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Effect of inorganic salt on the thermal degradation of nitrocellulose and reaction mechanism of its mixture

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Defence Technology（防务技术） 2023年第9期27卷 111-118页

作者： Guo-zhong xu xu Gao Mi Li zhong-xuan Han Lin Jiang School of Mechanical Engineering Nanjing University of Science and TechnologyChina

In this study,to better understand the reaction mechanism between inorganic salts and nitrocellulose,CaCO_(3) and Li_(2)CO_(3) were evaluated with respect to their effects on the thermal degradation of NC in nitrogen atmosphere using TG/DSC at three different heating rates(2,5,10 K/min).The numerical relationship between activation energy(E)and conversion rate was obtained by FWO and KAS method,and it was discovered that CaCO_(3) could improve the thermal stability of *** energy values were calculated by Kissinger method,and it was found that NC that contain Li2CO3had the highest activation energy while NC containing CaCO3had the lowest E *** combining the thermal analysis data with Malek method,the most probable mechanism model of thermal degradation is obtained as Sesták-Berggren model,which expression is f(α)=α^(m)(1-α)^(n).As a result of this study,there are certain guiding principles that can be applied to the pyrolysis reaction model and to the actual production process of nitrocellulose.

关键词： Thermal analysis Thermal decomposition mechanism Malek method Nitrocellulose Inorganic salt

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基于KNN-SVM的混合气体检测方法研究

光谱学与光谱分析 2025年第1期45卷 117-124页

作者：孙超胡润泽吴中旭刘年松丁建军江汉大学智能制造学院湖北武汉430056 精细爆破国家重点实验室湖北武汉430056

当今混合气体检测的研究中,针对多组分气体数据进行分类预测的数学算法百花齐放,如何快速且准确的检测出气体的成分和浓度逐渐成为当今研究的热门。然而在一些研究中,气体数据特征难以捕捉和判断,泛化能力不足,对气体数据进行分类预测... 详细信息

当今混合气体检测的研究中,针对多组分气体数据进行分类预测的数学算法百花齐放,如何快速且准确的检测出气体的成分和浓度逐渐成为当今研究的热门。然而在一些研究中,气体数据特征难以捕捉和判断,泛化能力不足,对气体数据进行分类预测的精度和效率表现较差。为此,针对一些数据偏差和泛化误差无界的问题,提出了一种K最近邻-支持向量机(KNN-SVM)算法,对一些难以作出分类的模糊气体数据进行二次分类,采用KNN和SVM两种算法共同抉择,更加全面的捕捉数据特征,根据实验确定各自算法的权重比从而提高判别气体类别的准确率,两种算法的集成也能提高算法的效率,对于不同种类的气体也能有良好的适应性的稳定性。该实验气体组分由12 mg·L^(-1)的C_(2)H_(2)、NO_(2)、SF_(6),10 mg·L^(-1)的NO_(2)、SF_(6)和5 mg·L^(-1)的C_(2)H_(2)(背景气体皆为N_(2))以及两瓶纯N_(2)的气瓶组成;通过互相混合和与N_(2)配比制备出实验设定的气体浓度。实验过程通过单一气体的检测可分别对三种气体获得60组训练集,并通过这60组数据可进行线性拟合得到每种气体的拟合线,得到气体浓度与气体吸收峰值的关系,通过实验检测得到的三种气体拟合线,其中C_(2)H_(2)拟合线的调整后R^(2)为0.991,NO_(2)拟合线的调整后R^(2)为0.981,SF_(6)拟合线的调整后R^(2)为0.987,可得气体检测的准确性。再通过互相混合进行检测可分别获得40组训练集,采用KNN-SVM算法对混合气体进行分类和预测,后通过拟合线即可反演出混合气体中每种气体的浓度。将该算法与传统SVM算法进行各种分类指标对比均可显示出该算法的有效性和优越性。实验结果表明,KNN-SVM算法在气体分类预测方面表现出卓越的性能,准确率高达99.167%,AUC(area under curve)值达99.375%。这一算法不仅提高了气体检测的准确性,还增强了泛化能力可适应多样化的气体组分,为实时气体检测系统提供了有力支持。

关键词：光声光谱气体检测 KNN-SVM 分类预测

Rate Function of Large Deviation for a Class of Nonhomogeneous Markov Chains on Supercritical Percolation Network

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Acta Mathematica Sinica,English Series 2011年第9期27卷 1813-1830页

作者： zhong Hao xu Dong HAN School of Finance and Statistics East China Normal University Shanghai 200241 P. R. China Department of Mathematics Shanghai Jiao Tong University Shanghai 200240 P. R. China

We model an epidemic with a class of nonhomogeneous Markov chains on the supercritical percolation network on Zd. The large deviations law for the Markov chain is given. Explicit expression of the rate function for la... 详细信息

关键词： Nonhomogeneous Markov chain large deviation rate function percolation network

The Parabrachial Nucleus as a Key Regulator of Neuropathic Pain

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Neuroscience Bulletin 2021年第7期37卷 1079-1081页

作者： Zilong Wang Zhen-zhong xu Department of Anesthesiology Center for Translational Pain MedicineDuke University Medical CenterDurhamNC 27710USA SUSTech Center for Pain Medicine School of MedicineSouthern University of Science and TechnologyShenzhen 518055China Department of Neurobiology and Department of Anesthesiology of the First Affiliated Hospital NHC and CAMS Key Laboratory of Medical NeurobiologyZhejiang University School of MedicineHangzhou 310058ZhejiangChina

Neuropathic pain is a chronic pain caused by peripheral or central nervous system injury or diseases that affect the somatosensory nervous *** is usually associated with abnormal sensations called dysesthesia and exaggerated pain from normally innocuous stimuli(allodynia)or noxious stimuli(hyperalgesia),and also aversive emotional responses[1,2].Neuropathic pain can be very difficult to treat,as classical analgesics like opioids produce inadequate pain relief and may cause tolerance and hyperalgesia,and even addiction after long-term use[3].Thus,it is of critical importance to study the mechanisms of development,maintenance,and resolution of neuropathic *** study from ***’s research team at Zhejiang University reveals a critical regulatory mechanism for neuropathic pain[4].

关键词： sensation diseases opioid

One-Dimensional ZnO Nanostructures： Solution Growth and Functional Properties

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Nano Research 2011年第11期4卷 1013-1098页

作者： Sheng xu zhong Lin Wang School of Materials Science and Engineering Georgia Institute of Technology Atlanta Georgia 30332-0245 USA

One-dimensional （1D） ZnO nanostructures have been studied intensively and extensively over the last decade not only for their remarkable chemical and physical properties, but also for their diverse current and future technological applications. This article gives a comprehensive overview of the progress that has been made within the context of 1D ZnO nanostructures synthesized via wet chemical methods. We will cover the synthetic methodologies and the corresponding growth mechanisms, various nanostructures grown, their doping and alloying, and position-controlled growth on substrates. Finally, we will review their functional properties in catalysis, hydrophobic surface modification, sensing, and electronic, optical, optoelectronic, and energy harvesting devices.

关键词： ZnO one dimensional nanostructures solution growth electronic optical optoelectronic energy harvesting devices

Pollution characteristics of polycyclic aromatic hydrocarbons (PAHs) in oily sludge from the zhongyuan Oilfield and its peripheral soils

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Chinese Journal Of Geochemistry 2009年第2期28卷 176-183页

作者： KUANG Shaoping xu zhong Qingdao University of Science and Technology Qingdao 266042 China

The purpose of this study is to determine the degree of contamination caused by polycyclic aromatic hydrocarbons (PAHs) in oily sludge and soils around it in the zhongyuan Oilfield. The contents of polycyclic aro-matic hydrocarbons in oily sludge samples were determined with HPLC. The contents of PAHs of oily sludge from three different oil production plants vary from high to low in the order of the Wenming oily sludge dumping site of No. 3 Oil Production Plant (3W)>the Mazhai oily sludge dumping site of No. 3 Oil Production Plant (3M)>the Wen'er oily sludge dumping site of No. 4 Oil Production Plant (4W). Naphthalene, acenaphthylene, acenaphthene, fluorine and phenanthrene are the major pollutants of PAHs in oily sludge. The contents of PAHs in soil samples around the oily sludge dumping sites vary widely from 434.49 to 2408.8 ng/g. Naphthalene, acenaphthene, fluorine, phenanthrene and pyrene are the characteristic factors of PAHs in soil samples of 3M and 3W, and naphthalene, acenaphthene, fluorine and phenanthrene are the characteristic factors of PAHs in soil samples of 4W. According to these data and the ratios of Fl/Py, PAHs in oily sludge samples come mainly from petrogenic sources, and soil samples are divided into petrogenic soil samples and mixed-source soil samples, and both petrogenic and pyrogenic soil samples in terms of the sources of PAHs. The classification by Nemero index P indicates that soils around the oily sludge dumping sites have been seriously polluted.

关键词：土壤样品含油污泥多环芳烃污染特征 PAHs 中原油田高效液相色谱法内梅罗指数

The role of autophagy in Parkinson's disease

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Neural Regeneration Research 2012年第2期7卷 141-145页

作者： LeiZhang Yaru Dong Xiaoheng xu zhong xu Department of Pediatrics the Second Hospital of Jifin University Changchun 130041 Jifin Province China Department of Ophthalmology the Second Hospital of Jifin University Changchun 130041 Jifin Province China

Although Parkinson＇s disease is the most common neurodegenerative movement disorder, the mechanisms of pathogenesis remain poorly understood. Recent findings have shown that deregulation of the autophagy-lysosome pathway is involved in the pathogenesis of Parkinson＇s disease. This review summarizes the most recent findings and discusses the unique role of the autophagy-lysosome pathway in Parkinson＇s disease to highlight the possibility of Parkinson＇s disease treatment strategies that incorporate autophagy-lysosome pathway modulation.

关键词： autophagy-lysosome pathway Parkinson's disease pathogenesis review

Synthesis and Crystal Structure of 2-tert-Butyl-5-(4-tert-butylbenzylthio)-4-chloropyridazin-3(2H)-one

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Chemical Research in Chinese Universities 2006年第6期22卷 763-764页

作者： xu Liang-zhong YU Guan-ping xu zhong-jie ZHANG Gong-sheng ZHAI Zhi-wei College of Chemistry and Molecular Engineering Qingdao University of Science and Technology Qingdao 266042 P. R. China

The title compound, 2-ten-butyl-6 （4-ten -butylbenzylthio） -4-chloropyridazin-3 （ 2H ） -one, was synthesized from 1 -ten-butylhydrazine, （ Z ） -2,3 -dichloro-3 -formylacrylic acid and （ 4 -tert -butylphenyl ） methanethiol in several steps. It crystallized in an orthorhombic space group Pnma with Mr = 364. 93 （ C19H25 ClN2OS）, a = 1. 0091 （2） nm, b = 0.7076（2） nm, c=2. 8103（5） nm, V=2.0066（6） nm^3, Z=4, Dc =1. 192 g/cm^3, F（000） =765, μ=0.301 mm , final R1 = 0. 0665, and wR = 0. 1913 for 1927 unique reflections. Inter- and intramolecular hydrogen bond C-H…O interactions stabilize the structure.

关键词： Pyridaben Synthesis Crystal structure

An Exact Generalized Test for Homogeneity of Inverse Gaussian Scale Parameters

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Acta Mathematicae Applicatae Sinica 2019年第4期35卷 761-769页

作者： xu-hua LIU Xing-zhong xu Wei-yan MU Department of Mathematics China Agricultural University Beijing 100083 China College of Mathematics Beijing Institute of Technology Beijing 100081 China School of Science Beijing University of Civil Engineering and Architecture Beijing 100044 China

In this paper, we propose a new generalized p-value for testing homogeneity of scale parameters λi from k independent inverse Gaussian populations. The proposed generalized p-value is proved to have exact frequentist property, and it is also invariant under the group of scale transformation. Simulation results indicate that the proposed test is better than existing approximate χ^2 test.

关键词： Inverse Gaussian distribution Generalized p-value Exact frequentist property