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91.
A 24-yr-old male patient that suffered from chronic tetany since school age. At the age of 20 tetanic convulsions occurred due to hypocalcemia. His mother also had chronic tetany due to pseudohypoparathyroidism. At the age of 24, hypocalcemia caused by pseudohypoparathyroidism was noted. Hypopotassemia persisted even when the hypocalcemia improved with the administration of 1 alpha-hydroxycholecalciferol and calcium lactate. Other findings were normal blood pressure, high levels of plasma renin activity and serum aldosterone, a fall in blood pressure after angiotensin II antagonist infusion, blunted pressor response to angiotensin II infusion and hyperplasia of the juxtaglomerular cells. These results were compatible with Bartter's syndrome. Plasma prostaglandins E2 and F2 alpha in standing position were suppressed after indomethacin administration. To our knowledge this is thought to be the first report of a case of pseudohypoparathyroidism associated with probable Bartter's syndrome.  相似文献   
92.
The decay constants of leaky surface waves in an indiffused LiNbO3Y-cut plane propagation can be controlled by electro-optic effect. According to our calculation, we can obtain about 20 dB/ cm optical switching devices for applied electric field of 3 V/μm. Our experiments show that optical switching of 14 dB/cm can be obtained for 300 V/150 μm.  相似文献   
93.
94.
Electromagnetic scattering from two-dimensional photonic crystals with two-dimensionally periodic defects is analyzed using a model of multilayered periodic arrays of parallel circular cylinders. The reflectance of the photonic crystals of finite thickness, which are free-standing or embedded in a dielectric slab, is obtained in terms of the lattice-sums, the T-matrix of a circular cylinder, and the generalized reflection matrix for a layered system. Numerical examples demonstrate that the refection and transmission bands of the crystals are reformed by introducing the periodic defects and their band natures are very sensitive to the polarization of excitation and the relative position of the defect element within a unit cell.  相似文献   
95.
The distribution of knowledge (by scientists) and data sources (advanced scientific instruments), and the need for large‐scale computational resources for analyzing massive scientific data are two major problems commonly observed in scientific disciplines. Two popular scientific disciplines of this nature are brain science and high‐energy physics. The analysis of brain‐activity data gathered from the MEG (magnetoencephalography) instrument is an important research topic in medical science since it helps doctors in identifying symptoms of diseases. The data needs to be analyzed exhaustively to efficiently diagnose and analyze brain functions and requires access to large‐scale computational resources. The potential platform for solving such resource intensive applications is the Grid. This paper presents the design and development of MEG data analysis system by leveraging Grid technologies, primarily Nimrod‐G, Gridbus, and Globus. It describes the composition of the neuroscience (brain‐activity analysis) application as parameter‐sweep application and its on‐demand deployment on global Grids for distributed execution. The results of economic‐based scheduling of analysis jobs for three different optimizations scenarios on the world‐wide Grid testbed resources are presented along with their graphical visualization. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   
96.
A Hybrid Intelligent Systems Approach for Die Design in Sheet Metal Forming   总被引:8,自引:4,他引:4  
Die design is heavily experience based and the die design process is an iterative procedure of trial and error in order to obtain a final die design for the successful manufacture of stampings. Most automotive industries use internal guidelines and past experience for die design. Even though powerful computer-aided design systems are being used in automotive industry, the lack of adequate analysis tools at the initial die geometry design stage hinders the die manufacturing process, and also necessitates lead times of the order of 5–30 weeks [1]. At the concept design stage, and during the initial die development process, the variations in geometry and process conditions are so large that it is prohibitively expensive to use 3D finite element analysis. The complexity of die design heuristic knowledge hinders the development and application of knowledge-based systems. Hybrid intelligent systems are computer programs in which at least one of the constituent models simulates intelligent behaviour [2]. These models could be knowledge-based systems, artificial neural networks, fuzzy logic systems, etc. In this approach both artificial neural networks, knowledge-based systems and finite-element analysis (FEA) for modelling the design process are used. A simulation-based design approach [3] for the die design process is followed. Artificial neural networks (ANNs) are preliminary design tools which indicate the formability of the component geometry, for the selected process and material conditions. The ANN module is trained from FEA results for a generic set of component geometries, process conditions, and material properties. The final die design validation is carried out by FEA. The intelligent frame-work incorporates rules for material selection, process parameter selection and their modification. Component geometry is a critical parameter which affects the manufacturability of the given part. Hence, an intelligent geometry handling module, which automatically modifies and optimises the geometry of the designed die, is implemented in the present system. Knowledge-based blackboard architecture is used for the integration of various analysis models such as CAD, FEA, and ANN, as an intelligent framework for die design [4]. The hybrid intelligent system provides an integrated decision support environment for simulation and analysis of the forming process, both during the initial die design phase and during the die tryout phase. The hybrid intelligent systems approach supports the capability for automatic evaluation of prospective die design for manufacturability, and performs automatic modification of design inputs. Applications of the hybrid intelligent system for die design are described together with a comparison with shop floor data.  相似文献   
97.
This paper presents the establishment of the provisional specifications and material strength standard of the high chromium (Cr) steels for fast breeder reactor (FBR) components. For the improvement of toughness and ductility of the steels, a series of mechanical tests and metallurgical examinations are performed for several kinds of high Cr steels with the controlled balance of tungsten (W) and molybdenum (Mo). In addition, the effect of heat treatment condition on material properties is also investigated. Based on these results, it is revealed that W should be diminished to achieve better ductility and toughness and that it is difficult to improve the long-term properties by changing heat treatment condition. Then the provisional specifications of the high Cr steel for FBR components are given and the provisional material strength standard is proposed for the specifications of the steel. The standard obtained in this study is utilized for the FBR plant design.  相似文献   
98.
Adult human liver microsomes supplemented with NADPH catalyzed the regioselective N-oxygenation of the aliphatic tertiary amine and S-oxidation of the phenothiazine sulfur atom of several 10-(N,N-dimethylaminoalkyl)phenothiazines. In addition, (+)- and (-)-4-bromophenyl-1,3-oxathiolane were converted to the corresponding S-oxides in the presence of NADPH and adult human liver microsomes. The (+) and (-) enantiomers of 4-bromophenyl-1,3-oxathiolane were converted to the S-oxides with low and high stereoselectivity, respectively. Studies on the biochemical mechanism for N-oxygenation of 10-(N,N-dimethylaminoalkyl)phenothiazines suggested that this reaction was catalyzed by the flavin-containing monooxygenase (form II), although cytochrome P-450 2D6 may also have contributed to N-oxide formation. S-Oxidation of chlorpromazine was catalyzed mainly by cytochrome P-450 3A. S-Oxidation of 10-(N,N-dimethylaminoalkyl)phenothiazines was catalyzed by a number of cytochromes P-450, including cytochromes P-450 2A6, 2C8, and 2D6. S-Oxygenation of (+)-4-bromophenyl-1,3-oxathiolane produced a mixture of the cis- and trans diastereomers in a process probably dependent on both hepatic monooxygenase systems. (-)-4-Bromophenyl-1,3-oxathiolane was converted almost exclusively to the trans-S-oxide in a process likely dependent on the adult human liver flavin-containing monooxygenase (form II). Development of regio- and stereochemical probes of adult human liver flavin-containing monooxygenase (form II) and cytochromes P-450 activity may be useful for eventual in vitro-in vivo correlations, but may require approaches quite distinct from that currently used for animal monooxygenases.  相似文献   
99.
100.
Earlier evidence suggests that gallbladder carcinoma (GBC) has three carcinogenic pathways; de novo development; adenoma-carcinoma sequence; and hyperplasia-carcinoma sequence associated with an anomalous arrangement of the pancreaticobiliary duct (AAPBD). We review gene abnormalities in GBC reported to date. p53 mutation and its protein overexpression are frequently observed in de novo carcinoma and GBC with AAPBD, but never found in carcinoma with adenoma. The incidence of K-ras codon 12 mutation in GBCs with AAPBD is significantly higher than that in the other types. Mutation of K-ras is never detected in carcinoma with adenoma. These findings suggest that diverse genetic pathways may exist in gallbladder carcinogenesis and reflect morphologic variations.  相似文献   
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