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21.
Thinking Machines' CM-5 machine is a distributed-memory, message-passing computer. In the paper we devise a performance benchmark for the base and vector units and the data communication networks of the CM-5 machine. We model the communication characteristics such as communication latency and bandwidths of point-to-point and global communication primitives. We show, on a simple Gaussian elimination code, that an accurate static performance estimation of parallel algorithms is possible by using those basic machine properties connected with computation, vectorization, communication and synchronization. Futhermore, we describe the embedding of meshes or hypercubes on the CM-5 fat-tree topology and illustrate the performance results of their basic communication primitives.  相似文献   
22.
A simple and dynamic electronic differential control method for an outer rotor motor driven electric vehicle based on fuzzy gain scheduling of PI gains method is proposed for constant torque and power region operation using brushless direct current (BLDC) machine. The proposed method is quite insensitive to torque fluctuations and transient speed oscillations due to surface mounted permanent magnet (SMPM) BLDC machines constraints in the field weakening region. To improve the dynamics and stability of the electronic differential system and eliminate the skidding of the wheels and reduce the heating of electric machine in the wide speed range operation, a robust control method is developed. Moreover, PI controller gains are updated continuously by fuzzy gain scheduling approach which has phase advance angle, steering angle and measured speed as controller input parameters in order to eliminate the errors caused from the variable road conditions and torque oscillations in the field weakening region. The proposed method is implemented with 2 × 1.5 kW BLDC motor drive controlled by a TMS320F28335 digital signal processor (DSP). The experimental results show that the proposed method exhibits greater stability under various load, road and vehicle speed conditions.  相似文献   
23.
Invasive candidiasis, defined as candidemia and disseminated candidiasis, is the most common fungal infection in hospitalized patients. In the current study, we used Fourier transform infrared (FT-IR) spectroscopy as a rapid, non-perturbing technique to investigate the effects of disseminated candidiasis on mouse liver tissues at the molecular level. The results revealed that the infection caused compositional changes in the tissues by decreasing the lipid content and the ratio of the saturated lipids to unsaturated lipids. An increase in the lipid/protein ratio was also observed. In addition, investigation of the olefinic band at 3014 cm(-1) showed that lipid peroxidation took place in the infected samples. These results indicate that FT-IR spectroscopy is a promising technique for the evaluation and diagnosis of disseminated candidiasis.  相似文献   
24.
In response to China's new “people-oriented urbanization” strategy, investigating the current integration situation of rural-to-urban migrants (RUMs) in cities is essential. However, existing studies have not focused on their subjective willingness and adaptive capacity. Moreover, the mechanism of RUMs' urban integration has not been fully explored.The conceptual framework of vulnerability, which originated from the discipline of natural hazards, is perfectly constructive to address these drawbacks. It consists of three main components, including exposure, sensitivity, and adaptive capacity. Vulnerability index has been constructed and calculated by combining the analytic hierarchy process (AHP) and Delphi method. The spatial pattern of vulnerability level is also analyzed with geographic information system (GIS). Furthermore, the underlying mechanism of vulnerability and its associated factors are investigated with the principle component regression.Three major conclusions are reached. First, the vulnerability level of the RUMs to social exclusion presents a heterogeneous pattern between inland and coastal cities in Shandong Province. Second, while the exposure and sensitivity level of each city correlate spatially with the vulnerability level, RUMs’ adaptive capacity further moderates it. Lastly, the level of urban development is revealed to be a key factor influencing vulnerability. This study offers meaningful references to promote inclusive urbanization and sustainable urban development.  相似文献   
25.
a-SiCx:H PIN diode has been fabricated within a single pump-down process under the same deposition conditions used for doped and undoped PECVD grown thin films, whose optical and electrical properties are determined and compared with a-Si:H. Current-voltage characteristics of PIN diode are evaluated and concluded to be limited by tunnelling of holes at p-i interface into valence band tail states. Electroluminescence measurements revealed radiative monomolecular recombinations. Deconvolution of the luminescence spectra is utilized to analyse recombination mechanism to be dominated by the transitions between band tails and deep states, which are created by the large density of both silicon and carbon dangling bonds, probable in the stoichiometric a-SiCx:H film. Finally, a small luminescence peak around 1.9 eV would be an evidence of reduced probability of tail to tail transitions, than that of the transitions between tail and deep states.  相似文献   
26.
Tailoring the surfaces of a nanocontainer with polymer brushes that have different affinities to the components of a phase-separating polymer blend should impart self-directing properties to the nanocontainers. Such nanocontainers could then be used to deliver a variety of functional species in tunable amounts and in a site-specific manner to polymer systems. This paper describes the surface modification, subsequent characterization of nanocontainers derived from ferritin, and the effects of surface modification on their self-directing properties in a binary phase-separating homopolymer blend. Wild ferritin was either PEGylated or alkylated by zero-length cross-linking to its surface carboxylate groups that were activated by carbodiimide. Modification was confirmed by ion-exchange chromatography, ζ-potential measurement, and electrospray ionization mass spectrometry. FT-IR spectrometry was used to quantify the extent of PEGylation by ratioing the intensity of the C-O-C asymmetric stretching vibration from the grafted PEG to that of the carbonyl stretching vibration (amide I band) from the protein. Importantly, modified ferritin was soluble in the organic solvent dichloromethane (DCM). Modified ferritin was introduced into a polymer blend of hydrophobic and hydrophilic polymers made up of poly(desaminotyrosyl tyrosine dodecyl ester carbonate) (PDTD) and PEG by solvent casting from solution in the common solvent DCM. Polymer thin films with an average thickness of ∼200 μm were obtained upon evaporation of the solvent. Transmission electron micrographs of microtomed polymer films demonstrated remarkable selectivity of PEGylated ferritin to PEG domains, while alkylated ferritin self-directs to the PDTD matrix.  相似文献   
27.
We surveyed environmentally friendly chemicals and mild processes that could be used to avoid the high absorbable organic halogen compounds (AOX) load and damage to the environment from the waste of wool plants. In this research, we sought to achieve a new zero‐AOX processing alternative to conventional processes such as chlorine/Hercosett processing and thus use environmentally friendly enzymes and chitosan as a biopolymer. We studied enzymatic, oxidative, and additive processes and various combinations of them to improve the shrink‐proofing and antifelting properties of wool. We performed our experiments with enzymatic treatments using commercial protease preparations, such as Perizym AFW, Alcalase 2.5L, Savinase 16L, and papain. The oxidative agents were hydrogen peroxide and sodium hypochloride, and the additive agents were based on polyurethane, polysiloxane, and silicone, as well as chitosan, a hydrophilic and natural polymer. We attempted to determine the agent or combination that best improved the shrink‐proofing properties. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2903–2908, 2004  相似文献   
28.
Doping of bulk semiconductors has revealed widespread success in optoelectronic applications. In the past few decades, substantial effort has been engaged for doping at the nanoscale. Recently, doped colloidal quantum dots (CQDs) have been demonstrated to be promising materials for luminescent solar concentrators (LSCs) as they can be engineered for providing highly tunable and Stokes‐shifted emission in the solar spectrum. However, existing doped CQDs that are aimed for full solar spectrum LSCs suffer from moderately low quantum efficiency, intrinsically small absorption cross‐section, and gradually increasing absorption profiles coinciding with the emission spectrum, which together fundamentally limit their effective usage. Here, the authors show the first account of copper doping into atomically flat colloidal quantum wells (CQWs). In addition to Stokes‐shifted and tunable dopant‐induced photoluminescence emission, the copper doping into CQWs enables near‐unity quantum efficiencies (up to ≈97%), accompanied by substantially high absorption cross‐section and inherently step‐like absorption profile, compared to those of the doped CQDs. Based on these exceptional properties, the authors have demonstrated by both experimental analysis and numerical modeling that these newly synthesized doped CQWs are excellent candidates for LSCs. These findings may open new directions for deployment of doped CQWs in LSCs for advanced solar light harvesting technologies.  相似文献   
29.
In this paper, an entropy-functional-based online adaptive decision fusion (EADF) framework is developed for image analysis and computer vision applications. In this framework, it is assumed that the compound algorithm consists of several subalgorithms, each of which yields its own decision as a real number centered around zero, representing the confidence level of that particular subalgorithm. Decision values are linearly combined with weights that are updated online according to an active fusion method based on performing entropic projections onto convex sets describing subalgorithms. It is assumed that there is an oracle, who is usually a human operator, providing feedback to the decision fusion method. A video-based wildfire detection system was developed to evaluate the performance of the decision fusion algorithm. In this case, image data arrive sequentially, and the oracle is the security guard of the forest lookout tower, verifying the decision of the combined algorithm. The simulation results are presented.  相似文献   
30.
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