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Direction of arrival estimation method based on quantum electromagnetic field optimization in the impulse noise

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Journal of Systems Engineering and Electronics 2021年第3期32卷 527-537页

作者： DU Yanan GAO Hongyuan chen menghan College of Information and Communication Engineering Harbin Engineering UniversityHarbin 150001China

In order to resolve direction finding problems in the impulse noise,a direction of arrival(DOA)estimation method is *** proposed DOA estimation method can restrain the impulse noise by using infinite norm exponential kernel covariance matrix and obtain excellent performance via the maximumlikelihood(ML)*** order to obtain the global optimal solutions of this method,a quantum electromagnetic field optimization(QEFO)algorithm is *** view of the QEFO algorithm,the proposed method can resolve the difficulties of DOA estimation in the impulse *** with some traditional DOA estimation methods,the proposed DOA estimation method shows high superiority and robustness for determining the DOA of independent and coherent sources,which has been verified via the Monte-Carlo experiments of different schemes,especially in the case of snapshot deficiency,low generalized signal to noise ratio(GSNR)and strong impulse *** that,the Cramer-Rao bound(CRB)of angle estimation in the impulse noise and the proof of the convergence of the QEFO algorithm are provided in this paper.

关键词： direction of arrival(DOA)estimation impulse noise infinite norm exponential kernel covariance matrix maximum-likelihood(ML)algorithm quantum electromagnetic field optimization(QEFO)algorithm Cramer-Rao bound(CRB)

Localization for mixed near-field and far-field sources under impulsive noise

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Journal of Systems Engineering and Electronics 2024年第2期35卷 302-315页

作者： GAO Hongyuan ZHANG Yuze DU Ya’nan chenG Jianhua chen menghan College of Information and Communication Engineering Harbin Engineering UniversityHarbin 150001China College of Intelligent Systems Science and Engineering Harbin Engineering UniversityHarbin 150001China

In order to solve the problem that the performance of traditional localization methods for mixed near-field sources(NFSs)and far-field sources(FFSs)degrades under impulsive noise,a robust and novel localization method is *** eliminating the impacts of impulsive noise by the weighted out-lier filter,the direction of arrivals(DOAs)of FFSs can be estimated by multiple signal classification(MUSIC)spectral peaks *** on the DOAs information of FFSs,the separation of mixed sources can be ***,the estimation of localizing parameters of NFSs can avoid two-dimension spectral peaks search by decomposing steering *** Cramer-Rao bounds(CRB)for the unbiased estimations of DOA and range under impulsive noise have been *** experiments verify that the proposed method has advantages in probability of successful estimation(PSE)and root mean square error(RMSE)compared with existing localization *** can be concluded that the proposed method is effective and reliable in the environment with low generalized signal to noise ratio(GSNR),few snapshots,and strong impulse.

关键词： source localization far-field source(NFS) near-field source(FFS) impulsive noise Cramer-Rao bound(CRB)

Efficient capture of difluorocarbene by pyridinium 1,4-zwitterionic thiolates:A concise synthesis of difluoromethylene-containing 1,4-thiazine derivatives

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Chinese Chemical Letters 2024年第4期35卷 367-370页

作者： Zhiwei chen Heyun Sheng Xue Li menghan chen Xin Li Qiuling Song Institute of Next Generation Matter Transformation College of Materials Science&Engineering and College of Chemical Engineering at Huaqiao UniversityXiamen 361021China Fujian University Key Laboratory of Molecule Synthesis and Function Discovery College of ChemistryFuzhou UniversityFuzhou 350108China State Key Laboratory of Organometallic Chemistry and Key Laboratory of Organofluorine Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China

A practical method for the construction of difluoromethylene-containing 1,4-thiazine moieties using readily available diethyl bromodifluoromethanephosphonate(BrCF_(2)PO(OEt)_(2))as difluorocarbene precusor has been *** transformation features the efficient capture of difluorocarbene by pyridinium 1,4-zwitterionic thiolates.A series of structurally novel and functionalized difluoromethylene-containing 1,4-thiazine derivatives were thus synthesized in good yields.

关键词： Difluoromethylene Pyridinium 1 4-zwitterionic thiolates 1 4-Thiazine derivatives

Direction finding of bistatic MIMO radar in strong impulse noise

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Journal of Systems Engineering and Electronics 2024年第4期35卷 888-898页

作者： chen menghan GAO Hongyuan DU Yanan chenG Jianhua ZHANG Yuze College of Information and Communication Engineering Harbin Engineering UniversityHarbin 150001China College of Intelligent Systems Science and Engineering Harbin Engineering UniversityHarbin 150001China

For bistatic multiple-input multiple-output(MIMO)radar,this paper presents a robust and direction finding method in strong impulse noise *** means of a new lower order covariance,the method is effective in suppressing impulse noise and achieving superior direction finding performance using the maximum likelihood(ML)estimation method.A quantum equilibrium optimizer algorithm(QEOA)is devised to resolve the corresponding objective function for efficient and accurate direc-tion *** results of simulation reveal the capability of the presented method in success rate and root mean square error over existing direction-finding methods in different application situations,e.g.,locating coherent signal sources with very few snapshots in strong impulse *** than that,the Cramér-Rao bound(CRB)under impulse noise environment has been drawn to test the capability of the presented method.

关键词： bistatic multiple-input multiple-output(MIMO)radar impulse noise direction finding lower order covariance quan-tum equilibrium optimizer algorithm(QEOA) maximum likeli-hood estimation method Cramér-Rao bound(CRB)

Effects of biodegradation on diamondoid distribution in crude oils from the Bongor Basin,Chad

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Energy Geoscience 2024年第2期5卷 120-128页

作者： Huanxin Song menghan chen Lirong Dou Dingsheng cheng Zhigang Wen Cooperative Innovation Center of Unconventional Oil and Gas Yangtze UniversityWuhanHubei430100China College of Resources and Environment Yangtze UniversityWuhanHubei430100China PetroChina Research Institute of Petroleum Exploration&Development Beijing100083China

The sensitivity of biodegradation on diamondoids was investigated using a series of biodegraded oil samples from the Ronier tectonic unit of Bongor Basin,*** results suggest that diamondoids,including adamantanes(As)and diamantanes(Ds),are relatively resistant to biodegradation and obvious biodegradation was observed in oils with a Peters-Moldowan(PM)biodegradation rank of 6 or ***,the sensibility of biodegradation on diamondoids is generally similar to hopanes and regular *** biodegradation evolves,the changes in concentration and components of diamondoids show that the biodegradation process is selective and *** significant increase of MD/MA and DMD/DMA for oils with a PM ranking 6^(+) indicates that diamantanes are generally more resistant to biodegradation than *** similar trends of DMA/MA,EA/MA,MD/D,DMD/MD and other relevant indexes,show that higher alkylation homologs are more resistant to *** commonly used diamondoid ratios,such as MAI,EAI,MDI and DMID-1,are obviously affected by biodegradation at the stage of high-level biodegradation,which may indicate that these ratios should be used with caution in case of severely degraded oils.

关键词： Diamondoids Biodegradation Sensitivity Crude oil Bongor Basin Chad

Deactivation induced by metal sulfate over MnCeOx catalyst in NH_(3)-SCR reaction at low temperature

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Journal of Rare Earths 2024年第6期42卷 1056-1065,I0002页

作者： Qiao Xie Dongqi An Linsen Zhou Tingzhen Li Zhenghua Hu menghan chen Menglan Ma Lei Zhang Jingfang Sun Lin Dong School of Environmental and Chemical Engineering Chongqing Three Gorges UniversityChongqing404000China Key Laboratory of Water Environment Evolution and Pollution Control in the Three Gorges Reservoir Chongqing Three Gorges UniversityChongqing.404000China Jiangsu Key Laboratory of Vehicle Emissions Control Center of Modern AnalysisSchool of EnvironmentNanjing UniversityNanjing210093China Institute of Materials China Academy of Engineering PhysicsMianyang621908China

Sulfate adsorption is one of the factors that cause the poisoning of catalyst in the low-temperature NH_(3) selective catalytic reduction reaction(NH_(3)-SCR).In this paper,by controlling the co-adsorption time of SO_(2) and O_(2) at 150℃,a range of sulfated MnCeOx catalysts with different contents of metal sulfate species were prepared to reveal the influence of metal sulfate species content on the catalytic performances and reaction mechanisms at low *** catalytic activity below 250℃rapidly decreases with increasing metal sulfate species *** results of characterizations shed light on the reduction of specific surface area,Mn^(4+)and Ce^(3+)content,and redox ability of MnCeOx owing to the formation of metal sulfate *** experiments reveal that metal sulfate species preferentially absorb on MnOx domains rather than on CeO_(2) domains,and the adsorbed metal sulfate species can suppress the Eley-Rideal and the Langmuir-Hinshelwood reaction mechanisms over the sulfated *** the above results are detrimental to the activity of sulfated MnCeOx in the low-temperature NH3-SCR reaction.

关键词： NH_(3)selective catalytic reduction MnCeOx catalyst Sulfation Low-temperature activity SO_(2)poisoning Rare earths

Effects of buckwheat milk Co-fermented with two probiotics and two commercial yoghurt strains on gut microbiota and production of short-chain Fatty Acids

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FOOD BIOSCIENCE 2023年第3期53卷 496-502页

作者： Wang, Yang Qu, Sijia chen, menghan Cui, Yue Shi, chenshan Pu, Xiaolu Gao, Wenhui Li, Quanhong Han, Junhua Zhang, Aixia Hebei Univ Sci & Technol Coll Food Sci & Biol Shijiazhuang 050018 Peoples R China Hebei Acad Agr & Forestry Sci Inst Biotechnol & Food Sci Shijiazhuang 050051 Peoples R China Shijiazhuang Junlebao Dairy Co Ltd Shijiazhuang 050221 Peoples R China China Agr Univ Coll Food Sci & Nutr Engn Beijing 100083 Peoples R China

The fascinating ingredient of buckwheat fermented by probiotics with functional superiorities was considered as a substitute for milk-based foods. In this work, buckwheat milk fermented by probiotic lactic acid bacteria (FBM) was prepared. The effects of FBM on body weight, gut microbiota and short chain fatty acids (SCFA) in mice were also discussed. Results showed that the acidity levels of FBM within 15 days were in the range of 70-100 degrees T, and total microbial counts were higher than 1 x 106 CFU/mL. FBM showed significant effect in controlling weight gain. Also, intestinal flora diversity in mice fed with FBM was improved. The abundance of Barnesiella, Rumi-nococcus, Bacteroides and Prevotella in FBM group was significantly increased. Meanwhile, the contents of six SCFA in the FBM group were significantly higher than the other two groups. These findings will provide referential information in revealing the probiotic functions and developing buckwheat-based products as dairy alternatives.

关键词： Sweet buckwheat Probiotics Intestinal flora Short-chain fatty acids

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中国耕地利用碳排放时空特征与影响因素分析

中国农机化学报 2023年第7期44卷 236-243页

作者：陈梦涵唐莹辽宁大学公共管理学院沈阳市110136

基于中国省级面板数据,对中国耕地利用碳排放总量进行核算,分析其时空演化特征,运用协整分析、Granger因果关系检验探究耕地利用碳排放与粮食产量间关系,运用STIRPAT模型及地理加权回归模型(GWR)揭示耕地利用碳排放的驱动因素。研究发现... 详细信息

基于中国省级面板数据,对中国耕地利用碳排放总量进行核算,分析其时空演化特征,运用协整分析、Granger因果关系检验探究耕地利用碳排放与粮食产量间关系,运用STIRPAT模型及地理加权回归模型(GWR)揭示耕地利用碳排放的驱动因素。研究发现:中国耕地利用碳排放总体呈上升趋势,但自2017年起进入负增长阶段,四种碳排放类型所占比重从大到小依次为废弃物处理碳排放(48.165%)、生产要素投入碳排放(46.924%)、耕地种植碳排放(3.513%)、自然源碳排放(1.416%);与此同时,空间相关性检验表明中国耕地利用碳排放具有显著的区域聚集特征;中国耕地利用碳排放结构上以生产要素投入碳排放和废弃物碳排放为主,且省际间的耕地利用碳排放类型存在较大差异;中国耕地利用碳排放总量与粮食产量之间存在长期均衡关系,同时存在着从耕地利用碳排放到粮食产量增长的单向因果关系;农村总人口数、农村居民可支配收入、农业机械水平均对耕地利用碳排放均有正向影响,影响系数分别为0.624、0.163、0.337,且各影响因素的回归系数在空间上呈现出明显的阶梯分布。研究结果表明:中国耕地利用碳排放时空差异特征明显,且我国农业生产仍存在高投入、高产出、高污染的特点,应基于各省(市)的实际情况,因地制宜地实施差异化的降碳政策。

关键词：耕地利用碳排放时空差异协整分析 GWR模型

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齿廓修形人字齿轮副时变啮合刚度计算方法

振动与冲击 2021年第9期40卷 175-183,194页

作者：林腾蛟陈梦寒杨金重庆大学机械传动国家重点实验室重庆400044

为准确计算考虑轮齿修形和受载变形的人字齿轮副啮合刚度,推导了含齿顶和齿根修形的人字齿轮齿面方程,基于势能法和数值积分公式,提出了计及齿廓修形参数和退刀槽宽度的人字齿轮啮合刚度精确计算方法,并通过有限元仿真分析验证了算法的... 详细信息

为准确计算考虑轮齿修形和受载变形的人字齿轮副啮合刚度,推导了含齿顶和齿根修形的人字齿轮齿面方程,基于势能法和数值积分公式,提出了计及齿廓修形参数和退刀槽宽度的人字齿轮啮合刚度精确计算方法,并通过有限元仿真分析验证了算法的正确性;而后分析了不同退刀槽宽度、修形参数及输入转矩等对人字齿轮副重合度和啮合刚度的影响规律。结果表明,单侧斜齿轮齿宽不变而退刀槽宽度增大,人字齿轮副啮合刚度增大;随着修形量和修形长度的增加,重合度和啮合刚度减小,而修形曲线阶次增大,重合度和啮合刚度呈增大趋势,但当修形曲线阶次高于四次时,啮合刚度变化不大;输入转矩增大时,重合度和啮合刚度先增大而后不再变化。

关键词：人字齿轮齿廓修形时变啮合刚度势能法