检索结果-南通市图书馆

交流输电线路交叉跨越区域下方电场影响因素研究

在线全文

学校读者我要写书评

暂无评论

电机与控制学报 2022年第6期26卷 40-52页

作者：宋福根吕学伟福州大学电气工程与自动化学院福建福州350000

随着我国高压交流输电技术的快速发展,同时由于土地走廊的限制,高压交流输电线路建设不可避免地出现了交叉跨越的情况。高压输电线路产生的工频电场对近地面的人类活动有一定影响,且交叉跨越区域下方的电场分布较为复杂。鉴于现有文献... 详细信息

随着我国高压交流输电技术的快速发展,同时由于土地走廊的限制,高压交流输电线路建设不可避免地出现了交叉跨越的情况。高压输电线路产生的工频电场对近地面的人类活动有一定影响,且交叉跨越区域下方的电场分布较为复杂。鉴于现有文献只从一条观测路径来探讨各个因素对下方电场的影响,选取离地1.5 m高的平面内4条具有代表性的观测线来研究。利用Ansys有限元仿真软件建立交流输电线路交叉跨越区域三维空间模型,分别研究导线离地高度、相序、交叉角度、相位差、排列方式等因素对下方区域近地面1.5 m高度内电场强度的影响规律,并提出减小下方区域近地面电场强度的措施,达到有效降低交流输电线路交叉跨越区域下方电场的效果,也可为交叉跨越区域的线路设计规划提供一定参考。

关键词：输电线路交叉跨越工频电场有限元仿真影响因素观测线

维普期刊数据库博看期刊

Multi-scale modeling for prediction of mechanical performance in brazed GH99 thin-walled structure

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第7期37卷 550-563页

作者： Yazhou LIU Shengpeng HU Yanyu song Wei fu Xiaoguo song Ning GUO Weimin LONG State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China Shandong Institute of Shipbuilding Technology Weihai 264209China China Machinery Intelligent Equipment Innovation Research Institute(Ningbo)Co. Ltd.Ningbo 315700China

Superalloy thin-walled structures are achieved mainly by brazing,but the deformation process of brazed joints is non-uniform,making it a challenging research *** paper records a thorough investigation of the effect of brazing parameters on the microstructure of joints and its mechanical properties,which mainly inquires into the deformation and fracture mechanisms in the shearing process of GH99/BNi-5a/GH99 *** macroscopic-microscopic deformation mechanism of the brazing interface during shearing was studied by Crystal Plasticity(CP)and Molecular Dynamics(MD)on the basis of the optimal brazing *** experimental results show that the brazing interface is mainly formed by(Ni,Cr,Co)(s,s)and possesses a shear strength of approximately 546 *** shearing fracture of the brazed joint occurs along the brazing seam,displaying the characteristics of intergranular *** simulations show that dislocations disassociate and transform into fine twinning with increased *** simulated the shear deformation process of the brazed *** multiscale simulation results are consistent with the experimental *** mechanical properties of thin-walled materials for brazing are predicted using MD and CP methods.

关键词： Multi-scale modeling Brazing Shear mechanisms Crystal plasticity GH99 superalloy

在线全文

学校读者我要写书评

暂无评论

新型农业经营主体信贷风险的识别与防范研究

经济纵横 2020年第8期 116-125页

作者：孙福兵宋福根东华大学旭日工商管理学院上海200051 浙江财经大学东方学院浙江嘉兴314408

新型农业经营主体信贷风险既具有一般小农户信贷风险周期性和季节性的特征,又具有规模企业信贷风险复杂性和关联性的特征。因此,要破解新型农业经营主体信贷约束,必须从源头上进行分析,识别防范信贷过程中的不确定性因素。本文基于1165... 详细信息

新型农业经营主体信贷风险既具有一般小农户信贷风险周期性和季节性的特征,又具有规模企业信贷风险复杂性和关联性的特征。因此,要破解新型农业经营主体信贷约束,必须从源头上进行分析,识别防范信贷过程中的不确定性因素。本文基于1165份新型农业经营主体有效信贷样本实证调查,设置包含3个一级指标、10个二级指标和33个三级指标的新型农业经营主体信贷风险影响因素评定指标体系,对新型农业经营主体信贷风险及其影响因素进行分类筛选和有效性验证,并运用Probit模型,对从事经济作物、大田作物和畜牧养殖生产经营的三类主体进行关键风险影响因素识别。结果显示:不同类别新型农业经营主体的信贷风险影响因素存在着明显差异,且畜牧养殖类新型农业经营主体信贷风险的影响因素相对最多,也最复杂。因此,应采取设立差别化准入门槛和审批条件、基于第一还款来源构建风险识别体系、利用金融科技手段降低信息不对称、利用供应链金融场景化分散降低风险等手段防范新型农业经营主体信贷风险的发生。

关键词：新型农业经营主体信贷风险经济作物大田作物畜牧养殖

Distribution and geochemical significance of alkylbenzenes for crude oil with different depositional environments and thermal maturities

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第2期21卷 777-790页

作者： Bing-Kun Meng Dao-fu song Yuan Chen Sheng-Bao Shi School of Petroleum Engineering and Environmental Engineering Yan'an UniversityYan'an716000ShaanxiChina State Key Laboratory of Petroleum Resources and Prospecting College of GeosciencesChina University of PetroleumBeijing102249China

A total of 45 alkylbenzenes were detected and identified in crude oils with different depositional environments and thermal maturities from the Tarim Basin,Beibuwan Basin,and songliao Basin using comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry(GC×GCTOFMS).By analyzing the distribution characteristics of C0-C5alkylbenzenes,it is found that the content of some alkylbenzenes varies greatly in crude *** on the distribution characteristics of 1,2,4,5-tetramethylbenzene(Te MB)and 1,2,3,4-Te MB,the ratio of 1,2,4,5-Te MB to 1,2,3,4-Te MB is proposed to indicate the organic matter origin and depositional environment of ancient *** samples originated mainly from lower hydrobiont,algae,bacteria and source rocks deposited under reducing/anoxic conditions have low 1,2,4,5-/1,2,3,4-Te MB values(less than 0.6),while oil samples originated mainly from terrestrial higher plants and source rocks deposited under oxic/sub-oxic conditions have higher 1,2,4,5-/1,2,3,4-Te MB values(greater than 1.0).The significant difference of 1,2,4,5-/1,2,3,4-Te MB values is controlled by 1,2,4,5-Te MB content.1,2,4,5-Te MB content in oils derived from source rocks deposited in oxidized sedimentary environment(greater than 1.0 mg/g whole oil)is higher than that in oils from source rocks deposited in reduced sedimentary environment(less than 1.0 mg/g whole oil).1,2,4,5-/1,2,3,4-Te MB ratio might not or slightly be affected by evaporative fractionation,biodegradation and thermal maturity.1,2,4,5-/1,2,3,4-Te MB ratio and 1,2,4,5-Te MB content can be used as supplementary parameter for the identification of sedimentary environment and organic matter *** should be noted that compared to the identification of organic matter sources,the 1,2,4,5-/1,2,3,4-Te MB parameter is more effective in identifying sedimentary environments.

关键词： 1 2 4 5-Tetramethylbenzene GC×GC-TOFMS Organic matter origin Depositional environment

Interpretation and characterization of rate of penetration intelligent prediction model

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第1期21卷 582-596页

作者： Zhi-Jun Pei Xian-Zhi song Hai-Tao Wang Yi-Qi Shi Shou-Ceng Tian gen-Sheng Li College of Petroleum Engineering China University of Petroleum(Beijing)Beijing102249China State Key Laboratory of Petroleum Resources and Prospecting Beijing102249China Kunlun Digital Technology Co. Ltd.Beijing102206China

Accurate prediction of the rate of penetration(ROP)is significant for drilling *** the intelligent ROP prediction model based on fully connected neural networks(FNN)outperforms traditional ROP equations and machine learning algorithms,its lack of interpretability undermines its *** study proposes a novel interpretation and characterization method for the FNN ROP prediction model using the Rectified Linear Unit(ReLU)activation *** leveraging the derivative of the ReLU function,the FNN function calculation process is transformed into vector *** FNN model is linearly characterized through further simplification,enabling its interpretation and *** proposed method is applied in ROP prediction scenarios using drilling data from three vertical wells in the Tarim *** results demonstrate that the FNN ROP prediction model with ReLU as the activation function performs exceptionally *** relative activation frequency curve of hidden layer neurons aids in analyzing the overfitting of the FNN ROP model and determining drilling data *** the well sections with similar drilling data,averaging the weight parameters enables linear characterization of the FNN ROP prediction model,leading to the establishment of a corresponding linear representation ***,the quantitative analysis of each feature's influence on ROP facilitates the proposal of drilling parameter optimization schemes for the current well *** established linear characterization equation exhibits high precision,strong stability,and adaptability through the application and validation across multiple well sections.

关键词： fully connected neural network Explainable artificial intelligence Rate of penetration ReLU active function Deep learning Machine learning

(NH_2CH_2CH_2NH_3)_4[W~ⅤO_2(OC_6H_4O)_2]_2(NH_3CH_2CH_2NH_3)·H_2O的合成、晶体结构、EPR以及与同构物的比较

在线全文

学校读者我要写书评

暂无评论

无机化学学报 2005年第11期21卷 1687-1690页

作者：鲁晓明宋富根王波李丽首都师范大学化学系北京100037

Cis-dioxo-catecholatotungsten(V) complex (NH2CH2CH2NH3)4[WⅤO2(OC6H4O)2]2(NH3CH2CH2NH3)·H2O (1) was synthesized at room temperature by the reaction of tetrabutyl ammonium decatungstate with catechol in the mixed solvent of CH3OH, CH3CN and NH2CH2CH2NH2. The crystal structure of complex was determined by X-ray diffraction structural analysis. The results show that complex belongs to monoclinic system with space group P21 / c, a=0.712 8(3) nm, b=3.082 3(11) nm, c=0.982 8(4) nm, β=102.639(6)°, V=2.106 8(14) nm3, Z=2, R1=0.062 8, wR2=0.183 7. Compared the complex with its analogous complexes (NH2CH2CH2NH3)3[MoⅤO2(OC6H4O)2], it is found that the coordination structure of W have no changes in the processing of electron transfer of tungsten-containing enzymes from the result of the similarity of the EPR spectra of the complexes and flavoenzyme from milk. CCDC: 272937.

关键词：钨氧转移酶活性结构因子仿生配合物晶体结构 EPR

[(NH_2CH_2CH_2NH_3)_2W^(Ⅵ)O_2(NHC_6H_4NH)_2]_2(NH_2CH_2CH_2NH_2)·H_2O配合物的合成与晶体结构

在线全文

学校读者我要写书评

暂无评论

无机化学学报 2005年第5期21卷 753-756页

作者：鲁晓明宋富根王波李丽首都师范大学化学系北京100037

Cis-dioxo-tungsten(Ⅵ ) complex, (NH2CH2CH2NH2)[(NH2CH2CH2NH3)2WⅥO2(NHC6H4NH)2]2·H2O is synthesized at room temperature by the reaction of sodium tungstate with o-phenylenediamine. The crystal structure of complex was determined by X-ray diffraction structural analysis. The results show that complex belongs to monoclinic system with space group P21 / c, a=0.712 8(2) nm, b=3.081 1(10) nm, c=0.981 9(3) nm, β=102.615(4)°, V=2.104 4(11) nm3, Z=2, μ=55.26 cm-1, F(000)=1 176. Compared the complex with its analogous biomimetic complexes of the cofactor of molybdoenzymes and tungstoenzymses, it is found that the variance of the coordination atoms and the metal ions center have no influence on the coordination feature, and exhibits distored octahedral coordination with cis-dioxo o-phenylenediamine. CCDC: 252834.

关键词： H2O 晶体结构 complex 配合物 crystal with 合成 system center the space group metal and room show The was its is

在线全文

学校读者我要写书评

暂无评论

基于UML的本体开发模式研究

计算机工程与科学 2009年第3期31卷 104-106,114页

作者：李刚宋福根东华大学旭日工商管理学院上海200051

本体开发技术已经成为近年来国际国内研究的热点问题,但知识管理系统的开发需要大量软件工程技术人员的参与。为了尽快地使软件工程领域人员快速熟悉与开发本体,本文提出基于软件工程常用的基本工具——UML技术进行本体开发的新模式,从... 详细信息

本体开发技术已经成为近年来国际国内研究的热点问题,但知识管理系统的开发需要大量软件工程技术人员的参与。为了尽快地使软件工程领域人员快速熟悉与开发本体,本文提出基于软件工程常用的基本工具——UML技术进行本体开发的新模式,从而有效地弥合人工智能与软件工程领域之间的鸿沟。重点提出了两个问题的解决方法:一是实现软件工程元模型与本体元模型之间的映射;二是实现UML描述本体向OWL本体的转换。最后通过一个实例验证了基于UML的本体开发模式。

关键词： UML 本体 OUP OWL

Rhodium-Catalyzed Asymmetric Transfer Hydrogenation of Heterocyclic Diaryl Ketones:Facile Access to Key Intermediate of Baloxavir

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2024年第1期42卷 43-47页

作者： Li Wang Renwei Xiao Jingyuan song Long-Sheng Zheng Qiwei Lang gen-Qiang Chen Xumu Zhang Shenzhen Key Laboratory of Small Molecule Drug Discovery and Synthesis Department of Chemistryand Medi-PingshanSouthern University of Science and TechnologyShenzhenGuangdong 518000China Academy for Advanced Interdisciplinary Studies Southern Universityof Science and TechnologyShenzhenGuangdong 518000China Chemistry and Chemical Engineering Guangdong Laboratory ShantouGuangdong 515031China

Transition metal-catalyzed asymmetric transfer hydrogenation has been proven to be a powerful approach for the synthesis of chiral ***,a highly efficient and enantioselective transfer hydrogenation of dibenzoheptaheterocyclic ketones catalyzed by an arene-tethered TsDPEN-based Rh(ll)catalyst has been successfully developed,and a variety of dibenzoheptaheterocyclic ketones were reduced by a 1/1 mixture of formic acid and DBU(1,8-diazabicyclo[5.4.0]undec-7-ene)with high yields and *** this method,the asymmetric reduction of 7,8-difluorodibenzo[b,e]thiepin-11(6H)-one has been realized,providing the key intermediate of baloxavir marboxil with>99% yield and>99% ee at a substrate/catalyst molar ratio of 1000.

关键词： Asymmetric transfer hydrogenation Baloxavir Chiral alcohol Enantioselectivity Heterocyclic diaryl ketone Rhodium(Ⅱ)