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131.
GA-ILP Method for Optimization of Water Distribution Networks   总被引:4,自引:4,他引:0  
Optimization of water distribution networks has been of central importance for recent decades. Genetic Algorithms (GA) are the most famous metaheuristics widely used for this purpose with great success. However, the fact that GA basically requires a large number of computations, has led to investigate for faster solvers. In this research, a new approach is proposed in which a simple GA is linked with the Integer-Linear Programming (ILP) method resulting in a hybrid optimization scheme. Using the mathematical method of ILP, the search space is significantly reduced thereby a limited number of evaluations are required to achieve a good solution. The approach is applied to two benchmark pipe-networks in order to show its ability in terms of accuracy and speed. The results are then compared with the previous works. The obtained results indicate that the proposed model is computationally efficient, like classic methods, while is still very promising in finding the global optimum like the nature-inspired metaheuristics.  相似文献   
132.
In this work, the authors investigated the apoptotic activities of Fe3 O4 /Ag nanocomposite biosynthesised by Spirulina platensis extract against MCF‐7 (human breast cancer cells). The physico‐chemical properties of prepared Fe3 O4 /Ag nanocomposite were studied by different spectroscopic methods. To evaluate the in vitro cytotoxic effect, MCF‐7 cells were treated with different concentrations of Fe3 O4 /Ag nanocomposite and examined by 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl‐tetrazolium bromide (MTT) assay. Moreover, apoptotic effects were also studied by Hoechst 33258 staining, caspase 3 activation assays, and annexin V‐fluorescein isothiocyanate (FITC) and propidium iodide staining. Microscopic observations of Fe3 O4 /Ag nanocomposites indicated approximately spherical shape and small particles in the size range of about 30–50 nm. The MTT assay result revealed that the Fe3 O4 /Ag nanocomposite causes a dose‐dependent cell proliferation reduction in MCF‐7 cells (IC50  = 135 μg/ml). Regarding to the Annexin V/PI staining result, the increase percentage of apoptotic cells (28.09%) was detected as compared to untreated cells. According to the caspase assay, Fe3 O4 /Ag nanocomposite enhances caspase 3 level. Furthermore, in vitro anti‐cancer activity of the nanocomposite was performed by Hoechst 33258 staining method. The proposed data suggest that Fe3 O4 /Ag nanocomposite may be an effective agent for the inhibition of breast cancer cells at in vitro level.Inspec keywords: nanomedicine, nanocomposites, toxicology, cancer, drug delivery systems, nanofabrication, cellular biophysics, nanoparticlesOther keywords: MCF‐7 cells, 5‐diphenyl‐tetrazolium, apoptotic effects, propidium iodide staining, dose‐dependent cell proliferation reduction, apoptotic cells, untreated cells, nanocomposite, Hoechst 33258 staining method, human breast cancer cells, physico‐chemical properties, spectroscopic methods, in vitro cytotoxic effect, in vitro anticancer activity, biosynthesis, caspase 3 activation assays, annexin V‐fluorescein isothiocyanate, FITC, Fe3 O4 ‐Ag  相似文献   
133.
The development and application of inventory models for deteriorating items is one of the main concerns of subject matter experts. The inventory models developed in this field have focused mainly on supply chains under the assumption of constant lead time. In this study, we develop an inventory model for a main class of deteriorating items, namely perishable products, under stochastic lead time assumption. The inventory system is modeled as a continuous review system (r, Q). Demand rate per unit time is assumed to be constant over an infinite planning horizon and the shortages could be backordered completely. For modeling the deterioration process, a non-linear holding cost is considered. Taking into account the stochastic lead time as well as a non-linear holding cost makes the mathematical model more complicated. We customize the proposed model for a uniform distribution function that could be tractable to solve optimally by means of an exact approach. We then solve an example taken from the literature to demonstrate the applicability and effectiveness of the proposed model. Finally, by doing several sensitivity analyses for the key parameters of the model, some managerial insights are proposed.  相似文献   
134.
The surface color change of compression wood in spruce (Picea abies L.) and tension wood in poplar (Populus nigra L.) due to drying was investigated using CIE LAB and CIELCh colorimetry techniques. The results showed that the compression wood was lighter, yellower, less red, and more statured in color with a deeper hue after drying. Similar changes were also seen with the tension wood, except that it was less yellow and less statured in the dry condition. The color change (ΔE) of compression wood was found to be more remarkable than that of tension wood. Overall, the difference in the colorimetric parameters between the reaction woods and their corresponding normal woods was less significant after drying.  相似文献   
135.
Use of logic statements and computer assist are explored as means for automation and improvement on design of operating procedures including those employed in abnormal and emergency situations. Operating procedures for downpower and loss of forced circulation are used for demonstration. Human-factors analysis is performed on generic emergency operating procedures for three strategies of control; manual, semi-automatic and automatic, using standard emergency operating procedures. Such preliminary analysis shows that automation of procedures is feasible provided that fault-tolerant software and hardware become available for design of the controllers. Recommendations are provided for tests to substantiate the promise of enhancement of plant safety. Adequate design of operating procedures through automation may alleviate several major operational problems of nuclear power plants. Also, automation of procedures is necessary for partial or overall automatic control of plants. Fully automatic operations are needed for space applications while supervised automation of land-based and offshore plants may become the thrust of new generation of nuclear power plants.  相似文献   
136.
The named compound was reacted with thiosemicarbazide and/or semicarbazide to produce the corresponding condensation products II and V respectively. Reaction of II with chloroacetic acid in ethanol containing anhydrous sodium acetate yielded III. Condensation of III with aromatic aldehydes yielded the corresponding arylidene derivatives (IV). Oxidation of the semicarbazone V with selenium dioxide gave 2-(1,2,3-selenadiazole-4-yl)benzimidazole (VIa, b) while with thionyl chloride it gave 2-(1,2,3-thiadiazole-4-yl)benzimidazole (VIIa, b). The chalcones of 2-acetyl and/or 1-methyl-2-acetylbenzimidazole were condensed with hydrazine hydrate, phenylhydrazine and/or hydroxylamine to produce 2-(5-aryl-1(H)-pyrazolin-3-yl)-, 2-(5-aryl-1-phenyl-2-pyrazolin-3-yl)- and 2-(5-aryl-2-isoxazolin-3-yl)benzimidazole (IX, X, XI) respectively.  相似文献   
137.
Abstract— In this paper, the design criteria for scaling up from small‐area organic light‐emitting‐diode (OLED) pixels to large‐area OLED light panels is described. Particular focus is placed on using phosphorescent OLEDs (PHOLEDs) to maximize panel efficacy and uniformity and minimize operating temperature. Data for a pair of all‐phosphorescent 15 × 15 cm OLED light panels are also presented: Panel 1 has 62‐lm/W efficacy, CRI = 81, CCT = 3180K, and lifetime to LT70 = 18,000 hours at 1000 cd/m2 and Panel 2 has 58‐lm/W efficacy, CRI = 82, CCT = 2640K, and lifetime to LT70 = 30,000 hours at 1000 cd/m2. Operating at a 3000 cd/m2 (7740 lm/m2), Panel 2 has 49‐lm/W efficacy with lifetime to LT70 = 4000 hours. Excellent panel lifetime is enabled by a stable light‐blue phosphorescent materials system and by the use of efficient phosphorescent emitters that ensure very low panel temperature without any additional thermal management.  相似文献   
138.
The location routing problem (LRP) considers locating depots and vehicle routing decisions simultaneously. In classic LRP the number of customers in each route depends on the capacity of the vehicle. In this paper a capacitated LRP model with auxiliary vehicle assignment is presented in which the length of each route is not restricted by main vehicle capacity. Two kinds of vehicles are considered: main vehicles with higher capacity and fixed cost and auxiliary vehicles with lower capacity and fixed cost. The auxiliary vehicles can be added to the transportation system as an alternative strategy to cover the capacity limitations and they are just used to transfer goods from depots to vehicles and cannot serve the customers by themselves. To show the applicability of the proposed model, some numerical examples derived from the well-known instances are used. Moreover the model has been solved by some meta-heuristics for large sized instances. The results show the efficiency of the proposed model and the solution approach, considering the classic model and the exact solution approach, respectively.  相似文献   
139.

The iris has been vastly recognized as one of the powerful biometrics in terms of recognition performance, both theoretically and empirically. However, traditional unprotected iris biometric recognition schemes are highly vulnerable to numerous privacy and security attacks. Several methods have been proposed to generate cancellable iris templates that can be used for recognition; however, these templates achieve lower accuracy of recognition in comparison to traditional unprotected iris templates. In this paper, a novel cancellable iris recognition scheme based on the salting approach is introduced. It depends on mixing the original binary iris code with a synthetic pattern using XOR operation. This scheme guarantees a high degree of privacy/security preservation without affecting the performance accuracy compared to the unprotected traditional iris recognition schemes. Comprehensive experiments on various iris image databases demonstrate similar accuracy to those of the original counterparts. Hence, robustness to several major privacy/security attacks is guaranteed.

  相似文献   
140.
High fill factors have only recently become commonplace in nonfullerene‐based organic solar cells, with the balance of charge carrier mobilities often cited as the contributing factor. Here an end‐group modification to a commonly used nonfullerene acceptor (O‐IDTBR) is reported, in which the rhodanine end groups are replaced with dicyano moieties, resulting in the acceptor O‐IDTBCN. This new acceptor affords significant improvement in the fill factor (73%) and photocurrent (19.8 mA cm?2) in organic solar cells with the low bandgap polymer PTB7‐Th. A narrowing of the bandgap, as a result of greater push–pull hybridization, allows complementary absorption to the donor and thus improved photon harvesting. Additionally, the measurement of charge carrier mobilities and lifetimes in both systems reveal that the PTB7‐Th:O‐IDTBCN blend possesses more balanced charge carrier mobilities, and longer lifetimes. Morphology studies reveal a slightly greater degree of molecular mixing of the O‐IDTBCN when blended with PTB7‐Th, despite the greater and more balanced charge carrier mobilities in this blend.  相似文献   
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