检索结果-南通市图书馆

湛江湾水体颗粒物后向散射特性及其遥感反演研究

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

光谱学与光谱分析 2024年第3期44卷 793-799页

作者：余果钟雅枫付东洋刘大召徐华兵广东海洋大学化学与环境学院广东湛江524088 广东海洋大学电子与信息工程学院广东湛江524088 南方海洋科学与工程广东省实验室(湛江) 南海资源大数据中心广东湛江524025 广东省海洋遥感与信息技术工程技术中心广东湛江524088

湛江湾2018年1月的原位调查,获得了原位遥感反射率(Rrs)、颗粒物后向散射系数(b_(bp))、叶绿素a(Chl a)和无机悬浮颗粒物(ISM)浓度等参数,分析了湛江湾水体颗粒物后向散射特性,并对颗粒物后向散射系数进行了遥感反演研究。研究结果显示... 详细信息

湛江湾2018年1月的原位调查,获得了原位遥感反射率(Rrs)、颗粒物后向散射系数(b_(bp))、叶绿素a(Chl a)和无机悬浮颗粒物(ISM)浓度等参数,分析了湛江湾水体颗粒物后向散射特性,并对颗粒物后向散射系数进行了遥感反演研究。研究结果显示:在研究区域观察到表层水体6个波段(420, 442, 470, 510, 590和700 nm)颗粒物后向散射系数的变异系数均在50%~60%之间,其变化范围为0.026 1~0.211 2 m^(-1),这意味着水体光学性质的复杂性。为了更好地量化b_(bp)的光谱特性,研究以510 nm为参考波段构建了b_(bp)幂函数光谱模型,获得的光谱模型斜率指数n=1.55。研究发现b_(bp)(510)与ISM呈现乘幂关系,与颗粒物组成(Chla/ISM)呈现指数关系,决定系数R2分别为0.74和0.62,表明研究区域颗粒物后向散射系数一阶驱动因子主要为无机悬浮颗粒物浓度,二阶驱动因子颗粒物组成对b_(bp)(510)变异也具有重要的贡献。为了准确估算湛江湾颗粒物后向散射系数,研究基于原位遥感反射率构建了随机森林模型,并与QAA-v6、 QAA-RGB和QAA-705三种半分析算法进行对比。随机森林模型的R2为0.86,平均绝对百分比误差MAPE为12%,均方根误差RMSE为0.02 m^(-1), QAA-v6、 QAA-RGB和QAA-705三种半分析算法R2分别为0.63、 0.71和0.53, MAPE分别为186%、 117%和243%, RMSE分别为0.16、 0.09和0.18 m^(-1),三种半分析算法虽然也具有较高的R2,但估计值和测量值之间存在显著差异,且MAPE和RMSE也较大,三种半分析算法显著低于随机森林方法的反演精度,表明运用遥感反演湛江湾b_(bp),随机森林方法具有较大的应用潜力。

关键词：颗粒物后向散射特性遥感反演湛江湾随机森林

Effect of endometrial thickness on the risk of ectopic pregnancy for frozen embryo transfer

在线全文

学校读者我要写书评

暂无评论

Reproductive and Developmental Medicine 2024年第2期8卷 75-81页

作者： Li-Juan Huang Qu Zheng Xue-Jiao Wang Zhao-Hui zhong Li-Juan fu Xing-Yu Lv Li-Hong Geng Xiao-Jun Tang Yu-Bin Ding Qi Wan Department of Obstetrics and Gynecology Women and Children’s Hospital of Chongqing Medical UniversityChongqing 401147China School of Public Health Joint International Research Laboratory of Reproduction and Development of the Ministry of Education of ChinaChongqing 400016China The Reproductive Center Chengdu Xinan Gynecology HospitalChengdu 610011China School of Public Health Research Center for Medical and Social DevelopmentChongqing Medical UniversityChongqing 400016China Department of Pharmacology Academician WorkstationChangsha Medical UniversityChangsha 410119China Department of Obstetrics and Gynecology West China Second HospitalSichuan UniversityChengdu 610041China

Objective:Few studies have explored the suitability of endometrial thickness(EMT)as a predictor of ectopic pregnancy(EP)in frozen embryo transfer(FET)*** study aimed to investigate the association between EMT and EP and explore the cutoff value of EMT to predict ***:This retrospective cohort study included women aged 20-45 years undergoing FET between March 2015 and September *** primary outcomes and measured variables were EP and EMT,*** threshold effect of EMT on EP was calculated based on a constructed smooth curve *** patients were divided into two groups based on the threshold for comparison.A subgroup analysis was conducted to examine whether the relationship between EMT and EP remained consistent across the different ***,a generalized linear model was used to analyze the interactions between the treatment factors and EMT in ***:In total,27,549 FET cycles were included,with 27,086 intrauterine and 463 ectopic *** risk of EP in the EMT≤8.7 mm group was 3.36 times higher than that in the EMT>8.7 mm group(odds ratio[OR]:3.36,95%confidence interval[CI]:2.57-4.05).Subgroup analysis further indicated that a thin EMT was a risk factor for EP,independent of other *** also noted that diminished ovarian reserve,tubal factor infertility,transfer of two embryos,or transfer of cleavage-stage embryos may further enhance the risk of EP in patients with thin ***:Thin endometrium was associated with an increased risk of *** with EMT less than 8.7 mm need close medical observation and management after embryo *** addition,diminished ovarian reserve,tubal factor infertility,transfer of two embryos,or transfer of cleavage-stage embryos may significantly enhance the effect of a thin endometrium on the risk of EP.

关键词： Endometrial thickness Thin endometrium Ectopic pregnancy FET cycle Risk factors

αExtractor: a system for automatic extraction of chemical information from biomedical literature

在线全文

学校读者我要写书评

暂无评论

Science China(Life Sciences) 2024年第3期67卷 618-621页

作者： Jiacheng Xiong Xiaohong Liu Zhaojun Li Hongzhong Xiao Guangchao Wang Zhenjiang Niu Chaoyuan Fei Feisheng zhong Gang Wang Wei Zhang Zunyun fu Zhiguo Liu Kaixian Chen Hualiang Jiang Mingyue Zheng Drug Discovery and Design Center State Key Laboratory of Drug ResearchShanghai Institute of Materia MedicaChinese Academy of SciencesShanghai 201203China University of Chinese Academy of Sciences Beijing 100049China AI Department Suzhou Alphama Biotechnology Co.Ltd.Suzhou 215125China College of Computer and Information Engineering Dezhou UniversityDezhou 253023China

Dear Editor,Great progress has been made using artificial intelligence(AI) techniques in learning knowledge from biomedical databases in recent years, revolutionizing the study of many fields, such as protein structure prediction and protein design(Madani et al., 2023). However, there is massive biomedical knowledge not curated in the form of structured data but hidden in primary scientific literature.

关键词： has such knowledge

在线全文

学校读者我要写书评

暂无评论

高效高精度隧洞岩体超前速度建模及成像

岩土工程学报 2024年第2期46卷 452-458页

作者：董士琦周黎明付代光张杨董新桐钟铁长江科学院水利部岩土力学与工程重点实验室湖北武汉430010 吉林大学仪器科学与电气工程学院吉林长春130061 东北电力大学电气工程学院吉林吉林132012

准确提取隧洞掌子面前方岩体的纵波速度信息并对异常地质体构造进行准确成像是提高地震波法超前地质预报精度的关键。时间域全波形反演(full waveform inversion, FWI)技术可以实现对掌子面前方岩体纵波速度的高精度建模;将FWI结合互相... 详细信息

准确提取隧洞掌子面前方岩体的纵波速度信息并对异常地质体构造进行准确成像是提高地震波法超前地质预报精度的关键。时间域全波形反演(full waveform inversion, FWI)技术可以实现对掌子面前方岩体纵波速度的高精度建模;将FWI结合互相关目标函数,可以解决隧洞中不同炮孔能量不均对反演结果的影响,并提高反演算法的抗噪性;结合隧洞地震数据混合震源编码策略,可以显著提高FWI计算效率;利用FWI提供的准确速度模型,进行基于双向照明补偿互相关成像条件的逆时偏移(reverse time migration, RTM),可以实现对异常地质构造的精准成像。通过多种隧洞常见地质体模型的数值试验验证了高效高精度隧洞岩体超前速度建模及成像方法的有效性,并为实际隧洞工程应用提供了理论支撑。

关键词：隧洞超前地质预报全波形反演混合震源编码互相关目标函数逆时偏移成像

喷丸强化对GH4096合金表面状态和疲劳性能的影响

在线全文

学校读者我要写书评

暂无评论

稀有金属材料与工程 2024年第6期53卷 1726-1734页

作者：田伟伏宇张少平钟燕付锐李福林中国航发四川燃气涡轮研究院四川成都610500 钢铁研究总院高温材料研究所北京100081

采用S110铸钢丸和Z300陶瓷丸对GH4096合金开展了喷丸强化试验,利用扫描电镜和三维轮廓仪分析了喷丸表面形貌,采用X射线衍射法分析了喷丸表面残余应力,采用扫描电镜EBSD分析了喷丸试样的截面显微组织,并对喷丸试样进行了650℃低周疲劳试... 详细信息

采用S110铸钢丸和Z300陶瓷丸对GH4096合金开展了喷丸强化试验,利用扫描电镜和三维轮廓仪分析了喷丸表面形貌,采用X射线衍射法分析了喷丸表面残余应力,采用扫描电镜EBSD分析了喷丸试样的截面显微组织,并对喷丸试样进行了650℃低周疲劳试验。结果表明:随着喷丸强度的增大喷丸表面的粗糙度升高,相同喷丸强度下陶瓷丸喷丸表面的粗糙度低于铸钢丸喷丸表面的粗糙度。铸钢丸喷丸表面的残余压应力在-860~-1000 MPa之间,随着喷丸强度的增加残余压应力略有降低;陶瓷丸喷丸表面的残余压应力在-1000~-1100 MPa之间,随着喷丸强度的增加残余压应力略有增加。GH4096合金喷丸后表面发生塑性形变,形成弹丸坑形貌,出现晶界弯曲,产生晶格畸变,造成大量位错塞集,形成密集分布的小角度晶界,晶粒取向也随之改变。喷丸强化可提高GH4096合金650℃高温下的低周疲劳寿命,复合喷丸对疲劳寿命的提升效果最明显,相同喷丸强度下陶瓷丸的强化效果优于铸钢丸。喷丸强化后试样的疲劳裂纹多萌生于强化层之下的亚表面,喷丸强化的效果受表面粗糙度、残余应力及强化层深度等共同影响。

关键词： GH4096合金喷丸强化表面形貌残余应力显微组织疲劳性能

农村小学“五育并举”课后服务校本课程体系建设

在线全文

学校读者我要写书评

暂无评论

教学与管理 2024年第2期 21-24页

作者：付荣钟叶衡阳幼儿师范高等专科学校小学教育系

课后服务课程体系建设是学校课后服务的中心工作,对落实“双减”要求、满足学生多样化发展需要、提高教师课程开发能力具有决定性影响。可在农村小学开发“五育并举”的课后服务校本课程:感悟乡土文化,培育乡土情怀;探究二十四节气文化... 详细信息

课后服务课程体系建设是学校课后服务的中心工作,对落实“双减”要求、满足学生多样化发展需要、提高教师课程开发能力具有决定性影响。可在农村小学开发“五育并举”的课后服务校本课程:感悟乡土文化,培育乡土情怀;探究二十四节气文化,提升实践能力;融合乡土游戏,提高身体素质;赏析民间艺术,提高美术素养;体验“农耕文化”,养成劳动观念,以此破解农村小学课后服务课程难题,实现农村学校教育提质增效。

关键词：农村小学课后服务课程体系五育并举

在线全文

学校读者我要写书评

暂无评论

基于床层传热的皮江法炼镁过程优化

东北大学学报（自然科学版） 2024年第4期45卷 523-529页

作者：傅大学狄跃忠王耀武东北大学多金属共生矿生态化冶金教育部重点实验室辽宁沈阳110819 东北大学冶金学院辽宁沈阳110819 福建省长汀金龙稀土有限公司福建龙岩366300

球团在还原罐内传热导致的温度梯度是限制皮江法还原反应的关键因素.本文采用数值方法研究了球团尺寸、装料方式、还原罐外壁温度等因素对床层温度分布、还原率分布的影响.结果表明:在球团直径为22.3 mm、还原时间相同时能够获得最大的... 详细信息

球团在还原罐内传热导致的温度梯度是限制皮江法还原反应的关键因素.本文采用数值方法研究了球团尺寸、装料方式、还原罐外壁温度等因素对床层温度分布、还原率分布的影响.结果表明:在球团直径为22.3 mm、还原时间相同时能够获得最大的还原率;生产过程中应尽量提高还原罐外壁温度;床层中心区域温度低,还原反应速率慢,反应滞后;通过中心留空的方法能够有效缩短还原周期,提高原料利用率;以单位体积、单位时间镁的产量为依据,对于内径为270 mm的还原罐,当中心留空区域的直径小于27 mm时,可获得最大生产效率.

关键词：镁皮江法真空硅热还原数值仿真传热

Separation of halogens and recovery of heavy metals from secondary copper smelting dust

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2024年第8期34卷 2686-2701页

作者： Zhi-lou LIU Zhi-kang CHEN fu-ze SUN Zhi-heng ZHANG Kang YAN Shui-ping zhong Hui LIU Rui-xiang WANG Jia-yuan LI Zhi-feng XU School of Metallurgy Engineering Jiangxi University of Science and TechnologyGanzhou 341000China School of Chemistry and Environmental Science Xiangnan UniversityChenzhou 423000China Ganzhou Engineering Technology Research Centre of Green Metallurgy and Process Intensification Ganzhou 341000China Key Laboratory of Ionic Rare Earth Resources and Environment Ministry of Natural ResourcesGanzhou 341000China

The separation of halogens and recovery of heavy metals from secondary copper smelting(SCS)dust using a sulfating roasting−water leaching process were *** thermodynamic analysis results confirm the feasibility of the phase transformation to metal sulfates and to gaseous HF and *** the sulfating roasting conditions of the roasting temperature of 250°C and the sulfuric acid excess coefficient of 1.8,over 74 wt.%of F and 98 wt.%of Cl were volatilized into flue *** 98.6 wt.%of Zn and 96.5 wt.%of Cu in the roasting product were dissolved into the leaching solution after the water leaching process,while the leaching efficiencies of Pb and Sn were only 0.12%and 0.22%,*** mechanism studies indicate the pivotal effect of roasting temperature on the sulphation reactions from various metal species to metal sulfates and the salting out reactions from various metal halides to gaseous hydrogen halides.

关键词： secondary copper smelting dust sulfating roasting water leaching halogen volatilization heavy metal separation

同方期刊数据库

VPI:Vehicle Programming Interface for Vehicle Computing

在线全文

学校读者我要写书评

暂无评论

Journal of Computer Science & Technology 2024年第1期39卷 22-44页

作者：吴宝福仲任王昱心万健张纪林施巍松 School of Computer Science and Technology Hangzhou Dianzi UniversityHangzhou 310018China Department of Computer Science Wayne State UniversityDetroitMI 48202U.S.A Department of Computer and Information Sciences University of DelawareNewarkDE 19716U.S.A

The emergence of software-defined vehicles(SDVs),combined with autonomous driving technologies,has en-abled a new era of vehicle computing(VC),where vehicles serve as a mobile computing ***,the interdisci-plinary complexities of automotive systems and diverse technological requirements make developing applications for au-tonomous vehicles *** simplify the development of applications running on SDVs,we propose a comprehen-sive suite of vehicle programming interfaces(VPIs).In this study,we rigorously explore the nuanced requirements for ap-plication development within the realm of VC,centering our analysis on the architectural intricacies of the Open Vehicu-lar Data Analytics Platform(OpenVDAP).We then detail our creation of a comprehensive suite of standardized VPIs,spanning five critical categories:Hardware,Data,Computation,Service,and Management,to address these evolving pro-gramming *** validate the design of VPIs,we conduct experiments using the indoor autonomous vehicle,Ze-bra,and develop the OpenVDAP prototype *** comparing it with the industry-influential AUTOSAR interface,our VPIs demonstrate significant enhancements in programming efficiency,marking an important advancement in the field of SDV application *** also show a case study and evaluate its *** work highlights that VPIs significantly enhance the efficiency of developing applications on *** meet both current and future technologi-cal demands and propel the software-defined automotive industry toward a more interconnected and intelligent future.

关键词： software-defined vehicle(SDV) vehicle computing(VC) vehicle programming interface(VPI) au-tonomous system