全文获取类型
收费全文 | 117篇 |
免费 | 0篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 29篇 |
金属工艺 | 2篇 |
机械仪表 | 1篇 |
能源动力 | 17篇 |
轻工业 | 1篇 |
石油天然气 | 1篇 |
无线电 | 20篇 |
一般工业技术 | 22篇 |
冶金工业 | 5篇 |
原子能技术 | 3篇 |
自动化技术 | 15篇 |
出版年
2023年 | 1篇 |
2022年 | 4篇 |
2021年 | 5篇 |
2020年 | 5篇 |
2019年 | 2篇 |
2018年 | 2篇 |
2017年 | 2篇 |
2015年 | 1篇 |
2014年 | 3篇 |
2013年 | 12篇 |
2012年 | 3篇 |
2011年 | 5篇 |
2010年 | 4篇 |
2009年 | 7篇 |
2008年 | 7篇 |
2007年 | 6篇 |
2006年 | 3篇 |
2005年 | 2篇 |
2004年 | 7篇 |
2003年 | 4篇 |
2002年 | 3篇 |
2000年 | 4篇 |
1999年 | 6篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有117条查询结果,搜索用时 15 毫秒
101.
New multidimensional digital structures that use the concept of
a generalized immittance converter are presented in this paper.
The proposed filter structures are regular and modular, and they
realize multiple transfer functions simultaneously; hence, they
are attractive for very large-scale integration implementation.
It is shown that these filter structures can be obtained by
using a few specific digital modules as building blocks. The
arrangements of the modules and the values of the multiplier
constants that are used in these modules can be obtained
directly from the specified discrete transfer function by using
a computer program. 相似文献
102.
M. Sharma R. Bhatia V. Gupta S. Chand P. Raghunathan S.V. Eswaran 《Synthetic Metals》2011,161(9-10):844-849
Two mono-adducts of fullerene C60 have been synthesised using new aryl azides in good yields. These were characterized with spectroscopic techniques and then used to fabricate bulk heterojunction solar cells with regioregular poly (3-hexylthiophene) (RR-P3HT). A photocurrent density of 3.89 mA/cm2, open-circuit voltage of 0.53 V and power conversion efficiency of 0.89% for adduct I and photocurrent density of 2.93 mA/cm2, open-circuit voltage of 0.53 V and power conversion efficiency of 0.71% for adduct II have been achieved. 相似文献
103.
Eswaran K. Sarwate A.D. Sahai A. Gastpar M.C. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》2010,56(1):25-39
The utility of limited feedback for coding over an individual sequence of discrete memoryless channels is investigated. This study complements recent results showing how limited or noisy feedback can boost the reliability of communication. A strategy with fixed input distribution P is given that asymptotically achieves rates arbitrarily close to the mutual information induced by P and the state-averaged channel. When the capacity-achieving input distribution is the same over all channel states, this achieves rates at least as large as the capacity of the state-averaged channel, sometimes called the empirical capacity. 相似文献
104.
For numerical simulations of the combustion of liquid fuels, a thoroughly validated and verified quantitative model for droplet evaporation is necessary. In this work a simple single droplet infinite conductivity model is simulated for low pressure (0.1 MPa) and various temperatures (550–1050 K) using a chosen property rule (see Eq. (7)) and five convection correlations (C1, C2, C3, C4, and C5, see (Table 1) to obtain the temporal evolution of droplet diameter squared, droplet surface temperature and average evaporation rates of vegetable oil derived biofuels – rapeseed methyl ester (RME) and sunflower methyl ester (SME) – under near-quiescent conditions. The predictions are compared with the experimental and analytical results of Morin et al. [1]. The model uses an effective Reynolds number to conflate the effects of forced and natural convection. It is observed that the predicted temporal history of droplet diameter for RME droplet matches more closely with correlation C1 for Tamb ? 748 K and correlation C2 for Tamb ? 803 K at various ambient temperatures (i.e., from low to high evaporation rate). The correct droplet lifetime is predicted best by C1 for all temperatures. For average evaporation rates for SME, C1 best fits the experimental data. For the average evaporation rate of RME, the present model with C1 gives a better prediction than the theoretical, and corrected theoretical results of Morin et al. [1], and is observed to match closely with their experimental results. The present results using C2 are also found close to the experimental results for RME and SME. It is observed that the oxidation of RME/SME is similar to n-decane – a pure component fuel. 相似文献
105.
The forced convection heat transfer characteristics for an incompressible and steady flow of power law liquids in fixed and extended beds of spherical particles has been studied numerically. The sphere-sphere hydrodynamic interactions have been accounted for by using a simple cell model. Within the framework of such a cell model, the momentum and energy equations have been solved using a finite difference method to obtain the velocity and temperature fields. Extensive numerical estimates of the local and average Nusselt numbers as functions of the physical, rheological and kinematic variables have been presented and discussed for the two commonly employed thermal boundary conditions. In broad terms, the Nusselt number for power law fluids (both shear-thinning and shear-thickening conditions) normalized with respect to the corresponding value for a Newtonian fluid shows weak additional dependence on the power law flow behaviour index. The shear-thinning behaviour is seen to promote heat transfer and as expected the shear-thickening behaviour impedes heat transfer in fixed and fluidised beds. All in all, the present results encompass wide ranges of conditions as follows: Reynolds number: 1-500; Peclet number: 1-500; bed voidage: 0.4-0.8 and the flow behaviour index: 0.5-1.8 thereby covering extremely shear-thinning and shear-thickening types of fluid behaviours. The paper is concluded by presenting detailed comparisons with the limited analytical and/or experimental results available for liquid-solid mass transfer in such systems. 相似文献
106.
This paper presents techniques for image reconstruction and recognition using autoencoders. Experiments are conducted to compare
the performances of three types of autoencoder neural networks based on their efficiency of reconstruction and recognition.
Reconstruction error and recognition rate are determined in all the three cases using the same architecture configuration
and training algorithm. The results obtained with autoencoders are also compared with those obtained using principal component
analysis method. Instead of whole images, image patches are used for training, and this leads to much simpler autoencoder
architectures and reduced training time. 相似文献
107.
Wind-induced and earthquake-induced vibrations of structures such as super-tall towers and bridges can be efficaciously controlled by tuned liquid dampers (TLDs). This work presents a numerical simulation procedure to study the performance of TLDs–structure system through sigma (\( \sigma \))-transformation-based fluid–structure coupled solver. For this, a ‘C’-based computational code has been developed. The structural equations, which are coupled with the fluid equations in order to achieve the transfer of sloshing forces to structure for damping, are solved by the fourth-order Runge–Kutta method, while the fluid equations are solved using finite-difference-based sigma-transformed algorithm. Different iterative and error schemes are used to optimize the code for larger convergence rate and higher accuracy. For validation, a few experiments are conducted with a three-storey structure using TLDs arrangement. The present numerical results of response of TLD-installed structures match well with the experimental results. The minimum displacement of structure is observed when the resonance condition of the coupled system is achieved through proper tuning of TLDs. Since real-time excitations are random in nature, the performance study of TLDs under random excitation has also been carried out in which the Bretschneider spectrum is used to generate the random input wave. 相似文献
108.
Suresh Kumar Vignesh Kumar Ponnuswamy Renuka Devi Saru Harish Eswaran Hemananthan 《IET nanobiotechnology / IET》2017,11(1):104
Thymoquinone (TQ), a major bioactive compound of Nigella sativa seeds has several therapeutic properties. The main drawback in bringing TQ to therapeutic application is that it has poor stability and bioavailability. Hence a suitable carrier is essential for TQ delivery. Recent studies indicate biodegradable polymers are potentially good carriers of bioactive compounds. In this study, polyethylene glycol (PEG) modified chitosan (Cs) nanocapsules were developed as a carrier for TQ. Aqueous soluble low molecular weight Cs and PEG was selected among different biodegradable polymers based on their biocompatibility and efficacy as a carrier. Optimisation of synthesis of nanocapsules was done based on particle size, PDI, encapsulation efficiency and process yield. A positive zeta potential value of +48 mV, indicating good stability was observed. Scanning electron microscope and atomic‐force microscopy analysis revealed spherical shaped and smooth surfaced nanocapsules with size between 100 to 300 nm. The molecular dispersion of the TQ in Cs PEG nanocapsules was studied using X‐ray powder diffraction. The Fourier transform infrared spectrum of optimised nanocapsule exhibited functional groups of both polymer and drug, confirming the presence of Cs, PEG and TQ. In vitro drug release studies showed that PEG modified Cs nanocapsules loaded with TQ had a slow and sustained release.Inspec keywords: nanomedicine, drug delivery systems, polymers, scanning electron microscopy, electrokinetic effects, atomic force microscopy, X‐ray diffraction, Fourier transform infrared spectraOther keywords: PEG modified chitosan nanocapsules, thymoquinone, bioactive compound, Nigella sativa seeds, bioavailability, polyethylene glycol, molecular weight, zeta potential, scanning electron microscope, atomic force microscopy, molecular dispersion, X‐ray powder diffraction, Fourier transform infrared spectrum 相似文献
109.
110.
A cardanol/m‐cresol‐based copolymer was esterified using di‐tert‐butyl dicarbonate (t‐BOC), which makes it a suitable candidate as a possible e‐beam resists. This work reports a full characterization of the product using the techniques of FTIR and UV–Visible spectroscopy, one dimensional 1H NMR, 13C NMR, DEPT‐135. Two dimensional NMR experiments such as, COSY, HSQC, and HMBC have been employed for exhaustive probing of the microstructural details of this derivatized copolymer. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献