全文获取类型
收费全文 | 1321篇 |
免费 | 63篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 10篇 |
化学工业 | 322篇 |
金属工艺 | 36篇 |
机械仪表 | 30篇 |
建筑科学 | 19篇 |
矿业工程 | 1篇 |
能源动力 | 66篇 |
轻工业 | 23篇 |
石油天然气 | 39篇 |
无线电 | 97篇 |
一般工业技术 | 434篇 |
冶金工业 | 143篇 |
原子能技术 | 41篇 |
自动化技术 | 127篇 |
出版年
2023年 | 17篇 |
2022年 | 38篇 |
2021年 | 52篇 |
2020年 | 23篇 |
2019年 | 38篇 |
2018年 | 48篇 |
2017年 | 39篇 |
2016年 | 48篇 |
2015年 | 39篇 |
2014年 | 36篇 |
2013年 | 65篇 |
2012年 | 75篇 |
2011年 | 83篇 |
2010年 | 51篇 |
2009年 | 61篇 |
2008年 | 62篇 |
2007年 | 54篇 |
2006年 | 59篇 |
2005年 | 42篇 |
2004年 | 36篇 |
2003年 | 32篇 |
2002年 | 30篇 |
2001年 | 15篇 |
2000年 | 17篇 |
1999年 | 13篇 |
1998年 | 9篇 |
1997年 | 12篇 |
1996年 | 12篇 |
1995年 | 11篇 |
1994年 | 11篇 |
1992年 | 11篇 |
1991年 | 13篇 |
1990年 | 9篇 |
1989年 | 7篇 |
1988年 | 11篇 |
1987年 | 12篇 |
1986年 | 9篇 |
1985年 | 11篇 |
1984年 | 11篇 |
1983年 | 15篇 |
1982年 | 17篇 |
1981年 | 11篇 |
1980年 | 14篇 |
1979年 | 15篇 |
1978年 | 10篇 |
1977年 | 15篇 |
1976年 | 10篇 |
1975年 | 10篇 |
1973年 | 7篇 |
1971年 | 7篇 |
排序方式: 共有1388条查询结果,搜索用时 9 毫秒
11.
V. L. Kolpashchikov O. G. Martynenko M. I. Shribak 《Journal of Engineering Physics and Thermophysics》1994,67(5-6):1106-1112
An optical method for temperature measurements is proposed based on the use of an autocollimation polarimeter and a sensitive birefringent plate. The basic expressions that describe the operation of the system are presented. It is shown that with the use of a quartz plate 1.5 mm thick the device makes it possible to determine values of temperature in the region of –80 to +150°C.Academic Scientific Complex A. V. Luikov Institute of Heat and Mass Transfer of the Academy of Sciences of Belarus, Minsk, Belarus. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 67, Nos. 5–6, pp. 475–482, November–December, 1994. 相似文献
12.
13.
Ulrich Schmatz Catherine Dubourdieu Oleg Lebedev Gerard Delabouglise Francois Weiss Jean-Pierre Senateur 《Journal of Low Temperature Physics》1996,105(5-6):1301-1306
Thin and thick YBCO Films have been grown by Aerosol Assisted as well as by thermal MOCVD. The Aerosol Assisted MOCVD technique allows the growth of YBCO films from a single liquid source at deposition rates of up to 10m/h.Transport measurements (I-V) on etched microbridges using a single pulse technique have been performed. The angular magnetic field dependence Jc() of the critical current density from Tc down to 50 K has been measured. Transport properties are reported and discussed with respect to the microstructural features as determined by X-ray diffraction and electron microscopy. 相似文献
14.
Kenichi Asai Oleg Kiselyov Chung-chieh Shan 《Higher-Order and Symbolic Computation》2011,24(4):311-340
Danvy??s functional unparsing problem (Danvy in J. Funct. Program. 8(6), 621?C625, 1998) is to implement a type-safe ??printf?? function, which converts a sequence of heterogeneous arguments to a string according to a given format. The dual problem is to implement a type-safe ??scanf?? function, which extracts a sequence of heterogeneous arguments from a string by interpreting (Friedman and Wand in LFP, pp. 348?C355, 1984 and in Essentials of Programming Languages, MIT Press, 2008) the same format as an equally heterogeneous sequence of patterns that binds zero or more variables. We derive multiple solutions to both problems (Wand in J. ACM 27(1), 164?C180, 1980) from their formal specifications (Wand in Theor. Comput. Sci. 20(1), 3?C32, 1982). On one hand, our solutions show how the Hindley-Milner type system, unextended, permits accessing heterogeneous sequences with the static assurance of type safety. On the other hand, our solutions demonstrate the use of control operators (Felleisen et al. in Proceedings of the 1988 ACM Conference on Lisp and Functional Programming, pp. 52?C62, ACM Press, New York, 1988; Wand in POPL 85: Conference Record of the Annual ACM Symposium on Principles of Programming Languages, vol. 16, ACM Press, New York, 1985; Meyer and Wand in Logics of Programs, Lecture Notes in Computer Science, vol. 193, pp. 219?C224, Springer, Berlin, 1985) to communicate with formats as coroutines (Wand in Proceedings of the 1980 ACM Conference on Lisp and Functional Programming, vol. 12, pp. 285?C299, ACM Press, New York, 1980 and Haynes et al. in LFP, pp. 293?C298, 1984). 相似文献
15.
Direct Method Based Control System for an Autonomous Quadrotor 总被引:1,自引:0,他引:1
Ian D. Cowling Oleg A. Yakimenko James F. Whidborne Alastair K. Cooke 《Journal of Intelligent and Robotic Systems》2010,60(2):285-316
This paper proposes a real time control algorithm for autonomous operation of a quadrotor unmanned air vehicle. The quadrotor
is a small agile vehicle, which as well as being a excellent test bed for advanced control techniques could also be suitable
for internal surveillance, search and rescue and remote inspection. The proposed control scheme incorporates two key aspects
of autonomy; trajectory planning and trajectory following. Using the differentially-flat dynamics property of the system,
the trajectory optimization is posed as a non-linear constrained optimization within the output space in the virtual domain,
not explicitly related to the time domain. A suitable parameterization using a virtual argument as opposed to time is applied,
which ensures initial and terminal constraint satisfaction. The speed profile is optimized independently, followed by the
mapping to the time domain achieved using a speed factor. Trajectory following is achieved with a standard multi-variable
control technique and a digital switch is used to re-optimize the reference trajectory in the event of infeasibility or mission
change. The paper includes simulations using a full dynamic model of the quadrotor demonstrating the suitability of the proposed
control scheme. 相似文献
16.
S. A. Zhdanok V. V. Martynenko S. I. Shabunya 《Journal of Engineering Physics and Thermophysics》1993,64(5):463-469
A mechanism of obtaining superadiabatic temperatures in a system of two porous plates is theoretically investigated. Data on the optimum pumping periods and on the value of the produced superadiabatic effect are presented.Academic Scientific Complex A. V. Luikov Institute of Heat and Mass Transfer of the Academy of Sciences of Belarus, Minsk. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 64, No. 5, pp. 569–576, May, 1993. 相似文献
17.
18.
Zheng Zhang Nuri William Emanetoglu Gaurav Saraf Yimin Chen Pan Wu Jian Zhong Yicheng Lu Jingqiu Chen Oleg Mirochnitchenko Masayori Inouye 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2006,53(4):786-792
DNA immobilization enhancement is demonstrated in a structure consisting of ZnO nanotips on 128 degrees Y-cut LiNbO3. The ZnO nanotips are grown by metalorganic chemical vapor deposition (MOCVD) on the top of a SiO2 layer that is deposited and patterned on the LiNbO3 SAW delay path. The effects of ZnO nanotips on the SAW response are investigated. X-ray diffraction and scanning electron microscopy are used to analyze the ZnO nanotips, which are of single crystalline quality, and they are uniformly aligned with their c-axis perpendicular to the substrate surface. The photoluminescence (PL) spectrum of the ZnO nanotips shows strong near bandedge transition with insignificant deep level emission, confirming their good optical property. DNA immobilization enhancement is experimentally validated by radioactive labeling tests and SAW response changes. The ZnO nanotips enhance the DNA immobilization by a factor of 200 compared to ZnO film with flat surface. DNA hybridization with complementary and noncomplementary second strand DNA oligonucleotides is used to study the selective binding of the structure. This device structure possesses the advantages of both traditional SAW sensors and ZnO nanostructures. 相似文献
19.
Vitaly Shubin Yury Shelygin Sergey Achkasov Oleg Sushkov Ilya Nazarov Alexey Ponomarenko Iuliia Alimova Anna Loginova Aleksey Tsukanov 《International journal of molecular sciences》2022,23(13)
The aim of this study was to determine the characteristics of Russian patients with microsatellite instability (MSI) tumors. MSI in the tumor was determined in 514 patients with colon cancer using PCR and subsequent fragment analysis for five markers (NR21, NR24, BAT25, BAT26, and NR27). In the presence of microsatellite instability, the mismatch repair (MMR) system genes were examined using the NGS and MLPA methods to establish the diagnosis of Lynch syndrome. The overall frequency of MSI tumors was 15%: at stage I—19% (9/48), at stage II—21% (44/213), at stage III—16% (26/160), and at stage IV—2% (2/93). Patients with MSI tumors differed in the age of diagnosis, tumor localization, time of cancer recurrence, and stage of the disease. The overall and disease-free survival of patients whose tumors had MSI status was higher than that of patients with microsatellite-stable status, p = 0.04 and p = 0.02, respectively. Analysis of overall and disease-free survival of patients with Lynch syndrome and patients with sporadic colon cancer, but with MSI status, did not reveal significant differences, p = 0.52 and p = 0.24, respectively. The age of patients with Lynch syndrome was significantly younger than that of patients with sporadic colon cancer whose tumors had MSI status (p < 0.001). 相似文献
20.
Using various versions of density functional theory (DFT), DFT M06/TZVP, DFT B3PW91/TZVP, DFT OPBE/TZVP, and, partially, the MP2 method, the possibility of the existence of 3d-element (M) compounds with nitrogen having unusual M: nitrogen ratio 1:12, unknown for these elements at the present, was shown. Structural parameter data were presented. It was shown that all MN4 groupings have tetragonal-pyramidal structure. It was noted that the bond lengths formed by nitrogen atoms and an M atom were equal to each other only in the case of M = Ti, V, Cr and Co, whereas for other Ms, they were slightly different; moreover, the bond angles formed by nitrogen atoms and an M atom were equal to 90.0°, or practically did not differ from this value. Thermodynamic parameters, NBO analysis data and HOMO/LUMO images for this compound were also presented. Good agreement between the calculated data obtained using the above three quantum chemical methods was also noted. 相似文献