基于多模体特征的科学家合作预测

科学学随着科学本身的发展已成为近年来国内外研究的热点,科研组织与知识传播的重要结构基础—科学家合作网络因此受到学者们的广泛关注。在此情况下,科学家合作网络中的合作形成及合作权重强弱成为很有意义的研究问题。该文提出了基于多模体特征和机器学习框架的链路预测和权重预测方法,将实验结果与几种经典方法进行对比,发现该方法可以有效提高预测的准确率,链路预测最高可提高8.9%,而权重预测最高可提高59.6%。该研究有助于预测科研网络中科学家合作的可能性及其合作权重,进而挖掘科学家合作网络的结构特性对学者科研产出和团队合作的深刻影响。

蛋白质超家族模体保守性及物理化学性质的分析

分析了全β类4个典型的蛋白质超家族中模体的功能,发现免疫球蛋白超家族和纤维结合蛋白类型Ⅲ超家族中的模体有相似的结构,但是它们行使不同的功能.血小板-白细胞C激酶底物的同源物结构域超家族和核酸结合超家族中的模体类型较多,虽然这些模体只是部分结构相似,然而它们却在各自的超家族中分别执行着相同的功能.文章进一步运用统计学方法研究了蛋白质超家族中保守模体的亲疏水特征、物理化学特征和结构特征.结果表明,模体差异有显著意义的残基存在于序列模体的保守位点上,相同的序列模体具有相似的二级结构.这些特征将对进一步识别超家族提供帮助.

“一带一路”国家贸易网络结构特征及韧性研究

“一带一路”倡议重在推动沿线国家进行高水平的经济融合,其重点在于明确各国家在贸易网络中的地位、角色及结构韧性。以“一带一路”沿线65个国家为研究对象,基于复杂网络理论,对国家间贸易网络结构进行模体检测,通过识别网络中重要模体和关键节点,对节点和三元模体国家进行中断模拟。结果表明:“一带一路”贸易网络呈现“小世界”特征,具有较高的连通性和网络凝聚力;“一带一路”贸易网络模体检测中,中国和波兰扮演了对外贸易的角色,土耳其扮演了贸易中转站的角色,俄罗斯和印度扮演了贸易输入国的角色,互惠性模式在贸易关系中有至关重要的作用;模体失效比国家节点失效对网络结构韧性的影响更大,且由中国、土耳其和俄罗斯组成的模体对贸易网络结构韧性影响是最大的。

UG在汽车转向泵模具设计中的应用

UG一些常用的特征在模具设计中有独特的效果,灵活应用UG拔模、拔模体、边倒圆、面倒圆特征在模具设计尤为重要。模具采用WAVE全方位关联起来,全参数设计流程,这样模具设计可避免出错,为后期模具修理通过方便。

Automatically extracting sheet-metal features from solid model

With the development of modern industry, sheet-metal parts in mass production have been widely applied in mechanical, communication, electronics, and light industries in recent decades; but the advances in sheet-metal part design and manufacturing remain too slow compared with the increasing importance of sheet-metal parts in modern industry. This paper proposes a method for automatically extracting features from an arbitrary solid model of sheet-metal parts; whose characteristics are used for classification and graph-based representation of the sheet-metal features to extract the features embodied in a sheet-metal part. The extracting feature process can be divided for valid checking of the model geometry, feature matching, and feature relationship. Since the extracted features include abundant geometry and engineering information, they will be effective for downstream application such as feature rebuilding and stamping process planning.

Technical scheme and application of pressure-relief gas extraction in multi-coal seam mining region

A pressure relief gas extraction technical model of a typical mining area is proposed based on coal and gas simultaneous extraction theory. Flac3 Dwas employed to model vertical stress and displacement contour plot characteristics of non-outburst coal seam(No. 4) on top of outburst coal seam(No. 2) along strike and incline directions. Field investigations were also conducted to verify the scientific nature of the simulation. The results demonstrate that gas pressure in No. 2 coal seam dropped to approximately 0.55 MPa in the pressure relief multi-coal seam. The highest expansion rate of the coal mine reached up to 2.58%.The pressure-relief angle was 76° along the incline direction and 60° along the strike direction. As the expansion rate and pressure-relief angle increased and the gas pressure decreased, a large amount of gas flowed into the gob of No. 4 from No. 2 coal seam and was later discharged through specific gas pipes,which eliminated No. 2 outburst risks. This study resulted in positive outcomes in that gas extraction time was reduced by 13.5 days, due to pressure relief, and drilling work load was reduced by 0.1161 m/t coal. This method ensures that gas is discharged from the outburst coal seam quickly and safely,demonstrating that the proposed technical model of pressure-relief gas extraction is effective in a multi-coal seam region.

The Influence of Gender and Other Characteristics on Rural Laborers' Employment Patterns in the Mountainous and Upland Areas of Sichuan,China

This study examines gender differences in rural laborers‘ employment patterns in the mountainous and upland areas of Sichuan, China. The analysis employs both representative survey data of 400 households and geographical data. Multinomial logistic regression models are used to analyze the influences of gender, among other factors, on employment decisions of rural males and females, where the factors considered include personal, household, community natural environmental characteristics. Dividing laborers into four categories, we find that the proportions of males who participating in on-farm, pluriactive, and off-farm work, and unemployment were 24.41%, 28.64%, 46.27%, and 0.68% respectively, while that of females who participating in on-farm, pluriactive, and offfarm work, and unemployment were 43.20%, 13.95%, 30.95%, and 11.90% respectively. As to individual characteristics, age(AGE) and physical condition(PHY) effects appeared to be more pronounced for men, while education(EDU) and marital status(MAR)effects appeared to be more pronounced for women. Regarding household and community characteristics, the effects of the presence in the household of children aged 6-(CHI), number of persons in the household(POP), and labor force(LAB), per capitaincome in village(INCV), and the development status of village enterprises(ENT) on women were greater than that on men. In addition, the presence in the household of elderly individuals aged 65+(OLD) and time to reach the nearest township(TIME) are shown to have opposite impacts on men and women. While the presence in the household of pupils(PUP) and per capital gross value of industrial output(GVIO) was found to be irresponsive to men and women taking pluriavtivity and off-farm job. With respect to natural environments characteristics, the effects on men were opposite of those on women. Unemployment of women was found to be particularly responsive to household characteristics. A multinomial regression approach is undertaken to analyze rural males‘ and females‘ decisions of the four employment patterns considered, an approach that reveals considerable heterogeneity that is concealed by the dichotomous approach employed in most previous studies. The study thus contributes to our understanding of rural employment patterns and gender difference in mountainous and upland areas.

Population sizes and group characteristics of Siberian Crane(Leucogeranus leucogeranus) and Hooded Crane(Grus monacha) in Poyang Lake Wetland

Both the Siberian Crane(Leucogeranus leucogeranus) and Hooded Crane(Grus monacha) have limited population sizes and are considered endangered by domestic Chinese and international agencies.To document the current size of their respective populations and characterize their groups,between October 2012 and April 2013 we undertook fieldwork at four nature reserve areas within the Poyang Lake wetlands.We divided Poyanghu National Nature Reserve(PYH) into the Wucheng(PWC) and Hengfeng areas(PHF),because each are each located in different counties.Our fieldwork showed that the Siberian Crane occurred mainly in PYH(364 in the PHF,158 in the PWC) and the Nanjishan Wetland National Nature Reserve(NJS,with 200 individuals).The Hooded Crane was mainly distributed in PYH(302 in the PHF and 154 in the PWC).Family groups accounted for more than 50% of the total number of groups among both species,with Hooded Cranes forming more family groups than Siberian Cranes.Typically,these groups were formed of two adults with one offspring(Siberian Crane),and two adults with two offspring(Hooded Crane),with the mean family group size of the Siberian Crane and Hooded Crane being respectively 2.65±0.53(n=43) and 3.09±0.86(n=47) individuals per group.The mean collective group size of the Siberian Crane and Hooded Crane included 28.09±24.94(n=23) and 28.94±27.97(n=16) individuals per group,respectively,with the proportion of juveniles among Hooded Cranes being more than double that seen among the Siberian Cranes.

Theoretical Analysis and Simulation of BJFET Obstructive Characteristics

A new bipolar junction field-effect transistor (BJFET) was described. The theoretical analysis and computer simulation of BJFET obstructive characteristic are achieved. The gate bias voltage affects the BJFET obstructive voltage greatly. The BJFET obstructive characteristic is relevant to structure parameters of channel width W and channel length L. The decrease-bias-voltage operation can weaken the device obstructive characteristic. The forward turn in device forward obstructive region can also affect the BJFET obstructive characteristic. BJFET has a good high temperature obstructive characteristic and can be applying to high temperature status as high voltage switch devices.

Mass Transfer Characteristics of H_2 and CO in Mimicked F-T Slurry Bubble Column Reactor

The equilibrium solubilities,volumetric gas-liquid mass transfer coefficients kLa of H_2 and CO were measured as functions of temperature(298―513 K),pressure(1―3 MPa),superficial gas velocity(0.5―3 cm/s) and solid volume fraction(5%―25%) in liquid paraffin/iron-based catalyst slurry bubble column reactor.The volumetric mass transfer coefficients kLa were obtained by measuring the dissolution rate of H_2 and CO.The influences of the operation conditions,such as pressure,temperature,superficial gas velocity and catalyst concentration on kLa,were investigated.Two empirical correlations were proposed to predict kLa values of H_2 and CO in liquid paraffin/solid particles slurry bubble column reactor.The results showed that the equilibrium solubilities of H-2 and CO increased with an increasing temperature and pressure,and the solubility of CO was greater than that for H_2.It was found that the equilibrium solubility can be expressed by Henry's law.The volumetric mass transfer coefficients of H_2 and CO were of the same order of magnitude,and increased with the increase of pressure,temperature and superficial gas velocity.The presence of solid particles decreased kLa values of both H_2 and CO.

Feature-based multiresolution techniques for product design

3D computer-aided design (CAD) systems based on feature-based solid modelling technique have been widely spread and used for product design. However, when part models associated with features are used in various downstream applications, simplified models in various levels of detail (LODs) are frequently more desirable than the full details of the parts. In particular, the need for feature-based multiresolution representation of a solid model representing an object at multiple LODs in the feature unit is increasing for engineering tasks. One challenge is to generate valid models at various LODs after an arbitrary rearrangement of features using a certain LOD criterion, because composite Boolean operations consisting of union and subtraction are not commutative. The other challenges are to devise proper topological framework for multiresolution representation, to suggest more reasonable LOD criteria, and to extend applications. This paper surveys the recent research on these issues.

Interface-Optical-Phonon Modes in Quasi-one-dimensional Wurtzite Rectangular Quantum Wires

By employing the dielectric continuum model and Loudon＇s uniaxial crystal model, the interface optical （IO） phonon modes in a freestanding quasi-one-dimensional （Q1D） wurtzite rectangular quantum wire are derived and analyzed. Numerical calculation on a freestanding wurtzite GaN quantum wire is performed. The resulte reveal that the dispersion frequencies of IO modes sensitively depend on the geometric structures of the Q1D wurtzite rectangular quantum wires, the free wave-number kz in z-direction and the dielectric constant of the nonpolar matrix. The degenerating behavior of the IO modes in Q1D wurtzite rectangular quantum wire has been clearly observed in the case of small wave-number kz and Iarge ratio of length to width of the rectangular crossing profile. The limited frequency behaviors of IO modes have been analyzed deeply, and detailed comparisons with those in wurtzite planar quantum wells and cylindrical quantum wires are also done. The present theories can be looked on as a generalization of that in isotropic rectangular quantum wires, and it can naturally reduce to the case of Q1D isotropic quantum wires once the anisotropy of the wurtzite material is ignored.

“一带一路”沿线国家投资网络结构及其影响因素：基于ERGM模型的研究

文章利用复杂网络分析方法，构建“一带一路”沿线国家的投资网络，分别从全局和局域层面考察投资网络的拓扑结构和关系模式，采用指数随机图模型（ERGM）从内生结构效应、行动者一关系效应和协变量网络效应剖析投资网络形成的影响因素。研究表明：（1）投资网络全局结构呈现“东亚和东南亚密集、中东欧隔断和中亚游离”的格局，投资活跃度整体偏低，高介数节点集中于少数核心国家。（2）模体分析体现了互惠性在沿线国家投资关系中至关重要的作用，但该区域投资集团化特征不显著，中国和印度、新加坡和波兰具有相似的投资模式，俄罗斯主要以吸引外商投资为主。（3）国家的经济水平是影响投资网络形成的关键因子，不同经济水平的国家间投资行为差异显著，高经济水平国家之间具有相互投资倾向，高经济水平和中等经济水平的国家具有对外投资倾向。（4）资源寻求型投资和技术寻求型投资是具有网络形成的重要推力，然而市场寻求型投资的驱动力较弱，且不存在劳动力寻求型投资；空间邻近、共同语言和投资协定的签订是该区域投资网络形成和发展的重要外生力量。因此，中国要发挥在网络中的枢纽优势，遵循适度均衡化的原则，重塑沿途国家投资格局，引领未来“一带一路”沿线国家走向经济一体化。

Effect of volume changes on complete deformation behavior of rocks

For the purpose of describing the deformation characteristics of rocks,the effect of volume changes on mechanical properties of rocks should be taken into account with relation to the development of constitutive model.Firstly,rocks are divided into three parts,i.e.,voids,a damaged part and an undamaged part in the course of loading.The void ratio was applied to describing the changes of voids or pores during the deformation process.Then,using statistical damage theory,a constitutive model was developed for rocks to describe their strain softening and hardening on the basis of investigating the relationship between the net stress and apparent stress,in which the influence of volume changes on rock behavior was correctly taken into account,such as the initial phase of compaction and the latter stage of dilation.Thirdly,a method of determining model parameters was also presented.Finally,this model was used to compare the theoretical results with those observed from experiments under conventional triaxial loading conditions.

Body Fuzzy Pattern Recognition in Woman Basic Block Design

Basic block is the foundation of clothing construction design because it is the media between body and clothes and the fitness of clothes should be based on the accuracy of basic block. That needs us to recognize body not to record it. This paper reports the Algorithm of woman body fuzzy pattern recognition. It is organized in three sections:(i) extracting woman body feature; (ii) establishing membership functions of feature indexes;(iii) presenting an Algorithm for woman body fuzzy pattern recognition by example.

Motion feature descriptor based moving objects segmentation

A novel moving objects segmentation method is proposed in this paper. A modified three dimensional recursive search （3DRS） algorithm is used in order to obtain motion information accurately. A motion feature descriptor （MFD） is designed to describe motion feature of each block in a picture based on motion intensity, motion in occlusion areas, and motion correlation among neighbouring blocks. Then, a fuzzy C-means clustering algorithm （FCM） is implemented based on those MFDs so as to segment moving objects. Moreover, a new parameter named as gathering degree is used to distinguish foreground moving objects and background motion. Experimental results demonstrate the effectiveness of the proposed method.

Title Evaluation study of teaching-oriented teaching team in colleges and universities based on analytic hierarchy process

You Complying with the school＇s education purpose of training applied talents, in colleges and universities, teaching-oriented teaching team should be read in conjunction with the construction of its evaluating index system as well as the improvement of the operation quality of teaching efficiency. In view of vague characteristic of evaluation, this paper uses analytic hierarchy process to carry on the fuzzy and synthetic appraisal for operation quality of teaching-oriented teaching teams in colleges and universities, reasonably ascertaining the weights of the evaluation indexes and improving the objectivity and accuracy of evaluation.

Dynamics of saltwater intrusion in the Modaomen Waterway of the Pearl River Estuary

Observations indicate an abnormal characteristic of saltwater intrusion in the upper Modaomen Waterway of the Pearl River Estuary,i.e.,the maximum salinity occurs during the neap tide or the coming moderate tide instead of during the spring tide.To explore the associated dynamic mechanisms,a high resolution three-dimensional numerical model was set up based on the Finite Volume Coastal Ocean Model(FVCOM),which covered the entire river network,the Pearl River Estuary,and the adjacent sea.Numerical experiments illustrated that the upper Modaomen Waterway is significantly influenced by the saltwater intrusion from the Hongwan Waterway,a narrow and shallow channel connecting the Modaomen Waterway to the sea.Specific topography,spring-neap tidal variation,local wind stress,and their interaction drive an up-estuary residual current in the Hongwan Waterway,which is much stronger during the neap tide than during the spring tide.As a result,more saltwater in the Hongwan Waterway is spilled over into the Modaomen Waterway during the neap tide or the coming moderate tide.This is the inherent dynamic mechanism why the saltwater intrusion in the upper Modaomen Waterway reaches its maximum during the neap tide or the coming moderate tide.Besides,we also found that the winter prevailing wind can pronouncedly enhance the saltwater intrusion in the Modaomen Waterway.