身体锻炼治疗抑郁症的元-元分析

目的:身体锻炼作为良好的健康促进方式是普遍的共识,并且已被推荐为抑郁症治疗手段,但已有的文献用于处方开具还需要依据循证医学的规律进行全面的总结和详细说明,故对身体锻炼治疗抑郁症效应的元分析文献进行系统综述。方法:基于循证医学研究范式,按照对综述进行综述的思路,采用元-元分析量化计算程序获得更高质量和更全面的数据,首先系统搜索并筛选出7篇符合要求的高质量元分析文献,随后基于62项研究所包含的3 723名被试的数据进行效果量等指标的统计。结果:身体锻炼对抑郁症治疗有中等效应(SMD=-0.63;95%CI=-0.78～-0.48,P<0.000 01);进一步的亚组分析表明,太极、气功的锻炼形式最为有效,每周3次以上、每次锻炼30 min以上、小/中等强度、25～36次的锻炼疗程效应更好;相对其他抑郁种类而言,身体锻炼治疗重度抑郁症MDD效果更佳;与药物治疗、心理治疗和宣传教育等其他治疗手段区别不明显,但身体锻炼合并其他治疗手段的疗效优于单一手段。结论:身体锻炼能够有效治疗抑郁症,未来可以根据这些内容进行运动处方的实践。

基于混合动态主元分析的故障检测方法

针对基于动态主元分析的故障检测方法存在的主元个数较多以及计算效率低等问题,本文提出基于混合动态主元分析(Hybrid Dynamic Principal Component Analysis,HDP-CA)的复杂过程故障检测方法。该方法采用分步策略消除数据之间的自相关和互相关性,提高了故障检测的精度和效率。对TE过程典型故障和热连轧过程中断带故障检测结果表明:HDPCA方法提取的主元个数少于DPCA方法提取的主元个数。并且,基于HDPCA的T2和SPE统计量的检测性能和检测精度都由于基于DPCA的统计量。因此,本文提出的方法可以准确有效地检测出故障。

基于k-ICA-PCA方法的多模态过程模态的划分

针对连续化工过程的多模态划分问题,提出了基于独立元分析-主元分析两步特征提取的k-独立元分析-主元分析(k-ICA-PCA)分类方法。传统的k-主元分析(k-PCA)分类方法假设过程数据仅仅包含高斯信息,然而在实际过程中数据往往无法满足这一假设。所提出的k-ICA-PCA方法在分类迭代过程中,不仅考虑了过程数据的高斯信息,而且考虑了数据的非高斯信息。将k-ICA-PCA分类方法应用到TE过程进行仿真实验,仿真结果验证了k-ICA-PCA方法相对于k-PCA分类方法更加有效和可行。

Comparison on construction of strut-and-tie models for reinforced concrete deep beams

With consideration of the differences between concrete and steel,three solutions using genetic evolutionary structural optimization algorithm were presented to automatically develop optimal strut-and-tie model for deep beams.In the finite element analysis of the first method,the concrete and steel rebar are modeled by a plane element and a bar element,respectively.In the second method,the concrete and steel are assigned to two different plane elements,whereas in the third method only one kind of plane element is used with no consideration of the differences of the two materials.A simply supported beam under two point loads was presented as an example to verify the validity of the three proposed methods.The results indicates that all the three methods can generate optimal strut-and-tie models and the third algorithm has powerful capability in searching more optimal results with less computational effort.The effectiveness of the proposed algorithm III has also been demonstrated by other two examples.

Stress distribution and fatigue life of built-up sleeved backup roll

The advantage of built-up sleeved backup roll was described. Based on the stress distribution analysis and simulation for the built-up sleeved backup roll by using finite element method, the effects of roll sleeve thickness and shrink range on the stress-strain field were studied. Finally, based on the methodology and strategy of the fatigue analysis, fatigue life of backup roll was estimated by using the stress-strain data obtained through finite element simulation. The results show that roll sleeve thickness and shrink range have a great influence on sleeve stress distribution of built-up sleeved roll. Under the circumstance of ensuring transferring enough torque, the shrink range should be kept small. However, thicker roll sleeve has longer roll service life when the shrink range is constant.

A Brief Summary of Finite Element Method Applications to Nonlinear Wave-structure Interactions

We review recent advances in the finite element method (FEM) simulations of interactions between waves and structures. Our focus is on the potential theory with the fully nonlinear or second-order boundary condition. The present paper has six sections. A review of previous work on interactions between waves and ocean structures is presented in Section one. Section two gives the mathematical formulation. In Section three, the finite element discretization, mesh generation and the finite element linear system solution methods are described. Section four presents numerical methods including time marching schemes, computation of velocity, remeshing and smoothing techniques and numerical radiation conditions. The application of the FEM to the wave-structure interactions are presented in Section five followed by the concluding remarks in Section six.

Prediction of XRF analyzers error for elements on-line assaying using Kalman Filter

Determination of chemical elements assay plays an important role in mineral processing operations.This factor is used to control process accuracy,recovery calculation and plant profitability.The new assaying methods including chemical methods,X-ray fluorescence and atomic absorption spectrometry are advanced and accurate.However,in some applications,such as on-line assaying process,high accuracy is required.In this paper,an algorithm based on Kalman Filter is presented to predict on-line XRF errors.This research has been carried out on the basis of based the industrial real data collection for evaluating the performance of the presented algorithm.The measurements and analysis for this study were conducted at the Sarcheshmeh Copper Concentrator Plant located in Iran.The quality of the obtained results was very satisfied;so that the RMS errors of prediction obtained for Cu and Mo grade assaying errors in rougher feed were less than 0.039 and 0.002 and in final flotation concentration less than 0.58 and 0.074,respectively.The results indicate that the mentioned method is quite accurate to reduce the on-line XRF errors measurement.

Numerical and theoretical verification of modified cam-clay model and discussion on its problems

Isotropic consolidation test and consolidated-undrained triaxial test were first undertaken to obtain the parameters of the modified cam-clay(MCC)model and the behavior of natural clayey soil.Then,for the first time,numerical simulation of the two tests was performed by three-dimensional finite element method(FEM)using ABAQUS program.The consolidated-drained triaxial test was also simulated by FEM and compared with theoretical results of MCC model.Especially,the behaviors of MCC model during unloading and reloading were analyzed in detail by FEM.The analysis and comparison indicate that the MCC model is able to accurately describe many features of the mechanical behavior of the soil in isotropic consolidation test and consolidated-drained triaxial test.And the MCC model can well describe the variation of excess pore water pressure with the development of axial strain in consolidated-undrained triaxial test,but its ability to predict the relationship between axial strain and shear stress is relatively poor.The comparison also shows that FEM solutions of the MCC model are basically identical to the theoretical ones.In addition,Mandel-Cryer effect unable to be discovered by the conventional triaxial test in laboratories was disclosed by FEM.The analysis of unloading-reloading by FEM demonstrates that the MCC model disobeys the law of energy conservation under the cyclic loading condition if the elastic shear modulus is linearly pressure-dependent.

Finite element failure analysis of continuous prestressed concrete box girders

In order to analyze the load carrying capacity of prestressed concrete box girders, failure behaviors of in-situ deteriorated continuous prestressed concrete box girders under loading are experimentally observed and a finite failure analysis method for predicting behaviors of box girders is developed. A degenerated solid shell element is used to simulate box girders and material nonlinearity is considered. Since pre-stressed concrete box girders usually have a large number of curve prestressed tendons, a type of combined element is presented to simulate the prestressed tendons of box girders, and then the number of elements can be significantly reduced. The analytical results are compared with full-scale failure test results. The comparison shows that the presented method can be effectively applied to the failure analysis of in-situ continuous prestressed concrete box girders, and it also shows that the studied old bridge still has enough load carrying capacity.

Inorganic Elements in Tuber of Chinese Herbal Medicine Radix Pseudostellariae from Guizhou Province

By analyzing the contents of inorganic elements in Radix Pseudostellariae from Guizhou Province, the aim was to assess the present quality of Radix Pseu- dostellariae, set limited standards of heavy metals, establish element fingerprints, and find out the characteristic elements. ICP-MS was used to measure the content of inorganic elements and map the element fingerprints. Additionally, WM/T2-2004 was applied to evaluate the quality of heavy metal elements, and the characteristic elements were determined by principal component analysis. The results showed that the contents of inorganic elements in Radix Pseudostellariae were between 0.057 and 959 mg/kg with the coefficients of variation ranging from 0.134 to 1.478, and the contents of Cd, As, Pb, and Hg were below the Standard of WM/T2-2004 in 90% of Radix Pseudostellariae. The standard limits of heavy metals in Radix Pseu- dostellariae were Cr≤6.5 mg/kg, Cu≤10 mg/kg, As≤2.0 mg /kg, Cd≤0.3 mg/kg, Hg≤0.15 mg/kg, and Pb≤4.0 mg/kg. The features of the inorganic eJements finger- prints could provide theoretical basis of identifying the quality of Radix Pseudostel- lariae and distinguishing Radix Pseudostellariae from other Chinese herbal medicines. The characteristic inorganic elements of Radix Pseudostellariae were found to be Cd, Cu, Co, Zn, Fe, Ca, Mg, and AI. Radix Pseudostellariae from Guizhou Province contained abundant inorganic elements, and the contents of heavy metals were below the evaluation criterion. The study provided a reference for the future development of the limiting values of heaw metals in Radix Pseudostellariae.

Computational analysis of genetic loci required for amphid structure and functions and their possibly corresponding microRNAs in C. elegans

Objective To examine the important roles of microRNAs （miRNAs） in regulating amphid structure and function, we performed a computational analysis for the genetic loci required for the sensory perception and their possibly corresponding miRNAs in C. elegans. Methods Total 55 genetic loci required for the amphid structure and function were selected. Sequence alignment was combined with E value evaluation to investigate and identify the possible corresponding miRNAs. Results Total 30 genes among the 55 genetic loci selected have their possible corresponding regulatory miRNA（s）, and identified genes participate in the regulation of almost all aspects of amphid structure and function. In addition, our data suggest that both the amphid structure and the amphid functions might be regulated by a series of network signaling pathways. Moreover, the distribution of miRNAs along the 3＇ untranslated region （UTR） of these 30 genes exhibits different patterns. Conclusion We present the possible miRNA-mediated signaling pathways involved in the regulation of chemosensation and thermosensation by controlling the corresponding sensory neuron and interneuron functions. Our work will be useful for better understanding of the miRNA-mediated control of the chemotaxis and thermotaxis in C. elegans.

Construction of Inorganic Elemental Fingerprint and Multivariate Statistical Analysis of Marine Traditional Chinese Medicine Meretricis concha from Rushan Bay

Meretricis concha is a kind of marine traditional Chinese medicine(TCM), and has been commonly used for the treatment of asthma and scald burns. In order to investigate the relationship between the inorganic elemental fingerprint and the geographical origin identification of Meretricis concha, the elemental contents of M. concha from five sampling points in Rushan Bay have been determined by means of inductively coupled plasma optical emission spectrometry(ICP-OES). Based on the contents of 14 inorganic elements(Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Se, and Zn), the inorganic elemental fingerprint which well reflects the elemental characteristics was constructed. All the data from the five sampling points were discriminated with accuracy through hierarchical cluster analysis(HCA) and principle component analysis(PCA), indicating that a four-factor model which could explain approximately 80% of the detection data was established, and the elements Al, As, Cd, Cu, Ni and Pb could be viewed as the characteristic elements. This investigation suggests that the inorganic elemental fingerprint combined with multivariate statistical analysis is a promising method for verifying the geographical origin of M. concha, and this strategy should be valuable for the authenticity discrimination of some marine TCM.

A Nonconforming Rectangular Finite Element Analysis for the Stokes Problem

A nonconforming rectangular finite element is presented, which satisfies the discrete B-B condition for the Stokes problem. And the element has two order convergence rate for the velocity and pressure.

2D Finite Element Computer Analysis of Strength for Brazed Joint of Cemented Carbide and Silver Brazing Filler Metal

Brazing has a wide acceptance in industries and its simplicity in variety of application attracts more and more patronage. The strength of brazing joint determines the reliability of brazed engineering components. So the need to ascertain the reliability or to predict its failure （without some destructive testing） becomes high even with a computer aided analysis using the Finite Element Analysis. Here, we have employed the services of FEA software, Abaqus CAE, as a tool for the computer calculation to investigate a joint case of cemented carbide brazed with silver-based filler metal. In this paper, 2D analysis has been adopted because the thickness of the material （in 2D） does not influence the final calculation results. We have applied constant loading and constant boundary condition to explore data from the elastic and plastic strain analysis through which we were able to predict the maximum joint strength with respect to the joint thickness. The pattern of the meshing was also significant. And the result could be transferable to a real-life field situation. The final results showed that there is an optimum thickness of the filler metal with the maximum strength which matches that obtained from experiment.

Dynamic limit equilibrium analysis of sliding block for rock slope based on nonlinear FEM

Traditional rigid body limit equilibrium method （RBLEM） was adopted for the stability evaluation and analysis of rock slope under earthquake scenario. It is not able to provide the real stress distribution of the structure, while the strength reduction method relies on the arbitrary decision on the failure criteria. The dynamic limit equilibrium solution was proposed for the stability analysis of sliding block based on 3-D multi-grid method, by incorporating implicit stepping integration FEM. There are two independent meshes created in the analysis： One original 3-D FEM mesh is for the simulation of target structure and provides the stress time-history, while the other surface grid is for the simulation of sliding surface and could be selected and designed freely. As long as the stress time-history of the geotechnical structure under earthquake scenario is obtained based on 3-D nonlinear dynamic FEM analysis, the time-history of the force on sliding surface could be derived by projecting the stress time-history from 3-D FEM mesh to surface grid. After that, the safety factor time-history of the sliding block will be determined through applying limit equilibrium method. With those information in place, the structure＇s aseismatic stability ean be further studied. The above theory and method were also applied to the aseismatic stability analysis of Dagangshan arch dam＇s right bank high slope and compared with the the result generated by Quasi-static method. The comparative analysis reveals that the method not only raises the FEM＇s capability in accurate simulation of complicated geologic structure, but also increases the flexibility and comprehensiveness of limit equilibrium method. This method is reliable and recommended for further application in other real geotechnical engineering.

Study on the FEM design of reinforced earth retaining wall with geogrid

At present,limit equilibrium method is often adopted in the design of reinforced earth retaining wall. Geotechnical engineers home and abroad have done a lot of work to improve the traditional calculation methods in recent years,while there are lots of defects. This paper first identifies the location of failure surface and safety factor through the finite element program of PLAXIS and then analyses the influencing factors of the stability of reinforced earth retaining wall with geogrid. The authors adopt strength reduction FEM (finite element method)in the design and stability analysis of reinforced earth retaining wall and have achieved some satisfying results. Without any assumptions,the new design method can automatically judge the failure mode of reinforced earth retaining wall,consider the influence of axial tensile stiffness of the reinforcement stripe on the stability of retaining wall,identify reasonable distance and length of the reinforcement stripe,and choose suitable parameters of reinforcement stripe,including strength,stiffness and pseudo-friction coefficient which makes the design optimal. It is proved through the calculation examples that this method is more reasonable,reliable and economical in the design of reinforced earth retaining wall.

Study on the Mechanical Properties of Irregular Curved Steel Box Girder for City Viaduct

This paper deeply analyses the influence of different local tectonic on stress performance of spatial curved steel box Girder Bridge, using the finite element analysis software to establish space finite element model of this bridge, calculation and analysis were made on the bridge of the strength, stiffness. It has certain reference value for guiding engineering design, have a good foundation for the mechanical properties and stability of linear and nonlinear further study of curved steel box girder.

Agricultural Credit Sources and Determinants of Credit Acquisition by Farmers in Idemili Local Government Area of Anambra State

The study is focused on agricultural credit sources and determinants of credit acquisition by farmers in ldemili local government area of Anambra State, Nigeria with specific objectives to： describe socio-economic characteristics of rural farmers; identify sources of agricultural credit available to rural farmers; determine socio-economic factors that influence agricultural credit acquisition of farmers; ascertain reasons for any credit misappropriation and identify problems that constrain farmers from agricultural credit acquisition. Ninety farmers were randomly selected by multi stage random sampling technique. Semi-structured questionnaire was used to elicit data for the study. Descriptive statistics and multiple regression model were used in achieving the objectives. Results indicated that 74.44% of respondents were males with a mean age of 45 years. Majority （76.67%） were married with large house hold sizes. Majority （93.33%） received different level of education, with sources of credit from friends/relatives （30.00%）, cooperative societies （43.33%）, money lenders （14.44%）, and cumulatively from formal sources （（12.22%）. The result of the multiple regression analysis revealed age, household size, membership of cooperative societies, marital status, education level, farm size and amount of loan repaid at varied signs and levels as significant predictors of amount of agricultural credit acquired by farmers. The most common reason given among the respondents （55.89%） of those who misappropriated acquired agricultural credit, was meeting nonfood needs of the household. The farmers encountered problems of high interest rate （78.89%）, lack of collateral （75.56%）, long distance from source of credit （50.00%）, poor harvest （37.78%）, moratorium （33.33%） and delay in loan approval/disbursement （44.44%） as constraints to acquire credit. The study recommends that the state government should pass policies aimed at providing free educative seminars to all illiterate farmers to teach them possible ways and methods of acquiring credit. To ensure mass attendance to such seminars, little incentives should be given to farmer participants.

Hipbone Biomechanical Finite Element Analysis and Clinical Study after the Resection of Ischiopubic Tumors

Objective To investigate the changes of hipbone biomechanics after the resection of ischiopubic tumors and their relationships with the complications in the convalescent stage, and directing the postoperative pelvic reconstruction. Methods DICOM data were used to create an intact hipbone finite element model and postoperative model. The biomechanical indices on the same region in the two models under the same boundary condition were compared. The differences of displacement, stress, and strain of the two models were analyzed with statistical methods. Results The distribution areas of the hipbone nodes' displacement, stress, and strain were similar before and after the simulated operation. The sacroiliac joint nodes' displacement (P=0.040) and strain (P=0.000), and the acetabular roof nodes' stress (P=0.000) and strain (P=0.005) of two models had significant differences, respectively. But the sacroiliac joint nodes' stress (P=0.076) and the greater sciatic notch nodes' stress (P=0.825) and strain (P=0.506) did not have significant differences. Conclusions The resection of ischiopubic tumors mainly affect the biomechanical states of the homolateral sacroiliac joint and acetabular roof. The complications in the convalescent stage are due to the biomechanical changes of the sacroiliac joint and the acetabular roof and disappearances of the stabilization and connection functions of the pubic symphysis and superior ramus of pubis.

Static Analysis of Buried Pipes Using Coupling between Layerwise Finite Element and Boundary Element Method

This work deals with the analysis of soil-structure interaction modeling of pipeline problems in static behavior using the coupling between FEM （finite element method） and BEM （boundary element method）. The representation of the pipe is made by MEF using one fmite element in the cylindrical panel formulated from the theory of equivalent discrete layers （Layerwise theory）, proposed by J. N. Reddy. The soil is represented by elastic continum infimite or semi-infinite and modeled using boundary elements with special curved surface, associated with cylindrical panel used to represent the soil-structure interaction within the soil, especially at the contact surface with the pipe.