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   12篇
  免费   0篇
化学工业   3篇
能源动力   1篇
无线电   2篇
一般工业技术   5篇
自动化技术   1篇
  2022年   1篇
  2021年   2篇
  2018年   1篇
  2009年   1篇
  2001年   1篇
  2000年   1篇
  1997年   1篇
  1996年   1篇
  1990年   2篇
  1988年   1篇
排序方式: 共有12条查询结果,搜索用时 15 毫秒
1.
2.
3.
The equations have been derived for the trigonal system to calculate the lattice strains produced by the non-hydrostatic pressure condition which arises when the sample is compressed between the anvils without any pressure transmitting medium.  相似文献   
4.
Pure and impurity added (with urea and thiourea) KDP single crystals were grown by the gel method using silica gels. Electrical conductivity measurements were carried out along both the unique axis and perpendicular directions at various temperatures ranging from 30 to 140‡ C by the conventional two-probe method. The present study shows that the conductivity in KDP crystals, for both the impurities considered, increases with the increase in impurity concentration and temperature. Activation energies were also determined and reported.  相似文献   
5.
Variations in the halfwidth values of X-ray reflections from fatigue-cycled, polycrystalline aluminium samples have been analysed. An oscillatory variation of the halfwidths with fatigue cycling has been observed. Analysis of the diffraction line profiles indicates that broadening arises mainly because of the build-up of microstrains during fatigue cycling. The present data indicate that (i) broadening due to fatigue cycling increases with glancing angle; (ii) changes in halfwidth and integral widths, due to fatigue cycling, are comparable and (iii) (b/b 0) versusN curves for fatigue cycling under constant stress amplitude and flight loading conditions are comparable.  相似文献   
6.
Development of an inexpensive electrocatalyst for hydrogen evolution (HER) and oxygen evolution reactions (OER) receives much traction recently. Herein, we report a facile one-pot ethyleneglycol (EG) mediated solvothermal synthesis of orthorhombic Co2P with particle size ~20–30 nm as an efficient HER and OER catalysts. Synthesis parameters like various solvents, temperatures, precursors ratios, and reaction time influences the formation of phase pure Co2P. Investigation of Co2P as an electrocatalyst for HER in acidic (0.5 M H2SO4) and alkaline medium (1.0 M KOH), furnishes low overpotential of 178 mV and 190 mV, respectively to achieve a 10 mA cm?2 current density with a long term stability and durability. As an OER catalyst in 1.0 M KOH, Co2P shows an overpotential of 364 mV at 10 mA cm?2 current density. Investigation of Co2P NP by XPS analysis after OER stability test under alkaline medium confirms the formation of amorphous cobalt oxyhydroxide (CoOOH) as an intermediate during OER process.  相似文献   
7.
This paper focuses on IOT based soft switching boost converter based solar energy applications for smart cities and making cities smarter and greener around the globe. It presents one of the applications of the Internet of Things to design and implementation of a highly efficient boost converter used for powering the Arduino and the Bluetooth device for controlling the switching of the led and buzzer by using smart city applications. The soft switching boost converter is essential to maximize the low-level voltage obtained from the solar board to the enhanced voltage conversion ratio for the efficient electric power generation. In this paper, the three separate methodologies of DC–DC boost converters with additional resonant/snubber circuit and resistive load associated with solar panel modules proposed with maximum power point tracking (MPPT) control. The MPPT is obtained by modified augmented perturb and observe algorithm. IoT helps Smart City(SC) systems to support various network functions throughout the generation, transmission, distribution and consumption of energy by incorporating IoT devices (such as sensors, actuators and smart meters), as well as by providing the connectivity, automation and tracking for such devices. It is utilized to extract the most extreme power from solar panel by controlling the duty ratio of the suggested soft switching based boost converter. In this paper a smart IOT system is used to control and monitoring the effect of reference power variations, parameter values to the voltage control to the converter. The solar panel, boost converter and the MPPT is modeled using MATLAB/SIMULINK environment and reach the power transfer efficiency up to 97%.  相似文献   
8.
Natural leather is processed from hides and skins of animals. Synthetic leathers are becoming popular as an alternative material owing to limited availability and varying size of natural leathers. There is a need to understand the properties of natural and synthetic leathers to select proper material for an application. In this study, materials used for apparel application such as natural sheep nappa leather and synthetic polyurethane (PU)‐based leather have been chosen and analyzed for comfort, chemical, physical, and structural properties. It was found that natural sheep nappa leather has enhanced water vapor permeability whereas other comfort properties such as softness and drape ability are comparable to synthetic PU leather. Whereas synthetic PU leather dominated most of the physical properties, especially percentage elongation and stitch tear strength, in specific directions on account of polyester knitted base fabric. Chemical properties of natural sheep nappa leather and synthetic PU leather depended on the individual material composition and characteristics. Scanning electron microscopic (SEM) analysis provided convincing evidence for some of the quantified comfort and physical properties. The results of this study would be useful in selection of proper material for apparel application as well as in providing directions for future research in synthetic leather manufacture. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009  相似文献   
9.
We evaluated organic and macromineral composition of selected fruits and leaves consumed by the short-nosed fruit bat, Cynopterus sphinx in South India. Results of principal components analysis (PCA) comparing soluble carbohydrates, crude protein, and crude fats indicate a higher percentage of protein in leaves and a higher percentage of carbohydrates and lipids in fruits. However, results of a paired t test comparing these organic components indicated no differences between fruits and leaves. Among the fruits analyzed, Musa x paradisiaca had the highest percentage of carbohydrates, and Psidium guajava had the highest percentage of lipids. Leaves of Cassia fistula, Moringa oleifera, coccinia cordifolia, and F. religiosa had the highest percentage of protein. PCA of selected macrominerals (Ca, Na, K, and P) indicate higher levels of Ca in leaves than in fruits. Results of t tests comparing these macrominerals revealed a difference between fruits and leaves for Ca, but not for the other macrominerals. Among the leaves analyzed, Ca was highest in mature leaves of C. fistula and lowest in leaves of F. religiosa. Leaves of M. oleifera and fruits of Achras sapota were highest in sodium. Among fruits analyzed for macrominerals, Ca was highest in F. bengalensis and lowest in Prosopis juliflora, A. sapota, and M. x paradisiaca. Potassium levels were highest in leaves of C. cordifolia and fruit pods of Prosopis juliflora. Phosphorus content was highest in leaves of M. oleifera and fruits of M. x paradisiaca. The relatively high concentrations of protein and calcium in leaves eaten by C. sphinx supports the hypothesis that leaves are important dietary sources for this plant-visiting bat.  相似文献   
10.
Numerous engineering complexities are simplified using optimization algorithms. In a solar power system, the necessity of the voltage regulator is obvious. To control the regulator existent research works used PI, PID controllers that might have an unwanted transient response. To overcome such drawbacks here, a fresh scheme is proposed for the designing of the adaptive sliding mode (SM) controller of a solar powered LUO converter using optimization algorithms. The PSO (‘Particle Swarm Optimization') is proved to expedite the convergence characteristic for many applications. Here, an ameliorated PSO version is developed. This algorithm is termed the Parameter Improved‐PSO (PIPSO) algorithm. In this algorithm, the parameters, say, inertia weight, social along with cognitive agents is updated in every generation. The Proportional Integrator (PI) controller is used. The gain of this controller is tuned using the PIPSO. This algorithm's objective function is to lessen ISE (‘Integral Squared Error’) of the converter's output voltage. This parameter is picked as the objective function of the optimization algorithm. The proposed PIPSO is established to show better outcomes when contrasted to the traditional PSO concerning tuning a collection of parameters. An analysis is also made to evaluate the effect of usage of the solar panel () in the proposed work.  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