全文获取类型
收费全文 | 543篇 |
免费 | 36篇 |
国内免费 | 7篇 |
专业分类
电工技术 | 13篇 |
综合类 | 2篇 |
化学工业 | 146篇 |
金属工艺 | 23篇 |
机械仪表 | 23篇 |
建筑科学 | 35篇 |
矿业工程 | 3篇 |
能源动力 | 37篇 |
轻工业 | 23篇 |
水利工程 | 7篇 |
石油天然气 | 7篇 |
无线电 | 54篇 |
一般工业技术 | 103篇 |
冶金工业 | 35篇 |
原子能技术 | 2篇 |
自动化技术 | 73篇 |
出版年
2023年 | 7篇 |
2022年 | 15篇 |
2021年 | 34篇 |
2020年 | 27篇 |
2019年 | 35篇 |
2018年 | 41篇 |
2017年 | 39篇 |
2016年 | 31篇 |
2015年 | 32篇 |
2014年 | 30篇 |
2013年 | 60篇 |
2012年 | 39篇 |
2011年 | 34篇 |
2010年 | 24篇 |
2009年 | 27篇 |
2008年 | 16篇 |
2007年 | 11篇 |
2006年 | 7篇 |
2005年 | 5篇 |
2004年 | 4篇 |
2003年 | 4篇 |
2002年 | 5篇 |
2001年 | 3篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 12篇 |
1997年 | 5篇 |
1996年 | 5篇 |
1995年 | 4篇 |
1994年 | 3篇 |
1993年 | 6篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1985年 | 2篇 |
1983年 | 1篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1970年 | 2篇 |
1969年 | 1篇 |
排序方式: 共有586条查询结果,搜索用时 15 毫秒
1.
Amini Amir Jafari Azin Vafaei Mostafa Mahmoodian Mehrnoosh 《Journal of Materials Science: Materials in Electronics》2022,33(3):1293-1306
Journal of Materials Science: Materials in Electronics - The main weakness of polymer gas sensors is its stability. Here, we report stability enhancement of a 100 nm polypyrrole (PPy) thin... 相似文献
2.
Arif Karademir Cem Aydemir Semiha Yenidogan Emine Arman Kandırmaz Rukiye G. Kıter 《Color research and application》2020,45(6):1170-1178
Alkyd resins are generally used in the production of printing inks. All industries look for alternative raw materials in the production of ink with the growing inclination toward using natural products. Resins forming the vehicle of the ink to be obtained from natural resources will provide benefits for the environment, nature, and living creatures. The aim of the study was to promote the use of natural resin in the ink system. Natural Pinus pinaster resin was added into vegetable and mineral oil-based solvents in pure form with alkyd resin in different amounts and ink varnishes of different combinations were prepared. Then, printing inks were produced from these varnishes in pure and hybrid form. Following the assessment of the rheological properties of the inks prepared, printing tests were conducted to assess the printing quality parameters. Ideal mixing ratios of the natural resins in the ink were determined for printability. The environmental importance and advantages of the use of natural resins were discussed. Recommendations were given in line with the results to encourage widespread use of natural resins in near future. 相似文献
3.
Salehi Maryam Zavarian Ali Asghar Arman Ali Hafezi Fatemeh Rad Ghasem Amraee Mardani Mohsen Hamze Kooros Luna Carlos Naderi Sirvan Ahmadpourian Azin 《SILICON》2018,10(6):2743-2749
Silicon - The characterization of ion beam current density distribution and beam uniformity is crucial for improving broad-beam ion source technologies. The design of the broad ion beam extraction... 相似文献
4.
5.
Imaging of the optic disc and retinal nerve fiber layer: the effects of age, optic disc area, refractive error, and gender. 总被引:3,自引:0,他引:3
Christopher Bowd Linda M Zangwill Eytan Z Blumenthal Cristiana Vasile Andreas G Boehm Parag A Gokhale Kourosh Mohammadi Payam Amini Timothy M Sankary Robert N Weinreb 《Journal of the Optical Society of America. A, Optics, image science, and vision》2002,19(1):197-207
We cross-sectionally examined the relationship between age, optic disc area, refraction, and gender and optic disc topography and retinal nerve fiber layer (RNFL) measurements, using optical imaging techniques. One eye from each of 155 Caucasian subjects (age range 23.0-80.8 y) without ocular pathology was included. Measurements were obtained by using the Heidelberg Retina Tomography (HRT), the GDx Nerve Fiber Analyzer, and the Optical Coherence Tomograph (OCT). The effects of age were small (R2 < 17%) and were limited to specific HRT, GDx, and OCT parameters. Disc area was significantly associated with most HRT parameters and isolated GDx and OCT parameters. Refraction and gender were not significantly associated with any optic disc or RNFL parameters. Although effects of age on the optic disc and RNFL are small, they should be considered in monitoring ocular disease. Optic disc area should be considered when cross-sectionally evaluating disc topography and, to a lesser extent, RNFL thickness. 相似文献
6.
R. Zarei M. Amini S. M. Taheri A. H. Rezaei 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2012,16(1):165-174
In Classical Bayesian approach, estimation of lifetime data usually is dealing with precise information. However, in real
world, some informations about an underlying system might be imprecise and represented in the form of vague quantities. In
these situations, we need to generalize classical methods to vague environment for studying and analyzing the systems of interest.
In this paper, we propose the Bayesian estimation of failure rate and mean time to failure based on vague set theory in the
case of complete and censored data sets. To employ the Bayesian approach, model parameters are assumed to be vague random
variables with vague prior distributions. This approach will be used to induce the vague Bayes estimate of failure rate and
mean time to failure by introducing and applying a theorem called “Resolution Identity” for vague sets. In order to evaluate
the membership degrees of vague Bayesian estimate for these quantities, a computational procedure is investigated. In the
proposed method, the original problem is transformed into a nonlinear programming problem which is then divided into eight
subproblems to simplifying computations. 相似文献
7.
Yevgeniy Kim Sanzhar Nurakhayev Ayan Nurkesh Zharylkasyn Zharkinbekov Arman Saparov 《International journal of molecular sciences》2021,22(5)
Cardiovascular disease is the leading cause of mortality and morbidity around the globe, creating a substantial socio-economic burden as a result. Myocardial infarction is a significant contributor to the detrimental impact of cardiovascular disease. The death of cardiomyocytes following myocardial infarction causes an immune response which leads to further destruction of tissue, and subsequently, results in the formation of non-contractile scar tissue. Macrophages have been recognized as important regulators and participants of inflammation and fibrosis following myocardial infarction. Macrophages are generally classified into two distinct groups, namely, classically activated, or M1 macrophages, and alternatively activated, or M2 macrophages. The phenotypic profile of cardiac macrophages, however, is much more diverse and should not be reduced to these two subsets. In this review, we describe the phenotypes and functions of macrophages which are present in the healthy, as well as the infarcted heart, and analyze them with respect to M1 and M2 polarization states. Furthermore, we discuss therapeutic strategies which utilize macrophage polarization towards an anti-inflammatory or reparative phenotype for the treatment of myocardial infarction. 相似文献
8.
Barimani Samaneh Amini Amir Chaharmahali Iman 《Journal of Computational Electronics》2021,20(3):1332-1342
Wave absorbers are considered to be fundamental building blocks for the manipulation of light. Almost all optical systems exploit absorbers to realize some functions. A highly tunable wide-band THz absorber is presented herein. Utilizing a dual-bias scheme with a single graphene layer leads to greater freedom to control the absorption response, while a conventional periodic array of graphene ribbons and a layer of graphene sheet are also exploited. Also, a circuit model representation for all the constituent parts of the proposed absorber is developed with an evolved design methodology. According to the simulation results, wide-band absorption from 3.5 to 6 THz is achieved.
相似文献9.
Arman Bonakdarpour George D. Vernstrom Alison K. Schmoeckel Jeff R. Dahn 《Electrochimica acta》2007,53(2):688-694
We report on extensive measurements of oxygen reduction activity of Pt and Pt-Co-Mn electrocatalysts using the rotating ring-disk electrode (RRDE) method. The electrocatalysts were prepared by sputtering from Pt or Pt, Co and Mn targets onto 3M's nano-structured thin film support (NSTF) structures. The area specific activity of Pt/NSTF, measured in 0.1 M HClO4 and at room temperature, is similar to that of bulk Pt. The area specific measurements show a 20 mV reduction in the Pt-Co-Mn/NSTF overpotential compared to Pt/NSTF. The corresponding kinetic gain in the area specific activity of the ternary alloy is about a factor of two. This ORR enhancement factor observed in the ternary Pt-Co-Mn/NSTF by RRDE measurements is similar to the results obtained in 50 cm2 H2/air fuel cells. 相似文献
10.
Morteza Sadeghi Arman Sadeghi Mohammad Hassan Saidi 《Microfluidics and nanofluidics》2014,16(1-2):207-224
Consideration is given to the buoyancy effects on the fully developed gaseous slip flow in a vertical rectangular microduct. Two different cases of the thermal boundary conditions are considered, namely uniform temperature at two facing duct walls with different temperatures and adiabatic other walls (case A) and uniform heat flux at two walls and uniform temperature at other walls (case B). The rarefaction effects are treated using the first-order slip boundary conditions. By means of finite Fourier transform method, analytical solutions are obtained for the velocity and temperature distributions as well as the Poiseuille number. Furthermore, the threshold value of the mixed convection parameter to start the flow reversal is evaluated. The results show that the Poiseuille number of case A is an increasing function of the mixed convection parameter and a decreasing function of the channel aspect ratio, whereas its functionality on the Knudsen number is not monotonic. For case B, the Poiseuille number is decreased by increasing each of the mixed convection parameter, the Knudsen number, and the channel aspect ratio. 相似文献