检索结果-南通市图书馆

Journal of Thermal Science 2024年第1期33卷 235-248页

作者： ZHU Yibin GUO Hui SUO yan'ge WU Minle YE yanghui LI Guoneng ZHANG Zhiguo School of Mechanical and Energy Engineering Zhejiang University of Science and TechnologyHangzhou 310023China

This work reports that the flame oscillation induced by acoustic excitation can effectively suppress soot generation in Rijke-type *** the acoustic frequency is close to the natural frequency of the burner system,it can produce resonance resulting in intense oscillation of the *** relationship between the soot suppression efficiency and the acoustic field of standing wave at different flame positions is *** with that under self-excited oscillation,when there is external forced acoustic force introduced to the flame,oscillation combustion occurred in a lager zone in the glass *** fundamental cause of different soot suppression efficiency at different positions is that the standing wave acoustic field causes the particles to move at different speeds in different positions of the glass *** axial particle velocity difference results in the formation of acoustic vortexes and the change of the flame *** high particle velocity causes the air in the glass tube to turn into the turbulent condition and make the flame temperature *** results show that the surface growth rate of soot is reduced,while the oxidation rate of soot is enhanced,which result in the soot suppression under acoustic *** study can provide some reference for the practical application of oscillate combustion in soot suppression.

关键词： soot suppression acetylene diffusion flame acoustic-excited oscillation standing wave

A Sample-Efficient Actor-Critic Algorithm for Recommendation Diversification

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2020年第1期29卷 89-96页

作者： LI Shuang yan yanghui REN Ju ZHOU Yuezhi ZHANG Yaoxue Department of Computer Science and Technology Tsinghua University

Diversifying recommendation results gains benefits from satisfying user’s existing interests as well as exploring novel information needs. Recently proposed Monte-Carlo based reinforcement learning method suffers from sample inefficiency, large variance, and even failing to perform well in large action space. We propose a novel actor-critic reinforcement learning algorithm for recommendation diversification in order to solve the above mentioned problems. The actor acts as the ranking policy, while the introduced critic predicts the expected future rewards of each candidate action. The critic target is updated by full Bellman equation and the actor network is optimized using expected gradient in the whole action space. To further stabilize and improve the performance, we also add policy-filtered critic supervision loss. Experiments on MovieLens dataset well demonstrate the effectiveness of our approach over multiple competitive methods.

关键词： Recommender system Diversity Reinforcement learning Actor-critic

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

微波光子联合时差/相差的高精确度测向技术

太赫兹科学与电子信息学报 2024年第7期22卷 716-722页

作者：唐龙朱扬辉王斌颜健桂林长海发展有限责任公司广西桂林541001

针对短基线时差测向精确度低、长基线相差测向存在模糊和传统的微波技术难以满足电子战设备分布式部署的长距离传输需求的问题,结合微波光子学,提出一种基于微波光子联合时差相差的分布式长距离单基线高精确度测向技术。该技术使用直调... 详细信息

针对短基线时差测向精确度低、长基线相差测向存在模糊和传统的微波技术难以满足电子战设备分布式部署的长距离传输需求的问题,结合微波光子学,提出一种基于微波光子联合时差相差的分布式长距离单基线高精确度测向技术。该技术使用直调模式微波光子传输设备,克服了微波信号经过长距离传输后引起的时差和相差变化影响,满足长距离微波光子的稳定传输;并在此基础上采用改进的时差曲面拟合插值方法解决相差模糊问题。仿真和实验测试验证了该技术实现分布式长距离单基线高精确度测向的可行性。

关键词：微波光子时差测向相差测向实时校正

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

希望的田野

城市环境设计 2016年第1期99卷 316-317页

作者：李泊衡晏阳卉王江侯世荣山东建筑大学中南大学

本项目以中国乡村地区教育空间如何可持续发展为背景,探讨一种适用于乡村教育的新型教与学模式,使之既能促进对当地地域空间文化的继承与发扬,又具有一定的普适性和示范性,从而为乡村空间发展的多样与统一提供智囊培育。当前中国大学生... 详细信息

本项目以中国乡村地区教育空间如何可持续发展为背景,探讨一种适用于乡村教育的新型教与学模式,使之既能促进对当地地域空间文化的继承与发扬,又具有一定的普适性和示范性,从而为乡村空间发展的多样与统一提供智囊培育。当前中国大学生在城市中的就业率并不乐观,而乡村地区更是缺少对技术人才的吸引力

关键词：功能单元村庄乡村教育农村教育空间节点

Sequence Stratigraphic Framework and its Formation Mechanism for the Break-up Sequence in the Baiyun Sag， Northern South China Sea

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Earth Science 2022年

作者： Chao Huang Jianye Ren yan Wang yanghui Zhao Hubei Key Laboratory of Marine Geological Resources， China University of Geosciences College of Marine Science and Technology， China University of Geoscience Wuhan Hebei Center of Marine Geological Resources Survey Key Laboratory of Submarine Geosciences， Second Institute of Oceanography， Ministry of Natural Resources

Modern research shows that the marginal deep-water area cracking above an unconformity interface and a main regional development often between a transgressive interface before product characteristics of a reflection configuration display a regressive formation， the stratigraphic entity called a lithospheric breakup sequence (BS). Detailed seismic profile interpretation and logging analysis show that there is also a large-scale progradation reflector composed of a progressive continental-shelf margin delta between the Baiyun Sag fracture unconformity interface and regional transgression surface in the deep-water area of the northern continental margin of the South China Sea. In this paper， the concepts of the Lithospheric Breakup Surface and breakup sequence are introduced to explore the isostatic adjustment process during the first period of lithospheric rupture in the continental margin of the South China Sea through the study of this special stratigraphic entity developed in the deep-water continental margin. The results show that the marginal rebound caused by fractures at 32 Ma and 23.8 Ma may have been the main controlling factor. The research in this paper is helpful in deepening the understanding of the lithospheric extensional fracture process in the northern South China Sea and has practical application value for the prediction of large deep-water reservoirs.

关键词：

北部湾中国鲎不同群体及雌雄个体形态差异分析

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

水产养殖 2024年第3期45卷 15-18,37页

作者：严雪瑜蒙扬辉卢玉典莫飞龙杨宾兰肖珊广西北部湾海洋生物多样性养护重点实验室北部湾大学海洋学院广西钦州535011 广西壮族自治区水产引育种中心广西南宁530031

采用t检验、主成分分析和判别分析等多元统计方法,分析和比较北海市和钦州市中国鲎群体的体质量(Y)和全长(X1)、头胸部长(X2)、头胸部宽(X3)、腹部长(X4)、腹部宽(X5)、剑尾长(X6)等7个可量性状,研究两者形态差异,并对北海群体进行雌雄... 详细信息

采用t检验、主成分分析和判别分析等多元统计方法,分析和比较北海市和钦州市中国鲎群体的体质量(Y)和全长(X1)、头胸部长(X2)、头胸部宽(X3)、腹部长(X4)、腹部宽(X5)、剑尾长(X6)等7个可量性状,研究两者形态差异,并对北海群体进行雌雄个体的形态差异分析。t检验结果显示,2组群体仅X6/X1差异极显著(P0.05)。主成分分析构建了1个主成分,其贡献率为50.16%。对北海群体的5项比例性状进行逐步判别分析,筛选出3个比例性状构建的判别方程对该群体的2组群体识别的正确率达73.3%。指出,北海市群体雌性个体体型大,X2和X6均大于雄性,但X4小于雄性。

关键词：中国鲎不同群体雌雄个体形态差异多元分析

基于现场监测和人工神经网络的填埋场二氧化碳释放浓度预测分析

在线全文

学校读者我要写书评

暂无评论

科技通报 2024年第2期40卷 101-107页

作者：谢海建彭滢霏石阳辉王巧严华祥左欣茹陈赟浙江大学建筑工程学院杭州310058 浙江大学平衡建筑研究中心杭州310028 浙江大学建筑设计研究院有限公司杭州310028 合肥工业大学资源与环境工程学院合肥230009

垃圾填埋场会产生大量的填埋气,其中40%~60%为CO_(2),CO_(2)会导致温室效应并降低填埋气的利用效率,因此掌握及预测填埋气中CO_(2)的释放规律对于控制其扩散及填埋场温室气体排放评估具有重要意义。本文分析了杭州某填埋场2018年全年CO_... 详细信息

垃圾填埋场会产生大量的填埋气,其中40%~60%为CO_(2),CO_(2)会导致温室效应并降低填埋气的利用效率,因此掌握及预测填埋气中CO_(2)的释放规律对于控制其扩散及填埋场温室气体排放评估具有重要意义。本文分析了杭州某填埋场2018年全年CO_(2)浓度,发现CO_(2)与H2S的浓度在春秋季表现出强线性相关性,秋季的皮尔逊相关性系数绝对值为0.77。同时,建立多层感知器(multi layerperceptron,MLP)的人工神经网络模型预测CO_(2)浓度,并选取箱型图法对数据进行前处理以剔除监测设备故障等非自然因素导致的异常值,选取PM_(2.5)、风速、风向、气温、空气湿度作为输入指标,结果表明模型预测结果与现场实测结果约为R=0.7,说明模型效果较好。基于该模型对缺失的9月份数据进行填补,其结果与CO_(2)全年释放规律吻合良好。本文基于现场监测数据建立的神经网络模型可用于填埋场CO_(2)释放的预测评估,对CO_(2)等填埋气释放的控制和填埋场现场管理具有指导意义。

关键词： MLP神经网络填埋气温室效应 CO_(2) 气象因素

Analysis of oral glucose tolerance test in pregnant women with abnormal glucose metabolism

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2005年第12期118卷 995-999页

作者： yanghui-xia GAOXue-lian DONGYue SHIChun-yan DepartmentofObstetricsandGynecology PekingUniversityFirstHospitalBeijing100034China

Background Due to the controversy of the oral glucose tolerance test (OGTT), diagnostic criteria for gestational diabetes mellitus (GDM) in the world and researches on GDM remain undeveloped in China. American Diabetes Association recently recommended the clinicians to diagnose GDM by OGTT results without the third-hour glucose value. This new criteria has not been used in China. Research on the value and sensitivity of the criteria in detecting GDM is rare. The aim of our study is to analyze the characteristics of OGTT in Chinese women with GDM or gestational impaired glucose tolerance (GIGT) and to evaluate the effect of omission of the third-hour plasma glucose (PG) level in OGTT on the sensitivity of diagnosing GDM and GIGT, and the relationship between PG values of 50 g GCT or OGTT and insulin therapy. Methods A retrospective analysis was performed on medical records of 647 cases with GDM from January 1, 1989 to December 31, 2002, and 233 with GIGT. Among 647 cases of GDM, 535 cases were diagnosed by 75 g OGTT. All OGTT results including 535 cases of GDM and 233 patients with GIGT were evaluated. Results There were 112 cases of GDM diagnosed by elevated fasting PG (FPG) without OGTT performed. Of 535 cases of GDM diagnosed by OGTT, 49.2% (263/535) women had FPG value ≥5.8 mmol/L; 90.1% (482/535) women with 1-hour PG values ≥10.6 mmol/L; 64.7% (359/535) with 2-hour PG levels ≥9.2 mmol/L. There were only 114 cases (21.3%) with abnormal 3-hour PG levels among 535 women with OGTT. Among those with abnormal 3-hour PG level, 49.1% (56/114) had abnormal glucose values in the other three points of OGTT, and 34.2% (39/114) with two other abnormal values of OGTT. Our study showed that omission of the 3-hour PG of OGTT only missed 19 cases of GDM and they would be diagnosed as GIGT. Among the 233 women with GIGT, only 4 cases had abnormal 3-hour PG. So, omission of the third-hour glucose value of OGTT only resulted in failure to diagnose 3.6% (19/535) women with G

关键词： diabetes gestational pregnancy glucose tolerance test

渝东南极端高温干旱对‘长林’系列油茶生长及果实性状的影响

在线全文

学校读者我要写书评

暂无评论

中国农学通报 2024年第4期40卷 39-44页

作者：曾清苹晏巧李彬李果耿养会吴念陈安民彭川周飞娄利华重庆市林业科学研究院重庆400036 重庆市秀山县林业局重庆409900

调查渝东南地区2022年夏季极端高温干旱复合因素对‘长林3号’、‘长林4号’、‘长林40号’及‘长林53号’油茶生长及果实性状的影响,以期为‘长林’系列油茶选育和推广提供理论依据。结果表明,高温干旱影响油茶植株生长,抑制茶果纵径... 详细信息

调查渝东南地区2022年夏季极端高温干旱复合因素对‘长林3号’、‘长林4号’、‘长林40号’及‘长林53号’油茶生长及果实性状的影响,以期为‘长林’系列油茶选育和推广提供理论依据。结果表明,高温干旱影响油茶植株生长,抑制茶果纵径、横径生长,降低油茶鲜出籽率,减少单果质量和单株产果量。在高温、干旱双重逆境胁迫下,苗木和成林以‘长林53号’抗旱能力最强,果实经济性状(单果质量、纵径、横径、籽质量、鲜出籽率及单株鲜果产量)表现最好;幼林以‘长林3号’抗旱能力最强,果实茶籽数量最多。综上所述,‘长林53号’在极端高温干旱情况下,生长发育和性状表现较好,抵御高温干旱胁迫能力突出,建议作为该区域的优良品种进行培育、推广。

关键词：极端高温干旱 ‘长林’系列油茶生长果实性状

Machine learning modeling identifies hypertrophic cardiomyopathy subtypes with genetic signature

在线全文

学校读者我要写书评

暂无评论

Frontiers of Medicine 2023年第4期17卷 768-780页

作者： Jiaqi Dai Tao Wang Ke Xu yang Sun Zongzhe Li Peng Chen Hong Wang Dongyang Wu yanghui Chen Lei Xiao Hao Liu Haoran Wei Rui Li Liyuan Peng Ting Yu yan Wang Zhongsheng Sun Dao Wen Wang Division of Cardiology Department of Internal MedicineTongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China Beijing Institutes of Life Science Chinese Academy of SciencesBeijing 100101China Hubei Key Laboratory of Genetics and Molecular Mechanism of Cardiologic Disorders Huazhong University of Science and TechnologyWuhan 430030China

Previous studies have revealed that patients with hypertrophic cardiomyopathy(HCM)exhibit differences in symptom severity and prognosis,indicating potential HCM subtypes among these ***,793 patients with HCM were recruited at an average follow-up of 32.78±27.58 months to identify potential HCM subtypes by performing consensus clustering on the basis of their echocardiography ***,we proposed a systematic method for illustrating the relationship between the phenotype and genotype of each HCM subtype by using machine learning modeling and interactome network detection techniques based on whole-exome sequencing *** independent cohort that consisted of 414 patients with HCM was recruited to replicate the ***,two subtypes characterized by different clinical outcomes were identified in *** with subtype 2 presented asymmetric septal hypertrophy associated with a stable course,while those with subtype 1 displayed left ventricular systolic dysfunction and aggressive *** learning modeling based on personal whole-exome data identified 46 genes with mutation burden that could accurately predict subtype ***,the patients in another cohort predicted as subtype 1 by the 46-gene model presented increased left ventricular end-diastolic diameter and reduced left ventricular ejection *** employing echocardiography and genetic screening for the 46 genes,HCM can be classified into two subtypes with distinct clinical outcomes.

关键词： machine learning methods hypertrophic cardiomyopathy genetic risk