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571.
In this paper, we investigate the simultaneous coordination of order quantity and reorder point in a two-stage supply chain (SC). While coordination of order quantity has received much attention in the supply chain management literature, coordination of the reorder point has been less-studied. The retailer's reorder point has a direct impact on product availability and customer service level (CSL) and therefore has a great impact on SC profitability. Our proposed model adopts a two-stage SC with stochastic demand and lead times over multiple periods. The proposed coordination model assures global optimization of order quantity–reorder point decisions. Using a pricing scheme with a discount factor, we extract conditions in which both downstream and upstream members have sufficient motivation to participate in the coordination scheme. Numerical experiments demonstrate that the proposed model can achieve channel coordination. Results of the modeling and analyses show that coordination of both reorder point and order quantity can lead to increased SC profitability as well as CSL improvement. 相似文献
572.
Mohammad Saniee Abadeh Hamid Mohamadi Jafar Habibi 《Expert systems with applications》2011,38(6):7067-7075
The capability of fuzzy systems to solve different kinds of problems has been demonstrated in several previous investigations. Genetic fuzzy systems (GFSs) hybridize the approximate reasoning method of fuzzy systems with the learning capability of evolutionary algorithms. The objective of this paper is to design and analysis of various kinds of genetic fuzzy systems to deal with intrusion detection problem as a new real-world application area which is not previously tackled with GFSs. The resulted intrusion detection system would be capable of detecting normal and abnormal behaviors in computer networks. We have presented three kinds of genetic fuzzy systems based on Michigan, Pittsburgh and iterative rule learning (IRL) approaches to deal with intrusion detection as a high-dimensional classification problem. Experiments were performed with DARPA data sets which have information on computer networks, during normal and intrusive behaviors. The paper presents some results and compares the performance of different generated fuzzy rule sets in detecting intrusion in a computer network according to three different types of genetic fuzzy systems. 相似文献
573.
Sulfur mustard is an alkylating agent that reacts with ocular, respiratory, cutaneous, and bone marrow tissues. Main late respiratory complications are chronic obstructive pulmonary disease, bronchiectasis, asthma, and bronchiolitis obliterans. The aim of the present study was to identify differentially expressed proteins in bronchoalveolar lavage (BAL) fluid of control healthy and sulfur mustard-exposed lung disease patients. The BAL protein profile of ten healthy and 30 exposed patients with mild, moderate, and severe conditions (ten males in each group) were separated with 2-D SDS-PAGE and differentially expressed protein spots were successfully identified with MALDI TOF TOF MS. Among the differentially expressed proteins we observed a significant increase in vitamin D binding protein isoforms, haptoglobin isoforms, and fibrinogen especially in exposed moderate and severe lung diseases patients (p<0.01). Moreover, compared with healthy controls, significant decreases was noted in calcyphosine, surfactant protein A, and transthyretin in these patients (p<0.01). Apolipoprotein A1 was detected in all patients' BAL fluid but none of the healthy controls. Furthermore, S100 calcium-binding protein A8 was only detected in BAL fluid of moderate and severe groups. These findings will be useful to improve current methods of monitoring and helps to identify new therapeutic targets for treatment of this complicated illness. 相似文献
574.
Jafar Taheri 《Nexus Network Journal》2009,11(1):77-88
Ghiyath al-D?n Jamsh?d Kashan? (al-Kash?) is the prominent mathematician and astronomer of ninth/fifteenth century of Islamic
civilization who founded the scientific methodology in practical and theoretical knowledge of mathematics in architecture.
He played a significant role in the interaction and concurrence among mathematicians and architects, by addressing the relation
between architecture and mathematics in two areas of knowledge, theoretical and practical, the latter itself including theoretical
practice and practical practice. This paper addresses the question of how Kashan?’s research has led to the foundation of
the first theoretical basis for the application of mathematics in architecture in the form of easily practicable solutions
for drawing, and measuring different types of ceilings, arches, vaults, domes, and ornaments, as well as estimating required
materials. Further, we will discuss how his knowledge in mathematics and astronomy were utilized in management, design and
construction of Samarkand observatory and its astronomical instruments. By exploring how the mathematical knowledge of a Persian
scientist was utilized in architecture and craftsmanship, we will shed some light on the hidden layers of Kashan?’s architectural
life, who until now has been considered only a mathematician and astronomer. 相似文献
575.
Alireza Shamsi Ali Amiri Payam Heydari Hasan Hajghasem Mansour Mohtashamifar Mehrnaz Esfandiari 《Microsystem Technologies》2014,20(10-11):1925-1931
Polymer based microfabrication technologies are used extremely in Bio-MEMS, especially in Microfluidic devices in recent years. In this paper, a novel method for fabrication of microstructures on a polymeric material using hot embossing lithography process is presented. The proposed method involves usage of low cost materials and procedure with respect to previous methods and can be processed in a short time. The master is made from SU-8 on an inexpensive glass substrate which is patterned by standard lithography. The embossing pressure can be increased in our master as the glass substrate used in this paper is more robust than Silicon. Master robustness and SU-8 to glass adhesion is optimized by some substrate pretreatments and SU-8 baking time and temperatures. Microchannels are replicated on a Polymethylmetacrylate (PMMA) stamp which is a plexiglass sheet with thickness of 1 mm. Significant embossing parameters including temperature, pressure and time are discussed and optimum values are determined. Microchannels are imprinted by depth of 50 μm and minimum width of 15 μm and aspect ratio more than 3. The microchannels are sealed by a PMMA cap using thermal annealing bonding. 相似文献
576.
Jafar F. Al-Sharab Frederic Cosandey Amit Singhal Ganesh Skandan James Bentley 《Journal of the American Ceramic Society》2006,89(7):2279-2285
Nanostructured MgAl2 O4 spinel was synthesized by a direct conversion process from cubic γ-Al2 O3 . The effect of post-annealing temperature (300°, 500°, and 800°C) on MgAl2 O4 phase formation was investigated using transmission electron microscopy, selected area electron diffraction (SAED), electron energy loss spectroscopy (EELS), and energy-dispersive spectroscopy (EDS). Relative diffraction intensities as well as lattice parameter measurements from SAED revealed that MgAl2 O4 spinel structure starts forming at temperatures as low as 300°C. EELS and EDS spectrum images also revealed an increase in elemental homogeneity with increasing annealing temperature. The degree of ordering of Mg and Al between octahedral and tetrahedral sites has been determined from relative diffraction intensities. Results show that annealing to 800°C leads to a spinel phase with an order parameter of 0.78. 相似文献
577.
Combinatorial Optimization of Group Key Management 总被引:3,自引:0,他引:3
Mohamed Eltoweissy M. Hossain Heydari Linda Morales I. Hal Sudborough 《Journal of Network and Systems Management》2004,12(1):33-50
Given the growing number of group applications in many existing and evolving domains recent attention has been focused on secure multicasting over the Internet. When such systems are required to manage large groups that undergo frequent fluctuations in group membership, the need for efficient encryption key management becomes critical. This paper presents a new key management framework based on a combinatorial formulation of the group multicast key management problem that is applicable to the general problem of managing keys for any type of trusted group communication, regardless of the underlying transmission method between group participants. Specifically, we describe Exclusion Basis Systems and show exactly when they exist. In addition, the framework separates key management from encrypted message transmission, resulting in a more efficient implementation of key management. 相似文献
578.
Mohammad Yazdani-Asrami S. Asghar Gholamian Seyyed Mehdi Mirimani Jafar Adabi 《Journal of Superconductivity and Novel Magnetism》2018,31(12):3899-3910
High-temperature superconducting (HTS) technology is the most promising, advanced, and beneficial technological developments of the last two decades in terms of fabricating more efficient, compact, and reliable electrical power apparatus. The second-generation HTS wires are now quite competitive with traditional conductors from the cost point of view. In addition, they are of high interest in electrical machine manufacturing due to their unique merits such as high current density, high magnetic field, and low loss. The most significant issue for any superconducting devices which work with alternating current or magnetic field is the AC loss of the HTS tapes. Since HTS tapes are always exposed to an external magnetic field in electrical machine applications, it is vital to consider the effect of this external field on their AC magnetizing (ACMG) loss. It is well-known that external magnetic field decreases the current carrying capability of the wire. In real life, critical current density of HTS tapes is dependent to magnetic field but this dependency sometime was not considered in modeling stage in order to make it faster and simple. In this paper, the electromagnetic properties of HTS tapes for use in superconducting electric machines have been investigated with a particular focus on the ACMG loss of YBCO tapes. For this purpose, a two-dimensional finite element model has been implemented based on the H formulation in order to study the effect of dependency of critical current density to magnetic field on the variation of ACMG loss. The modeling results will be helpful for electrical machine designers to have a better understanding about this effect and have a more accurate estimate of ACMG loss in design stage. 相似文献
579.
Jafar Albinmousa Muhammed J. Adinoyi Nesar Merah 《Fatigue & Fracture of Engineering Materials & Structures》2019,42(10):2276-2289
Multiaxial monotonic and cyclic behaviors of ZK60‐T5 magnesium extrusion are investigated. Strain‐controlled tests were performed at standard laboratory condition with fully reversed straining. Twinning‐detwinning deformation plays an important role in the cyclic axial behavior for tests that were performed under strain amplitudes higher than 0.4%. However, the hysteresis loop for the 0.4% was found symmetric and no sign of twinning‐detwinning deformation was observed. On the contrary, the cyclic shear behavior was found to be similar to conventional alloys and no significant asymmetric or twinning‐detwinning deformations were observed. The multiaxial fatigue tests suggest that multiaxiality and nonproportionality are not detrimental to fatigue life. Three multiaxial fatigue damage models were used: Smith‐Watson‐Topper, Fatemi‐Socie, and Jahed‐Varvani. While Fatemi‐Socie and Jahed‐Varvani models show comparable estimation, Smith‐Watson‐Topper overestimates shear and nonproportional lives. 相似文献
580.