全文获取类型
收费全文 | 226篇 |
免费 | 6篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 1篇 |
综合类 | 5篇 |
化学工业 | 69篇 |
金属工艺 | 2篇 |
机械仪表 | 5篇 |
建筑科学 | 1篇 |
能源动力 | 14篇 |
轻工业 | 4篇 |
水利工程 | 2篇 |
石油天然气 | 2篇 |
无线电 | 18篇 |
一般工业技术 | 70篇 |
冶金工业 | 6篇 |
自动化技术 | 34篇 |
出版年
2023年 | 7篇 |
2022年 | 6篇 |
2021年 | 4篇 |
2020年 | 8篇 |
2019年 | 8篇 |
2018年 | 18篇 |
2017年 | 13篇 |
2016年 | 11篇 |
2015年 | 10篇 |
2014年 | 8篇 |
2013年 | 21篇 |
2012年 | 11篇 |
2011年 | 17篇 |
2010年 | 11篇 |
2009年 | 14篇 |
2008年 | 10篇 |
2007年 | 7篇 |
2006年 | 3篇 |
2005年 | 5篇 |
2004年 | 2篇 |
2002年 | 4篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1988年 | 6篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1983年 | 2篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1978年 | 1篇 |
排序方式: 共有233条查询结果,搜索用时 9 毫秒
1.
In vertical co-current gas-liquid flow, the transition from annular to intermittent flow occurs when gas core becomes interrupted by liquid bridges due to the instability of the interfacial capillary waves. An analytical model is formulated to explain the liquid bridging in terms of the growth of finite amplitude interfacial capillary waves. Experimental results show that the longest wave length, which is associated with the transition, is about eight times the wave length of waves moving with the velocity of the liquid film. 相似文献
2.
Development of nano indium tin oxide (ITO) grains by alkaline hydrolysis of In(III) and Sn(IV) salts
Indium tin oxide (ITO) nano powders of different compositions (In: Sn = 90: 10, 70: 30 and 50: 50) were prepared by heat treatment
(300-450°C) of mixed hydroxides of In(III) and Sn(IV). The hydroxides were obtained by the reaction of aq. NH3 with mixed aq. solutions of In(NO3)3 and SnCl4. FTIR and TG/DTA studies revealed that powders existed as In(OH)3H2O—SnO3H2H2O in the solid state and then they transformed to In2O3—SnO2 via some metastable intermediates after 300°C. Cubic phase of In2O3 was identified by XRD for the oxides up to 30% of Sn. Particle size measurements of the solid dispersed in acetone and SEM
study for microstructure showed that the oxides were in the nano range (55-75 nm) whereas the size range determined from Debye-Scherrer
equation were 11–24 nm. 相似文献
3.
4.
E. Sriram Prasath Sreraman Muralidharan Chiranjib Mitra Prasanta K. Panigrahi 《Quantum Information Processing》2012,11(2):397-410
We investigate the entanglement properties of the two magnon states and explicate conditions under which, the two magnon state
becomes useful for several quantum communication protocols. We systematically study the temporal behaviour of concurrence
to find out the effect of exchange interaction on entanglement. The two magnon state, which is potentially realizable in quantum
dots using Heisenberg exchange interaction, is found to be suitable for carrying out deterministic teleportation of an arbitrary
two qubit composite system. Further, conditions for which the channel capacity reaches “Holevo bound”, allowing four classical
bits to be transmitted through two qubits are derived. Later, an unconventional protocol is given to demonstrate that this
state can be used for sharing of a two qubit entangled state among two parties. 相似文献
5.
Swapan Kumar Mandal Rabindra Nath Datta Prasanta Kumar Das Dipak Kumar Basu 《应用聚合物科学杂志》1988,35(4):987-994
The reaction between bis(diisopropyl) thiophosphoryl disulfide (DIPDIS) and silica has been investigated. The study reveals that DIPDIS can be used as a coupling agent for silica. The chemical bond between the silanol groups of silica and DIPDIS has been established through the isolation and characterization of isopropyl alcohol that is eliminated from the reaction. The chemical nature of the bond is also supported by the IR analysis of the reaction products of silica and DIPDIS obtained both in the presence and absence of rubber. From the exploratory studies it is indicated that DIPDIS can also react with NR even during mixing of ingredients. When used with 2-mercaptobenzothiazole (MBT) or N-oxydiethylene-2-benzothiazole sulfenamide (OBTS) in the presence of silica, DIPDIS exhibits notable activation of cure and enhances the torque, modulus, tensile strength, and the scorch safety. 相似文献
6.
为全面了解对美国中部Illinois州具有浅层排水系统的轮作农业地区的面源污染问题,利用主成分分析方法及多元线性回归,对Little Vermillion River流域磷流失影响因素主成分进行分析.结果表明,磷流失的影响因素基本分为3大主成分:一是生物主成分,包括温度、植被类型、覆盖因子、生物量、散蒸量;二是水力主成分,降雨及流量;三是人为干扰主成分,施肥量及耕作内容.其中水力主成分对流失的影响最大,尤其是对浅层排水中磷流失的影响. 相似文献
7.
In this paper, the forced convective heat transfer enhancement with nanofluids in a 90° pipe bend has been presented. Numerical investigation is carried out for the turbulent flow through the pipe employing finite volume method. The governing differential equations are discretized using hexahedral cells, and the resulting algebraic equations are solved using Commercial solver Fluent 6.3. In order to close the time averaged Navier–Stokes equations, the two-equation k–? turbulence model with a standard wall function have been used. The duct Reynolds number is varied in the range of 2,500–6,000. It is observed that the heat transfer is enhanced significantly by varying the volume fraction of the nanofluid. It is also found that the heat transfer is increased with Reynolds number. A strong secondary flow is observed due to the presence of the wall. Turbulent kinetic energy near outer wall is found to be higher than the inner wall of the bend. A comparative assessment for the heat transfer enhancement with different types of nanofluids is also presented. The computed results of area weighted average Nusselt numbers are validated with some of the existing literature. 相似文献
8.
Bikash K. Behera Anindita Banerjee Prasanta K. Panigrahi 《Quantum Information Processing》2017,16(12):312
Quantum cheques could be a forgery-free way to make transaction in a quantum networked banking system with perfect security against any no-signalling adversary. Here, we demonstrate the implementation of quantum cheque, proposed by Moulick and Panigrahi (Quantum Inf Process 15:2475–2486, 2016), using the five-qubit IBM quantum computer. Appropriate single qubit, CNOT and Fredkin gates are used in an optimized configuration. The accuracy of implementation is checked and verified through quantum state tomography by comparing results from the theoretical and experimental density matrices. 相似文献
9.
Prasanta Das Samir Charola Milan Dinda Himanshu Patel Subarna Maiti 《International Journal of Hydrogen Energy》2017,42(21):14471-14484
Hydrogen can be cited as prospective source of clean power. In this work hydrogen rich syn-gas generated from the agro-waste, empty cotton bolls was injected into an IC engine in continuous mode along with gasoline. At the air-fuel ratio of 23.40, specific fuel consumption of 0.35 kg kWh?1, the engine could be operated with higher efficiency than with gasoline alone. A distinct reduction in emission characteristics could also be seen. Empty cotton bolls derived after removal of cotton from the flower in field, was first studied for fuel properties. The reasonably high heating value (HHV) of 17.54 MJ kg?1 suggested that it could be a precursor to hydrogen via two stepped thermo-chemical process. The first step involved slow pyrolysis of the biomass at 500 °C for 60 min at a heating rate of 10 °C min?1 yielding 39.71% bio-char by weight. The C, H, N, S and O contents of the produced bio-char was 59.91, 2.91, 0.72, 0.47 and 35.99% respectively and its HHV was 26.7 MJ kg?1. Steam gasification of this bio-char, at 700 °C and water flowrate of 7 mL min?1 exhibited maximum hydrogen yield of 67.42% (v/v) in the syn-gas mixture. Subsequent enrichment of the gas using ethanolamine/ethylene diamine and KMnO4 solutions resulted in more than 90% (v/v) hydrogen in the combustible gas mixture and the test engine could be effectively operated. 相似文献
10.