 （x = 5,10, 15 and 20 wt%） composite materials are produced by ball milling for 20 rain. The results of XRD measurement show that the composite materials contain icosahedral quasicrystal phase （I-phase）, FCC phase with a Ti2Ni type crystal and C14 Laves phase. After adding ZrH2, the composite materials include not only the individual phases mentioned above, but also the ZrH phase. These composite materials are used as the negative electrode material of the nickel-metal hydride batteries. The electrochemical hydrogen storage characteristics of the material after adding ZrH is investigated. The TiasZr38Ni17 ＋xZrH2 （x=5, 10, 15 and 20wt%） composite material has reached the maximum discharge capacity （83.2 mA h/g） when x equals 10. This maximum discharge capacity is much higher than that of Ti45Zr38Ni17 alloy without ZrH. After adding ZrH2. the high-rate discharge ability and the cycling stability are enhanced simultaneously. The improvement of the electrochemical properties can be attributed to the synergistic effects of ZrH2, and the synergistic effects in the composite electrodes are probably attributed to the entry of most of hydrogen atoms from weakly bond strength of the Zr-H to the l-phase structure in electrochemical reaction.

关键词： Quasicrystals Electrochemical measurements Electrochemical properties Energy storage

在线全文

学校读者我要写书评

暂无评论

芜菁种质资源抗旱性鉴定与筛选

中国瓜菜 2024年第8期37卷 100-108页

作者：何苗姜元昊朱超凡王亚海吴忠祥赵建勋轩正英南疆设施农业兵团重点实验室·塔里木大学园艺与林学学院新疆阿拉尔843300

为系统评价芜菁幼苗的抗旱性,筛选抗旱种质,以40份芜菁种质为试验材料,采用苗期盆栽试验,设置干旱和正常浇水两种处理,测定芜菁幼苗形态指标、叶绿素含量、旱害指数、死亡率等19个抗旱性评价指标,并利用相关性分析、主成分分析、隶属函... 详细信息

为系统评价芜菁幼苗的抗旱性,筛选抗旱种质,以40份芜菁种质为试验材料,采用苗期盆栽试验,设置干旱和正常浇水两种处理,测定芜菁幼苗形态指标、叶绿素含量、旱害指数、死亡率等19个抗旱性评价指标,并利用相关性分析、主成分分析、隶属函数法等对芜菁幼苗进行抗旱性综合评价和抗旱鉴定指标筛选。结果表明,与正常浇水处理相比,干旱胁迫降低了芜菁的株高、茎粗、叶长和叶宽、地上鲜质量和干质量、叶绿素含量等指标,但对地下部相关指标的影响有正负两种结果。根据综合评价结果,可将40份芜菁种质划分为3种类型,包括11份干旱敏感种质、5份抗旱种质、24份中度抗旱种质,其中抗旱性强的芜菁材料是B9,对干旱最为敏感的材料是B2;主成分分析结果表明,株高、叶长、叶宽、叶柄长、主根长、根体积、地上鲜质量、地下鲜质量、地下干质量、根冠比、旱害指数可作为芜菁幼苗抗旱性评价的重要指标。

关键词：芜菁苗期抗旱性鉴定和筛选

维普期刊数据库博看期刊

在线全文

学校读者我要写书评

暂无评论

蔬菜产地处理过程碳排放模型建立与计算分析

冷藏技术 2024年第3期47卷 6-11页

作者：赵建勋田长青唐明生黄铭暄中国科学院理化技术研究所低温科学与技术重点实验室北京100190 中国科学院大学北京100491

近年来人们对优质蔬菜的需求不断增加,蔬菜产地处理环节的应用率不断提高,由此势必会增设大量的产地冷链设备与其他产地处理设备,从而增加蔬菜产地处理过程的碳排放量。本文基于蔬菜产地处理的具体环节和碳排放来源类别,采用排放因子法... 详细信息

近年来人们对优质蔬菜的需求不断增加,蔬菜产地处理环节的应用率不断提高,由此势必会增设大量的产地冷链设备与其他产地处理设备,从而增加蔬菜产地处理过程的碳排放量。本文基于蔬菜产地处理的具体环节和碳排放来源类别,采用排放因子法构建了蔬菜产地处理过程的碳排放计算模型。通过计算得出,每1 kg蔬菜在整个产地处理过程中会产生0.134千克的碳排放。基于碳排放模型计算结果分析,本文从减少采收损失、缩短贮藏时间、重复使用外包装三个方面对蔬菜产地处理过程碳减排提出了相应建议。

关键词：蔬菜处理产地蔬菜冷链碳排放

Room-temperature NH_3 sensors with high sensitivity and short response/recovery times

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2014年第4期59卷 447-451页

作者： Qingcheng Liang Di Li Shang Gao Dayong Jiang jianxun zhao Jieming Qin Jianhua Hou School of Materials Science and Engineering Changchun University of Science and Technology

Micro-sensors are fabricated by co-electrospinning In2O3and SnO2nanofibers on the substrates of SiO2/Si with interdigitated Pt signal *** total sensor area is 1.36 mm 9 0.55 mm and the active area is only0.63 mm 9 0.55 *** NH3sensing properties are obtained based on the sensors at room *** sensitivity is at most 28 when the sensors are exposed to NH3of 10 *** response time is 8 s or so and the recovery time is nearly 2 *** only fine selectivity,but also longtime stability is *** results not only demonstrate the obtained micro-sensors are very promising devices for NH3detection,but also show a possible route for large-scale NH3sensor fabrication at the industrial level.

关键词：微传感器恢复时间高灵敏度快速响应室温 NH3 SiO2 Si 器具

Effect of Nitrogen and Sulfur Co‑Doped Graphene on the Electrochemical Hydrogen Storage Performance of Co_(0.9)Cu_(0.1)Si Alloy

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2023年第6期36卷 1023-1037页

作者： Wenhao Fan jianxun zhao Dayong Liu Qingcheng Liang Wanqiang Liu Qingshuang Wang Heng Liu Peng Chen Shang Gao Xinlong Bao Yong Cheng Xinwei Wang Xin Guo School of Materials Science and Engineering Changchun University of Science and TechnologyChangchun 130022China Engineering Research Center of Optoelectronic Functional Materials Ministry of EducationChangchun 130022China College of Electronic Science and Engineering Jilin UniversityChangchun 130022China School of Life Science and Technology Changchun University of Science and TechnologyChangchun 130022China Research Center for Nanotechnology Changchun University of Science and TechnologyChangchun 130022China Research Institute of Changchun University of Science and Technology in Chongqing Chongqing 401120China State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryCASChangchun 130022China

Co_(0.9)Cu_(0.1)Si alloy was prepared by mechanical alloying ***-doped graphene(NG)and nitrogen–sulfur codoped graphene(NSG)were prepared by hydrothermal method.5 wt%graphene oxide,NG and NSG were doped into Co_(0.9)Cu_(0.1)Si alloy,respectively,by ball milling to improve the electrochemical hydrogen storage performance of the composite material.X-ray diffraction and scanning electron microscopy were used to characterize the structure and morphology of the composite material,and the LAND battery test system and three-electrode battery system were used to test the electrochemical performance of the composite *** composite material showed better discharge capacity and better cycle stability than the pristine *** addition,in order to study the optimal ratio of NSG,3%,5%,7%and 10%of NSG were doped into Co_(0.9)Cu_(0.1)Si alloy,***_(0.9)Cu_(0.1)Si alloy doped with 5%NSG had the best performance among all the *** best discharge capacity was 580.1 mAh/g,and its highest capacity retention rate was 64.1%.The improvement in electrochemical hydrogen storage performance can be attributed to two *** the one hand,the electrocatalytic performance of graphene is improved by co-doping nitrogen and sulfur,on the other hand,graphene has excellent electrical conductivity.

关键词： Co_(0.9)Cu_(0.1)Si alloy Nitrogen-sulfur co-doped graphene(NSG) Composite material Electrochemical hydrogen storage

Compressed Sensing Applied to Wireless Sensor Networks Security

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

Compressed Sensing Applied to Wireless Sensor Networks Secur...

Progresses on cryo-tribology:lubrication mechanisms,detection methods and applications

2012年计算机应用与系统建模国际会议

作者： jianxun zhao Jihai Huang Zhongzhou University

Secure communication in wireless sensor networks (WSNs) is a challenging problem due to the scale and resource limitations. This means that most existing security protocols such as cryptography are not applicable in WSNs. However, more recent researches argue that encryption based on compressed sensing (CS) has the inherent advantage for security. And a measurement matrix used for sensing is usually constructed by a secret key. But establishment and assignment of the secret key is very difficult for wireless scenarios. In this context, we propose a security scheme for WSNs, which allows two legitimate nodes to establish a common secret key by exploiting joint channel characteristics of wireless channel. These characteristics between any two nodes are unique, unpredictable and decor relating rapidly in space. The established keys can then be used to construct measurement matrix and reconstruction matrix for the two nodes respectively. For improving bit rate and agreement of secret keys, some methods are also proposed in the paper. Analysis and simulation results show that, our proposed scheme ensures a high level of security for WSNs and also has the advantage of low computability complexity.

关键词： Compressed Sensing Joint Channel Characteristics Key Generation Wireless Sensor Networks

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

International Journal of Extreme Manufacturing 2023年第2期5卷 62-88页

作者： Wenyan Cui Hongzhan Chen jianxun zhao Quansheng Ma Qiang Xu Tianbao Ma State Key Laboratory of Tribology in Advanced Equipment Tsinghua UniversityBeijing 100084People’s Republic of China

Tribology at cryogenic temperatures has attracted much attention since the 1950s with the acceleration of its applications in high-tech equipment such as cryogenic wind tunnels,liquid fuel rockets,space infrared telescopes,superconducting devices,and planetary exploration,which require solid lubrication for moving parts at low temperatures down to 4 K in cryogenic liquid,gaseous,or vacuum ***,the research progress regarding cryo-tribology is *** tribological properties and mechanisms of solid lubricants listed as carbon materials,molybdenum disulfide,polymers,and polymer-based composites with decreasing temperature are *** friction coefficient increases with decreasing temperature induced by thermally activated *** mechanism of transfer film formation should be considered as a significant way to enhance the tribological properties of solid *** addition,applications of solid lubrication on moving parts under cryogenic conditions,such as spherical plain bearings and roller bearings,are *** technology for tribological testing of materials and bearings at cryogenic temperatures is summarized,where the environmental control,motion and loading realization,as well as friction and wear measurement together in a low-temperature environment,result in the difficulties and challenges of the low-temperature *** particular,novel technologies and tribotesters have been developed for tribotests and tribological studies of solid lubricants,spherical plain bearings,and roller bearings,overcoming limitations regarding cooling in vacuum and resolution of friction measurement,among others,and concentrating on in-situ observation of friction *** not only promote a deep understanding of friction and wear mechanism at low temperatures,but also provide insights into the performance of moving parts or components in cryogenic applications.

关键词： low temperature cryogenic tribotester self-lubricating materials bearing

在线全文

学校读者我要写书评

暂无评论

粗糙集知识约简中的蚁群优化算法研究

科技通报 2013年第8期29卷 53-55页

作者：赵建勋中州大学郑州450044

蚁群算法具有全局优化和收敛速度上的优势,适合处理粗糙集的知识约简问题。因此,在求解决策表属性最小约简中,将属性的重要性作为启发式信息引入蚁群算法,并把相对核加入到初始信息素分布中。这样可以从整体上降低问题的规模,同时加快... 详细信息

蚁群算法具有全局优化和收敛速度上的优势,适合处理粗糙集的知识约简问题。因此,在求解决策表属性最小约简中,将属性的重要性作为启发式信息引入蚁群算法,并把相对核加入到初始信息素分布中。这样可以从整体上降低问题的规模,同时加快了系统的收敛速度。实验分析表明,本文提出的优化算法在实际应用过程中与传统算法相比,具有更好的综合性能。

关键词：蚁群粗糙集约简属性核

细胞培皿内毫米波辐照剂量的时域有限差分法分析

在线全文

学校读者我要写书评

暂无评论

生物医学工程学杂志 2005年第2期22卷 327-330页

作者：赵建勋鲁德强西安电子科技大学生物医学工程系西安710071 浙江大学生物电磁学实验室杭州310031

对细胞层次上进行的毫米波(MMW)生物学效应实验中使用的培皿内的毫米波辐照剂量进行了分析。以一种常用的培皿为代表,通过时域有限差分法计算了在6 mm波长时培皿内辐照到细胞上的毫米波功率密度和细胞对毫米波的功率吸收密度分布的数据... 详细信息

对细胞层次上进行的毫米波(MMW)生物学效应实验中使用的培皿内的毫米波辐照剂量进行了分析。以一种常用的培皿为代表,通过时域有限差分法计算了在6 mm波长时培皿内辐照到细胞上的毫米波功率密度和细胞对毫米波的功率吸收密度分布的数据,并对结果进行了定性和定量分析。计算和分析结果表明,辐照到细胞上的毫米波功率密度和细胞对毫米波的功率吸收密度在培皿内的分布情况比较复杂,呈现出明显的不均匀性,不同位置毫米波辐照剂量差异明显,对实验结果的影响不可忽略。

关键词：培皿毫米波辐照剂量时域有限差分法细胞功率密度密度分布生物学效应定量分析分析结果