检索结果-南通市图书馆

Inverse Calculation and Regularization Process for the Solar Aspect System(SAS) of HXI Payload on ASO-S Spacecraft

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第4期24卷 13-34页

作者： Ji-Rui Yu Ping Ruan Yang su Ying-Hong He Jin-You Tao zhe Zhang Song Guo Bin Xue Jian-Feng Yang Xi'an Institute of Optics and Precision Mechanics of Chinese Academy of Sciences Xi'an 710119China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of SciencesNanjing 20034China School ofAstronomy and Space Science Universityof Science and Technology of ChinaHefei 230026China

For the ASO-S/HXI payload, the accuracy of the flare reconstruction is reliant on important factors such as the alignment of the dual grating and the precise measurement of observation orientation. To guarantee optimal functionality of the instrument throughout its life cycle, the Solar Aspect System (SAS) is imperative to ensure that measurements are accurate and reliable. This is achieved by capturing the target motion and utilizing a physical model-based inversion algorithm. However, the SAS optical system’s inversion model is a typical ill-posed inverse problem due to its optical parameters, which results in small target sampling errors triggering unacceptable shifts in the solution. To enhance inversion accuracy and make it more robust against observation errors, we suggest dividing the inversion operation into two stages based on the SAS spot motion model. First, the as-rigid-aspossible (ARAP) transformation algorithm calculates the relative rotations and an intermediate variable between the substrates. Second, we solve an inversion linear equation for the relative translation of the substrates, the offset of the optical axes, and the observation orientation. To address the ill-posed challenge, the Tikhonov method grounded on the discrepancy criterion and the maximum a posteriori (MAP) method founded on the Bayesian framework are utilized. The simulation results exhibit that the ARAP method achieves a solution with a rotational error of roughly±3 5 (1/2-quantile);both regularization techniques are successful in enhancing the stability of the solution, the variance of error in the MAP method is even smaller—it achieves a translational error of approximately±18μm (1/2-quantile) in comparison to the Tikhonov method’s error of around±24μm (1/2-quantile). Furthermore, the SAS practical application data indicates the method’s usability in this study. Lastly, this paper discusses the intrinsic interconnections between the regularization methods.

关键词： methods:data analysis sun:flares sun:X-rays gamma rays

Severe Global Environmental Issues Caused by Canada’s Record-Breaking Wildfires in 2023

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2024年第4期41卷 565-571页

作者： zhe WANG Zifa WANG Zhiyin ZOU Xueshun CHEN Huangjian WU Wending WANG Hang su Fang LI Wenru XU Zhihua LIU Jiaojun ZHU State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China International Center for Climate and Environment Sciences Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Institute of Applied Ecology Chinese Academy of SciencesShenyang 110016China

Due to the record-breaking wildfires that occurred in Canada in 2023,unprecedented quantities of air pollutants and greenhouse gases were released into the atmosphere.The wildfires had emitted more than 1.3 Pg CO_(2)and 0.14 Pg CO_(2)equivalent of other greenhouse gases(GHG)including CH4 and N_(2)O as of 31 August.The wildfire-related GHG emissions constituted more than doubled Canada’s planned cumulative anthropogenic emissions reductions in 10 years,which represents a significant challenge to climate mitigation efforts.The model simulations showed that the Canadian wildfires impacted not only the local air quality but also that of most areas in the northern hemisphere due to long-range transport,causing severe PM_(2.5)pollution in the northeastern United States and increasing daily mean PM_(2.5)concentration in northwestern China by up to 2μg m-3.The observed maximum daily mean PM_(2.5)concentration in New York City reached 148.3μg m-3,which was their worst air quality in more than 50 years,nearly 10 times that of the air quality guideline(i.e.,15μg m-3)issued by the World Health Organization(WHO).Aside from the direct emissions from forest fires,the peat fires beneath the surface might smolder for several months or even longer and release substantial amounts of CO_(2).The substantial amounts of greenhouse gases from forest and peat fires might contribute to the positive feedback to the climate,potentially accelerating global warming.To better understand the comprehensive environmental effects of wildfires and their interactions with the climate system,more detailed research based on advanced observations and Earth System Models is essential.

关键词： Canada forest fire greenhouse gases PM_(2.5) transboundary air pollution

Design of weak current measurement system and research on temperature impact

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第4期35卷 46-56页

作者： Chu-Xiang Zhao San-Gang Li Rong-Rong su Li Yang Ming-zhe Liu Qing-Yue Xue Shan Liao Zhi Zhou Qing-Shan Tan Xian-Guo Tuo Yi Cheng College of Nuclear Technology and Automation Engineering Chengdu University of Technology1#DongsanluErxianqiaoChengdu 610059China Applied Nuclear Technology in Geosciences Key Laboratory of Sichuan Province Chengdu University of Technology1#DongsanluErxianqiaoChengdu 610059China University of Science and Technology of China Hefei 230026China School of Physics and Electronic Engineering Sichuan University of Science and EngineeringZigong 643000China

A dedicated weak current measurement system was designed to measure the weak currents generated by the neutron ionization chamber.This system incorporates a second-order low-pass filter circuit and the Kalman filtering algorithm to effectively filter out noise and minimize interference in the measurement results.Testing conducted under normal temperature conditions has demonstrated the system's high precision performance.However,it was observed that temperature variations can affect the measurement performance.Data were collected across temperatures ranging from -20 to 70℃,and a temperature correction model was established through linear regression fitting to address this issue.The feasibility of the temperature correction model was confirmed at temperatures of -5 and 40℃,where relative errors remained below 0.1% after applying the temperature correction.The research indicates that the designed measurement system exhibits excellent temperature adaptability and high precision,making it particularly suitable for measuring weak currents.

关键词： Weak current measurement system Neutron ionization chamber Kalman filter algorithm Temperature correction model

Mechanisms of fracture propagation from multi-cluster using a phase field based HMD coupling model in fractured reservoir

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第3期21卷 1829-1851页

作者： Yun-Jin Wang Bo Wang Hang su Tu Chang Ren-Cheng Dong Li-zhe Li Wei-Yu Tang Ting-Xue Jiang Fu-Jian Zhou State Key Laboratory of Petroleum Resources and Engineering China University of Petroleum-Beijing China University of Petroleum-Beijing at Karamay China National Oil and Gas Exploration and Development Corporation Ltd. University of Texas at Austin SINOPEC Research Institute of Petroleum Engineering

Natural fractures(NFs) are common in shale and tight reservoirs, where staged multi-cluster fracturing of horizontal wells is a prevalent technique for reservoir stimulation. While NFs and stress interference are recognized as significant factors affecting hydraulic fracture(HF) propagation, the combined influence of these factors remains poorly understood. To address this knowledge gap, a novel coupled hydromechanical-damage(HMD) model based on the phase field method is developed to investigate the propagation of multi-cluster HFs in fractured reservoirs. The comprehensive energy functional and control functions are established, while incorporating dynamic fluid distribution between multiple perforation clusters and refined changes in rock mechanical parameters during hydraulic fracturing. The HMD coupled multi-cluster HF propagation model investigates various scenarios, including single HF and single NF, reservoir heterogeneity, single HF and NF clusters, and multi-cluster HFs with NF clusters. The results show that the HMD coupling model can accurately capture the impact of approach angle(θ),stress difference and cementation strength on the interaction of HF and NF. The criterion of the open and cross zones is not fixed. The NF angle(a) is not a decisive parameter to discriminate the interaction.According to the relationship between approach angle(θ) and NF angle(a), the contact relationship of HF can be divided into three categories(θ = a, θ a). The connected NF can increase the complexity of HF by inducing it to form branch fracture, resulting in a fractal dimension of HF as high as2.1280 at angles of ±45°. Inter-fracture interference from the heel to the toe of HF shows the phenomenon of no, strong and weak interference. Interestingly, under the influence of NFs, distant HFs from the injection can become dominant fractures. However, as a gradually increases, inter-fracture stress interference becomes the primary factor influencing HF propagation, gradually superseding the dominance of NF induce

关键词： HMD coupling Phase field Natural fracture Flow distribution Hydraulic fracturing Inter-fracture interference

Prediction of treatment response to antipsychotic drugs for precision medicine approach to schizophrenia:randomized trials and multiomics analysis

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Military Medical Research 2024年第1期11卷 19-33页

作者： Liang-Kun Guo Yi su Yu-Ya-Nan Zhang Hao Yu zhe Lu Wen-Qiang Li Yong-Feng Yang Xiao Xiao Hao Yan Tian-Lan Lu Jun Li Yun-Dan Liao zhe-Wei Kang Li-Fang Wang Yue Li Ming Li Bing Liu Hai-Liang Huang Lu-Xian Lv Yin Yao Yun-Long Tan Gerome Breen Ian Everall Hong-Xing Wang Zhuo Huang Dai Zhang Wei-Hua Yue Institute of Mental Health Peking University Sixth HospitalBeijing 100191China National Clinical Research Center for Mental Disorders Peking University Sixth HospitalBeijing 100191China NHC Key Laboratory of Mental Health and Research Unit of Diagnosis and Treatment of Mood Cognitive Disorder(2018RU006) Chinese Academy of Medical SciencesBeijing 100191China Peking University Huilongguan Clinical Medical School Beijing Huilongguan HospitalBeijing 100096China Department of Psychiatry Jining Medical UniversityJining 272067ShandongChina Henan Key Lab of Biological Psychiatry the Second Affiliated Hospital of Xinxiang Medical UniversityXinxiang 435001HenanChina Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences and Yunnan Province Kunming Institute of ZoologyChinese Academy of SciencesKunming 650223China Institute of Psychiatry Psychology and NeuroscienceKing’s College LondonLondon WC2R 2LSUK State Key Laboratory of Cognitive Neuroscience and Learning Beijing Normal UniversityBeijing 100875China Analytic and Translational Genetics Unit Massachusetts General HospitalBostonMA 02114USA Stanley Center for Psychiatric Research the Broad Institute of MIT and HarvardCambridgeMA 02141USA Department of Medicine Harvard Medical SchoolBostonMA 02115USA Department of Biostatistics and Computational Biology School of Life SciencesFudan UniversityShanghai 200438China Department of Neurology Xuanwu HospitalCapital Medical UniversityBeijing 100053China State Key Laboratory of Natural and Biomimetic Drugs Key Laboratory for Neuroscience for Ministry of EducationSchool of Pharmaceutical SciencesPeking University Health Science CenterBeijing 100191China PKU-IDG/McGovern Institute for Brain Research Peking UniversityBeijing 100871China Chinese Institute for Brain Research Beijing 102206China

Background:Choosing the appropriate antipsychotic drug(APD)treatment for patients with schizophrenia(SCZ)can be challenging,as the treatment response to APD is highly variable and difficult to predict due to the lack of effective biomarkers.Previous studies have indicated the association between treatment response and genetic and epigenetic factors,but no effective biomarkers have been identified.Hence,further research is imperative to enhance precision medicine in SCZ treatment.Methods:Participants with SCZ were recruited from two randomized trials.The discovery cohort was recruited from the CAPOC trial(n=2307)involved 6 weeks of treatment and equally randomized the participants to the Olanzapine,Risperidone,Quetiapine,Aripiprazole,Ziprasidone,and Haloperidol/Perphenazine(subsequently equally assigned to one or the other)groups.The external validation cohort was recruited from the CAPEC trial(n=1379),which involved 8 weeks of treatment and equally randomized the participants to the Olanzapine,Risperidone,and Aripiprazole groups.Additionally,healthy controls(n=275)from the local community were utilized as a genetic/epigenetic reference.The genetic and epigenetic(DNA methylation)risks of SCZ were assessed using the polygenic risk score(PRS)and polymethylation score,respectively.The study also examined the genetic-epigenetic interactions with treatment response through differential methylation analysis,methylation quantitative trait loci,colocalization,and promoteranchored chromatin interaction.Machine learning was used to develop a prediction model for treatment response,which was evaluated for accuracy and clinical benefit using the area under curve(AUC)for classification,R^(2) for regression,and decision curve analysis.Results:Six risk genes for SCZ(LINC01795,DDHD2,SBNO1,KCNG2,SEMA7A,and RUFY1)involved in cortical morphology were identified as having a genetic-epigenetic interaction associated with treatment response.The developed and externally validated prediction model,which incorporated clinical information,

关键词： Schizophrenia Antipsychotic drug Treatment response Prediction model Genetics Epigenetics

基于D^(*)算法的粤港澳大湾区臭氧工业能源产值率路径优化研究

在线全文

学校读者我要写书评

暂无评论

数学的实践与认识 2024年第3期54卷 18-28页

作者：苏哲亿嘉应学院经济与管理学院广东梅州514015

为协同粤港澳大湾区臭氧污染防控与工业发展,立足于臭氧浓度、工业生产总值、工业能源消费等视角,探索湾区工业布局优化路径;以2014-2018年湾区城市年均臭氧浓度、工业能源产值率为基础指标,绘制湾区各城市节点的臭氧浓度和工业能源产... 详细信息

为协同粤港澳大湾区臭氧污染防控与工业发展,立足于臭氧浓度、工业生产总值、工业能源消费等视角,探索湾区工业布局优化路径;以2014-2018年湾区城市年均臭氧浓度、工业能源产值率为基础指标,绘制湾区各城市节点的臭氧浓度和工业能源产值率分布空间图,引入D^(*)算法,运算得出激进型、温和型、平衡型三种优化路径,对协同降低湾区臭氧浓度与提高湾区工业能源产值率提供参考思路.

关键词：粤港澳大湾区 D^(*)算法臭氧污染工业能源产值率

深层-超深层致密储层天然裂缝分布特征及发育规律

在线全文

学校读者我要写书评

暂无评论

石油与天然气地质 2024年第1期45卷 1-14页

作者：曾联波巩磊宿晓岑毛哲中国石油大学(北京)油气资源与探测国家重点实验室北京102249 东北石油大学环渤海能源研究院河北秦皇岛066004

天然裂缝是深层-超深层致密储层的有效储集空间和主要渗流通道,影响着致密储层油气的运移、富集、单井产能、开发方式及开发效果。通过对近年来致密储层裂缝研究成果总结和文献综述,分析了深层-超深层致密储层天然裂缝分布特征及发育规... 详细信息

天然裂缝是深层-超深层致密储层的有效储集空间和主要渗流通道,影响着致密储层油气的运移、富集、单井产能、开发方式及开发效果。通过对近年来致密储层裂缝研究成果总结和文献综述,分析了深层-超深层致密储层天然裂缝分布特征及发育规律。将致密储层天然裂缝分为大尺度裂缝、中尺度裂缝、小尺度裂缝和微尺度裂缝4个级别。不同尺度裂缝分布具有幂律分布的特点,裂缝尺度越大,数量越少;裂缝尺度越小,数量越多。大、中尺度裂缝主要起渗流作用,小尺度裂缝主要起渗流和储集作用,而微尺度裂缝主要起储集作用。在地层埋藏过程中的应力体制演化决定了不同时期天然裂缝的类型、产状及其力学性质;构造应力大小、岩石力学层的力学性质和厚度差异控制了多尺度裂缝的形成分布及其发育程度。构造变形导致不同构造部位的局部应力和应变分布产生差异,增强了裂缝发育的非均质性。逆冲断层通过控制其上盘地层变形控制了“裂缝域”的分布规律;走滑断层的组合样式、活动方式和岩石力学层共同控制了相关裂缝的三维空间展布。裂缝形成演化过程中的开启-闭合规律决定了裂缝的储集空间,记录了裂缝有效性的演化历史。

关键词：断裂带结构有效性演化天然裂缝多尺度裂缝致密储层深层-超深层

基于改进量子头脑风暴算法的UAV三维航迹规划

在线全文

学校读者我要写书评

暂无评论

华中科技大学学报（自然科学版） 2024年第1期52卷 112-117,132页

作者：孙希霞丁喆蔡超潘甦南京邮电大学物联网学院江苏南京210003 华中科技大学人工智能与自动化学院湖北武汉430074

针对复杂环境中的无人飞行器航迹规划问题,提出了一种基于改进量子头脑风暴优化(QBSO)算法的UAV三维航迹规划方法.在进化前期,两个种群独立进化,从而提升算法的全局搜索能力.在进化后期,对每个种群中的个体进行排序,每个种群中较优的(... 详细信息

针对复杂环境中的无人飞行器航迹规划问题,提出了一种基于改进量子头脑风暴优化(QBSO)算法的UAV三维航迹规划方法.在进化前期,两个种群独立进化,从而提升算法的全局搜索能力.在进化后期,对每个种群中的个体进行排序,每个种群中较优的(排名前50%)个体形成一个新种群,该新种群按照QBSO的进化机制继续进行进化,从而加快算法收敛速度.此外,为进一步提升算法的全局搜索能力,提出了一种改进的待变异个体产生方式.实验结果表明:与基本BSO、QBSO、改进BSO及全局最优BSO算法相比,改进QBSO算法在解决航迹规划问题上具有更高的全局搜索能力、收敛精度和更强的稳定性.

关键词：无人飞行器航迹规划量子头脑风暴优化进化机制收敛精度

清朝统一多民族国家的建构:以宫廷南疆匠役、艺人为考察中心

在线全文

学校读者我要写书评

暂无评论

云南社会科学 2024年第1期 124-135页

作者：孙喆王苏佳中国人民大学清史研究所

新疆自古以来就是四方文明竞逐、多元文化碰撞融会之地,形成了独具特色的文化艺术风格。清乾隆时期统一新疆以后,一批批拥有独特技艺的南疆回人,包括金银匠、玉匠、画匠、编织匠、乐舞艺人、求雨祈晴人等陆续由南疆被选送至京城。清朝... 详细信息

新疆自古以来就是四方文明竞逐、多元文化碰撞融会之地,形成了独具特色的文化艺术风格。清乾隆时期统一新疆以后,一批批拥有独特技艺的南疆回人,包括金银匠、玉匠、画匠、编织匠、乐舞艺人、求雨祈晴人等陆续由南疆被选送至京城。清朝对包括南疆回人在内的各民族工匠、艺人的招纳和重用,塑造了清代宫廷文化的多民族属性,是有清一代物质文化交流与民族融合的缩影。他们做成的器物和参与的各类宫廷活动,也以文化符号的方式,生动展现了清代统一多民族国家的形成和发展。

关键词：清朝多民族国家建构南疆匠役艺人