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改性铜基催化剂催化乙炔氢氯化反应的研究

现代化工 2024年第2期44卷 167-170,179页

作者：张津齐张丽张莹李雅侠冯颖沈阳化工大学化学工程学院辽宁沈阳110142 沈阳化工大学机械与动力工程学院辽宁沈阳110142

利用浸渍法将2,5-二甲基吡嗪(DMP)和氯化铜负载到活性炭上,在140℃、乙炔体积空速为50 h-1、氯化氢与乙炔摩尔比为1.05∶1的条件下,测试了其对乙炔氢氯化反应的催化性能。利用ICP-AES、红外光谱、XRD和TG等手段对催化剂进行表征。结果表... 详细信息

利用浸渍法将2,5-二甲基吡嗪(DMP)和氯化铜负载到活性炭上,在140℃、乙炔体积空速为50 h-1、氯化氢与乙炔摩尔比为1.05∶1的条件下,测试了其对乙炔氢氯化反应的催化性能。利用ICP-AES、红外光谱、XRD和TG等手段对催化剂进行表征。结果表明,加入2,5-二甲基吡嗪后,Cu表观质量分数为17%的催化剂的乙炔转化率可达74.02%,氯乙烯选择性可达97.19%。2,5-二甲基吡嗪提高铜基催化剂活性的原因在于其可以减少铜物种聚集,提高活性组分的分散度;可以产生Cu-N配位化学键,锚定铜物种使其稳定;可以抑制催化剂积碳,减少积碳引起的失活现象。

关键词：乙炔氢氯化催化剂 2,5-二甲基吡嗪氯化铜活性炭

Password-Authenticated Multiple Key Exchange Protocol for Mobile Applications

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China Communications 2012年第1期9卷 64-72页

作者： Li Wenmin Wen qiaoyan Su qi zhang Hua jin Zhengping State Key Laboratory of Networking and Switching Technology Beijing Uniwrsity of Posts and Telecommunications Beijing100876 P. R. China

To achieve privacy and authentication sinmltaneously in mobile applications, various Three-party Password-authenticated key exchange （3PAKE） protocols have been proposed. However, some of these protocols are vulnerable to conventional attacks or have low efficiency so that they cannot be applied to mobile applications. In this paper, we proposed a password-authenticated multiple key exchange protocol for mobile applications using elliptic curve cryptosystem. The proposed protocol can achieve efficiency, reliability, flexibility and scalability at the same time. Compared with related works, the proposed protocol is more suitable and practical for mobile applications.

关键词： mobile applications key exchange password elliptic curve cryptosystem security

Low-power and area-optimized VLSI implementation of AES coprocessor for Zigbee system

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The Journal of China Universities of Posts and Telecommunications 2009年第3期16卷 89-94页

作者： LI Zhen-rong ZHUANG Yi-qi zhang Chao jin Gang Key Laboratory of the Ministry of Education for Wide Band-Gap Semiconductor Materials and Devices Xidian University Xi'an 710071 China

A low-power and low-cost advanced encryption standard （AES） coprocessor is proposed for Zigbee system-on-a-chip （SoC） design. The cost and power consumption of the proposed AES coprocessor are reduced considerably by optimizing the architectures of SubBytes/InvSubBytes and MixColumns/InvMixColumns, integrating the encryption and decryption procedures together by the method of resource sharing, and using the hierarchical power management strategy based on finite state machine （FSM） and clock gating （CG） technologies. Based on SMIC 0.18 μm complementary metal oxide semiconductor （CMOS） technology, the scale of the AES coprocessor is only about 10.5 kgate, the corresponding power consumption is 69.1 μW/MHz, and the throughput is 32 Mb/s, which is reasonable and sufficient for Zigbee system. Compared with other designs, the proposed architecture consumes less power and fewer hardware resources, which is conducive to the Zigbee system and other portable devices.

关键词： Zigbee AES architecture encryption decryption application specific integrated circuit (ASIC)

Laser Amplification Mechanism in an Nd^(3+)-Doped Polymer Optical Fibre

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Chinese Physics Letters 2001年第10期18卷 1337-1340页

作者： GUO Yang ZHENG Xing MING Hai zhang qi-jin Department of Physics University of Science and Technology of ChinaHefei 230026 Department of Materials Science and Engineering University of Science and Technology of China Hefei 230026

The Judd-Ofelt theory was applied to optical-absorption transitions in an Nd^(3+)-doped polymer opticalfibre to obtain the intensity parameters (Ω_(2) = 0.83 x 10^(-20) cm^(2), 4 = 1.64 x 10^(-20) cm^(2), Ω_(6) = 4.04 x 10-20 cm^(2)), the radiative lifetime (371 μs) and the quantum efficiency (0.73) of the 4G5/2level, from which we found tlat the transition probability from 4G5/2 to 4I9/2 (Aij = 1995.7s^(-1)) is higher than others. Thus, in the polymer system, the traditional four-level laser system for Nd3+ was substituted by a three-level system. Furthermore, we have calculated the emission cross section (σeij = 2.45 × 10^(-21) cm^(2)), and solved the differential equations of the single-pass gain. In comparison with inorganic opticalfibres, an increased saturated intensity is observed.

关键词： system intensity lifetime

新课改背景下山东省中小学实验教学管理的现状及其研究

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中小学实验与装备 2024年第2期34卷 21-23页

作者：张其进王妍卉陈爱华山东省教育发展服务中心 271100 山东省济南市莱芜高新区实验学校 271100

中小学实验教学是培养学生动手能力、培养创新精神、全面提高学生综合素质的重要手段,建设一套适应德智体美劳总体要求、适应素质教育、统一课程标准要求的实验教学体系是实验教学发展的必然要求。当前,实验教学管理工作面临着诸多挑战... 详细信息

中小学实验教学是培养学生动手能力、培养创新精神、全面提高学生综合素质的重要手段,建设一套适应德智体美劳总体要求、适应素质教育、统一课程标准要求的实验教学体系是实验教学发展的必然要求。当前,实验教学管理工作面临着诸多挑战,必须利用现代化的管理手段,全面推进实验教学工作提升,为培养新时代创新性人才打下基础。

关键词：中小学实验教学教育装备

Dynamic Scene Graph Generation of Point Clouds with Structural Representation Learning

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Tsinghua Science and Technology 2024年第1期29卷 232-243页

作者： Chao qi Jianqin Yin Zhicheng zhang jin Tang School of Artificial Intelligence Beijing University of Posts and TelecommunicationsBeijing 100876China Standard and Metrology Research Institute China Academy of Railway Sciences Corporation LimitedBeijing 100081China

Scene graphs of point clouds help to understand object-level relationships in the 3D *** graph generation methods work on 2D structured data,which cannot be used for the 3D unstructured point cloud *** point-cloud-based methods generate the scene graph with an additional graph structure that needs labor-intensive manual *** address these problems,we explore a method to convert the point clouds into structured data and generate graphs without given ***,we cluster points with similar augmented features into groups and establish their relationships,resulting in an initial structural representation of the point ***,we propose a Dynamic Graph Generation Network(DGGN)to judge the semantic labels of targets of different *** dynamically splits and merges point groups,resulting in a scene graph with high *** show that our methods outperform other baseline *** output reliable graphs describing the object-level relationships without additional manual labeled data.

关键词： scene graph generation structural representation point cloud

Characterization of Clusters in a Novel Nd^(3+)-Doped Polymer Optical Fiber

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Chinese Physics Letters 1998年第4期15卷 272-274页

作者： YANG Bao MING Hai zhang qi-jin XIE Jian-ping Department of Physics University of Science and Technology of ChinaHefei 230026 Department of Materials Science and Engineering University of Science and Technology of ChinaHefei 230026

A step index-type Nd^(3+) -doped polymer optical fiber(POF)was prepared by using bulk polymerization of solution of Nd^(3+) -octanoate(NOA)and methyl and methacrylate.A method of wide-angle x-ray diffraction was used to measure the solubility of *** a high concentration Nd^(3+) doped POF,a residual absorption at 810nm could not be saturated,which is attributed to the high clustered ion rate in the Nd^(3+) POF.A model based on the rate equations to infer the clustered ion rate by the measurement of transmission is presented.

关键词： POF saturated attributed

A New Method to Study the Sol-gel Transition Process of Organic/Inorganic Hybrid Materials

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Chemical Research in Chinese Universities 2005年第5期21卷 606-610页

作者： GUO Bin GAO Jian-gang CHEN Da-zhu LIU Jian-ping HE Ping-sheng zhang qi-jin Structure Research Laboratory University of Science and Technology of China Hefei 230026 P. R. China Department of Polymer Science and Engineering University of Science and Technology of China Hefei 230026 P. R. China

The sol-gel transition process of PMMA/SiO2 hybrid materials was first studied by means of the dynamic torsional vibration method. The different stages of the transition can be described by the change of torque. The temperature-dependent measurement of the gel time（ tg ） gives the possibility to determine the apparent activation energy.（ Ea ） of this transition according to Flory＇s gelation theory. The non-equilibrium thermodynamic fluctuation theory was used to predict the transition behavior. The isothermal transition experiments on hybrid sols with different TEOS（tetraethyl orthosilicate） contents were carried out. The results show that the Ea of a hybrid sol is higher than that of a non- hybrid sol of a TEOS-water-ethanol system. The increasing of TEOS content in a hybrid sol has no obvious effect on the Ea value, but it can enhance the sol-gel .reaction rate.

关键词： Sol-gel transition Organic/inorganic Hybrid material DTVM

Chemico-biological conversion of carbon dioxide

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Journal of Energy Chemistry 2024年第2期89卷 371-387,I0009页

作者： Liangwei Hu Junzhu Yang qi Xia jin zhang Hongxin Zhao Yuan Lu Zhejiang Province Key Laboratory of Plant Secondary Metabolism and Regulation College of Life Sciences and MedicineZhejiang Sci-Tech UniversityHangzhou 310018ZhejiangChina Key Laboratory of Industrial Biocatalysis Ministry of EducationTsinghua UniversityBeijing 100084China Department of Chemical Engineering Tsinghua UniversityBeijing 100084China College of Biological and Chemical Engineering Jiaxing UniversityJiaxing 314000ZhejiangChina

The unabated carbon dioxide(CO_(2))emission into the atmosphere has exacerbated global climate change,resulting in extreme weather events,biodiversity loss,and an intensified greenhouse *** address these challenges and work toward carbon(C)neutrality and reduced CO_(2)emissions,the capture and utilization of CO_(2)have become imperative in both scientific research and *** cutting-edge approach to achieving efficient catalytic performance involves integrating green bioconversion and chemical *** innovative strategy offers several advantages,including environmental friendliness,high efficiency,and *** study provides a comprehensive review of existing technical routes for carbon sequestration(CS)and introduces two novel CS pathways:the electrochemicalbiological hybrid and artificial photosynthesis *** also thoroughly examines the synthesis of valuable Cnproducts from the two CS systems employing different catalysts and *** both systems heavily rely on electron transfer,direct and mediated electron transfer has been discussed and summarized in ***,this study explores the conditions suitable for different catalysts and assesses the strengths and weaknesses of *** also explored the biocompatibility of the electrode materials and developed novel *** materials were specifically engineered to combine with enzymes or microbial cells to solve the biocompatibility problem,while improving the electron transfer efficiency of ***,this review summarizes the relevant systems developed in recent years for manufacturing different products,along with their respective production efficiencies,providing a solid database for development in this *** novel chemical-biological combination proposed herein holds great promise for the future conversion of CO_(2)into advanced organic ***,it offers exciting prospects for utilizing CO_(2)in synthesizing

关键词： Carbon dioxide Bioelectric synthesis Artificial photosynthesis Synthetic product