检索结果-南通市图书馆

开发区居住空间特征及其形成机制——对北京经济技术开发区的调查

在线全文

学校读者我要写书评

暂无评论

地理科学进展 2017年第1期36卷 99-111页

作者：冯健项怡之北京大学城市与环境学院北京100871 中国电建集团华东勘测设计研究院杭州311122

利用北京经济技术开发区的第一手问卷调查数据,研究开发区居住空间特征及其形成机制。研究表明:开发区居住人口收入和受教育程度相对较高,外来人口已成为开发区后期居住人口增长的主要动力来源;开发区的住房类型构成呈现多样化特点,政... 详细信息

利用北京经济技术开发区的第一手问卷调查数据,研究开发区居住空间特征及其形成机制。研究表明:开发区居住人口收入和受教育程度相对较高,外来人口已成为开发区后期居住人口增长的主要动力来源;开发区的住房类型构成呈现多样化特点,政策和住房户型原因是影响住宅分化的重要因素;开发区在收入和社会阶层方面存在居住分化现象,具体表现为高收入和低社会阶层两级分化的空间隔离;作为新兴的郊区社区,开发区居民维权意识强烈,但社区联系较弱;上班通勤距离仍是影响居民居住地选择的最重要因素,改善居住环境、对优质教育资源的追求也是极重要的因素。最后,从居民、开发商、地方政府、企业、母城及周边区域等多元主体共同作用的角度探讨了开发区居住空间的形成机制。当前,国内开发区大多面临从"产业功能地域"向综合型的"城市化功能地域"转型,但开发区既是"产业集聚区"又被作为"卧城"的复杂状况,也带来其居住空间特征及形成机制的复杂性。研究成果对于丰富城市居住空间理论有重要意义。

关键词：开发区居住空间居住分异郊区化北京经济技术开发区

Huge Tunneling Magnetoresistance in Magnetic Tunnel Junction with Heusler Alloy Co_(2)MnSi Electrodes

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Physics 2021年第3期34卷 273-280,I0047页

作者： Yu-jie Hu Jing huang Jia-ning Wang Qun-xiang Li Department of Chemical Physics&Hefei National Laboratory for Physical Sciences at the Microscale University of Science and Technology of ChinaHefei 230026China School of Materials and Chemical Engineering Anhui Jianzhu UniversityHefei 230601China

Magnetic tunnel junction with a large tunneling magnetoresistance has attracted great attention due to its importance in the spintronics *** performing extensive density functional theory calculations combined with the nonequilibrium Green’s function method,we explore the spin-dependent transport properties of a magnetic tunnel junction,in which a non-polar SrTiO_(3) barrier layer is sandwiched between two Heusler alloy Co_(2)MnSi *** results clearly reveal that the near perfect spin-filtering effect appears in the parallel magnetization *** transmission coefficient in the parallel magnetization configuration at the Fermi level is several orders of magnitude larger than that in the antiparallel magnetization configuration,resulting in a huge tunneling magnetoresistance(i.e.>10^(6)),which originates from the coherent spin-polarized tunneling,due to the half-metallic nature of Co_(2)MnSi electrodes and the significant spin-polarization of the interfacial Ti_(3)d orbital.

关键词： Magnetic tunnel junction Spin-dependent transport First-principles Tunneling magnetoresistance

Numerical simulation of powder effect on solidification in directed energy deposition additive manufacturing

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2021年第9期31卷 2871-2884页

作者： Xin-xin YAO jian-yu LI Yi-fei WANG xiang GAO Zhao ZHANG State Key Laboratory of Structural Analysis for Industrial Equipment Department of Engineering MechanicsFaculty of Vehicle Engineering and MechanicsDalian University of TechnologyDalian 116024China

An integrated simulation of powder effects on particle temperature and microstructural evolution in laser directed energy deposition additive manufacturing process was carried *** spatial distribution of the flying powder particles was simulated by the discrete element method to calculate the energy for the flying powder particles under the laser−particle interaction with electromagnetic wave *** with the phase field method,the influence of particle size on the microstructural evolution was *** microstructural evolution is validated through comparison with experimental *** indicate that the narrow particle size distribution is beneficial to obtaining a more uniform temperature distribution on the deposited layers and forming smaller equiaxed grains near the side surfaces of the *** powder particle size is beneficial to the conversion of the electromagnetic energy into *** with small size are recommended to form equiaxed grains and to improve product *** powder flow rate improves the laser energy efficiency,and higher powder flow rate leads to more uniform equiaxed grains on both sides of the cross-section.

关键词： additive manufacturing powder particle phase field microstructural evolution particle size distribution

在线全文

学校读者我要写书评

暂无评论

组合式轧辊轧制过程的稳定性分析

中南大学学报（自然科学版） 2009年第1期40卷 164-168页

作者：向勇杨建军刘建华中南大学机电工程学院湖南长沙410083 涟源钢铁有限公司湖南娄底417009

采用MAC软件计算组合式轧辊辊芯与辊套温度场,建立相应的传热方程与热应力分析模型及其边界条件。研究结果表明:与轧件接触的轧辊表面的温度在开始轧制时迅速上升,随着轧制过程的进行,温度趋于呈稳定周期性变化,温度达到稳定的时间大约... 详细信息

采用MAC软件计算组合式轧辊辊芯与辊套温度场,建立相应的传热方程与热应力分析模型及其边界条件。研究结果表明:与轧件接触的轧辊表面的温度在开始轧制时迅速上升,随着轧制过程的进行,温度趋于呈稳定周期性变化,温度达到稳定的时间大约为2h;当轧辊旋转到与轧件接触处,温度达到最高,最高温度约为300℃,此时辊套轧辊结构稳定,据此生产的组合式轧辊在轧制过程中性能优越。

关键词：温度场有限元轧辊辊套

Alloying behavior and characterization of(CoCrFeNiMn)_(90)M_(10)(M=Al,Hf)high-entropy materials fabricated by mechanical alloying

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2022年第7期32卷 2253-2265页

作者： Nai-ran WANG Shou-ren WANG Xiao-xiang GOU Ze-cheng SHI jian-xiang LIN Guo-qiang LIU Yan WANG School of Materials Science and Engineering University of JinanJinan 250022China School of Mechanical Engineering University of JinanJinan 250022China

The alloying behavior and microstructures of the(CoCrFeNiMn)_(90)M_(10)(M=Al,Hf)high-entropy alloy(HEA)powders fabricated by mechanical alloying were *** CoCrFeNiMn)_(90)Al_(10) powders have duplex solid-solution *** contrast,nanocrystalline HfNi_(3) anchoring in amorphous structures is found in the(CoCrFeNiMn)_(90)Hf_(10) ***(CoCrFeNiMn)_(90)Al_(10) powders show better ferromagnetic behaviors,mainly explained by the facilitated motion of the magnetic domain induced by the coherent interface between duplex *** with our previous work,the rules of forming solid-solution and amorphous phase in as-milled HEA powders are preliminarily *** is found that,compared with the as-cast HEA reported previously,the variation range of mixing enthalpy with atomic size difference of the solid-solution formed in as-milled HEA powders is ***,the variation ranges between mixing enthalpy and entropy with atomic size difference of the amorphous phase in HEA powder become wider than those of high-entropy bulk metallic glass.

关键词： high-entropy powder mechanical alloying ferromagnetic properties alloy design phase stability

Study on Formation Mechanism of Farmer Production Consumption Ecologization——Empirical Analysis Based on TPB Model

在线全文

学校读者我要写书评

暂无评论

Asian Agricultural Research 2017年第3期9卷 4-9,13页

作者： jian HU Zhenhong QI Weihong huang Lanya WU College of Economics and Management Huazhong Agricultural University Hubei Rural Development Research Center

Ecological transformation of production consumption is an effective channel of establishing ecological agriculture mechanism. In this paper,based on TPB( Theory of Planed Behavior),using factor analysis and regression analysis,empirical test on formation mechanism of farmer production consumption ecologization behavior transformation is conducted. Research results show that behavior attitude,subjective norm and control cognition of farmer production consumption ecologization have significantly positive influences on behavior response of farmer production consumption ecologization. Among them,power of behavior attitude is farmer's economic rationality and ecological rationality; power of subjective norm is system norm,government guidance and social pressure; power of control cognition is policy judgment and ability perception. Finally,for the analyzed conclusions,policy suggestions are proposed from many aspects,which could provide reference effect for guiding farmer production consumption ecologization and establishing rural eco-civilization.

关键词： Farmer Production consumption TPB model Action mechanism Ecological behavior

Prognostic and predictive value of interstitial cells of Cajal populations following stapled transanal rectal resection(STARR)in patients with obstructed defecation syndrome

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

Gastroenterology Report 2018年第4期6卷 270-276,I0001,I0002页

作者： Hong-Cheng Lin Hua-Xian Chen Liang huang Ya-Xi Zhu Qian Zhou Juan Li Yu-Jie Xu Dong-Lin Ren jian-Ping Wang Department of Colorectal Surgery The Sixth Affiliated Hospital of Sun Yat-sen UniversityGuangzhou510655 GuangdongChina Guangdong Institute of Gastroenterology Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor DiseasesGuangzhou510655 GuangdongChina Department of Pathology The Sixth Affiliated Hospital of Sun Yat-sen UniversityGuangzhouGuangdongChina

Objective:The present study was designed to evaluate the functional outcome of stapled transanal rectal resection(STARR)and to examine the relationship between the population density of the interstitial cells of Cajal(ICC)and the efficacy of the STARR operation in the management of obstructed defecation syndrome(ODS)***:Full-thickness rectal samples were obtained from 50 ODS patients who underwent *** were analysed using ICC *** and functional parameters obtained with defecography and anorectal manometry were compared with 20 ***:ICCs were significantly decreased in patients in the submucosal(SM),intramuscular(IM)andmyenteric(MY)regions when compared with the control group(P<0.05).The mean pre-operative Cleveland Constipation Score(CCS)was 24.264.1,whilst the CCS at 1,2,3,4 and 5 years post-operatively decreased significantly(P<0.05).At 3 post-operative years,58.3%(28/48)of the patients reported a favorable outcome(CCS10).On univariate analysis,the functional results were worse in those with pre-operative digitation(P=0.017),a decreased ICC-MY cell population(P=0.067),a higher resting anal canal pressure(P=0.039)and a higher rectal sensory threshold(P=0.073).Multivariate analysis showed the decreased ICC-MY cell population was an independent predictor for low unfavorable functional outcome(odds ratio=0.097,95%confidence interval:0.012–0.766).Conclusions:STARR achieved acceptable results at the cost of a slight deterioration over amore prolonged *** with a decreased ICC number in the rectal specimen showed an unfavorable functional outcome where pre-operative histological assessment of a full-thickness rectal samplemight predict for the functional outcome following STARR.

关键词： interstitial cells of Cajal obstructed defecation syndrome stapled transanal rectal resection(STARR) functional outcomes

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

一种计算时间序列关联维的逐步递归法

电子与信息学报 2005年第6期27卷 879-883页

作者：党建武黄建国江西财经大学电子学院南昌330013 西北工业大学 22信箱西安710072

该文提出了一种计算时间序列关联维数的逐步递归法。该方法可按给定的置信度和相关性指标,逐步递归、识别并计算出一维时间序列的无标度区及关联维数。理论分析和仿真结果验证了该方法的有效性和客观性。

关键词：时间序列关联维重构相空间分形

在线全文

学校读者我要写书评

暂无评论

基于图像语义翻译的图文融合情感分析方法

计算机工程与应用 2023年第11期59卷 180-187页

作者：黄健王颖西安科技大学通信与信息工程学院西安710600

多模态情感分析问题中,图像在不同情况或者对其关注点不同会产生不同的情感,为了解决图像语义理解问题,提出了基于图像语义翻译的图文融合情感分析(ImaText-IST)方法。将图像送入图像翻译模块将其翻译为图像描述,该模块融入了不同的情... 详细信息

多模态情感分析问题中,图像在不同情况或者对其关注点不同会产生不同的情感,为了解决图像语义理解问题,提出了基于图像语义翻译的图文融合情感分析(ImaText-IST)方法。将图像送入图像翻译模块将其翻译为图像描述,该模块融入了不同的情感表达来进行图像描述捕捉,分别生成积极、中性和消极三个情感极性的图像描述。通过三个情感极性的图像描述和数据集中的文本进行情感相关性分析,从而使得对图像情感理解更加准确。将图像语义描述、目标以及文本进行情感预测,分别采用特征融合及辅助语句的方式进行情感分析。实验结果表明,辅助语句的方式(Axu-ImaText-IST)能更好地理解图文的情感,在社交情感媒体数据集Twitter-15和Twitter-17的Accuracy和Macro-F1均高于基准模型。

关键词：图文融合多模态情感分析图像描述情感相关性