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Search Results: 1 - 10 of 403921 matches for " <br>陈正乾 "
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Study of risk analysis methodology for taxation information system
税务信息系统风险分析方法研究*

SONG Min,QIN Zheng,CHEN Liang,WANG Bing-qian,CHEN Lei,<br>宋敏,,,王秉,
计算机应用研究 , 2008,
Abstract: This paper considered the risk analysis methodology for taxation information system. Firstly, identied the characters of objective information system. Secondly, introduced a matrix-based relatively quantitative methodology. Finally, gave a case study.
Selective Neural Network Ensemble with Bias
带偏置的选择性神经网络集成构造方法

WANG Zheng-Qun,CHEN Shi-Fu,CHEN Zhao-Qian,<br>王,世福,
计算机科学 , 2005,
Abstract: Neural network ensemble is a learning paradigm, which integrates many neural networks into an ensemble to solve a problem jointly. In this paper, the relationship between the ensemble and its component neural networks is analyzed and a novel approach for the construction of the selective neural network ensemble with bias is proposed. The genetic algorithm is used to select part of the trained individual networks to be integrated and the bias is deter- mined to correct the combination of the ensemble simultaneously. Theoreticalanalysis and experimental results show that this approach allows one to design effective neural network ensemble.
An Optimized Neural Network Linear Ensemble for Classification
优化分类型神经网络线性集成

WANG Zheng-Qun,CHEN Shi-Fu,CHEN Zhao-Qian,<br>王,世福,
软件学报 , 2005,
Abstract: 构造多神经网络集成系统,系统的输出由个体神经网络的输出线性加权产生.提出了一种度量个体神经网络在不同的权重下集成性能的判别函数,函数表示了由个体神经网络输出刻画的模式类内会聚性和类间散布性.应用遗传算法解决了求解最优个体网络集成权重问题.分析了该判别函数的合理性及其与Bayes决策规则的关系.用两个手写体汉字特征数据集和4个UCI数据库中的数据集比较了所提出的神经网络集成方法和其他几种神经网络集成方法的性能.
MICROSTRUCTURAL FEATURE IN Al-In MONOTECTIC ALLOY PROCESSED UNDER MICROGRAVITY
微重力偏晶合金凝固特征

HUANG Zheng,ZHAO Deqian,CHEN Xichen Beijing University of Aeronautics,Astronautics Institute of Physics,Academia Sinica,Beijing,<br>黄,赵德,熙琛
金属学报 , 1990,
Abstract: The microstructural feature of Al-In monotectic alloy processed under microgravity has been investigated in comparison between space and ground-based samples. It was found that in the space sample, there are a lot of In particles in Al dendrite, but no more in the ground-based one. Moreover, the In particles dis- tribute with regularity and the Al dendrite has an obvious boundary layer marked by a string of particles. Thus, the distinction between them may reflect the chara- cteristics of the solid/liquid interface during solidification under different gravity conditions.
The antibacterial polyketides of Aspergillus terreus OUCMDZ- 1925 from Yellow River delta
黄河三角洲土曲霉Aspergillus terreus OUCMDZ-1925中具抗菌活性的聚酮类天然产物

CHEN Zheng-Qian,LIU Pei-Pei,WANG Yi,ZHU Wei-Ming,<br>,刘培培,王乂,朱伟明
菌物学报 , 2013,
Abstract: 作者利用化学与生物活性相集成的筛选方法,从采自黄河三角洲地区——东营黄河口的梭鱼Chelon haematocheilus的内脏中分离鉴定了1株耐盐真菌土曲霉Aspergillus terreus OUCMDZ-1925,其发酵产物具有抗枯草芽孢杆菌活性。进一步采用色谱分离、波谱鉴定,从其固体发酵(大米培养基)中分离鉴定了5个化合物,即右旋丁内酯I(1)、丁内酯IV(2)、丁内酯II(3)、丁内酯III(4)和3,5,6-三甲基-2,4-二羟基苯甲酸甲酯(5)。并发现化合物1–3和5对金黄色葡萄球菌(ATCC 51650)有强的抑菌活性(最小抑菌浓度均为0.31μg/mL,阳性对照环丙沙星的最小抑菌浓度为0.16μg/mL),化合物1和2对产气杆菌(ATCC 13408)以及化合物1和3对枯草芽孢杆菌(ATCC 93151)有中等的抑菌活性(最小抑菌浓度分别为6.25μg/mL和12.50μg/mL,阳性对照环丙沙星的最小抑菌浓度分别为1.25μg/mL和5.0μg/mL),化合物1–5对大肠杆菌(ATCC 25922)以及化合物4对金黄色葡萄球菌(ATCC 51650)有弱的抑制活性,且化合物1的产量高,达2.5g/kg,为其后续研究提供了新的药源。
Preparation of monoclonal antibody against chloramphenicol and establishment of direct competitive ELISA for determination of chloramphenicol
抗氯霉素单克隆抗体的制备及直接竞争ELISA方法的建立

CHEN Zheng-xian,SHI Man-ling,LI Yin-lai,YE Xing-qian,SHEN Li-rong,<br>,施曼玲,李因来,叶兴,沈立荣
浙江大学学报(农业与生命科学版) , 2010,
Abstract: Through immunization of BALB/c mice with synthesized CAP-ovalbumin (CAP-OVA), a hybridoma cell line, the 4C9 which could produce monoclonal antibody against chloramphenicol (CAP) and propagate stably, was established. With the myeloma cells, the ascites containing monclonal antibody (McAb) were prepared. The indirect competitive ELISA (ciELISA) test revealed the heavy chain and light chain of McAb were IgG1 and κ, respectively. The ELISA titer of ascites was 1:1×10~6. The percentages of cross-activity to thiamphenicol, florfenicol and other antibiotics were all less than 0.01%. A horseradish peroxidase (HRP)-labeled antibody was synthesized by the sodium periodate reaction, then a direct competitive enzyme-linked immunosorbent assay (cdELISA) was developed. Quantization of the CAP was linear from 0.1 to 100 ng·mL~(-1), and the hemi-inhibitory concentration (IC_(50)) was 5.81 ng·L~(-1). The recovery test showed that the detection limit for CAP was 0.1 ng·L~(-1) in cdELISA. Comparative test showed that detected sensibility of the monoclonal antibody was nearly equivalent to the commercial CAP ELISA kit.
优化分类型神经网络线性集成
群?,世福?,
软件学报 , 2005,
Abstract: 构造多神经网络集成系统,系统的输出由个体神经网络的输出线性加权产生.提出了一种度量个体神经网络在不同的权重下集成性能的判别函数,函数表示了由个体神经网络输出刻画的模式类内会聚性和类间散布性.应用遗传算法解决了求解最优个体网络集成权重问题.分析了该判别函数的合理性及其与bayes决策规则的关系.用两个手写体汉字特征数据集和4个uci数据库中的数据集比较了所提出的神经网络集成方法和其他几种神经网络集成方法的性能.
带偏置的选择性神经网络集成构造方法
世福
计算机科学 , 2005,
Abstract: 训练多个神经网络并将其结果进行合成,能显著地提高神经网络系统的泛化能力。本文提出了一种带偏置的选择性神经网络集成构造方法。对个体网络引入偏置项,增加可选网络的数量。选择部分网络集成,改善网络集成的性能。把个体网络的偏置项统一为集成偏置项,在训练出个体神经网络后,使用遗传算法选择部分网络集成,同时确定集成偏置项。理论分析和实验结果表明,该方法能够取得很好的网络集成效果。
大学生自杀意念的危险因素和保护因素
Risk Factors and Protective Factors of Suicide Ideation in College Students
 [PDF]


Advances in Psychology (AP) , 2016, DOI: 10.12677/AP.2016.611142
Abstract:
自杀意念是指偶然体验的自杀行为动机,个体胡思乱想或打算自杀,但并未采取或实现此目的的外显行为。多项研究表明,自杀意念是评估自杀危险性的重要指标,所以研究自杀意念的危险因素和保护因素,对大学生自杀行为的预防有重要意义。自杀意念的危险因素众多,主要包括生物因素、心理因素和社会环境因素,如人格特质、绝望、学业问题等等;而目前对自杀意念保护因素的研究主要集中在自尊和社会支持上。多数研究者比较关注自杀意念的危险因素,而仅有很少数研究关注了自杀意念的保护因素。未来研究需要更为关注自杀意念保护因素、研究方法的多元化,以及哪些因素可以缓冲个体的自杀意念而使他们没有采取自杀行为。
Suicide ideation refers to experiencing suicidal motivations; the individual has random thoughts or plans suicide, but without adopting external behavior for this purpose. A large body of researches have indicated suicide ideation is the important indicator of assessing the risk of suicide; therefore it is crucial for preventing the college students’ suicide behavior to study the risk and protective factors of suicide ideation. There are many risk factors for suicide ideation, mainly including biological factors, psychological factors and social environmental factors, such as personality traits, despair, academic problems, etc.; whereas the studies of the suicide ideation’ protective factors currently mainly cover the self-esteem and social supports. Most researchers are more concerned about the risk factors for suicide ideation, and only a few studies have focused on the protective factors of suicide ideation. Future research needs to focus more on the protection of suicidal ideation, the diversification of research methods and which factors can buffer the individual’s suicidal thoughts so that they do not take suicidal behavior.
微重力偏晶合金凝固特征
,赵德,熙琛
金属学报 , 1990,
Abstract: 对在微重力条件下获取的Al-In(95wt-%)偏晶合金的显微组织特征进行了分析,结果表明,在空间制取的试样的Al枝晶中,还存在着大量的In质点;并且这些质点的分布具有某种规律性,由此形成了与地基样品显微组织上的明显差异,反映出一种与重力效应相关的材料凝固特性。
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