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Numerical analysis of applying special pavements to solve the frost heave diseases of high-speed railway roadbeds in seasonally frozen ground regions

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Research in Cold and Arid Regions 2015年第4期7卷 340-347页

作者： chang yuan FuJun Niu QiHao Yu XinBin Wang Lei Guo YanHui You State Key Laboratory of Frozen Soil Engineering Cold and Arid Regions Environmental and Engineering Research InstituteCAS University of Chinese Academy of Sciences

The Haerbin-Dalian Passenger Dedicated Line is the first high-speed railway constructed in the seasonally frozen ground regions of northeastern China. Frost heave diseases occurred in the first winter of its operation （between October 2012 and January 2013）, and frost heave was observed mainly in the roadbed fills that were considered not susceptible to frost heave. This paper proposes applying two special pavements -- black pavement and insulation-black pavement -- to improve the thermal regime of the roadbed. Three numerical models of the roadbed temperature field were built based on the field con- ditions of the changchun section （D3K692＋840 to D3K692＋860）. The results show that：（1） Compared with cement pave- ment, black pavement and insulation-black pavement could reduce the freezing index at the roadbed surface by 37% and 64%, respectively, which could influence the maximum frozen depth; （2） the maximum frozen depths under the black pavement and insulation-black pavement were respectively 1.3-1.4 m and 1 m. Compared with cement pavement, they could reduce the maximum frozen depth by 0.4 m and 0.7-0.8 m, respectively, which would reduce the permitted amount of frost heave by 4 mm and 7-8 ram, which would meet the deformation limit established by the Code for Design on Special Subgrade of Railway; （3） the freezing periods of the black pavement and the insulation-black pavement were, respectively, approximately four months and two months. Compared with cement pavement, they could reduce the freezing period by approximately 19 days and 40 days, respectively, and delay the initial freezing time by 9 days and 18 days; and （4） compared with cement pavement, black pavement and black-insulation pavement could reduce the frozen areas of roadbeds in the cold season, which suggests that these two special pavements could provide better thermal stability for roadbeds.

关键词： frost heave numerical simulation special pavement thermal regime

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GPS接收机抗干扰自适应天线的设计

系统工程与电子技术 2009年第7期31卷 1556-1559页

作者：冯起朱畅袁乃昌国防科技大学电子科学与工程学院湖南长沙410073

针对自适应算法实现过程中运算量大的问题,提出了数字与模拟相结合实现功率倒置自适应处理的方法。这种方法减小了数字信号处理部分的计算量,并为有用信号提供了一个独立的射频通道,提高了系统处理的实时性,而且降低了系统的复杂程度。... 详细信息

针对自适应算法实现过程中运算量大的问题,提出了数字与模拟相结合实现功率倒置自适应处理的方法。这种方法减小了数字信号处理部分的计算量,并为有用信号提供了一个独立的射频通道,提高了系统处理的实时性,而且降低了系统的复杂程度。通过实验验证了功率倒置阵的抗干扰特性,给出了在不同的角度上存在干扰信号时系统的稳态方向图的测试结果。与GPS接收机的对接测试表明,该自适应天线系统能大大提高接收机的抗干扰能力,而且易于对现有接收机进行升级。

关键词：卫星导航自适应阵功率倒置 GPS接收机

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超分辨谱估计法在测速雷达中的应用

兵工学报 2011年第11期32卷 1343-1347页

作者：谭渊杨勇袁乃昌国防科学技术大学电子科学与工程学院微波中心湖南长沙410073

介绍了连续波测速雷达测量旋转弹丸转速的方法,并对底部刻槽弹丸的RCS和转速计算进行了理论分析,推导出转速计算公式,然后运用现代超分辨谱估计的旋转不变法代替传统的FFT算法对回波信号进行频谱估计,并在不同信噪比下对其频谱估计能力... 详细信息

介绍了连续波测速雷达测量旋转弹丸转速的方法,并对底部刻槽弹丸的RCS和转速计算进行了理论分析,推导出转速计算公式,然后运用现代超分辨谱估计的旋转不变法代替传统的FFT算法对回波信号进行频谱估计,并在不同信噪比下对其频谱估计能力进行了仿真计算和实验测试,给出了信噪比与测量误差之间的关系曲线。结果表明:在相同信噪比的情况下,该高精度转速测量方法相比传统FFT算法,测试精度明显提高。

关键词：信息处理技术旋转不变法转速测量刻槽多普勒

Fimbrialtols K–M, highly functionalized ent-kaurane diterpenoids from traditional Chinese plant Flickingeria fimbriata(B1.) Hawkes

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Chinese Chemical Letters 2017年第3期28卷 593-596页

作者： Gang Ding Jing Wang Jiao-Dong Fei Rong-Tao Li Hong-Mei Jia Tao Zhang chang-yuan Yu Zhong-Mei Zou 无 Institute of Medicinal Plant Development Chinese Academy of Medical Sciences and Peking Union Medical College Beijing 100193 China Beijing University of Chemical Technology Beijing 100029 China Hainan Branch of lnstitute of Medicinal Plant Development Chinese Academy of Medical Sdences and Peking Union Medical College Beijing 100193 China

Three new ent-kaurane diterpenoids fimbrialtols K–M（3–5） with highly substituted functionalities were isolated from the extract of Flickingeria fimbriata（B1.） Hawkes. The structures of these new compounds were determined by NMR and HR-ESIMS. The relative configurations of these compounds were determined by analysis of NOESY correlations. The absolute configurations of these new compounds were established by CD methods together with considering the biosynthetic pathway. Compounds 3 and4 contain a cinnamic carboxyl group, whereas compound 5 possesses a benzoic carboxyl group representing the first report in more than known 600 ent-kaurane diterpenoids.

关键词： Flickingeria fimbriata(B1.) Hawkes ent-Kaurane diterpenoids Fimbrialtols NMR CD

An MDL approach to efficiently discover communities in bipartite network

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Journal of Central South University 2014年第4期21卷 1353-1367页

作者：徐开阔曾春秋元昌安李川唐常杰 College of Computer Science & Technology Chengdu University of Information Technology School of Computing and Information Sciences Florida International University Guangxi Teachers Education University School of Computer Science Sichuan University

An minimum description length(MDL) criterion is proposed to choose a good partition for a bipartite network. A heuristic algorithm based on combination theory is presented to approach the optimal partition. As the heuristic algorithm automatically searches for the number of partitions, no user intervention is required. Finally, experiments are conducted on various datasets, and the results show that our method generates higher quality results than the state-of-art methods, cross-association and bipartite, recursively induced modules. Experiment results also show the good scalability of the proposed algorithm. The method is applied to traditional Chinese medicine(TCM) formula and Chinese herbal network whose community structure is not well known, and found that it detects significant and it is informative community division.

关键词： community detection bipartite network minimum description length

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卫星导航接收机自适应阵仿真测试评估

电波科学学报 2008年第5期23卷 847-850,857页

作者：冯起朱畅袁乃昌国防科技大学电子科学与工程学院湖南长沙410073

卫星导航接收机自适应天线系统能够对消干扰,保证在射频干扰和敌方释放干扰存在的情况下正常提供导航定位功能。为了评估自适应天线的抗干扰能力,必须建立适当的测试环境和测试方法。提出的一种在暗室中进行自适应天线测试的方法,具有... 详细信息

卫星导航接收机自适应天线系统能够对消干扰,保证在射频干扰和敌方释放干扰存在的情况下正常提供导航定位功能。为了评估自适应天线的抗干扰能力,必须建立适当的测试环境和测试方法。提出的一种在暗室中进行自适应天线测试的方法,具有保密性好,保证测试环境和外界互不干扰等优点。给出了自行研制的一种导航接收机自适应天线的测试结果。

关键词：卫星导航自适应阵抗干扰性能

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光电成像系统的性能优化

光学精密工程 2015年第1期23卷 1-9页

作者：韩昌元中国科学院长春光学精密机械与物理研究所吉林长春130033

探讨了光学系统和阵列探测器构成的光电成像系统的整体性能和优化设计问题。针对阵列探测器的不断快速更新换代,研究了如何对光学系统进行改进以优化光电成像系统的性能。从采样成像系统的取样定理出发,研究了光电成像系统的传递函数特... 详细信息

探讨了光学系统和阵列探测器构成的光电成像系统的整体性能和优化设计问题。针对阵列探测器的不断快速更新换代,研究了如何对光学系统进行改进以优化光电成像系统的性能。从采样成像系统的取样定理出发,研究了光电成像系统的传递函数特性,讨论了采样成像系统的相位平均传递函数,分析了光电成像系统的加工与使用误差对传递函数的影响。同时,给出了光电成像系统的信噪比计算公式。文中提出用于遥感观测的大型光电成像系统的光学系统传递函数的归一化空间频率等于0.5左右可与阵列探测器的奈奎斯特频率相匹配。结果显示,如此设计可在满足信噪比的同时使传递函数在奈奎斯特频率处达到0.1左右,分辨率达到奈奎斯特频率并且不产生频谱混叠效应。

关键词：光电成像系统光学设计像质评价传递函数信噪比

Hepatitis B virus coinfection in human immunodeficiency virus-infected patients: A review

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World Journal of Gastroenterology 2014年第40期20卷 14598-14614页

作者： Hsin-Yun Sun Wang-Huei Sheng Mao-Song Tsai Kuan-Yeh Lee Sui-yuan chang Chien-Ching Hung Department of Internal Medicine National Taiwan University Hospital National Taiwan University College of Medicine Department of Internal Medicine Far Eastern Memorial Hospital Department of Internal Medicine National Taiwan University Hospital Hsin-Chu Branch Department of Clinical Laboratory Sciences and Medical Biotechnology National Taiwan University College of Medicine Department of Laboratory Medicine National Taiwan University Hospital Department of Medical Research China Medical University Hospital China Medical University

Hepatitis B virus(HBV)infection is a leading cause of chronic hepatitis,liver cirrhosis,and hepatocellular carcinoma *** to the shared modes of transmission,coinfection with HBV and human immunodeficiency virus(HIV)is not *** is estimatedthat 10%of HIV-infected patients worldwide are coinfected with *** areas where an HBV vaccination program is implemented,the HBV seroprevalence has declined *** HIV/HBV-coinfected patients,HBV coinfection accelerates immunologic and clinical progression of HIV infection and increases the risk of hepatotoxicity when combination antiretroviral therapy(cART)is initiated,while HIV infection increases the risk of hepatitis events,cirrhosis,and end-stage liver disease related to chronic HBV *** the advances in antiviral therapy,concurrent,successful longterm suppression of HIV and HBV replication can be achieved in the cART *** reduce the disease burden of HBV infection among HIV-infected patients,adoption of safe sex practices,avoidance of sharing needles and diluent,HBV vaccination and use of cART containing tenofovir disoproxil fumarate plus emtricitabine or lamivudine are the most effective ***,due to HIV-related immunosuppression,using increased doses of HBV vaccine and novel approaches to HBV vaccination are needed to improve the immunogenicity of HBV vaccine among HIV-infected patients.

关键词： Viral hepatitis Seroepidemiology Sexually transmitted diseases Nucleoside reverse-transcriptase inhibitor Vaccination

A study of using grey system theory and artificial neural network on the climbing ability of <i>Buergeria robusta</i>frog

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Open Journal of Ecology 2013年第2期3卷 83-93页

作者： yuan-Hsiou chang Tsai-Fu Chuang Department of Design for Sustainable Environment Mingdao University Chanhua Chinese Taipei Department of Landscape and Architecture Mingdao University Chanhua Chinese Taipei

Ecological engineering is an emerging study of integrating both ecology and engineering, concerned with the design, monitoring, and construction of ecosystems. In recent years, the threat to amphibian animals is becoming more and more serious. In particular, the loss of habitats caused by changes to the way land is used by human beings has hit amphibians particularly hard. Amphibians are known to be particularly vulnerable to human activities because they rely on both terrestrial and aquatic habitats for survival. With the increasing development of many areas in recent years, concrete structures are often installed along water bodies in order to increase the safety of local residents. The construction of concrete banks along rivers associated with human development has become a serious problem in Taiwan. Most ecosystems used by amphibians are lakes and stream banks, yet no related design solutions to accommodate the needs of amphibians. The need to develop the relevant design specification considering protecting the amphibian is imperative. Buergeria robusta, an endemic species in Taiwan, is tree frog widely distributed in lowland montane regions. Their breeding season is from April to September. They like to rest on trees or hide at caves during the daytime and move to the stream nearby in dusk for breeding. Males usually emit weak mating call while standing on stones. Sticky eggs are attached to undersides of rocks and stones. Tadpoles are found in slow flowing water of streams [1]. The goal of this study is to improve the understanding of the relationship between the climbing ability and the physical characteristics of amphibians. In this study, we use Artificial Neural Network to simulate the climbing ability of Buergeria robusta. Besides, Grey System Theory is also adopted to improve the performance of Artificial Neural Network. Artificial Neural Network (ANN) is a computing system that uses a large number of artificial neurons imitating natural neural ability

关键词： Ecological Engineering Artificial Neural Network Grey System Theory Buergeria robusta