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61.
Accurate estimates of crop evapotranspiration ETc, that quantify the total water used by a crop, are needed to optimize irrigation scheduling for horticultural crops and to minimize water degradation. During early growth, accurate assessments of ETc are difficult in vegetable crops because of high soil evaporation due to frequent irrigation. A model to estimate ETc for vegetable crops, using only daily reference evapotranspiration data as an input parameter, was developed. It calculates crop transpiration and soil evaporation based on ground cover and daily radiation intercepted by the canopy. The model uses a two-stage soil evaporation method adapted to conditions of variable reference evapotranspiration. The model was evaluated against data using measurements from two seasons of lettuce crop, two tomato fields in the same season, and one season of broccoli crop production. Using all of the crop data, the root-mean-square error for measured versus modeled daily ETc was 0.72 mm day?1, indicating that the model works well.  相似文献   
62.
A model is presented that uses a daily mean evapotranspiration ETo rate to estimate energy-limited (potential or Stage 1) soil evaporation, and it also uses daily mean ETo and a soil hydraulic β factor to estimate soil hydraulic property-limited (Stage 2) evaporation. The model provides good estimates of cumulative soil evaporation on both hourly and daily bases when compared to observed soil evaporation in three field trials. Crop coefficient Kc values from cumulative hourly and cumulative daily soil evaporation estimates and ETo data were comparable. Using a soil hydraulic factor (β = 2.6) in the model gave a fair approximation for the widely used Kc curves for initial growth of crops presented in the United Nations Food and Agricultural Organization's Irrigation and Drainage Paper 24. However, using a site-specific β factor should improve soil evaporation and Kc estimates for site-specific applications.  相似文献   
63.
The nutritional and therapeutic benefits of prebiotics have attracted the keen interest of consumers and food processing industry for their use as food ingredients. Fructo-oligosaccharides (FOS), new alternative sweeteners, constitute 1-kestose, nystose, and 1-beta-fructofuranosyl nystose produced from sucrose by the action of fructosyltransferase from plants, bacteria, yeast, and fungi. FOS has low caloric values, non-cariogenic properties, and help gut absorption of ions, decrease levels of lipids and cholesterol and bifidus-stimulating functionality. The purified linear fructose oligomers are added to various food products like cookies, yoghurt, infant milk products, desserts, and beverages due to their potential health benefits. This review is focused on the various aspects of biotechnological production, purification and potential applications of fructo-oligosaccharides.  相似文献   
64.
Multimedia Tools and Applications - Chronic Kidney Disease (CKD) is being typically observed as a health threatening issue, especially in developing countries, where receiving proper treatments are...  相似文献   
65.
In this study, identification of environmental reservoirs of Salmonella enterica subsp. enterica serovar Typhimurium (abbreviated as Salmonella Typhimurium) in sediments, water, and aquatic flora collected from the Ganges River (Ganges riverine material) was carried out by adopting a two-step strategy. Step 1 comprised a selective serovar-specific capture of Salmonella Typhimurium from potential reservoirs. Step 2 involved culture-free detection of selectively captured Salmonella Typhimurium by ttr gene-specific molecular beacon (MB) based quantitative polymerase chain reaction (q-PCR). The ttr gene-specific MB designed in this study could detect 1 colony-forming unit (cfu)/PCR captured by serovar-specific DNA aptamer. Sediments, water, and aquatic flora collected from the Ganges River were highly contaminated with Salmonella Typhimurium. The preanalytical step in the form of serovar-specific DNA aptamer-based biocapture of bacterial cells was found to enhance the sensitivity of the fluorescent probe in the presence of nonspecific DNA . Information about the presence of environmental reservoirs of Salmonella Typhimurium in the Ganges River region may pave the way for forecasting and management of nontyphoidal salmonellosis in south Asia.  相似文献   
66.
A mathematical model has been developed for the understanding of temperature distribution in knee joint. Temperature rises in knee joint as a result of frictional energy. This heated synovial fluid enters into the articular cartilage by the process of filtration and supplies heat to cartilage and bone. This cooled fluid again mixes well with the lubricant in the joint cavity. The problem is formulated as a two-region flow and diffusion model: flow and thermal diffusion within the intra-articular gap; and within the porous matrix covering the approaching bones at the joint. The solution of the coupled mixed boundary value problem is solved by using perturbation method. It has been observed that, in certain diseased and or old synovial joints, the movement of the fluid into or out of the cartilage resisted, and therefore, the temperature does rise. The temperature does rise in old and diseased joints as observed by varying the values of parameters from its normal values. These values refer to old age and/or diseases affecting degeneration of synovial fluid and or cartilage.  相似文献   
67.
32 diabetic and 31 metabolic healthy pregnant women are studied to answer the following questions: Is there a difference in the albumin-excretion rate (AER) during the pregnancy in primary normoalbuminuric type 1 diabetics and non-diabetics? Is there a difference 6 months post partum between the 2 groups? The average age of the diabetics (D) is 28, of the non-diabetics (ND) 27 years; the diabetics suffer from diabetes mellitus 12.5 years. In the 16th week of pregnancy, we find a AER (D vs. ND) of 5.0 vs. 2.37 micrograms/min (not significant [n.s.]), creatinin in serum 0.77 vs. 0.75 mg/dl (p < 0.05), creatinin clearance 92.5 vs. 103.4 ml/min (n.s.). In the 28th and in the 34th to 38th week, there is no significant elevation of the AER compared to the 16th week; but there is a significant elevation in the diabetics vs. the non-diabetics. 6 months post partum, the AER (D vs. ND) are: 6.13 vs. 5.11 micrograms/min (n.s. vs. 16th week and D vs. ND); in each group one person is found with a positive microalbuminuria (MA): 48.2 micrograms/min (D) and 27.4 mg/min (ND). Another diabetic woman shows post partum an isolated higher value of creatinin in serum: 1.5 mg/dl (without MA). This parameter is post partum significant higher (0.97 [D], 0.96 [ND] mg/dl) than in the 16th week of pregnancy (0.77 [D], 0.75 [ND] mg/dl). The creatinin clearance decreases post partum (pp): 92.2 ml/min (pp) vs. 102.0 ml/min (28th week) in the diabetics (n.s.) and 80.6 ml/min (pp) vs. 111.0 ml/min (28th week) in the non-diabetics (p < 0.05). Concerning the studied renal parameters, there is a significant difference of the albumin-excretion rates during the pregnancy between preconceptional normoalbuminuric type 1 diabetic and non-diabetic women, but 6 months post partum, there is no significant difference. The diabetics show a significant increase of the creatinin in urine and in serum and no significant change of the creatinin clearance 6 months post partum.  相似文献   
68.
Circulating p53 antibodies (ELISA method), p53 genetic alterations (SSCP), and protein overexpression (immunohistochemistry) were studied in 41 patients with colorectal adenocarcinomas and 10 control patients. Carcinoembryonic antigen (CEA) and carbohydrate antigen 19.9 (CA 19-9) were evaluated in parallel. Ten patients with p53 antibodies and p53 overexpression were selected. Tumor DNA extracts from these 10 patients were analyzed by SSCP. Of all 41 patients, 10 (24%) showed significant levels of p53 antibodies, and p53 accumulation was detected in 20 (48%) patients. In six patients, p53 antibody concentrations decreased rapidly after surgery; in two patients, these levels returned to normal values. Of the 10 selected tumors, eight revealed TP53 gene mutations. Only two patients with high values of both CEA and CA 19-9 developed p53 antibodies. In conclusion, beside classical tumor markers, circulating p53 antibodies may be considered as additional markers for the management of patients with colorectal adenocarcinomas.  相似文献   
69.
Simultaneous measurement of effective thermal conductivity, thermal diffusivity, specific heat, and thermal effusivity of date palm fibers reinforced plaster concrete have been studied by CT meter device using a ring sensor technique. Samples of different weight percentages 1, 1.5, and 2% for different length fibers have been considered. It is found that the thermal conductivity, thermal diffusivity, and effusivity decrease as the fraction of fibers increases, even an increase for the specific heat is recorded. A modeling application reveals good correspondence with the experimental results. Moreover, a scanning microscopy study has shown a good interaction between the gypsum matrix and date palm fiber cells. Finally, it should be noted that date palm fibers and plaster are mutually compatible and many new building components can be made by incorporating these materials.  相似文献   
70.
Bali  Rekha  Shukla  A.K. 《Tribology Letters》2001,9(3-4):233-239
Synovial fluid is an excellent source of nutrients for the cells of the cartilage, through which water and other solutes like glucose are permeable. It has long been established that the tissue imbibes and exudes fluid when deformed, metabolities are believed to move to and from the cells through the ground substance by mechanical effects and by diffusion. Local variation of the permeability within the articular cartilage plays an important role in nutritional transport. To account for the effects of structural configuration of tissue, rate, depth and amount of solute penetration, we have modelled the cartilage by mixture of two distinct constituents, i.e., an incompressible fluid phase and an incompressible porous solid phase. It is observed that when local permeability decreases, the concentration decreases. When fluid flows into the cartilage due to metabolism, the solid portion of the porous matrix increases. Due to the increased solidity of the cartilage matrix, less fluid enters into the cartilage and nutritional transport decreases. In the case of diseased joints the nutritional transport is very difficult, owing to increased rigidity or local variation of permeability within the cartilage. The concentration distribution at the same depth in articular cartilage for low-molecular-weight solutes is less than that for high-molecular-weight solutes. Thus, for low-molecular-weight solutes, the phenomenon of nutrition transport is diffusion dominated whereas for high-molecular-weight solutes, it is dominated by mechanical pumping action. The paper further concludes that in the process of imbibition and exudation, the cells of the middle area of the cartilage surface get more nutrition as compared to the cells at the periphery, so the earliest signs of cartilage degeneration appear in the unstressed areas. Therefore joint motion is assumed necessary for cartilage nutrition. It also concludes that as the viscoelastic parameter increases, the concentration decreases in the articular cartilage so that the cells of the cartilage get less nutrition and can deteriorate.  相似文献   
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