全文获取类型
收费全文 | 393篇 |
免费 | 2篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 6篇 |
化学工业 | 28篇 |
金属工艺 | 23篇 |
机械仪表 | 23篇 |
建筑科学 | 8篇 |
能源动力 | 25篇 |
轻工业 | 86篇 |
水利工程 | 1篇 |
武器工业 | 1篇 |
无线电 | 11篇 |
一般工业技术 | 134篇 |
冶金工业 | 2篇 |
原子能技术 | 6篇 |
自动化技术 | 43篇 |
出版年
2024年 | 1篇 |
2023年 | 2篇 |
2022年 | 5篇 |
2021年 | 6篇 |
2020年 | 6篇 |
2019年 | 7篇 |
2018年 | 12篇 |
2017年 | 15篇 |
2016年 | 11篇 |
2015年 | 9篇 |
2014年 | 23篇 |
2013年 | 125篇 |
2012年 | 34篇 |
2011年 | 33篇 |
2010年 | 19篇 |
2009年 | 12篇 |
2008年 | 7篇 |
2007年 | 6篇 |
2006年 | 8篇 |
2005年 | 4篇 |
2004年 | 1篇 |
2003年 | 2篇 |
2002年 | 2篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1997年 | 8篇 |
1996年 | 2篇 |
1994年 | 1篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 3篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1974年 | 6篇 |
1973年 | 3篇 |
1972年 | 1篇 |
1966年 | 1篇 |
1959年 | 1篇 |
1954年 | 1篇 |
排序方式: 共有397条查询结果,搜索用时 15 毫秒
1.
PRADEEP VASUDEVAN PATRICK MAREK SCOTT DAIGLE THOMAS HOAGLAND KUMAR S. VENKITANARAYANAN 《Journal of Food Safety》2002,22(4):209-217
Vibrio parahaemolyticus is a foodborne pathogen isolated from coastal waters of the United States, and from seafoods including fish. No information is available on the viability of V. parahaemolyticus on raw, chilled and frozen fish. A three‐strain mixture of V. parahaemolyticus was inoculated on fish fillets (pH 6.4) to obtain a bacterial load of 104 (high) or 103 (low) CFU/fillet, and stored at 4C or 8C for 9 days or at – 18C for seven weeks. At 4C and 8C, and at both levels of inoculation, V. parahaemolyticus survived on the fillets for the entire duration of the study. However, there was a significant reduction (P < 0.01) in V. parahaemolyticus population on the fillets by 9 days of storage. In the frozen fillets, there was a sharp decline (P < 0.01) in the population of V. parahaemolyticus by day 5 of storage. Although chilling and freezing significantly (P < 0.01) inactivated high numbers of V. parahaemolyticus on fish, they cannot be relied upon as a method to reduce V. parahaemolyticus on fish, since the time and magnitude of reduction depends on the initial load of the pathogen and the storage temperature. 相似文献
2.
The defect structure of monoclinic ZrO2 was studied by measuring the transfer numbers and electrical conductivity as functions of O2 pressure and temperature. The data suggest a defect structure of doubly ionized oxygen vacancies at low pressures, i.e. <10−19 atm, and singly ionized oxygen interstitials at pressures >10−9 atm. Zirconia is primarily an ionic conductor below #700°C and an electronic conductor at 700° to 1000°C for 10−22 ≤Po2 ≤1 atm. 相似文献
3.
UJJAL?KUMAR?SUREmail author ABHIJIT?SAHA APARNA?DATTA BALAPRASAD?ANKAMWAR FARAH?SURTI SANNAK?DUTTA?ROY DEBASISH?ROY 《Bulletin of Materials Science》2016,39(1):159-165
A stable aqueous dispersion (5 mg ml?1) of graphene was synthesized by a simple protocol based on three-step reduction of graphene oxide (GO) dispersion synthesized using the modified version of Hummers and Offeman method. Reduction of GO was carried out using sodium borohydride, hydrazine hydrate and dimethyl hydrazine as reducing agents. The chemically synthesized graphene was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–visible absorption spectroscopy, Fourier transform infrared (FTIR) and Raman spectroscopy, thermogravimetric analysis (TGA), optical microscopy. The stability of aqueous dispersions of graphene was confirmed through zeta potential measurements and the negative zeta potentials of 55–60 mV were obtained indicating the high stability of aqueous graphene dispersions. 相似文献
4.
N KRISHNA JYOTHI K K VENKATARATNAM P NARAYANA MURTY K VIJAYA KUMAR 《Bulletin of Materials Science》2016,39(4):1047-1055
The free standing and dimensionally stable gel polymer electrolyte films of polyacrylonitrile (PAN): potassium iodide (KI) of different compositions, using ethylene carbonate as a plasticizer and dimethyl formamide as solvent, are prepared by adopting ‘solution casting technique’ and these films are examined for their conductivities. The structural, miscibility and the chemical rapport between PAN and KI are investigated using X-ray diffraction, Fourier transform infrared spectroscopy and differential scanning calorimetry methods. The conductivity is enhanced with the increase in KI concentration and temperature. The maximum conductivity at 30°C is found to be 2.089 × 10?5 S cm?1 for PAN:KI (70:30) wt%, which is nine orders greater than that of pure PAN (< 10?14 S cm?1). The conductivity-temperature dependence of these polymer electrolyte films obeys Arrhenius behaviour with activation energy ranging from 0.358 to 0.478 eV. The conducting carriers of charge transport in these polymer electrolyte films are identified by Wagner’s polarization technique and it is found that the charge transport is predominantly due to ions. The better conducting sample is used to fabricate the battery with configuration K/PAN + KI/I2+ C + electrolyte and good discharge characteristics of battery are observed. 相似文献
5.
6.
The present exercise is an attempt to generalize a probability model referring to the waiting time distribution for conception in a mixed group of fecund females with two varying levels of fecundity, based on a census sample truncated at time T =t from the date of resumption of fecundity following an earlier conception (Biswas, 1975, Sankhya, Series B, 37, Part III). The generalization is made in two aspects, viz. instead of fixed conception rates, time-dependent rates decreasing with the age of the woman have been used. Additionally, unlike the model of Biswas (1975) consisting of two different fecund groups, three different levels of fecundity have been taken into consideration in this paper. Estimates of the proportion of fecund females over time, viz. πi(t) (i = 1, 2, 3) are attempted by the method of maximum likelihood on the basis of a census sample truncated at time T = t under the generalized set up. 相似文献
7.
The objective of this work is to study the cryogenic sheet metal forming behaviour of precipitation hardening AW-6016-T4. In this regard, the flow curves and forming limit curves were obtained by tension and Nakazima experimental testing methods in the temperature ranges from ?196 to 25 °C. It was found that strength and elongation increase with decreasing temperature. Small but perceived differences between microstructure of the material deformed at the room and cryogenic temperatures respectively were identified by electron backscatter diffraction (EBSD) analysis. However, no significant difference in the precipitation kinetics during continuous heating in the DSC has been observed. This study has demonstrated the potential of cryogenic forming by manufacturing a B-pillar part with 8 mm depth of side design element as compared to 6 mm at room temperature. 相似文献
8.
9.
This article concerns the development of a simple yet very efficient heuristic procedure for optimizing the design or a reactor system employing continuous stirred tanks in series using Michaelis-Menten kinetics. The heuristic procedure employs a modified form or the well known Golden Search method to estimate the optimal number of reactors to be employed. The procedure was tested on an IBM personal computer under a wide range of values for three model parameters, namely the economy or scale factor, the scaled Michaelis-Menten constant and the desired degree of conversion to be attained. The results of this study indicated that the heuristic optimization procedure is capable of obtaining solutions that are either identical or very close to the actual optimal solutions in a very efficient manner. 相似文献
10.
High-performance industrial drives widely employ induction motors with position sensorless vector control (SLVC). The state-of-the-art SLVC is first reviewed in this paper. An improved design procedure for current and flux controllers is proposed for SLVC drives when the inverter delay is significant. The speed controller design in such a drive is highly sensitive to the mechanical parameters of the induction motor. These mechanical parameters change with the load coupled. This paper proposes a method to experimentally determine the moment of inertia and mechanical time constant of the induction motor drive along with the load driven. The proposed method is based on acceleration and deceleration of the motor under constant torque, which is achieved using a sensorless vector-controlled drive itself. Experimental results from a 5-hp induction motor drive are presented. 相似文献