全文获取类型
收费全文 | 1537篇 |
免费 | 48篇 |
国内免费 | 2篇 |
学科分类
工业技术 | 1587篇 |
出版年
2023年 | 19篇 |
2022年 | 37篇 |
2021年 | 49篇 |
2020年 | 42篇 |
2019年 | 53篇 |
2018年 | 50篇 |
2017年 | 53篇 |
2016年 | 43篇 |
2015年 | 33篇 |
2014年 | 46篇 |
2013年 | 154篇 |
2012年 | 65篇 |
2011年 | 75篇 |
2010年 | 74篇 |
2009年 | 54篇 |
2008年 | 54篇 |
2007年 | 50篇 |
2006年 | 44篇 |
2005年 | 31篇 |
2004年 | 21篇 |
2003年 | 21篇 |
2002年 | 17篇 |
2001年 | 10篇 |
2000年 | 20篇 |
1999年 | 27篇 |
1998年 | 29篇 |
1997年 | 36篇 |
1996年 | 25篇 |
1995年 | 25篇 |
1994年 | 28篇 |
1993年 | 27篇 |
1992年 | 22篇 |
1991年 | 27篇 |
1990年 | 14篇 |
1989年 | 21篇 |
1988年 | 16篇 |
1987年 | 20篇 |
1986年 | 14篇 |
1985年 | 24篇 |
1984年 | 22篇 |
1983年 | 10篇 |
1982年 | 8篇 |
1981年 | 12篇 |
1980年 | 10篇 |
1979年 | 7篇 |
1978年 | 9篇 |
1977年 | 6篇 |
1976年 | 8篇 |
1975年 | 5篇 |
1973年 | 5篇 |
排序方式: 共有1587条查询结果,搜索用时 15 毫秒
11.
The Journal of Supercomputing - In this article, the authors suggested a rotation-invariant local binary pattern-based weighted generalized closest neighbor (RILBP-WGCN) method for HSI... 相似文献
12.
Sinha Swati Shaw Siddharth Biswas Kunal De Debashis Das Samir Chandra Sarkar Angsuman Bandyopadhyay Jaya 《Microsystem Technologies》2021,27(11):4087-4100
Microsystem Technologies - Single-Walled Carbon Nanotubes (SWCNTs) are widely used as potential carriers in drug delivery systems. The objective of this work was to observe the effects of pristine,... 相似文献
13.
A mathematical model for the transient heat flow analysis in arc-welding processes is proposed, based on a unique set of boundary conditions. The model attempts to make use of the relative advantages of analytical as well as numerical techniques in order to reduce the problem size for providing a quicker solution without sacrificing the accuracy of prediction. The variation of thermo-physical properties with temperature has been incorporated into the model to improve the thermal analysis in the weld and heat-affected zones. The model has been evaluated using a five-point explicit finite difference method for analysing the welding heat flow in thin plates of two different geometric configurations. The temperature distribution closer to the heat source, primarily in the weld zone and the heat-affected zones, are predicted by the numerical technique. The thermal characteristics beyond the heat-affected zone are amenable to standard analytical techniques. The behaviour of the boundary condition in the model has been investigated in detail.Nomenclature
q
Rate of heat per unit thickness (Wm–1)
-
d
Plate thickness (m)
-
v
Velocity of source (m s–1)
-
t
Time (s)
-
T
Temperature value at the desired point (K)
-
T
0
Initial temperature (K)
-
K
Thermal conductivity (W m–1 K–1)
-
Density (kg m–3)
-
c
p
Specific heat (J kg–1 K–1)
-
Thermal diffusivity (m2 s–1)
-
n
-
Distance of point considered from the source (=x–vt) (m)
-
K
0
Modified Bessel function of second kind and zero order
-
r
Radial distance from the source (r=(x
2+y
2)1/2) (m)
-
Model width (m)
-
a
Plate width (m)
-
Distance from the source =(2+4 ×10–4)1/2 (m)
- n
相似文献
14.
Biswas Uttara Rakshit Jayanta Kumar Das Joyashree Bharti Gaurav Kumar Suthar Bhuvneshwer Amphawan Angela Najjar Monia 《SILICON》2021,13(3):885-892
Silicon - In the present report, a photonic crystal based micro-ring resonator (MRR) structure is proposed which is very compact in size and has very fast response and is employed for temperature... 相似文献
15.
Removal of chromium (VI) from dilute aqueous solutions by activated carbon developed from Terminalia arjuna nuts activated with zinc chloride 总被引:1,自引:0,他引:1
Different structured activated carbons were prepared from Terminalia arjuna nuts, an agricultural waste, by chemical activation with zinc chloride for the adsorption of Cr(VI) from dilute aqueous solutions. The most important parameter in chemical activation was found to be the chemical ratio (activating agent/precursor, g/g). Carbonization temperature and time are the other two important variables, which had significant effect on the pore structure of carbon. A high surface area of was obtained at a chemical ratio of 300%, carbonization time and temperature of 1 h and 500 °C, respectively. The activated carbon developed shows substantial capability to adsorb Cr(VI) from dilute aqueous solutions. The parameters studied include pH, adsorbent dosage, contact time, and initial concentrations. The kinetic data were best fitted to the Lagergren pseudo-first-order model. The isotherm equilibrium data were well fitted by the Langmuir and Freundlich models. The maximum removal of chromium was obtained at pH 1.0 (about 99% for adsorbent dose of 2 g/l and 10 mg/l initial concentration). 相似文献
16.
The rates of absorption of CO2 into water and 0.1 kmol/m3 aqueous solutions of MEA, DEA and AMP were measured in a stirred cell with a flat gas-liquid interface in the presence of fine activated carbon particles. Experiments showed that the rates of absorption increased significantly with increases in the loading of activated carbon up to about 6 kg/m3 and thereafter remained constant. 相似文献
17.
This paper reports on the experimental investigation carried out to evaluate fractional dispersed phase holdup for a gas‐liquid mixture in a modified multi‐stage bubble column (with contraction and expansion disks), which has been conceived, designed and fabricated as a wet scrubber for control of air pollution; in addition it has versatile use as a gas‐liquid contactor in chemical process industries. A correlation developed for predicting fractional dispersed phase holdup has been found to be encouraging and highly significant from statistical analysis. 相似文献
18.
This article presents a series of user studies to develop a new eye-gaze tracking–based pointing system. We developed a new target prediction model that works for different input modalities and combined the eye-gaze tracking–based pointing with a joystick controller that can reduce pointing and selection times. The system finds important applications in cockpit of combat aircraft and for computer novice users. User studies confirmed that users can perform significantly faster using this new eye-gaze tracking–based system for both military and everyday computing tasks compared to existing input devices. As part of the study it was also found that the amplitude of maximum power component obtained through Fourier Transform of pupil signal significantly correlates with selection times and perceived cognitive load of users in terms of Task Load Index scores. 相似文献
19.
Bahni Ray Dipankar Bandyopadhyay Ashutosh Sharma Sang Woo Joo Shizhi Qian Gautam Biswas 《Microfluidics and nanofluidics》2013,15(1):19-33
Spatiotemporal deformations of the free charged surface of a thin electrolyte film undergoing a coupled electrokinetic flow composed of an electroosmotic flow (EOF) on a charged solid substrate and an electrophoretic flow (EPF) at its free surface are explored through linear stability analysis and the long-wave nonlinear simulations. The nonlinear evolution equation for the deforming surface is derived by considering both the Maxwell’s stresses and the hydrodynamic stresses. The electric potential across the film is obtained from the Poisson–Boltzmann equation under the Debye–Hückel approximation. The simulations show that at the charged electrolyte–air interface, the applied electric field generates an EPF similar to that of a large charged particle. The EOF near the solid–electrolyte interface and the EPF at the electrolyte–air interface are in the same (or opposite) directions when the zeta potentials at the two interfaces are of the opposite (or same) signs. The linear and nonlinear analyses of the evolution equation predict the presence of travelling waves, which is strongly modulated by the applied electric field and the magnitude/sign of the interface zeta potentials. The time and length scales of the unstable modes reduce as the sign of zeta potential at the two interfaces is varied from being opposite to same and also with the increasing applied electric field. The increased destabilization is caused by a reverse EPF near the free surface when the interfaces bear the same sign of zeta potentials. Flow reversal by EPF at the free surface occurs at smaller zeta potential of the free surface when the film is thicker because of less influence of the EOF arising at the solid–electrolyte boundary. The amplitude of the surface waves is found to be smaller when the unstable waves travel at a faster speed. The films can undergo pseudo-dewetting when the free surface is almost stationary under the combined influences of EPF and EOF. The free surface instability of the coupled EOF and EPF has some interesting implications in the development of micro/nano fluidic devices involving a free surface. 相似文献
20.
Pal Tumpa Saha Ramesh Biswas Suparna 《International Journal of Wireless Information Networks》2022,29(3):373-392
International Journal of Wireless Information Networks - In this work, energy efficient routing protocol variants considering different sink mobility in hierarchical cluster based wireless sensor... 相似文献