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   86篇
  免费   2篇
  国内免费   1篇
综合类   1篇
化学工业   8篇
金属工艺   2篇
机械仪表   5篇
建筑科学   1篇
能源动力   9篇
轻工业   16篇
无线电   1篇
一般工业技术   23篇
原子能技术   2篇
自动化技术   21篇
  2024年   1篇
  2023年   1篇
  2022年   1篇
  2021年   12篇
  2020年   2篇
  2019年   4篇
  2018年   22篇
  2017年   8篇
  2016年   5篇
  2015年   2篇
  2014年   5篇
  2013年   7篇
  2012年   2篇
  2011年   4篇
  2010年   4篇
  2009年   4篇
  2008年   1篇
  2007年   2篇
  2003年   1篇
  1976年   1篇
排序方式: 共有89条查询结果,搜索用时 15 毫秒
61.
Neural Computing and Applications - Analysis of the carbon nanotubes suspended nanofluids in a channel with non-parallel stretchable walls is presented. Water is taken as the base fluid for the...  相似文献   
62.
Journal of Failure Analysis and Prevention - Most accidents in chemical process industry, as well as a large number of fires in general, are triggered by accidental spilling of flammable liquids....  相似文献   
63.
    
The COVID-19 pandemic has introduced a new battle in human history for a safe and fearless life. Therefore, this cross-sectional survey was conducted (Punjab, Pakistan) on healthy recovered, home quarantined COVID-19 patients to draw conclusive health support guidelines in the fight against this pandemic. COVID-19 recovered patients (n = 80) of age ≥14 years were randomly selected during the period November 2020 to February 2021. A nutrition and lifestyle changes questionnaire, containing ten sections and seventy questions, was completed through the telephone/WhatsApp. Data were transferred into an Excel spreadsheet and statistically analyzed by applying chi-square, correlation, and a t test of independent values using SPSS-16 software. The patients had an age range of 14 to 80 years, of which 52 (65%) were male and 28 (35%) were female, and 32 (40%) had a normal BMI. The patients had a peak COVID-19 recovery period of 2 weeks, and a mean recovery period of 2.8 ± 1.4 weeks. Certain variables, including gender (males), age (>40 years), sleep (≤5 hr), less/no physical activity, obesity, diabetes mellitus, and autoimmune diseases, were significantly associated with delayed recovery. Poor nutritional outcomes, including lower intakes of water, legumes, nuts, meat, and milk/yogurt; and higher consumption of fast/fried/junk/spicy foods and cold water/drinks, were also significantly associated with a longer recovery period. The results were similar for not taking daily doses of multivitamins, and vitamins C, D, E, and zinc. This study identified that staying physically active, maintaining sensible body weight, having a sleep of 7 hr, consuming more foods of plant origin especially plant-based proteins from nuts and legumes, taking supplemental doses of multivitamins, vitamin D, E, and zinc, along with drinking ≥2 L of water daily can provide a significant role in early and safe recovery from COVID-19.  相似文献   
64.
    

Velocity and temperature slip effects on squeezing flow of nanofluid between parallel disks in the presence of mixed convection is considered. Equations that govern the flow are transformed into a set of differential equations with the help of transformations. For the purpose of solution, homotopy analysis method is used. The BVPh2.0 package is utilized for the said purpose. Deviations in the velocity, temperature and the concentration profiles are depicted graphically. Mathematical expressions for skin friction coefficient, Nusselt and the Sherwood numbers are derived and the variations in these numbers are portrayed graphically. From the results obtained, we observed that the coefficient of skin friction increases with increase in Hartmann number M for the suction flow (A > 0), while in the blowing flow (A < 0) a fall is seen with increasing M. However, for rising values of velocity parameter β the effect of skin friction coefficient is opposite to that accounted for M. Variations in thermophoresis parameter N T and thermal slip parameter γ give rise in Nusselt number for both the suction and injection at wall. For both the suction and injection at wall, Sherwood number gets a rise with growing values of Brownian motion parameter N B, while a drop is seen in Sherwood number for increasing values of thermophoresis parameter N T. For the sake of comparison, the same problem is also solved by employing a numerical scheme called Runge–Kutta–Fehlberg (RKF) method. Results thus obtained are compared with existing ones and are found to be in agreement.

  相似文献   
65.
    

Various applications of bioconvection phenomena in the field of medicine and biotechnology boost us to present the study of laminar wall jet flow in this specific direction. For the purpose, we have considered nanofluid containing gyrotactic microorganisms in the presence of normally applied magnetohydrodynamic forces along with Soret effects. Boundary layer approximation and similarity transformation are utilized to convert governing equations into ordinary differential equations. Influence of different emerging parameters on velocity, temperature and concentration profiles of solute, nanoparticle and motile microorganisms has been investigated. The role of physical quantities like Nusselt number, Sherwood number and density number of microorganisms is also highlighted. Increase in Nusselt number and density number of motile microorganism is observed for incremental values of bioconvection Peclet number. Soret number reflects increasing effect on Nusselt number and decreasing effect on Sherwood number because solute diffusion faces resistance due to higher values of Soret number and in return decreases rate of mass transfer. Also bioconvection Rayleigh number imposes decreasing effect on density number of the motile microorganisms.

  相似文献   
66.
Liquefied petroleum gas (LPG) has been in use as household fuel all over the world for several decades. Until the late 1980s, its use in the developing world was largely confined to the economically well-off strata of the society but it has since spread over a much larger catchment. The increasing use of LPG has enhanced and generalized the risk of a “boiling liquid expanding vapor explosion” (BLEVE). This is evidenced from the reports which appear now and then of a LPG cylinder having exploded in a household, some workshop, or on a bus or a train. In fact some very major tragedies have been triggered by such explosions which also set off fires and cause secondary accidents. This paper describes what BLEVEs are and how can they be controlled. The paper focuses on hazards of BLEVE in large installations which deal with LPG, and other pressure-liquefied gases and discusses the nature, mechanism, and means of control of BLEVEs.  相似文献   
67.
In this paper, we apply Homotopy Analysis Method (HAM) to find appropriate solutions for the Zakharov–Kuznetsov equations with fully nonlinear dispersion which are of utmost importance in applied and engineering sciences. Numerical results re-confirm the reliability of the proposed algorithm (HAM).  相似文献   
68.
Metal oxide nanoparticles and their composites with conducting polymers, specifically Polyaniline (PANI) were utilized for fabricating nanoscale supercapacitor (SC) electrode materials. In the present study, we have synthesized pristine Pr2O3, NiO, Co3O4 nanoparticles, binary PANI-Pr2O3, PANI-NiO, PANI-Co3O4, ternary Pr2O3–NiO–Co3O4, and quaternary PANI-Pr2O3–NiO–Co3O4 spherical core-shell nanocomposite using co-precipitation and ultra-sonication methods. The grown samples were characterized with different analytical techniques. The XRD pattern revealed that the as-synthesized products were crystalline with Pr2O3 hexagonal phase, NiO cubic phase, and Co3O4 cubic phase in pure and nanocomposites. The Williamson-Hall, Scherrer, and size-strain plot methods were employed to study the crystalline development and contribution of micro-strain. FTIR pattern exhibited the metal-oxygen and PANI bond vibrations. FE-SEM images shown the spherical core-shell shape morphology of quaternary nanocomposite. EDX evident the presence of praseodymium, cobalt, and nickel in synthesized samples. UV–vis spectroscopy confirmed the absorption in the visible region. The IV graphs showed a higher conductivity of quaternary nanocomposite. The cyclic voltammetry results revealed that the quaternary nanocomposite has a higher specific capacitance 500 Fg-1 as compared to binary nanocomposites 134 F g?1 (PANI-Pr2O3), 143 F g?1 (PANI-Co3O4), 256 F g?1 (PANI-NiO), and PANI (90.8 F g?1) at a scan rate of 5 m Vs?1. The GCD results also showed that the quaternary nanocomposite has a higher specific capacitance of 905 F g?1 at current density 1 A g?1 with maximum energy density and power density of 87.99 kWhkg-1 and 2.6 k W kg?1, respectively. The EIS curve also confirmed that the quaternary nanocomposite has a lower polarization resistance (Rp) and solution resistance (Rs). The higher capacitance of quaternary nanocomposite can facilitate ion transfer, and the formation of its core-shell structure flourish to enhance surface-dependent electrochemical properties. Furthermore, this study gives a novel research idea to manufacture electrode materials for supercapacitors.  相似文献   
69.
In this article, the Legendre wavelet operational matrix of integration is used to solve boundary ordinary differential equations with non-analytic solution. Although the standard Galerkin method using Legendre polynomials does not work well for solving ordinary differential equations in which at least one of the coefficient functions or solution function is not analytic, it is shown that the Legendre wavelet Galerkin method is very efficient and suitable for solving this kind of problems. Several numerical examples are given to illustrate the efficiency and performance of the presented method.  相似文献   
70.
Deep-hole drilling is a relatively complex drilling production process due to the high-hole diameter to length ratio which makes the tool shaft prone to vibration and results typically in low-quality holes from geometry and surface finish viewpoints. This study is aimed at investigating deep-hole drilling process for AISI D2 material taking into account different process input parameters. The hole quality is studied and improved using a response surface-based design of an experiment technique which resulted in a better hole quality.  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