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Flowfield of a helicopter submerged inlet with power output shaft

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Acta Mechanica Sinica 2021年第1期37卷 156-168,I0003页

作者： He-Xia Huang Hui-Jun Tan Zheng-Kang Lin Zi-Jie Li shu Sun hao chen Zhi-Xiang Xiao Jiangsu Province Key Laboratory of Aerospace Power System College of Energy and Power EngineeringNanjing University of Aeronautics and AstronauticsNanjing210016China School of Aerospace Engineering Tsinghua UniversityBeijing100084China

The submerged inlet is an attractive configuration for advanced helicopters due to its high stealth performance and low external *** this paper,a submerged inlet,integrated with a ROBIN helicopter fuselage and a simplified power output shaft,is experimentally and numerically investigated to obtain the basic flow characteristics under a freestream velocity of 23.6 m/*** results indicate that the pylon ahead of the inlet induces a horseshoe *** the vortex is ingested into the inlet,it has little effect on the internal flows and can be *** the airflow enters into the inlet,it interacts with the shaft with a large incidence angle,yielding a vortex *** the leeside of the shaft,the two side flows of the shaft impinge at the center plane,generating a local high-pressure region at the azimuthal angle of 180°,which forces the boundary layer to roll up a counter-rotating vortex *** addition,the airflow adjacent to the cowl lip accelerates rapidly,resulting in a local low-pressure region at the azimuthal angle of 0°.Therefore,the inlet duct has a strong circumferential pressure gradient,which originates from an azimuthal angle of 180°to 0°and induces a vortex pair at the azimuthal angle of 0°.The three vortex pairs are the main origins of the distortion at the duct exit plane,among which the one near the cowl lip with the azimuthal angle of 0°plays the dominant ***,as the velocity ratio increases from 3.9 to 5.5,the circumferential pressure gradient and the cowl lip vortex get intensified,which causes that the total-pressure recovery coefficient drops by 0.5%and the distortion index increases by 28%.

关键词： Submerged inlet Helicopter Vortex pair

Hash signature saving in distributed video coding

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Journal of Zhejiang University-Science C(Computers and Electronics) 2011年第2期12卷 163-170页

作者： Xin-hao chen Institute of Information and Communication Engineering Zhejiang University Hangzhou 310027 China Zhejiang Provincial Key Laboratory of Information Network Technology Hangzhou 310027 China

In transform-domain distributed video coding (DVC), the correlation noises (denoted as N) between the source block and its temporal predictor can be modeled as Laplacian random variables. In this paper we propose that the noises (denoted as N′) between the source block and its co-located block in a reference frame can also be modeled as Laplacian random variables. Furthermore, it is possible to exploit the relationship between N and N′ to improve the performance of the DVC system. A practical scheme based on theoretical insights, the hash signature saving scheme, is proposed. Experimental results show that the proposed scheme saves on average 83.2% of hash signatures, 13.3% of bit-rate, and 3.9% of encoding time.

关键词： Distributed video coding (DVC) Hash Laplacian

Distributed video coding with adaptive selection of hash functions

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Journal of Zhejiang University-Science C(Computers and Electronics) 2011年第5期12卷 387-396页

作者： Xin-hao chen Institute of Information and Communication Engineering Zhejiang UniversiO Hangzhou 310027 China Zhejiang Provincial Key Laboratory of Information Network Technology Hangzhou 310027 China

We address the compression efficiency of feedback-free and hash-check distributed video coding,which generates and transmits a hash code of a source information *** hash code helps the decoder perform a motion search.A hash collision is a special case in which the hash codes of wrongly reconstructed information sequences occasionally match the hash code of the source information *** deteriorates the quality of the decoded image *** this paper,the statistics of hash collision are analyzed to help the codec select the optimal trade-off between the probability of hash collision and the length of the hash code,according to the principle of rate-distortion ***,two novel algorithms are proposed:(1) the nonzero prefix of coefficients (NPC),which indicates the count of nonzero coefficients of each block for the second algorithm,and also saves 8.4% bitrate independently;(2) the adaptive selection of hash functions (AHF),which is based on the NPC and saves a further 2%-6% bitrate on *** detailed optimization of the parameters of AHF is also presented.

关键词： Hash Collision Distributed video coding Wyner-Ziv

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宽带相控阵雷达孔径渡越与距离徙动联合校正

电光与控制 2025年第1期32卷 8-14页

作者：张亮杨静陈浩周必雷杜庆磊空军预警学院武汉430000 济南市教育局济南250000

宽带相控阵雷达探测高速运动目标时,目标回波快时间频率与空、时二维耦合,容易出现孔径渡越和距离徙动双重问题。针对该情况,提出一种联合校正方法:当雷达工作于窄发模式时,通过频域补偿和一维时间尺度(TS)进行解耦;当雷达工作于宽发模... 详细信息

宽带相控阵雷达探测高速运动目标时,目标回波快时间频率与空、时二维耦合,容易出现孔径渡越和距离徙动双重问题。针对该情况,提出一种联合校正方法:当雷达工作于窄发模式时,通过频域补偿和一维时间尺度(TS)进行解耦;当雷达工作于宽发模式时,通过二维TS进行解耦。针对雷达工作模式界定问题给出了明确条件。仿真结果表明,所提方法可有效解决孔径渡越、距离徙动引起的目标回波跨阵元、跨脉冲问题,联合校正后目标有效检测临界信噪比较理想状态损失不超过3 dB。

关键词：宽带雷达相控阵孔径渡越距离徙动联合校正时间尺度

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179例艾滋病病毒感染者及艾滋病患者生存质量研究

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华南预防医学 2015年第2期41卷 117-123页

作者：隋丹丹林鹏陈抒豪宫艳华傅秋龙黄喜明佛山市疾病预防控制中心广东佛山528051 广东省疾病预防控制中心佛山市禅城区疾病预防控制中心佛山市南海区疾病预防控制中心

目的了解佛山市CD4^＋T淋巴细胞计数≤350个/mm^3的艾滋病病毒感染者及艾滋病患者（HIV/AIDS）的生存质量现况,探讨影响生存质量的相关因素,为HIV/AIDS提供针对性的干预措施。方法采用WHO QOL HIV-BREF量表对2013年10月至2014年3月在佛... 详细信息

目的了解佛山市CD4^＋T淋巴细胞计数≤350个/mm^3的艾滋病病毒感染者及艾滋病患者（HIV/AIDS）的生存质量现况,探讨影响生存质量的相关因素,为HIV/AIDS提供针对性的干预措施。方法采用WHO QOL HIV-BREF量表对2013年10月至2014年3月在佛山市疾病预防控制机构或医疗机构进行随访的CD4^＋T淋巴细胞计数≤350个/mm^3的HIV/AIDS进行调查,并收集该人群在＂艾滋病综合防治信息管理系统＂上的相关信息,包括基本的人口学信息及相关影响因素,并采用多元线性回归分析方法进行生存质量的影响因素分析。结果本研究共调查HIV/AIDS179例,男性占72.07%,平均年龄为（39.56±11.65）岁,以30-39岁年龄组居多,占33.52%;文化程度以初中为主,占51.40%;婚姻状况以已婚有配偶为主,占51.40%;职业以有职业为主,占80.45%;50.28%的病例是HIV感染者,49.72%是艾滋病患者;非本市户籍者占64.25%;感染途径以异性性传播为主,占63.69%。调查对象在心理领域（13.17±2.72）、独立性（14.12±2.75）及社会关系领域（12.94±2.53）的得分均低于常模（均P〈0.01）,在精神支柱/信仰/宗教领域（14.29±3.06）的得分高于常模（P〈0.01）。多元线性回归分析结果显示,与生存质量有关的影响因素有性别、学历、是否本地户籍、感染途径、是否接受抗机会性感染药物治疗、是否获得宣传材料、是否接受抗病毒治疗及是否获得安全套（P〈0.05或P〈0.01）,其中输血/血制品感染的人群在生理领域、独立性和精神支柱/信仰/宗教3个方面的生存质量得分较低（偏回归系数分别为-4.67、-4.00、-7.24）。结论 CD4^＋T淋巴细胞计数≤350个/mm^3的HIV/AIDS其生存质量低于普通人群,且对该人群的生存质量的影响因素较多,应针对相应的领域制定相关的措施以提高HIV/AIDS的生存质量。

关键词： HIV感染 CD4淋巴细胞计数生活质量因素分析,统计学

The YSZ,Planck - YSZ,XMM scaling relation and its difference between cool-core and non-cool-core clusters

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Research in Astronomy and Astrophysics 2019年第7期19卷 151-162页

作者： Yue Zhu Yuan-hao Wang Hai-Hui Zhao shu-Mei Jia cheng-Kui Li Yong chen Key Laboratory for Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China Department of Physics and Institute of Theoretical Physics Nanjing Normal UniversityNanjing 210023China

We construct a sample of 70 clusters using data from XMM-Newton and Planck to investigate the YSZ,Planck-YSZ,XMM scaling relation and the cool-core influences on this ***,XMM is calculated by accurately de-projected temperature and electron number density profiles derived from ***,Planckis the latest Planck data restricted to our precise X-ray cluster size θ*** study the cool-core influences on the YSZ,Planck-YSZ,XMM scaling relation,we apply two criteria,namely the limits of central cooling time and classic mass deposition rate,to distinguish cool-core clusters(CCCs) from non-cool-core clusters(NCCCs).We also use YSZ,Planckfrom other papers,which are derived from different methods,to confirm our *** intercept and slope of the YSZ,Planck-YSZ,XMM scaling relation are A =-0.86 ± 0.30 and B = 0.83 ± 0.06 *** intrinsic scatter is σins= 0.14 ± *** ratio of YSZ,Planck/YSZ,XMM is 1.03 ± 0.05,which is in excellent statistical agreement with *** in the YSZ,Planck-YSZ,XMM scaling relation between CCCs and NCCCs are found in the *** are independent of the cool-core classification criteria and YSZ,Planckcalculation methods,although the discrepancies are more significant under the classification criteria of classic mass deposition *** intrinsic scatter of CCCs(0.04) is quite small compared to that of NCCCs(0.27).The ratio of YSZ,Planck/YSZ,XMM for CCCs is 0.89 ± 0.05,suggesting that CCCs’ YSZ,XMM may overestimate the Sunyaev-Zel’dovich(SZ)*** contrast,the ratio of YSZ,Planck/YSZ,XMM for NCCCs is 1.14 ± 0.12,which indicates that NCCCs’ YSZ,XMM may underestimate the SZ signal.

关键词： galaxies:clusters:intracluster medium X-rays:galaxies:clusters cosmology:observations

Recent progress in metal-organic frameworks(Part II—material application)

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Science China Chemistry 2025年

作者： Jiandong Pang Wentao Jiang Xue-Wen Zhang hao-Long Zhou Yuxiu Sun Wei Gong Bin Wang Fuyin Ma Linwei He Long chen Qiang chen He-Qi Zheng Yuanjing Cui Wen-Jie Shi Chao Zhang Mei Wang Yue-Biao Zhang Jie-Peng Zhang Chongli Zhong Yong Cui shuao Wang Jian-Rong Li Guodong Qian Tong-Bu Lu Huan Pang Xian-He Bu Institute for New Energy Materials and Low Carbon Technologies School of Materials Science and Engineering Tianjin University of Technology School of Chemistry and Chemical Engineering Yangzhou University School of Materials Science and Engineering Nankai University School of Physical Science and Technology ShanghaiTech University MOE Key Laboratory of Bioinorganic and Synthetic Chemistry GBRCE for Functional Molecular Engineering School of Chemistry IGCMESun Yat-sen University Department of Chemistry Shantou University School of Chemical Engineering and Technology Tiangong University School of Chemistry and Chemical Engineering Shanghai Jiao Tong University State Key Laboratory of Radiation Medicine and Protection School for Radiological and Interdisciplinary Sciences Soochow University College of Materials Science & Engineering Beijing University of Technology State Key Laboratory of Silicon and Advanced Semiconductor Materials Cyrus Tang Center for Sensor Materials and ApplicationsSchool of Materials Science & Engineering Zhejiang University

As a class of functional crystalline porous materials, metal-organic frameworks(MOFs) gained rapid development in the past three decades and a large number of MOFs with ordered structures, high surface areas, and functionalized channels have been investigated. MOFs and MOF-derived/composite materials show great potential in many application fields. In this review, we discussed the main applications of MOFs and MOF-derived/composite materials in small molecule storage, separation, luminescence, sensing, multitype catalysis, and energy storage. In addition, challenges and problems in the future research of MOFsrelated fields are also discussed.

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Improved quality of life in patients with gastric cancer after esophagogastrostomy reconstruction

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World Journal of Gastroenterology 2009年第25期15卷 3183-3190页

作者： hao Zhang Zhe Sun Hui-Mian Xu Ji-Xian Shan shu-Bao Wang Jun-Qing chen State Key Department of General Surgery Department of Surgical Oncology First Affiliated Hospital of China Medical University Shenyang 110001 Liaoning Province China

AIM:To compare postoperative quality of life (QOL) in patients with gastric cancer treated by esophagogastrostomy reconstruction after proximal ***: QOL assessments that included functional outcomes (a 24-item survey about treatment-specific symptoms) and health perception (Spitzer QOL Index) were performed in 149 patients with gastric cancer in the upper third of the stomach, who had received proximal gastrectomy with additional ***: Fifty-four patients underwent reconstruction by esophagogastric anterior wall end-to-side anastomosis combined with pyloroplasty (EA group); 45 patients had reconstruction by esophagogastric posterior wall end-to-side anastomosis (EP group); and 50 patients had reconstruction by esophagogastric end-to-end anastomosis (EE group). The EA group showed the best postoperative QOL, such as recovery of body weight, less discomfort after meals, and less heart burn or belching at 6 and 24 mo postoperatively. However, the survival rates, surgical results and Spitzer QOL index were similar among the three ***: Postoperative QOL was better in the EA than EP or EE group. To improve QOL after proximal gastrectomy for upper third gastric cancer, the EA procedure using a stapler is safe and feasible for esophagogastrostomy.

关键词： Gastric cancer Proximal gastrectomy Esophagogastrostomy Quality of life

Modeling and Analysis of Interstand Tension Control in 6-high Tandem Cold Rolling Mill

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Journal of Iron and Steel Research International 2014年第9期21卷 830-836页

作者： Xin ZHANG shu-zong chen hao-yu ZHANG Xi-wen ZHANG Dian-hua ZHANG Jie SUN State Key Laboratory of Rolling and Automation Northeastern University School of Materials Science and Engineering Shenyang University of Technology Rolling Technology Center of Liaoning

The interstand tension control is one of the most important ways to meet tight tolerances for strip product quality during tandem cold rolling process. Using coordinate analysis and parabolic approximation for the mass flow balance principle, the strip velocities eliminating the use of forward slips and backward slips were calculated. In order to reduce the effect of roll eccentricity on the tension measurement, a filter based on bilinear transformation was de- signed. Applying a first-order Taylor series approximation, the transfer function matrix model of interstand tension stress was derived. The actual measurements on-site and the final calculation results showed that the established model had high calculation accuracy and was beneficial for interstand tension control of random cold rolling process.

关键词： tension control tandem cold rolling mill bilinear transformation transfer function matrix model