全文获取类型
收费全文 | 1632篇 |
免费 | 115篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 23篇 |
综合类 | 2篇 |
化学工业 | 464篇 |
金属工艺 | 34篇 |
机械仪表 | 20篇 |
建筑科学 | 69篇 |
矿业工程 | 6篇 |
能源动力 | 45篇 |
轻工业 | 219篇 |
水利工程 | 11篇 |
石油天然气 | 2篇 |
无线电 | 98篇 |
一般工业技术 | 272篇 |
冶金工业 | 137篇 |
原子能技术 | 6篇 |
自动化技术 | 341篇 |
出版年
2024年 | 5篇 |
2023年 | 20篇 |
2022年 | 44篇 |
2021年 | 63篇 |
2020年 | 36篇 |
2019年 | 57篇 |
2018年 | 64篇 |
2017年 | 62篇 |
2016年 | 66篇 |
2015年 | 56篇 |
2014年 | 90篇 |
2013年 | 115篇 |
2012年 | 127篇 |
2011年 | 110篇 |
2010年 | 99篇 |
2009年 | 96篇 |
2008年 | 93篇 |
2007年 | 81篇 |
2006年 | 62篇 |
2005年 | 44篇 |
2004年 | 41篇 |
2003年 | 32篇 |
2002年 | 49篇 |
2001年 | 21篇 |
2000年 | 28篇 |
1999年 | 15篇 |
1998年 | 23篇 |
1997年 | 20篇 |
1996年 | 18篇 |
1995年 | 17篇 |
1994年 | 8篇 |
1993年 | 16篇 |
1992年 | 13篇 |
1991年 | 11篇 |
1990年 | 3篇 |
1989年 | 5篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1983年 | 4篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1979年 | 4篇 |
1976年 | 3篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1970年 | 1篇 |
1968年 | 1篇 |
排序方式: 共有1749条查询结果,搜索用时 15 毫秒
1.
Belcher Calvin H. Zheng Baolong MacDonald Benjamin E. Langlois Eric D. Lehman Benjamin Pearce Charles Delaney Robert Apelian Diran Lavernia Enrique J. Monson Todd C. 《Journal of Materials Science》2022,57(9):5518-5532
Journal of Materials Science - For transformers and inductors to meet the world’s growing demand for electrical power, more efficient soft magnetic materials with high saturation magnetic... 相似文献
2.
Cuevas-Glory Luis F. Sosa-Moguel Odri Pino Jorge Sauri-Duch Enrique 《Food Analytical Methods》2015,8(4):1005-1013
Food Analytical Methods - The habanero pepper (Capsicum chinense Jacq.) is very aromatic and is the hottest pepper in the world. In this study, a headspace solid-phase microextraction/gas... 相似文献
3.
Scientometrics - The purpose of this study is to ascertain the suitability of GS’s url-based method as a valid approximation of universities’ academic output measures, taking into... 相似文献
4.
Mostafa Dellahi Hattab Maker Guillermo Botella Enrique Alameda-Hernandez Azeddine Mouhsen 《International Journal of Circuit Theory and Applications》2020,48(6):887-905
The three-phase four-wire shunt active power filter (SAPF) was developed to suppress the harmonic currents generated by nonlinear loads, and for the compensation of unbalanced nonlinear load currents, reactive power, and the harmonic neutral current. In this work, we consider instantaneous reactive power theory (PQ theory) for reference current identification based on the following two algorithms: the classic low-pass filter (LPF) and the second-order generalized integrator (SOGI) filter. Furthermore, since an important process in SAPF control is the regulation of the DC bus voltage at the capacitor, a new controller based on the Lyapunov function is also proposed. A complete simulation of the resultant active filtering system confirms its validity, which uses the SOGI filter to extract the reference currents from the distorted line currents, compared with the traditional PQ theory based on LPF. In addition, the simulation performed also demonstrates the superiority of the proposed approach, for DC bus voltage control based on the Lyapunov function, compared with the traditional proportional-integral (PI) controller. Both novel approaches contribute towards an improvement in the overall performance of the system, which consists of a small rise and settling time, a very low or nonexistent overshoot, and the minimization of the total harmonic distortion (THD). 相似文献
5.
6.
Enrique Alexandre Antonio Pena Manuel Sobreira 《IEEE transactions on information technology in biomedicine》2006,10(4):809-811
This paper discusses the convenience of using two-dimensional (2-D) coding techniques for the compression of electrocardiogram (ECG) signals. These signals present a very clear periodicity that can be exploited by the use of a 2-D time/frequency transform to decorrelate it as much as possible. A brief theoretical approach is given to justify the use of this technique, and a comparison is made between a 2-D and a one-dimensional (1-D) uniform quantization scenarios. The influence of the error as well as the frame size on the estimation of the fundamental period is studied. 相似文献
7.
A quasi-analytical method for computing the quasi-static-TEM parameters of the generalized coplanar waveguide (GCPW) is reported. The structure is assumed to be enclosed in a rectangular frame and embedded in a layered medium. Essentially, the method is an analytically enhanced spectral domain formulation. Its application leads to virtually exact results in very short CPU times, making it suitable for CAD purposes. Although the method is somewhat more time consuming than conformal mapping approaches, it is a useful alternative because of its exactness and ability to deal with multilayer structures. © 1994 John Wiley & Sons, Inc. 相似文献
8.
9.
Gonzalo Martínez‐Barrera Enrique Vigueras‐Santiago Susana Hernndez‐Lpez Gonzalo Martínez‐Barrera Witold Brostow Carmina Menchaca‐Campos 《Polymer Engineering and Science》2005,45(10):1426-1431
Fiber reinforced concrete (FRC) contains fibers physically mixed with gravel, sand, cement, and water. So far, adequate mechanical performance of FRC has been obtained at high cost and using complex technologies; important here is the geometry and surface characteristics of the polymers. We have modified polymeric‐fiber surfaces by using gamma radiation. Irradiated polypropylene (PP) fibers were submitted to 0, 5, 10, 50, and 100 kGy of gamma irradiation dosages. First, tensile strength of PP fibers was evaluated, and then fibers blended at 0, 1.0, 1.5, and 2.0% in volume with Portland cement, gravel, sand, and water. The highest values of compressive strength were obtained with irradiated‐fibers at 10 kGy and 1.5% in volume of fiber. The result is 101 MPa, as compared to 35 MPa for simple concrete without fibers. POLYM. ENG. SCI., 45:1426–1431, 2005. © 2005 Society of Plastics Engineers 相似文献
10.
Yaojun Lin Yizhang Zhou Enrique J. Lavernia Kevin M. McHugh 《Metallurgical and Materials Transactions A》2004,35(11):3633-3635
From the geometrical standpoint, this article presents a qualitative theoretical analysis and prediction of the transient
to steady-state transition during the spray-rolling process, a novel manufacturing technique for aluminum strips. The analytical
results indicate that, when the deposited materials at the specific points on one roll surface overlap their counterparts
on the other roll surface, spray rolling transits from the transient state to the steady state. The specific points are the
limiting deposition positions of the atomized droplets on the roll surface initially. 相似文献