全文获取类型
收费全文 | 996篇 |
免费 | 2篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 7篇 |
综合类 | 3篇 |
化学工业 | 176篇 |
金属工艺 | 26篇 |
机械仪表 | 27篇 |
建筑科学 | 2篇 |
矿业工程 | 12篇 |
能源动力 | 5篇 |
轻工业 | 25篇 |
水利工程 | 17篇 |
石油天然气 | 53篇 |
无线电 | 50篇 |
一般工业技术 | 122篇 |
冶金工业 | 434篇 |
原子能技术 | 24篇 |
自动化技术 | 19篇 |
出版年
2022年 | 12篇 |
2021年 | 9篇 |
2020年 | 14篇 |
2019年 | 11篇 |
2018年 | 30篇 |
2017年 | 22篇 |
2016年 | 24篇 |
2015年 | 9篇 |
2014年 | 15篇 |
2013年 | 25篇 |
2012年 | 21篇 |
2011年 | 12篇 |
2010年 | 13篇 |
2009年 | 13篇 |
2008年 | 9篇 |
2007年 | 14篇 |
2006年 | 7篇 |
2004年 | 10篇 |
2003年 | 9篇 |
2002年 | 8篇 |
2000年 | 8篇 |
1999年 | 11篇 |
1998年 | 123篇 |
1997年 | 74篇 |
1996年 | 52篇 |
1995年 | 36篇 |
1994年 | 30篇 |
1993年 | 22篇 |
1992年 | 8篇 |
1991年 | 10篇 |
1990年 | 22篇 |
1989年 | 8篇 |
1988年 | 19篇 |
1987年 | 9篇 |
1986年 | 19篇 |
1985年 | 9篇 |
1984年 | 7篇 |
1983年 | 7篇 |
1982年 | 11篇 |
1981年 | 12篇 |
1980年 | 10篇 |
1979年 | 18篇 |
1978年 | 11篇 |
1977年 | 29篇 |
1976年 | 50篇 |
1975年 | 15篇 |
1973年 | 8篇 |
1972年 | 8篇 |
1971年 | 7篇 |
1965年 | 6篇 |
排序方式: 共有1002条查询结果,搜索用时 75 毫秒
991.
IP Gunn 《Canadian Metallurgical Quarterly》1996,8(8):683-687
RATIONALE AND OBJECTIVES: The application of information technology to teaching radiology will profoundly change the way learning is mediated to students. In this project, the integration of veterinary medical students' knowledge of sonography was promoted by a computer-assisted instruction program and a subsequent practical class. METHODS: The computer-assisted instruction program emphasized the physical principles of clinical sonography and contained simulations and user-active experiments. In the practical class, the students used an actual sonographic machine for the first time and made images of a tissue-equivalent phantom. Students' responses to questionnaires were analyzed. RESULTS: On completing the overall project, 96% of the students said that they now understood sonographic concepts very or reasonably well, and 98% had become very or moderately interested in clinical sonography. CONCLUSIONS: The teaching and learning initiatives enhanced an integrated approach to learning, stimulated student interest and curiosity, improved understanding of sonographic principles, and contributed to an increased confidence and skill in using sonographic equipment. 相似文献
992.
Human bites of the hand cause small wounds that are often incorrectly treated as "minor' injuries. We reviewed the management and outcome of patients with human bite or "punch' injuries of the hand. Significant morbidity resulted from late presentation and inadequate initial management. We propose a treatment protocol, in which all patients are immediately referred and admitted to hospital for surgical debridement. 相似文献
993.
II Morozov IP Dergacheva VG Petin BV Dubovik GV Morozova 《Canadian Metallurgical Quarterly》1996,36(5):671-675
The influence of microwaves and heat on dynamics of heating of samples of intact and inactivated bacteria Escherichia coli and solutions of some basic molecular components of cell was investigated. It was shown that microwaves induce different dynamics of heating of all samples. On the contrary, thermal action induces identical dynamics of heating of all this samples except vegetable oil which was heated more intensively. 相似文献
994.
NI Larionova IP Gladysheva OV Polekhina LP Kurochkina EN Gorbatova 《Canadian Metallurgical Quarterly》1996,61(1-2):139-148
We describe an adaptation of competitive RT-PCR to quantitate rat IFN-gamma mRNA expression. An IFN-gamma DNA mimic that shared the same primers and had an identical sequence to the target mRNA except for deletion of 66 nucleotides was created by a simple PCR amplification from target cDNA. To reduce variations of initial RNA concentrations, beta-actin cDNAs from each target RNA sample were normalized using the densitometric data. A known amount of pretitrated DNA competitor was then used to analyze the relative levels of target cDNA in different samples by PCR co-amplification. The amplification efficiency for both target and competitor remained constant throughout the PCR reaction, and the ratio of target to competitor PCR product remained proportional to the initial ratio of target to competitor. Relative mRNA levels among samples determined by this method were comparable to levels determined by northern blot analysis. They were also comparable to levels of IFN-gamma protein estimated by ELISA. We conclude that this method can be used to estimate the relative abundance of the target mRNA. This method is adaptable to quantitation of other cytokines and is particularly valuable if there are numerous samples or if the amount of initial mRNA is limited. 相似文献
995.
996.
Antonov S. A. Matveeva A. I. Pronchenkov I. A. Bratko R. V. Nikulshin P. A. Kilyakova A. Yu. Gerasimov A. V. 《Chemistry and Technology of Fuels and Oils》2022,58(4):575-581
Chemistry and Technology of Fuels and Oils - The article examines the chemical composition and physicochemical properties of heavy naphthenic-aromatic oil and its fractions. In comparison with... 相似文献
997.
V. G. Mykhaylenko O. V. Antonov O. I. Lukyanova T. O. Berezka 《Thermal Engineering》2018,65(12):922-926
The possibility of electromembrane softening treatment of network water at a thermal power station is shown. Technology for the manufacturing of an inert anode free from noble metals or their compounds is proposed. Performed resource tests have demonstrated that such an anode can be in operation in chloride–sulfate solutions for several years almost without wear. A mathematical model describing the electrical current utilization efficiency as a function of process parameters and electrolysis regimes in the electromembrane softening of water has been developed. The results of calculating the current utilization efficiency coefficient by this model are in satisfactory agreement with experimental results. The current utilization coefficient in the formation of NaOH does not depend on the anolyte composition but appreciably decreases with increasing catholyte concentration and slightly grows with increasing current density at a constant catholyte concentration. Experiments have not disclosed any essential dependence between the specific water and CO 3 2- ion transports and the process parameters. Experiments on estimating the depth of the electromembrane softening of initial water for the heat supply networks of Kharkiv have demonstrated that the electromembrane method provides the residual hardness of 0.3–0.4 mg-equiv/dm3, which is almost four times lower than for water subjected to soda–lime treatment. The experiments performed on a test bench setup have confirmed that the application of heterogeneous cation-exchange membranes (both MK-40 (OAO Shchekinoazot) and CMI 9000 (Membrane International)) provides the possibility to attain a high current utilization ratio above 88%. The carbonate index of water after electromembrane softening corresponds to the normative requirements to water for heat supply networks with a heat transfer agent temperature below 150°C (no higher than 0.4 (mg-equiv/dm3)2]. This provides the possibility to use the treated water immediately in heat supply networks without further ion-exchange softening. Some technical and economic parameters of the softening process and the technical parameters of an industrial electromembrane softener are given, and the possibilities of the utilization of wastes and byproducts are considered. 相似文献
998.
A. E. Ushakov A. A. Safonov I. V. Sergeichev A. Yu. Konstantinov F. K. Antonov 《Journal of Machinery Manufacture and Reliability》2014,43(1):36-41
A method for estimating the strength of structural elements made of composite materials with a thermosetting matrix, which was characterized by the presence of exfoliation-like defects and process-induced deformations, was proposed. In order to determine the process-induced deformations, a mathematical model, which considered thermal and chemical deformations, heat release in the course of matrix polymerization, as well as changes in the matrix properties in transition from the superelastic to the solid state, was implemented. A modeling of the deformation of a standard blank with an interstitial exfoliation-like defect was carried out. A quantitative defect of the effect of the process-induced deformations and the initial dimensions of the defects on the load at which the defect begins to grow was made. 相似文献
999.
G. I. Antonov O. M. Semenenko A. V. Kushchenko G. N. Shcherbenko 《Refractories and Industrial Ceramics》1992,33(3-4):207-208
Conclusions Laboratory-production investigations were made to develop a technology for periclasespinel refractories using sintered spinel based on bauxite and periclase. It is shown that bauxite is an acceptable replacement for alumina in synthesizing magnesia-alumina spinel. Control batches of ladle brick were made, and these had satisfactory properties.Translated from Ogneupory, No. 4, pp. 12–13, April, 1992. 相似文献
1000.
G. I. Antonov Yu. L. Kamenetskii N. M. Kvasman A. G. Antonov 《Refractories and Industrial Ceramics》1989,30(5-6):292-295
Conclusions The density (porosity) in forsterite components has been examined as a function of pressure and represented as exponential and logarithmic equations.Berezhnoi's pressing equation and method have been used to calculate some pressing parameters for forsterite components.Translated from Ogneupory, No. 5, pp. 28–30, May, 1989. 相似文献