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Lightweight foam-like nitrogen-doped carbon nanotube complex achieving highly efficient electromagnetic wave absorption

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Journal of Materials Science & Technology 2024年第1期168卷 114-123页

作者： Zongcheng Li Jin Liang Zhiheng Wei Xin cao Jiahui Shan Chunwei Li Xiaoyi Chen Dong Zhou Ruizhe xing Chunjia Luo Jie Kong MOE Key Lab of Materials Physics and Chemistry in Extraordinary Conditions Shaanxi Key Laboratory of Macromolecular Science and TechnologySchool of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Key laboratory of Flexible Electronics of Zhejiang Province Ningbo Institute of Northwestern Polytechnical UniversityNingbo 315103China Polymer Materials and Engineering Department School of Materials Science and EngineeringChang’an UniversityXi’an 710064China

With the increased electromagnetic wave(EMW)threat to military and human health,the develop-ment of EMW-absorbing materials is ***-organic framework derivatives containing magnetic nanoparticles and a carbon matrix are potential candidates for designing efficient EMW-absorbing ***,a zeolitic imidazolate framework-67(ZIF-67)-embedded three-dimensional melamine foam is pyrolyzed to afford carbon foam-based nitrogen-doped carbon nanotube composites,named 3D foam-like CoO/Co/*** CoO/Co particles are confined in the dielectric carbon nanotube *** carbon nanotubes provide considerable conductive loss,while CoO/Co magnetic particles are con-ducive to providing magnetic loss and adjusting impedance ***,the numerous defect structures introduced by heteroatomic doping(nitrogen)cause dipole polarization and simultaneously adjust impedance ***,the unique porous nanotube structure promotes multiple re-flections and scattering of EMWs,further optimizing impedance ***/Co/N-CNTs composites exhibit a minimum reflection loss of−52.3 dB at a matching thickness of 2.0 mm,while the correspond-ing effective absorption bandwidth is 5.28 GHz at a matching thickness of 2.2 *** study reports a novel approach to fabricating a lightweight high-performance EMW-absorbing material.

关键词： Lightweight porous carbon materials Carbon nanotubes CoO/Co magnetic particles Electromagnetic synergistic effect Impedance matching

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Effect of nitrogen introduction methods on the microstructure and properties of gradient cemented carbides

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International Journal of Minerals,Metallurgy and Materials 2011年第6期18卷 709-716页

作者： Tian-en Yang Ji Xiong Lan Sun Zhi-xing Guo Ding cao School of Manufacturing Science and Engineering Sichuan University Chengdu 610065 China

Gradient cemented carbides with the surface depleted in cubic phases were prepared following normal powder metallurgical procedures. Gradient zone formation and the influence of nitrogen introduction methods on the microstructure and performance of the alloys were investigated. The results show that the simple one-step vacuum sintering technique is doable for producing gradient cemented carbides. Gradient structure formation is attributed to the gradient in nitrogen activity during sintering, but is independent from nitrogen introduced methods. A uniform carbon distribution is found throughout the materials. Moreover, the transverse rupture strength of the cemented carbides can be increased by a gradient layer. Different nitrogen carriers give the alloys distinguishing microstructure and mechanical properties, and a gradient alloy with ultrafine-TiC0.5N0.5 is found optimal.

关键词： gradient cemented carbide gradient methods nitrogen microstructure mechanical properties sintering

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Proton pitch angle distributions in the Martian induced magnetosphere: A survey of Tianwen-1 Mars Ion and Neutral Particle Analyzer observations

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Earth and Planetary Physics 2023年第5期7卷 533-539页

作者： TaiFeng Jin BinBin Ni LingGao Kong AiBing Zhang Lei Li Song Fu xing cao WenYa Li BinBin Tang LiangHai Xie YiTeng Zhang ShuYue Pang XiaoTong Yun HengLe Du FuHao Qiao LiMin Wang JiJie Ma Department of Space Physics School of Electronic InformationWuhan UniversityWuhan 430072China Chinese Academy of Sciences Center for Excellence in Comparative Planetology Hefei 230026China National Space Science Center Chinese Academy of SciencesBeijing 100190China Beijing Key Laboratory of Space Environment Exploration Beijing 100190China Key Laboratory of Science and Technology on Space Environment Situational Awareness Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China State Key Laboratory of Space Weather Chinese Academy of SciencesBeijing 100190China

The pitch angle distributions of ions and electrons can be affected by various processes;thus,they can serve as an important indicator of the physical mechanisms driving the dynamics of space *** observations from the Mars Ion and Neutral Particle Analyzer onboard the Tianwen-1 orbiter,we calculated the pitch angle distributions of protons in the Martian induced magnetosphere by using information from the magnetohydrodynamically simulated magnetic field,and we statistically analyzed the spatial occurrence pattern of different types of pitch angle *** though no symmetrical features were seen in the dataset,we found the dominance of the field-aligned distribution type over the energy range from 188 to 6232 *** of the occurrence rate showed the preferential presence of a trapped-like distribution at the lower altitudes of the surveyed nightside *** our results are more or less restricted by the adopted magnetic field,they indicate the complexity of the near-Mars proton pitch angle distributions and infer the possibility of wave–particle interactions in the Martian induced magnetosphere.

关键词： Martian plasma environment ion pitch angle distribution Tianwen-1 Mars Ion and Neutral Particle Analyzer(MINPA)

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A mix & act liposomes of phospholipase A2-phosphatidylserine for acute brain detoxification by blood‒brain barrier selective-opening

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Acta Pharmaceutica Sinica B 2024年第4期14卷 1827-1844页

作者： Zinan Zhang Wenbin cao Huanchun xing Shuai Guo Lijuan Huang Lin Wang Xin Sui Kui Lu Yuan Luo Yongan Wang Jun Yang State Key Laboratory of Toxicology and Medical Countermeasures Beijing Institutes of Pharmacology and ToxicologyBeijing 100850China Tianjin University of Science and Technology Tianjin 300222China Hebei University of Science and Technology Shijiazhuang 050018China

In the treatment of central nervous system disease,the blood-brain barrier(BBB)is a major obstruction to drug delivery that must be *** this study,we propose a brain-targeted delivery strat-egy based on selective opening of the *** strategy allows some simple bare nanoparticles to enter the brain when mixed with special opening material;however,the BBB still maintains the ability to completely block molecules from passing *** on the screening of BBB opening and matrix delivery mate-rials,we determined that phospholipase A2-catalyzed 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoserine li-posomes can efficiently carry drugs into the brain *** an effective dose,this delivery system is safe,especially with its effect on the BBB being *** mix&act delivery system has a simple structure and rapid preparation,making it a strong potential candidate for drug delivery across the BBB.

关键词： Liposomes Phospholipase A2 Phosphoserine Blood-brainbarrier Selectively open Mix&act

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Controlled one-pot synthesis of RuCu nanocages and Cu@Ru nanocrystals for the regioselective hydrogenation of quinoline

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Nano Research 2016年第9期9卷 2632-2640页

作者： Yueguang Chen Zhanjun Yu Zheng Chen Rongan Shen Yu Wang xing cao Qing Peng Department of Chemistry and Collaborative Innovation Center for Nanomaterial Science and Engineering Tsinghua UniversityBeijing 100084China

RuCu nanocages and core–shell Cu@Ru nanocrystals with ultrathin Ru shells were first synthesized by a one-pot modified galvanic replacement reaction. The construction of bimetallic nanocrystals with fully exposed precious atoms and a high surface area effectively realizes the concept of high atom-efficiency. Compared with the monometallic Ru/C catalyst, both the RuCu nanocages and Cu@Ru core–shell catalysts supported on commercial carbon show superior catalytic performance for the regioselective hydrogenation of quinoline toward 1,2,3,4-tetrahydroquinoline. RuCu nanocages exhibit the highest activity, achieving up to 99.6% conversion of quinoline and 100% selectivity toward 1,2,3,4-tetrahydroquinoline. [Figure not available: see fulltext.] © 2015, Tsinghua University Press and Springer-Verlag Berlin Heidelberg.

关键词： bimetallics one-pot synthesis nanocages core-shell nanocrystals hydrogenation of quinoline

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不充分就业感知对员工兼职创业投入的影响机制研究

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管理学报 2022年第2期19卷 205-212页

作者：曹星魏峰同济大学经济与管理学院大理大学经济与管理学院

基于情感-认知评价的理论视角,在控制了工作满意度路径之后,通过对311名兼职创业者的实证数据进行分析,探究了员工不充分就业感知的两个维度——资质过剩感和成长缺乏感对员工兼职创业投入的作用机理。研究结果表明:资质过剩感、成长缺... 详细信息

基于情感-认知评价的理论视角,在控制了工作满意度路径之后,通过对311名兼职创业者的实证数据进行分析,探究了员工不充分就业感知的两个维度——资质过剩感和成长缺乏感对员工兼职创业投入的作用机理。研究结果表明:资质过剩感、成长缺乏感以及两者的交互作用会强化员工与本职工作的疏离感;工作疏离感正向影响员工兼职创业投入;工作疏离感在资质过剩感、成长缺乏感及其交互作用对兼职创业投入的影响中发挥了中介作用。

关键词：不充分就业感知资质过剩感成长缺乏感工作疏离感兼职创业投入

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Assessing Agricultural Sustainable Development Based on the DPSIR Approach: Case Study in Jiangsu, China

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Journal of Integrative Agriculture 2013年第7期12卷 1292-1299页

作者： ZHOU Shu-dong Felix Mueller Benjamin Burkhard cao xing-jin HOU Ying Jiangsu Research Base of Rural Development and Land Policy Nanjing Agricultural University Institute for Natural Resource Conservation Department of Ecosystem Management University of Kiel

According to the contemporary ecosystem approach, the linkages of human actions with their environment have to be assessed in an integrative manner. The Driver-Pressure-State-Impact-Response （DPSIR） model is applied to identify and describe processes and interactions in human-environmental systems. An example application from a research project dealing with the development of sustainable management strategies for the agriculture in Jiangsu, China, illustrates the potentials and limitations of its sustainable development. The concept and indicators of ecological integrity are used to assess the indicators in the dimensions of DPSIR between 2003 and 2006. The main drivers included population growth which caused increasing demand for food, growing environmental demands, and rapidly decreasing of land and other natural resources. The main environmental problem was water pollution. The results show that in the dimension of driver, total grain output and agricultural land productivity both increased. Labor intensive agriculture has been promoted to increase agricultural land productivity. In the dimension of pressure, on the positive side, infrastructure got greatly improved, the input level such as total power of machinery, and level of fertilizer use increased, and level of pesticides use decreased, but on the negative side, cultivated land per capita and irrigation rate decreased, natural resources keep decreased. Environmental pollution indicators such as industrial wastewater discharge and acid rain rate increased in Jiangsu Province. In the aspect of state, ecosystem state was improved, plant coverage index increased, biological abundance index increased, fertilizer productivity increased, eco-environmental quality index increased, but land degradation index also increased. In the aspect of impact, output level increased, output efficiency enhanced, farmer＇s social economic benefit improved. In the aspect of response, social support was greatly improved, input for e

关键词： agricultural sustainable development DPSIR ecosystem China

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不连续创新下新兴技术创新网络形成机理研究——基于云计算和智能手机技术的案例分析

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中南大学学报（社会科学版） 2023年第3期29卷 141-156页

作者：马慧曹兴湖南第一师范学院商学院湖南长沙410205 中南大学商学院湖南长沙410083

新兴技术具有不连续创新的特征,推动了新兴技术创新网络的形成及其演化。结合生命周期理论,深入分析了新兴技术不连续创新形成的机理,揭示了不连续创新下新兴技术创新网络的形成过程。选取云计算和智能手机技术为研究对象,通过构建新兴... 详细信息

新兴技术具有不连续创新的特征,推动了新兴技术创新网络的形成及其演化。结合生命周期理论,深入分析了新兴技术不连续创新形成的机理,揭示了不连续创新下新兴技术创新网络的形成过程。选取云计算和智能手机技术为研究对象,通过构建新兴技术创新网络,分别分析正向不连续和反向不连续创新对新兴技术创新网络形成的影响。研究发现:不连续创新下新兴技术具有知识创造带来的技术垂直跨越的特征,以及知识融合带来的技术水平跃迁的特征,并在新兴技术创新网络形成中,呈现网络中心向外辐射和网络边界向内渗透的两种模式;云计算技术是现有技术领域的重大突破,具有正向不连续创新特征,云计算技术创新网络呈现出快速增长、结构模块化和中心不变等特征;智能手机技术体现了多技术领域的跨界融合,具有反向不连续创新特征,智能手机技术创新网络呈现出动态平衡、结构中心化和中心突变等特征。

关键词：新兴技术不连续创新创新网络

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Investigation on RQ Embrittlement Mechanism of FeCuNbSiB Soft Magnetic Alloy

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Journal of Iron and Steel Research(International) 2000年第2期7卷 45-49页

作者： cao xing-guo HUANG Jin-liang CHEN Wen-zhi ZHOU Shou-xiong Luoyang Institute of Technology Central Iron & Steel Research Institute

The XRD, TEM, PAT, Curie temperature and internal friction methods were used to study systematically the embrittlement mechanism of rapidly quenched ( RQ ) nanocrystalline soft magnetic alloy *** test results confirmed that the RQ embrittlement mechanism of amorphous alloy FeCuNbSiB was not related to crystallization but that was related to structural relaxation. Furthermore, the structural relaxation temperature of amorphous alloy FeCuNbSiB was much lower than that of used commonly amorphous alloy Fe78B13Si9. It meant that the RQ embrittlement is easier to happen for nanocrystalline alloy FeCuNbSiB than amorphous alloy Fe-B-Si.

关键词： FeCuNbSiB RQ embrittlement mechanism structural relaxation crystallization

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Preparation and characterization of monodisperse spherical particles of X-ray nano-phosphors based on Gd_2O_2S:Tb

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Chinese Science Bulletin 2009年第17期54卷 2982-2986页

作者： xing MingMing cao WangHe PANG Tao LING XiaoQiao CHEN Ning Optoelectronic Technology Institute Dalian Maritime University Dalian 116026 China

Monodisperse spherical Gd2O2S:Tb nanoparticles have been prepared using an improved homogeneous precipitation method combined with solid-gas sulfuration technology. The effects of Tb3+-doped concentration on luminescent intensity and color purity of samples were investigated, and the optimal Tb3+-doped concentration was determined. Under the excitation of X-ray, the obtained sample shows excellent luminescent properties, and its luminescent intensity is increased by about 50% under lower sulfuration temperature compared with that of the Gd2O2S:Tb nanoparticles prepared by complex precipitation method.

关键词：纳米荧光粉球形颗粒铽掺杂单分散 X射线制备均匀沉淀法基础

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