首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   63篇
  免费   5篇
综合类   1篇
化学工业   20篇
建筑科学   1篇
能源动力   4篇
轻工业   5篇
水利工程   1篇
无线电   4篇
一般工业技术   15篇
冶金工业   1篇
自动化技术   16篇
  2023年   2篇
  2022年   5篇
  2021年   2篇
  2020年   2篇
  2019年   3篇
  2018年   2篇
  2017年   4篇
  2016年   1篇
  2015年   4篇
  2014年   5篇
  2013年   9篇
  2012年   3篇
  2011年   6篇
  2010年   3篇
  2009年   6篇
  2008年   3篇
  2007年   3篇
  2004年   1篇
  2002年   1篇
  1992年   1篇
  1982年   1篇
  1981年   1篇
排序方式: 共有68条查询结果,搜索用时 31 毫秒
1.
The Journal of Supercomputing - This paper designs and develops a computational intelligence-based framework using convolutional neural network (CNN) and genetic algorithm (GA) to detect COVID-19...  相似文献   
2.
A kinetic flux-vector splitting (KFVS) scheme for the shallow water magnetohydrodynamic (SWMHD) equations in one- and two-space dimensions is formulated and applied. These equations model the dynamics of a thin layer of nearly incompressible and electrically conducting fluids for which the evolution is nearly two-dimensional with magnetic equilibrium in the third direction. The proposed numerical scheme is based on the direct splitting of macroscopic flux functions of the SWMHD equations. In two-space dimensions the scheme is derived in a usual dimensionally split manner; that is, the formulae for the fluxes can be used along each coordinate direction. The high-order resolution of the scheme is achieved by using a MUSCL-type initial reconstruction and Runge-Kutta time stepping method. Both one- and two-dimensional test computations are presented. For validation, the results of KFVS scheme are compared with those obtained from the space-time conservation element and solution element (CE/SE) method. The accuracy, efficiency and simplicity of the KFVS scheme demonstrate its potential in modeling SWMHD equations.  相似文献   
3.
4.
5.
A conservative finite volume approach, originally proposed by Filbet and Laurençot [2004a. Numerical simulation of the Smoluchowski coagulation equation. SIAM Journal on Scientific Computing 25(6), 2004-2048] for the one-dimensional aggregation, is extended to simulate two-component aggregation. In order to apply the finite volume scheme, we reformulate the original integro-ordinary differential population balance equation for two-component aggregation problems into a partial differential equation of hyperbolic-type. Instead of using a fully discrete finite volume scheme and equidistant discretization of internal properties variables, we propose a semidiscrete upwind formulation and a geometric grid discretization of the internal variables. The resultant ordinary differential equations (ODEs) are then solved by using a standard adaptive ODEs-solver. Several numerical test cases for the one and two-components aggregation process are considered here. The numerical results are validated against available analytical solutions.  相似文献   
6.
BACKGROUND: Plant essential oils are widely used as fragrances and flavours. Therefore, the essential oils from the leaves of Cinnamomum pubescens Kochummen (CP) and the whole plant of Etlingera elatior (EE) were investigated for their antioxidant, antibacterial and phytochemical properties. RESULTS: CP and EE were found to contain appreciable levels of total phenolic contents (50.6 and 33.41 g kg?1 as gallic acid equivalent) and total flavonoid contents (205.6 and 244.8 g kg?1 as rutin equivalent), respectively. DPPH free radical scavenging activity of CP is superior to EE (P < 0.05) showing IC50 of 77.2 and 995.1 µg mL?1, respectively. Methicillin‐resistant Staphylococcus aureus (MRSA), Bacillus subtilis, Pseudomonas aeruginosa and Salmonella choleraesuis were tested against CP and EE. Only MRSA was the most susceptible bacteria to CP. GC/MS studies resulted in the identification of 79 and 73 compounds in CP and EE, respectively. The most abundant components of EE included β‐pinene (24.92%) and 1‐dodecene (24.31%). While the major compound in CP were 1,6‐octadien‐3‐ol,3,7‐dimethyl (11.55%), cinnamaldehyde (56.15%) and 1‐phenyl‐propane‐2,2‐diol diethanoate (11.38%). CONCLUSION: This study suggests that the essential oils from Cinnamomum pubescens Kochummen and Etlingera elatior could be potentially used as a new source of natural antioxidant and antibacterial in the food and pharmaceutical industries. Copyright © 2010 Society of Chemical Industry  相似文献   
7.
The effects of bottom topography and horizontal temperature gradients on the shallow water flows are theoretically investigated. The considered systems of partial differential equations (PDEs) are non-strictly hyperbolic and non-conservative due to the presence of non-conservative differential terms on the right hand side. The solutions of these model equations are very challenging for a numerical scheme. Thus, our primary goal is to introduce an improved numerical scheme which can handle the non-conservative differential terms efficiently and accurately. In this paper, the space–time conservation element and solution element (CESE) method is extended to approximate these model equations. The proposed scheme has capability to overcome all difficulties posed by this nonlinear system of PDEs. The performance of the scheme is analyzed by considering several case studies of practical interest and the results of suggested scheme are compared with those of central NT scheme. The accuracy of the scheme is verified qualitatively and quantitatively.  相似文献   
8.
The National Institute for Occupational Safety and Health has carried out a field study to determine the vibration and impact levels that self-contained breathing apparatus are subjected to in simulated fire fighting use. Also, the forces that facemask retaining straps experience in simulated fire fighting use were measured. Notes: Dr. Crouch is on the staff of the National Institute for Occupational Safety and Health. Shamsul Abedin is with the Engineering and Test Division of Dayton T. Brown, Inc. Mention of company names or products does not constitute endorsement by the National Institute for Occupational Safety and Health.  相似文献   
9.
This study proposed an oil palm by-product as a low-cost adsorbent for the removal of hexavalent chromium [Cr (VI)] from aqueous solution. Adsorption of Cr (VI) by sulphuric acid and heat-treated oil palm fibre was conducted using batch tests. The influence of pH, contact time, initial chromium concentration and adsorbent dosage on the removal of Cr (VI) from the solutions was investigated. The optimum initial pH for maximum uptake of Cr (VI) from aqueous solution was found to be 1.5. The removal efficiency was found to correlate with the initial Cr (VI) concentration, adsorbent dosage as well as the contact time between Cr (VI) and the adsorbent. The adsorption kinetics tested with pseudo first order and pseudo second order models yielded high R(2) values from 0.9254 to 0.9870 and from 0.9936 to 0.9998, respectively. The analysis of variance (ANOVA) showed significant difference between the R(2) values of the two models at 99% confidence level. The Freundlich isotherm (R(2)=0.8778) described Cr (VI) adsorption slightly better than the Langmuir isotherm (R(2)=0.8715). Difficulty in desorption of Cr (VI) suggests the suitability of treated oil palm fibre as a single-use adsorbent for Cr (VI) removal from aqueous solution.  相似文献   
10.
This article introduces a technique for reconstructing crystal size distributions (CSDs) described by well-established batch crystallization models. The method requires the knowledge of the initial CSD which can also be used to calculate the initial moments and initial liquid mass. The solution of the reduced four-moment system of ordinary differential equations (ODEs) coupled with an algebraic equation for the mass gives us moments and mass at the discrete points of the given computational time domain. This information can be used to get the discrete values of size independent growth and nucleation rates. The discrete values of growth and nucleation rates along with the initial distribution are sufficient to reconstruct the final CSD. In the derivation of current technique the Laplace transformation of the population balance equation (PBE) plays an important role. The proposed technique has dual purposes. Firstly, it can be used as a numerical technique to solve the given population balance model (PBM) for batch crystallization. Secondly, it can be used to reconstruct the final CSD from the initial one and also vice versa. The method is very efficient, accurate and easy to implement. Several numerical test problems of batch crystallization processes are considered here. For validation, the results of the proposed technique are compared with those from the high resolution finite volume scheme which solves the given PBM directly.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号