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地球静止轨道卫星系统兼容性多维度分析方法

国防科技大学学报 2022年第1期44卷 77-84页

作者：董苏惠高翔韩锐姚秀娟闫毅中国科学院国家空间科学中心复杂航天系统电子信息技术重点实验室北京100190 中国科学院大学北京100049 国家无线电监测中心北京100037

针对地球静止轨道(Geostationary Satellite Orbit,GSO)卫星系统间的兼容性分析,设计了单波束和多波束GSO卫星系统间的上行及下行干扰场景,并在卫星的轨位、系统链路可用度及干扰系统地球站选址等多维度对GSO卫星系统间的干扰进行了评估... 详细信息

针对地球静止轨道(Geostationary Satellite Orbit,GSO)卫星系统间的兼容性分析,设计了单波束和多波束GSO卫星系统间的上行及下行干扰场景,并在卫星的轨位、系统链路可用度及干扰系统地球站选址等多维度对GSO卫星系统间的干扰进行了评估,提出了不同轨位间隔条件下满足国际电信联盟干扰协调限值的干扰系统地球站最近选址的建议,细化了各维度研究上的颗粒度,在不同维度间进行横向对比,分析了GSO卫星系统在不同维度下的干扰变化特性曲线和各维度对干扰分析结果的影响程度。在系统链路可用度一定的条件下,两个卫星系统的轨位间隔>2°时,干扰数值变化缓慢;轨位间隔≤2°时,干扰数值变化较快;轨位间隔≤0.1°时,干扰数值急剧上升。以国际电信联盟实际登记的CHNSAT-81.5和INSAT-KA82.5E卫星的网络资料为例,将计算得到的GSO系统波束间的干扰噪声比、载波干扰比与Visualyse软件结果进行验证对比,结果误差保持在0.7 dB范围内,证明该方法具有有效的评估性能。

关键词：地球静止轨道卫星系统兼容性分析多维度干扰评估地球站选址干扰规避

Neutral pyrimidine C-H donor as anion receptor

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Journal of Central South University 2016年第5期23卷 1023-1031页

作者：袁迎雪吴娜娜韩逸飞宋相志王洪波 College of Chemistry and Chemical Engineering Central South University Changsha 410083 China Key Laboratory of Optoelectronic Chemical Materials and Devices of Ministry of Education (Jianghan University) Wuhan 430056 China

Anion receptors including pyrimidine subunit were designed and synthesized and their binding abilities with various anions were investigated by fluorescence and ~1H NMR titration experiments.DFT calculations provided some information for anion recognition.It is confirmed that both of two new pyrimidine anion receptors have the selectivity for Cl-.

关键词：阴离子识别受体嘧啶供体中性 dft计算离子选择性结合能力

提升小波与能量检测联合优化下的频谱感知方法

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光电子．激光 2022年第4期33卷 414-420页

作者：彭艺魏翔朱桢以谢钊萍昆明理工大学信息工程与自动化学院云南昆明650504

传统的频谱感知方法易受噪声波动的干扰,而且在低信噪比的无线通信条件下检测精度较差。通过结合提升小波去噪与动态门限能量检测算法,能有效提高传统频谱感知方法的抗噪声性能和检测精度。首先对含噪信号进行奇偶抽样,分解信号,去除噪... 详细信息

传统的频谱感知方法易受噪声波动的干扰,而且在低信噪比的无线通信条件下检测精度较差。通过结合提升小波去噪与动态门限能量检测算法,能有效提高传统频谱感知方法的抗噪声性能和检测精度。首先对含噪信号进行奇偶抽样,分解信号,去除噪声部分,再重构为去噪新信号,然后通过能量检测方法来统计信号的能量积累,设置动态门限,最后以动态门限判断用户信号是否存在。提升小波去噪能够有效地去除采样信号中的噪声,减少噪声对能量检测法检测精度的影响,动态门限能根据噪声波动进行调整来适应复杂的噪声环境。仿真结果表明,提升小波去噪结合动态门限能量检测算法相比于传统的频谱感知要有更优的检测精度。此方法不但提高了其对不确定噪声的抵抗性,使之能适应复杂的通信环境,而且提高了频谱感知过程的可靠性。

关键词：提升小波动态门限能量检测频谱感知认知无线电

Integration of bio-inspired lanthanide-transition metal cluster and P-doped carbon nitride for efficient photocatalytic overall water splitting

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National Science Review 2021年第9期8卷 41-49页

作者： Rong Chen Gui-Lin Zhuang Zhi-Ye Wang yi-Jing Gao Zhe Li Cheng Wang Yang Zhou Ming-Hao Du Suyuan Zeng La-Sheng Long xiang-Jian Kong Lan-Sun Zheng Collaborative Innovation Center of Chemistry for Energy Materials State Key Laboratory of Physical Chemistry of Solid Surface and Department of Chemistry College of Chemistry and Chemical Engineering Xiamen University College of Chemical Engineering Zhejiang University of Technology College of Chemistry and Chemical Engineering Liaocheng University

Photosynthesis in nature uses the Mn4CaO5cluster as the oxygen-evolving center to catalyze the water oxidation efficiently in photosystem II. Herein, we demonstrate bio-inspired heterometallic Ln Co3(Ln=Nd, Eu and Ce) clusters, which can be viewed as synthetic analogs of the Ca Mn4O5cluster.Anchoring Ln Co3on phosphorus-doped graphitic carbon nitrides (PCN) shows efficient overall water splitting without any sacrificial reagents. The Nd Co3/PCN-c photocatalyst exhibits excellent water splitting activity and a quantum efficiency of 2.0%at 350 nm. Ultrafast transient absorption spectroscopy revealed the transfer of a photoexcited electron and hole into the PCN and Ln Co3for hydrogen and oxygen evolution reactions, respectively. A density functional theory (DFT) calculation showed the cooperative water activation on lanthanide and O-O bond formation on transition metal for water oxidation. This work not only prepares a synthetic model of a bio-inspired oxygen-evolving center but also provides an effective strategy to realize light-driven overall water splitting.

关键词： bio-inspired lanthanide-transition metal cluster photocatalytic overall water splitting synergistic effects oxygen-evolving center

Tongxinluo Improves Apolipoprotein E-Deficient Mouse Heart Function

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Chinese Medical Journal 2018年第5期131卷 544-552页

作者： Guo-Qiang Yuan song Gao Yong-Jian Geng Yao-Ping Tang Min-Juan Zheng Harnath S Shelat Scott Collins Han-Jing Wu yi-Ling Wu 'Department of Collateral Disease Research Institute of Integrated Traditional Chinese Medicine and Western Medicine of Hebei Shijiazhuang Hebei 050035 China Department of Cardiovascular Disease Hebei Yiling Hospital Shijiazhuang Hebei 050091 China Department of Internal Medicine McGovern Medical School The University of Texas Health Science Center at Houston Houston TX 77030 USA Center for Cell Signaling Institute of Molecular Medicine Houston Health Science Center The University of "IX Houston TX 77030 USA Department of Pediatric Cardiology Baylor College of Medicine Houston TX 77030 USA

Background： Our previous studies have shown that Tongxinluo （TXL）, a compound Chinese medicine, can decrease myocardial ischemia-reperfusion injury, protect capillary endothelium function, and lessen cardiac ventricle reconstitution in animal models. The aim of this study was to illuminate whether TXL can improve hypercholesterolemia-impaired heart function by protecting artery endothelial function and increasing microvascular density （MVD） in heart. Furthermore, we will explore the underlying molecular mechanism of TXL cardiovascular protection. Methods： After intragastric administration of TXL （0.1 ml/10 g body weight） to C57BL/6J wild-type mice （n = 8） and ApoE-/- mice （n=8）, total cholesterol, high-density lipoprotein-cholesterol, very-low-density lipoprotein （VLDL）-cholesterol, triglyceride, and blood glucose levels in serum were measured. The parameters of heart rate （HR）, lelt ventricular diastolic end diameter, and left ventricular systolic end diameter were harvested by ultrasonic cardiogram. The left ventricular ejection fraction, stroke volume, cardiac output, and let1 ventricular fractional shortening were calculated. Meanwhile, aorta peak systolic flow velocity （PSV）, end diastolic flow velocity, and mean flow velocity （MFV） were measured. The pulsatility index （PI） and resistant index were calculated in order to evaluate the vascular elasticity and resistance. Tile endothelium-dependent vasodilatation was evaluated by relaxation of aortic rings in response to acetylcholine. Western blotting and real-time quantitative reverse transcription polymerase chain reaction were performed for protein and gene analyses of vascular endothelial growth factor （VEGF）. lnamunohistochenaical detection was perlbrmed for myocardial CD34 expression. Data in this study were compared by one-way analysis of variance between groups. A value of P 〈 0.05 was considered statistically significant. Results： Although there was no significant decrease of cholesterol level （F = 2.300, P = 0.240）, TXL inhibited the level of triglyc

关键词： Heart Function： Microvascular Protection：Tongxinluo

SNR WALL AND COOPERATIVE SPECTRUM SENSING IN COGNITIVE RADIO UNDER NOISE UNCERTAINTY

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Journal of Electronics(China) 2010年第5期27卷 611-617页

作者： Wang Haijun Su Xin Xu yi Chen xiang Wang Jing Tsinghua National Laboratory for Information Science and Technology Tsinghua University Beijing 100084China

Cooperative energy spectrum sensing has been proved effective to detect the spectrum holes in Cognitive Radio(CR).However,its performance may suffer from the noise uncertainty,which is portrayed by the SNR wall in some literatures.In this paper we analyze the spectrum sensing per-formance under noise uncertainty and find an alternative approach to obtain the SNR wall.Then the average SNR wall is proposed to illustrate the statistically average impact of noise uncertainty.In addition,the cooperative sensing performance under noise uncertainty with AND rule is discussed.Analyses and numerical results show that cooperative sensing can significantly improve the sensing performance under the condition of noise uncertainty.

关键词： Cooperative spectrum sensing Noise uncertainty SNR wall

基底偏压对电弧离子镀制备AlCrVN涂层微结构及力学性能的影响

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表面技术 2023年第3期52卷 181-188页

作者：田灿鑫邹长伟王泽松项燕雄谢伟李助军刘怡飞岭南师范学院广东湛江524048 广州铁路职业技术学院广州510430

目的研究基底偏压对AlCrVN涂层微结构及力学性能的影响。方法采用电弧离子镀技术,使用合金靶AlCrV,纯N2作为引弧介质和氮源,在不同的基底偏压下制备AlCrVN涂层,对AlCrVN涂层的物相结构、微观形貌、硬度、摩擦因数及磨损率进行测试分析,... 详细信息

目的研究基底偏压对AlCrVN涂层微结构及力学性能的影响。方法采用电弧离子镀技术,使用合金靶AlCrV,纯N2作为引弧介质和氮源,在不同的基底偏压下制备AlCrVN涂层,对AlCrVN涂层的物相结构、微观形貌、硬度、摩擦因数及磨损率进行测试分析,作为对比制备了AlCrN涂层。结果AlCrVN涂层为柱状晶结构,由面心立方CrN为基础的(CrV)N置换固溶体相和Cr2N六方相2种晶相组成,随着基底偏压的增大,涂层衍射峰强度及位置变化不明显;涂层表面的大颗粒数量减少,凹坑增多;涂层硬度由50V时的22 GPa增大到150 V时的24.2 GPa,200 V时硬度值减小到22 GPa;摩擦因数由0.42增大到0.71;磨损率由6.4×10^(-7)mm^(3)/(N·m)逐渐增大到13.2×10^(-7)mm^(3)/(N·m)。结论基底偏压对AlCrVN涂层性能影响较大,低偏压(50V)时,涂层的摩擦因数、磨损率最低,耐磨性能最好。含V元素的AlCrVN涂层的力学和摩擦学性能都优于AlCrN涂层。

关键词：阴极电弧离子镀 AlCrVN涂层偏压硬度耐磨性能

Medical students as disaster volunteers:A strategy for improving emergency department surge response in times of crisis

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World Journal of Critical Care Medicine 2021年第5期10卷 163-169页

作者： R Ponampalam Jeremy Zhenwen Pong xiang-yi Wong Department of Emergency Medicine Singapore General HospitalSingapore 169608Singapore Duke-NUS Medical School National University of SingaporeSingapore 169857Singapore

Disasters resulting in mass casualty incidents can rapidly overwhelm the Emergency Department(ED).To address critical manpower needs in the ED’s disaster response,medical student involvement has been advocated.Duke-National University of Singapore Medical School is in proximity to Singapore General Hospital and represents an untapped manpower resource.With appropriate training and integration into ED disaster workflows,medical students can be leveraged upon as qualified manpower.This review provides a snapshot of the conceptualization and setting up of the Disaster Volunteer Corps-a programme where medical students were recruited to receive regular training and assessment from emergency physicians on disaster response principles to fulfil specific roles during a crisis,while working as part of a team under supervision.We discuss overall strategy and benefits to stakeholders,emphasizing the close symbiotic relationship between academia and healthcare services.

关键词： Disaster medicine Disaster response Medical students Volunteers Medical education

Effect of annealing treatment on microstructures and properties of austenite-based Fe-28Mn-9Al-0.8C lightweight steel with addition of Cu

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China Foundry 2021年第3期18卷 207-216页

作者： Zhuo Chen Ming-xiang Liu Jian-kang Zhang Lei Yang Yun-hu Zhang Chang-jiang song Qi-jie Zhai Center for Advanced Solidification Technology(CAST) School of Materials Science and EngineeringShanghai UniversityShanghai 200444China

The mechanical properties of an austenite-based Fe-Mn-Al-C lightweight steel were improved by co-precipitation of nanoscale Cu-rich and κ-carbide particles.The Fe-28Mn-9Al-0.8C-(0,3)Cu (wt.%) strips were near-rapidly solidified and annealed in the temperature range from 500 ℃ to 700 ℃.The microstructure evolution and mechanical properties of the steel under different annealing processes were studied.Microstructural analysis reveals that nanoscale κ-carbides and Cu-rich particles precipitate in the austenite and ferrite of the steel in this annealing temperature range.Co-precipitation of nanoscale Cu-rich particles and κ-carbides provides an obvious increment in the yield strength.At the annealing temperature of 600 ℃,both the yield strength and ultimate tensile strength of Fe-28Mn-9Al-0.8C-3Cu (wt.%) steel strip are the highest.The total elongation is 25%,which is obviously higher than that of Cu-free steel strips,for the addition of Cu reduces the large sized κ-carbides precipitated along austenite/ferrite interfaces.When the annealing temperature rises to 700 ℃,the strength and ductility of the two steel strips deteriorate due to the formation of massive intergranular κ-carbides precipitated along austenite/ferrite interfaces.It can be concluded that a proper co-precipitation of Cu-rich particles and κ-carbides would improve the properties of austenite-based Fe-Mn-Al-C steel.

关键词： austenite-based steel Cu-rich particle near-rapid solidification co-precipitation strengthening annealing treatment