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排序方式: 共有173条查询结果,搜索用时 62 毫秒
71.
Malaysia has identified photovoltaic systems as one of the most promising renewable sources. A great deal of efforts has been undertaken to promote the wide applications of PV systems. With the recent launch of a PV market induction programme known as SURIA 1000 in conjunction with other relevant activities undertaken under the national project of Malaysia Building Integrated Photovoltaic (MBIPV), the market of PV systems begins to be stimulated in the country. As a result, a wide range of technical, environmental and economic issues with regard to the connection of PV systems to local distribution networks becomes apparent. Numerous studies were therefore carried out in collaboration with Malaysian Energy Centre to address a number of those important issues. The findings of the studies are presented in the paper and can be served as supplementary information to parties who are directly and indirectly involved in the PV sector in Malaysia.  相似文献   
72.
Gladys  Marinelly  Maria  Sara   《Information & Management》2005,42(8):1051-1066
This paper proposes a specific set of criteria for evaluating discrete-event Simulation Software capable of simulating continuous operations. A quality specifications model was developed; it identified 40 sub-characteristics and 131 metrics to assess the quality of this type of software; it is then to be used in the selection process. The application was demonstrated in one organization that provides consulting services in the logistics’ area of the Venezuelan oil industry and it was used to examine four commercial software systems that might fulfill the technical requirements established by the organization. The selection and evaluation technique successfully identified the software that best suited their needs.  相似文献   
73.
This study investigates the service quality in the maintenance of mechanical and engineering services. The determinants of service quality are identified and their means of evaluation are examined. A method of assessment is devised based on the SERVQUAL approach, and its use is then illustrated using a small empirical survey of clients and service providers and the ‘Gap’ model used to quantify the relationships between customer satisfaction, expected service, perceived service and service quality gap.  相似文献   
74.
This work proposes a procedure for calibration and validation of complex models by systematically obtaining identifiable parameter subsets according to the available data. The procedure uses the new RDE criteria calculated from the Fisher Information Matrix (FIM) as the ratio of normalized D to modified E criteria (RDE). It does not require expert knowledge and it defines automatically the dimension of the identifiable subset without requiring a threshold for the RDE. It was applied successfully to the study of the IWA-ASM2d model, which was implemented, calibrated and validated for an anaerobic/anoxic/oxic (A2/O) pilot WWTP operated under three different influent ammonium concentrations (15, 20 and 30 mg/L) and two internal recycling ratios (IRR = 2 and 5). Starting from 51 among all the ASM2d parameters, a sensitivity analysis around the ASM2d default values was performed. From the sensitivity ranking, the 20 best-ranked parameters were named “seeds”, since each one served for growing a parameter subset for model calibration. The subset generation process added to the seed a parameter that presented the highest RDE among all the remaining parameters of the sensitivity ranking. The process of parameter addition was repeated until the RDE decreased from the current iteration to the previous one. The best subset determined by the methodology {bPAO, YPO4, μA} presented the highest possible value of the RDE. Finally, the simulation of the WWTP with this subset fitted adequately the experimental data while the parameters obtained had low confidence intervals.  相似文献   
75.
Commercially available fish oils with n−3 fatty acid contents ranging from 29 to 34% were converted enzymically, with Amano P lipase, to mixtures of glycerides with n−3 fatty acid contents ofca. 50%, in weight recovery yields of 23–50%, depending upon extraction procedures. Glyceride mixtures with n−3 fatty acid contents above 70% were obtained in yields of 14–21%. The processes are based on the relative stability of the ester linkages that involve n−3-fatty acyl groups and the regioselectivity of the enzyme toward acyl groups at the 1,3-positions of glycerol. This paper was presented at the 82nd AOCS Annual Meeting, May 12–15, 1991.  相似文献   
76.
To enhance clinicians' understanding of the child-rearing values Puerto Rican mothers consider important in parenting preschool-age children, the authors conducted focus groups, interviewed cultural consultants, and searched the literature. Eighty low-income, urban mainland Puerto Rican mothers with young children ranked in order of importance to them 13 child-rearing values that were presented. Mothers ranked honesty, respect, and responsibility most highly, followed by loyalty to family, affection, and sharing. They ranked values associated in the literature with Anglo culture (e.g., assertiveness, independence, and creativity) as being of lesser importance. Implications for therapy and educational interventions with parents and children are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
77.
The kinetics of the thermal decomposition reaction of diethylketone triperoxide (3,3,6,6,9,9-hexaethyl-1,2,4,5,7,8-hexaoxacyclononane, DEKTP) in ethylbenzene solution were studied in the temperature range of 120.0–150.0 °C and at an initial concentration range of 0.01–0.10 M. This peroxide was used as a new initiator in methyl methacrylate (MMA) polymerization process at high temperatures (110.0–140.0 °C) in ethylbenzene solution. The effects of initiator concentration and reaction temperature on the polymerization rate were investigated in detail. Thus, activation parameters of the solution polymerization process (ΔE d* = 83.3 kJ mol−1 and ΔE p* − ΔE t*/2 = 54.0 kJ mol−1) will be obtained. DEKTP can effectively act as initiator in MMA polymerization and its performance is similar to that presented by a multifunctional initiator resulting in high-molecular weight polymethylmethacrylate with a high reaction rate.  相似文献   
78.
A three-year field study was conducted from 2006 to 2008 to monitor the spatial and temporal trends of organic pollutants in migrating juvenile Snake River spring Chinook salmon (Oncorhynchus tshawytscha) sampled from the Lower Snake and Middle Columbia River Basins. Specifically, hatchery-reared juvenile salmon were monitored as they navigated the Federal Columbia River Power System (FCRPS) by either transport barge (Barged) or remained in the river (In-River) from Lower Granite Dam to a terminal collection dam, either John Day Dam or Bonneville Dam. Levels of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and organochlorine (OC) pesticides were detected in the bodies of both In-River and Barged salmon during the 2006, 2007 and 2008 outmigrating season. At the terminal dam, In-River fish had greater concentrations of persistent organic pollutants POPs than Barged salmon. Of the POPs detected, dichlorodiphenyltrichloroethanes (DDTs) were found at the greatest concentrations in the salmon bodies. These elevated lipid-normalized concentrations in the In-River fish were due to lipid depletion in all years as well as increased exposure to POPs in some years as indicated by an increase in wet weight contaminant concentrations. Salmon were also exposed to polycyclic aromatic hydrocarbons (PAHs) as indicated by the phenanthrene (PHN) signal for biliary fluorescent aromatic compounds (FACs) at the hatcheries or prior to Lower Granite Dam. There were detectable levels of biliary FACs as fish migrated downstream or were barged to the terminal dam. Therefore, the potential exists for these organic pollutants and lipid levels to cause adverse effects and should be included as one of the variables to consider when examining the effects of the FCRPS on threatened and endangered juvenile salmon.  相似文献   
79.
Insulin resistance is defined as a reduced ability of insulin to stimulate glucose utilization. C57BL/6 mice fed with a high-fat diet (HFD) are a model of insulin resistance. In skeletal muscle, hydrogen peroxide (H2O2) produced by NADPH oxidase 2 (NOX2) is involved in signaling pathways triggered by insulin. We evaluated oxidative status in skeletal muscle fibers from insulin-resistant and control mice by determining H2O2 generation (HyPer probe), reduced-to-oxidized glutathione ratio and NOX2 expression. After eight weeks of HFD, insulin-dependent glucose uptake was impaired in skeletal muscle fibers when compared with control muscle fibers. Insulin-resistant mice showed increased insulin-stimulated H2O2 release and decreased reduced-to-oxidized glutathione ratio (GSH/GSSG). In addition, p47phox and gp91phox (NOX2 subunits) mRNA levels were also high (~3-fold in HFD mice compared to controls), while protein levels were 6.8- and 1.6-fold higher, respectively. Using apocynin (NOX2 inhibitor) during the HFD feeding period, the oxidative intracellular environment was diminished and skeletal muscle insulin-dependent glucose uptake restored. Our results indicate that insulin-resistant mice have increased H2O2 release upon insulin stimulation when compared with control animals, which appears to be mediated by an increase in NOX2 expression.  相似文献   
80.
In vitro digestors can be used to provide bioaccessibility values to help assess the risk from incidental human ingestion of contaminated soils. It has been suggested that these digestors may need to include a lipid sink to mimic human uptake processes. We compare the correspondence between in vivo polycyclic aromatic hydrocarbon (PAH) uptake for eight different PAH contaminated soils with PAH release in in vitro digestors in the presence and absence of a lipid sink. Lipid sinks were essential to the success of the in vitro digestors in predicting juvenile swine PAH uptake. In the presence of the lipid sink, results of the In Vitro Digestion model (IVD) closely corresponded with a slope of 0.85 (r(2) = 0.45, P < 0.07) to the in vivo results. The Relative Bioaccessibility Leaching Procedure (RBALP) results did not correspond to the in vivo study but did tightly reflect total soil PAH concentration. We conclude that the basis of this difference between digestors is that the RBALP used an aggressive extraction technique that maximized PAH release from soil. Systemic uptake in juvenile swine was not linked to soil PAH concentration but rather to the thermodynamic properties of the soil.  相似文献   
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