检索结果-南通市图书馆

Impact of volcanism on the formation and hydrocarbon generation of organic-rich shale in the Jiyang Depression, Bohai Bay Basin, China

引用

Petroleum Science 2024年第3期21卷 1539-1551页

作者： Jia-Hong Gao Xin-ping Liang Zhi-Jun Jin Quan-You Liu Chang-Rong Li xiao-Wei Huang Ju-Ye Shi Peng Li State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Efficient Development Institute of EnergyPeking University Petroleum Exploration and Production Research Institute SINOPECBeijing100871 China School of Energy Resources China University of Geosciences Beijing100083 China

Globally,most organic-rich shales are deposited with volcanic ash *** ash,a source for many sedimentary basins,can affect the sedimentary water environment,alter the primary productivity,and preserve the organic matter(OM)through physical,chemical,and biological *** an increasing number of breakthroughs in shale oil exploration in the Bohai Bay Basin in recent years,less attention has been paid to the crucial role of volcanic impact especially its influence on the OM enrichment and hydrocarbon ***,we studied the petrology,mineralogy,and geochemical characteristics of the organic-rich shale in the upper submember of the fourth member(Es_(4)^(1))and the lower submember of the third member(Es_(3)^(3))of the Shahejie Formation,aiming to better understand the volcanic impact on organic-rich shale *** results show that total organic carbon is higher in the upper shale intervals rich in volcanic ash with enriched light rare earth elements and moderate Eu *** indicates that volcanism promoted OM formation before or after the *** positive correlation between Eu/Eu*and Post-Archean Australian Shale indicates hydrothermal activity before the volcanic *** plane graph of the hydrocarbon-generating intensity(S1+S2)suggests that the heat released by volcanism promoted hydrocarbon ***,the nutrients carried by volcanic ash promoted biological blooms during Es_(4)^(1 )and Es_(3)^(3) deposition,yielding a high primary *** blooms consume large amounts of oxygen and form anoxic environments conducive to the burial and preservation of ***,this study helps to further understand the organic-inorganic interactions caused by typical geological events and provides a guide for the next step of shale oil exploration and development in other lacustrine basins in China.

关键词： Volcanic ash Hydrocarbon generation Organic-rich shale Shahejie Formation Jiyang Depression

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Short-term displacement prediction for newly established monitoring slopes based on transfer learning

引用

China Geology 2024年第2期7卷 351-364页

作者： Yuan Tian Yang-landuo Deng Ming-zhi Zhang xiao Pang Rui-ping Ma Jian-xue Zhang Institute of Remote Sensing and Geographical Information Systems Peking UniversityBeijing 100871China Beijing Key Laboratory of Spatial Information Integration and Its Applications Beijing 100871China Institute of Public Safety Research Department of Engineering PhysicsTsinghua UniversityBeijing 100084China China Institute of Geo-Environment Monitoring Beijing 100081China Technology Innovation Center for Geohazard Monitoring and Risk Early Warning Ministry of Natural ResourcesBeijing 100081China

This study makes a significant progress in addressing the challenges of short-term slope displacement prediction in the Universal landslide Monitoring Program,an unprecedented disaster mitigation program in China,where lots of newly established monitoring slopes lack sufficient historical deformation data,making it difficult to extract deformation patterns and provide effective predictions which plays a crucial role in the early warning and forecasting of landslide hazards.A slope displacement prediction method based on transfer learning is therefore ***,the method transfers the deformation patterns learned from slopes with relatively rich deformation data by a pre-trained model based on a multi-slope integrated dataset to newly established monitoring slopes with limited or even no useful data,thus enabling rapid and efficient predictions for these ***,as time goes on and monitoring data accumulates,fine-tuning of the pre-trained model for individual slopes can further improve prediction accuracy,enabling continuous optimization of prediction results.A case study indicates that,after being trained on a multi-slope integrated dataset,the TCN-Transformer model can efficiently serve as a pretrained model for displacement prediction at newly established monitoring *** three-day average RMSE is significantly reduced by 34.6%compared to models trained only on individual slope data,and it also successfully predicts the majority of deformation *** fine-tuned model based on accumulated data on the target newly established monitoring slope further reduced the three-day RMSE by 37.2%,demonstrating a considerable predictive *** conclusion,taking advantage of transfer learning,the proposed slope displacement prediction method effectively utilizes the available data,which enables the rapid deployment and continual refinement of displacement predictions on newly established monitoring slopes.

关键词： landslide Slope displacement prediction Transfer learning Integrated dataset Transformer Pre-trained model Universal landslide Monitoring Program(ULMP) Geological hazards survey engineering

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Three-Dimensional Sound Source Location Algorithm for Subsea Leakage Using Hydrophone

引用

China Ocean Engineering 2024年第2期38卷 326-337页

作者： LI Hao-jie CAI Bao-ping YUAN xiao-bing KONG Xiang-di LIU Yong-hong Javed Akbar KHAN CHU Zheng-de YANG Chao TANG An-bang College of Mechanical and Electronic Engineering China University of PetroleumQingdao 266580China Shenzhen Urban Public Safety Technology Institute Shenzhen 518000China Institute of Hydrocarbon Recovery Universiti Teknologi PETRONASBandar Seri IskandarPerak Darul Ridzuan 32610Malaysia

Leakages from subsea oil and gas equipment cause substantial economic losses and damage to marine ecosystem,so it is essential to locate the source of the ***,due to the complexity and variability of the marine environment,the signals collected by hydrophone contain a variety of noises,which makes it challenging to extract useful signals for *** solve this problem,a hydrophone denoising algorithm is proposed based on variational modal decomposition(VMD)with grey wolf ***,the average envelope entropy is used as the fitness function of the grey wolf optimizer to find the optimal solution for the parameters K andα.Afterward,the VMD algorithm decomposes the original signal parameters to obtain the intrinsic mode functions(IMFs).Subsequently,the number of interrelationships between each IMF and the original signal was calculated,the threshold value was set,and the noise signal was removed to calculate the time difference using the valid signal obtained by ***,the arrival time difference is used to locate the origin of the *** localization accuracy of the method in finding leaks is investigated experimentally by constructing a simulated leak test rig,and the effectiveness and feasibility of the method are verified.

关键词： grey wolf optimizer variational modal decomposition mean envelope entropy correlation coefficient time difference of arrival

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Analyzing the surface passivity effect of germanium oxynitride:a comprehensive approach through first principles simulation and interface state density

引用

Nuclear Science and Techniques 2024年第5期35卷 74-84页

作者： Sheng-Jie Du Xiu-Xia Li Yang Tian Yuan-Yuan Liu Ke Jia Zhong-Zheng Tang Jian-ping Cheng Zhi Deng Yu-lan Li Zheng-Cao Li Sha-Sha Lv College of Nuclear Science and Technology Joint Laboratory of Jinping Ultra‑Low Radiation Background Measurement of Ministry of Ecology and Environment Key Laboratory of Beam Technology of Ministry of Education Beijing Normal UniversityBeijing Normal UniversityBeijing 100875China Joint Research Center Nuctech Company LimitedBeijing 100084China Department of Engineering Physics Key Laboratory of Particle&Radiation Imaging of Ministry of EducationTsinghua UniversityBeijing 100084China Key Laboratory of Advanced Materials(MOE) School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China

High-purity germanium(HPGe)detectors,which are used for direct dark matter detection,have the advantages of a low threshold and excellent energy *** surface passivation of HPGe has become crucial for achieving an extremely low energy *** this study,first-principles simulations,passivation film preparation,and metal oxide semiconductor(MOS)capacitor characterization were combined to study surface *** calculations of the energy band structure of the -H,-OH,and -NH_(2) passivation groups on the surface of Ge were performed,and the interface state density and potential with five different passivation groups with N/O atomic ratios were accurately analyzed to obtain a stable surface *** on the theoretical calculation results,the surface passivation layers of the Ge_(2)ON_(2) film were prepared via magnetron sputtering in accordance with the optimum atomic ratio *** microstructure,C-V,and I-V electrical properties of the layers,and the passivation effect of the Al/Ge_(2)ON_(2)/Ge MOS were characterized to test the interface state *** mean interface state density obtained by the Terman method was 8.4×10^(11) cm^(-2) eV^(-1).The processing of germanium oxynitrogen passivation films is expected to be used in direct dark matter detection of the HPGe detector surface passivation technology to reduce the detector leakage currents.

关键词： Surface passivation High purity germanium detector Germanium nitrogen oxide Interface state density

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Light-responsive Self-Immolative L-glutamic Acid-based Polyester Nanoparticles for Controlled Drug Release via Passerini Three-Component Polymerization

引用

Chinese Journal of Polymer Science 2024年第5期42卷 570-578,I0005页

作者： xiao-Fei Sun Xu Zhang Shu-ping Song Ya-Qun Yao Yan Zhang Cheng-Liang Wang Jing-Jiang Sun Qing-Fu Wang Key Laboratory of Rubber-plastics Ministry of EducationSchool of Polymer Science and EngineeringQingdao University of Science and TechnologyQingdao266042China Qingdao Research Academy of Environmental Science Qingdao266012China

L-glutamic acid(LA)is a bio-based,non-toxic,environmentally friendly material derived from *** present study reports the application of Passerini three-component polymerization(P-3CP)for the straightforward preparation of LA-based light-responsive polyesters(PLTDs)under mild *** with molar masses up to 8500 g/mol and high yields exceeding 90%are *** chemical structures and light-responsive self-immolative behavior of PLTDs are comprehensively characterized by employing ultraviolet-visible(UV-Vis)spectroscopy,size exclusion chromatography(SEC),nuclear magnetic resonance(NMR)spectroscopy,and liquid chromatography mass spectrometry(LC-MS).Meanwhile,monodisperse PLTD-based doxorubicin-loaded nanoparticles(PLTD-DOX-NP)(size=193 nm,PDI=0.018)are formulated by nanoprecipitation *** light-induced depolymerization,the PLTD-DOX-NP undergoes rapid decomposition,resulting in a burst release of 80%cargo within 13 ***,according to biological toxicity tests,the PLTD-NP possesses adequate biosafety,both before and after ***,the incorporation of P-3CP with biorenewable LA-based monomer adheres to the principles of green chemistry,significantly simplifying the synthetic pathway of light-responsive polymers.

关键词： L-glutamic acid Passerini three-component polymerization Light-responsive Polyester Nanoparticles

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Visible-light photoredox-catalyzed carboxylation of aryl epoxides with CO_(2)

引用

Chinese Chemical Letters 2024年第7期35卷 281-284页

作者： Tian-Yu Gao xiao-Yan Mo Shu-Rong Zhang Yuan-Xu Jiang Shu-ping Luo Jian-Heng Ye Da-Gang Yu Key Laboratory of Green Chemistry&Technology of Ministry of Education College of ChemistrySichuan UniversityChengdu 610064China State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology Zhejiang University of TechnologyHangzhou 310014China State Key Laboratory of Elemento-Organic Chemistry Nankai UniversityTianjin 300071China

Herein, we report the first visible-light photoredox-catalyzed carboxylation of aryl epoxides with CO_(2)to synthesize hydroxy acid derivatives. A variety of valuable β-, γ-, δ-, ε–hydroxy acid derivatives are obtained in moderate to high yields under mild conditions. This protocol shows noteworthy functionalgroup compatibility, high chemo-and regioselectivities under transition-metal-free conditions with an inexpensive organo-dye as photosensitizer. Mechanistic studies indicate that the benzylic carbanion is generated as an intermediate via the sequential single electron transfer(SSET) process.

关键词： Carbon dioxide Epoxides Visible-light photoredox catalysis Hydroxy acid Sequential single electron transfer

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Five quinolizidine alkaloids with anti-tobacco mosaic virus activities from two species of Sophora

引用

Chinese Chemical Letters 2024年第6期35卷 380-384页

作者： Ji Zhang Tong Zhang Qiao An Peng Zhang Cai-Yan Tian Chun-Mao Yuan ping Yi Zhan-Xing Hu xiao-Jiang Hao State Key Laboratory of Functions and Applications of Medicinal Plants Guizhou Medical UniversityGuiyang 550014China Natural Products Research Center of Guizhou Province Guiyang 550014China School of Pharmaceutical Sciences Guizhou Medical UniversityGuiyang 550025China School of Pharmacy Guizhou University of Traditional Chinese MedicineGuiyang 550025China State Key Laboratory of Phytochemistry and Plant Resources in West China Kunming Institute of BotanyChinese Academy of ScienceKunming 650201China Research Unit of Chemical Biology of Natural Anti-Virus Products Chinese Academy of Medical SciencesKunming 650201China

Three novel matrine-type alkaloids(1-3)and two unprecedented aloperine-type alkaloids(4 and 5)were isolated from the root of Sophora tonkinensis and the seeds of Sophora alopecuroides ***,compound 1 possessed an unprecedented 6/5/6 tricyclic skeleton,while compounds 2 and 3 characterized by rare 6/6/5/6 tetracyclic system and 6/6/6/6/6 pentacyclic system ***,compound 4 possessed an unprecedented 6/7/6/6 tetracyclic core,and compound 5 characterized by rare 6/6/6/6tetracyclic *** structures were elucidated by comprehensive spectroscopic data analysis and electronic circular dichroism(ECD)*** tests indicated that compound 5 displayed significant anti-tobacco mosaic virus(TMV)activity compared with the positive control ningnanmycin.

关键词： Matrine-type alkaloids Aloperine-type alkaloids Sophora tonkinensis Sophora alopecuroides Anti-tobacco mosaic virus

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Survey on hospice care attitude of family members of advanced cancer patients at different ages

引用

World Journal of Clinical Cases 2024年第21期12卷 4626-4631页

作者： xiao-Li Liu Lun-lan Li Department of Oncology Hefei Third People's HospitalHefei 230000Anhui ProvinceChina Department of Nursing School of NursingAnhui Medical UniversityHefei 230000Anhui ProvinceChina Department of Human Resources The First Affiliated Hospital of Anhui Medical UniversityHefei 230000Anhui ProvinceChina

BACKGROUND Hospice care plays an important role in improving the quality of life of advanced cancer patients,but controversy remains over whether age affects the attitudes of family members toward hospice *** To investigate the attitudes of family members of advanced cancer patients of different ages toward hospice *** The study participants were 175 family members of patients with advanced cancer from January 2020 and October *** participants were divided into youth(60 years,n=51)*** investigated and compared the degree of awareness regarding hospice care,attitudes,and whether the family members of patients would choose hospice *** Among the family members of 175 patients,approximately 28%(49/175)were aware of hospice *** of hospice care,the proportion of hospice care acceptance and adaptation attitudes,and the proportion of those who chose hospice care in the youth group were higher in the middle-aged and elderly groups(P0.05).Hospice care was chosen mainly to relieve pain and reduce unnecessary treatment,whereas the reasons for not choosing hospice care were mainly distrust and ethical *** The family members of patients with advanced cancer had relatively low awareness of hospice care,while youth had a higher awareness of hospice care,acceptance,and adaptation attitudes,and were more willing to choose hospice care.

关键词： Hospice care Attitude Advanced cancer Family members Age Awareness Acceptance

来源：

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

Design and test of the key components for a combing-type tobacco harvester

引用

International Journal of Agricultural and Biological Engineering 2024年第1期17卷 145-153页

作者： Chaoran Sun Shaohui Tan Songling Sun Mingtao xiao Limei Chen Wenke Ai Zhihua Qiu ping Jiang Yang He School of Mechanical and Electrical Engineering Hunan Agricultural UniversityChangsha 410128China Truking Technology Limited Ningxiang 410600HunanChina Construction of tobacco leaf production infrastructure of Hunan Province Company of China National Tobacco Corporation office Changsha 410009China

In response to the problems of low efficiency,high labor intensity,and low mechanization in manual tobacco harvesting,a comb-off tobacco picking device for southern hilly tobacco areas was designed following the agronomic requirements and the principle of manual picking of tobacco harvesting in southern *** device was composed of the power chassis,picking mechanism,and storage *** study involved the theoretical analysis,structural design,and modeling of the key components,such as chassis structure,combing-type picking mechanism,and power synchronization *** results of the motion analysis and calculation of the picking process demonstrated that the adjustment range of the comb chain elevation angles was from 12.4°to 20.9°,the comb rod installation distance was 76.2 mm,and the synchronizing mechanism transmission ratio was 3:***-factor test and three-factor three-level orthogonal test was performed with the forward speed of the chassis,the distance between the picking device baffles and the elevation angle of the chain with the combing bar as test factors,and the rate of broken and missed tobacco picking as evaluation *** was revealed that the optimal combination of the forward speed of the chassis,the distance between the baffles,and the chain elevation angle were 1.5 km/h,75 mm,and 12.4°,***,verification tests suggested that the breakage rate of tobacco leaves was 9.99%,and the probability of missed tobacco picking was 7.31%,both of which satisfy the agriculture requirements and the operational requirements in the agricultural machinery certification syllabus.

关键词： harvesting machinery leaf tobacco combing-type tiered harvest synchronizing mechanism

来源：

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

Iodine Nutrition, Thyroid-stimulating Hormone, and Related Factors of Postpartum Women from three Different Areas in China: A Cross-sectional Survey

引用

Biomedical and Environmental Sciences 2024年第3期37卷 254-265页

作者： SHAN xiao Yun ZOU Yan HUANG Li Chun JIANG Shan ZHOU Wei Wen QIN Qiu lan LIU Chang Qing LUO xiao Yan LU Jia Xi MAO De Qian LI Min YANG Zhen Yu YANG Li Chen Key Laboratory of Trace Element Nutrition of National Health Committee National Institute for Nutrition and HealthChinese Center for Disease Control and PreventionBeijing 100050China Hunan Key Laboratory of Typical Environmental Pollution and Health Hazards School of Public HealthHengyang Medical SchoolUniversity of South ChinaHengyang 241001HunanChina Zhejiang Provincial Center for Disease Prevention and Control Hangzhou 310051ZhejiangChina Guangxi Zhuang Autonomous Region Center for Disease Control and Prevention Nanning 530028GuangxiChina Hebei Provincial Center for Disease Control and Prevention Shijiazhuang 050021HebeiChina

Objective Studies on the relationship between iodine,vitamin A(VA),and vitamin D(VD)and thyroid function are *** study aimed to analyze iodine and thyroid-stimulating hormone(TSH)status and their possible relationships with VA,VD,and other factors in postpartum *** A total of 1,311 mothers(896 lactating and 415 non-lactating)from Hebei,Zhejiang,and Guangxi provinces were included in this *** urinary iodine concentration(UIC),TSH,VA,and VD were *** The median UIC of total and lactating participants were 142.00µg/L and 139.95µg/L,*** median TSH,VA,and VD levels in all the participants were 1.89 mIU/L,0.44μg/mL,and 24.04 ng/mL,*** differences in the UIC were found between lactating and non-lactating *** and TSH levels were significantly different among the three *** rural UIC was higher than the urban *** mothers had a higher UIC and a higher prevalence of excessive *** UICs and TSHs levels were observed in both the VD deficiency and insufficiency groups than in the VD-sufficient *** adjustment,no linear correlation was observed between UIC and VA/*** interaction was found between vitamins A/D and UIC on TSH *** The mothers in the present study had no iodine ***,area type,BMI,and VD may be related to the iodine status or TSH levels.

关键词： Median urinary iodine concentration Thyroid-stimulating hormone Vitamin A Vitamin D Postpartum women

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：