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81.
An amperometric biosensor for determination of biochemical oxygen demand in wastewater has been developed to overcome the time consuming monitoring procedures. The performance and stability of the immobilized membrane have been investigated at 37 °C and pH 6.8. Immobilized microbial membranes maintain their stability and activity after intermittent use for 400 cycles when stored at 4 °C in sodium phosphate buffer pH 6.8. The response time of the BOD sensor was only 90 min, being independent of the concentration, and the lower detection limit was 1 mg/l. The obtained BOD values showed correlation with that of the conventional method for BOD determination (BOD5) with a deviation of ±10%. Moreover, the sensor exhibits good repeatability (3.39–4.45%) and reproducibility (1.85–2.25%). Software was added to upgrade this sensor and to make it a promising candidate for online monitoring.  相似文献   
82.
This study examines the nature and development of behavioral consistency pressures in children. Specifically, we examined the effectiveness of the foot-in-the-door procedure in producing consistent prosocial behavior and self-attributions in kindergartners and second and fifth graders. Children were either induced to comply with a request to share prize coupons or were not given this initial prosocial experience. Those who complied either were labeled as helpful by an adult or were not. Later, children were given the opportunity to help under public or private circumstances. Moreover, children's understanding of trait stability, their internal preference for consistent behavior, and their belief that adults prefer behavioral consistency were assessed. Consistent responding began to occur within the foot-in-the-door procedure in the second grade, and this developmental shift was paralleled by a shift in children's understanding of trait stability. Furthermore, once the foot-in-the-door effect appeared among the second and fifth graders, its strength was significantly affected by the children's internal preference for consistency. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
83.
Generation     
The structure and function of the target-language generation module for KBMT-89 is described. The lexical selection module (which includes thematic-role subcategorization, a meaning distance metric, and syntactic subcategorization) is presented. We also describe the generation mapping rules, and rule interpretation in the generation of f-structures for target language utterances.  相似文献   
84.
A wearable health care system based on knitted integrated sensors.   总被引:2,自引:0,他引:2  
A comfortable health monitoring system named WEALTHY is presented. The system is based on a textile wearable interface implemented by integrating sensors, electrodes, and connections in fabric form, advanced signal processing techniques, and modern telecommunication systems. Sensors, electrodes and connections are realized with conductive and piezoresistive yarns. The sensorized knitted fabric is produced in a one step process. The purpose of this paper is to show the feasibility of a system based on fabric sensing elements. The capability of this system to acquire simultaneously several biomedical signals (i.e. electrocardiogram, respiration, activity) has been investigated and compared with a standard monitoring system. Furthermore, the paper presents two different methodologies for the acquisition of the respiratory signal with textile sensors. Results show that the information contained in the signals obtained by the integrated systems is comparable with that obtained by standard sensors. The proposed system is designed to monitor individuals affected by cardiovascular diseases, in particular during the rehabilitation phase. The system can also help professional workers who are subject to considerable physical and psychological stress and/or environmental and professional health risks.  相似文献   
85.
A modification of Association of Official Analytical Chemists (AOAC) method 983.23 for the quantitative determination of total lipid in food composites was evaluated for the measurement of total fat. The procedure is based on the Bligh and Dyer chloroform/methanol total lipid extraction. Relative to AOAC 983.23, the proposed method is less labor-intensive and is applicable to batch analysis of a larger number of samples, thus reducing the cost of analysis and increasing sample throughput. Total lipid values from the proposed method are comparable to those from AOAC 983.23 and slightly higher than total fat determined by acid hydrolysis (AOAC 954.02, 945.44, or 922.06). Recoveries of standard additions of different food-grade oils from a mixed food composite were essentially quantitative, ranging from 96 to 101%. Total lipid measured in Total Diet Standard Reference Material 1548 (SRM 1548, National Institute of Standards and Technology) was 101% of the certified mean total fat content and within the certified range. The method is to be suitable for analysis of food composites with between 0.15 and 1.5 g total fat (3 to 30% by weight). More than 600 samples of a variety of total diet composites were collected and assayed as diet quality control samples for two National Heart, Lung and Blood Institute-sponsored multicenter clinical feeding trials: DELTA (Dietary Effects on Lipoproteins and Thrombogenic Activity) and DASH (Dietary Approaches to Stop Hypertension). The mean coefficient of variation was 1.2% for duplicate assays of these samples over the course of two years and multiple analysts. In addition, total lipid values for more than 200 samples of a diet composite quality control material, used in this laboratory over a two-year period, had a 3.99% coefficient of variation. Although the accuracy of all gravimetric total fat methods with respect to the U.S. Food and Drug Administration’s Nutritional Labeling and Education Act (NLEA) definition of total fat as the sum of triglycerides remains to be determined, the reported modification of AOAC 983.23 yields a total fat content of acceptable accuracy relative to other gravimetric methods, and with proper quality control the method has excellent precision.  相似文献   
86.
We propose a modification of an algorithm introduced by Martínez (1987) for solving nonlinear least-squares problems. Like in the previous algorithm, after the calculation of an approximated Gauss-Newton directiond, we obtain the next iterate on a two-dimensional subspace which includesd. However, we simplify the process of searching the new point, and we define the plane using a scaled gradient direction, instead of the original gradient. We prove that the new algorithm has global convergence properties. We present some numerical experiments.  相似文献   
87.
The Low-Affinity Nerve Growth Factor Receptor (LNGFR), also known as CD271, is a member of the tumor necrosis factor receptor superfamily. The CD271 cell surface marker defines a subset of multipotential mesenchymal stromal cells and may be used to isolate and enrich cells derived from bone marrow aspirate. In this study, we compare the proliferative and differentiation potentials of CD271+ and CD271 mesenchymal stromal cells. Mesenchymal stromal cells were isolated from bone marrow aspirate and adipose tissue by plastic adherence and positive selection. The proliferation and differentiation potentials of CD271+ and CD271 mesenchymal stromal cells were assessed by inducing osteogenic, adipogenic and chondrogenic in vitro differentiation. Compared to CD271+, CD271 mesenchymal stromal cells showed a lower proliferation rate and a decreased ability to give rise to osteocytes, adipocytes and chondrocytes. Furthermore, we observed that CD271+ mesenchymal stromal cells isolated from adipose tissue displayed a higher efficiency of proliferation and trilineage differentiation compared to CD271+ mesenchymal stromal cells isolated from bone marrow samples, although the CD271 expression levels were comparable. In conclusion, these data show that both the presence of CD271 antigen and the source of mesenchymal stromal cells represent important factors in determining the ability of the cells to proliferate and differentiate.  相似文献   
88.
HIV‐1 integrase (IN) active site inhibitors are the latest class of drugs approved for HIV treatment. The selection of IN strand‐transfer drug‐resistant HIV strains in patients supports the development of new agents that are active as allosteric IN inhibitors. Here, a docking‐based virtual screening has been applied to a small library of natural ligands to identify new allosteric IN inhibitors that target the sucrose binding pocket. From theoretical studies, kuwanon‐L emerged as the most promising binder and was thus selected for biological studies. Biochemical studies showed that kuwanon‐L is able to inhibit the HIV‐1 IN catalytic activity in the absence and in the presence of LEDGF/p75 protein, the IN dimerization, and the IN/LEDGF binding. Kuwanon‐L also inhibited HIV‐1 replication in cell cultures. Overall, docking and biochemical results suggest that kuwanon‐L binds to an allosteric binding pocket and can be considered an attractive lead for the development of new allosteric IN antiviral agents.  相似文献   
89.
Gymnosporia arenicola Jordaan (Celastraceae) is a shrub or small tree, which naturally occurs in coastal sand dunes of Southern Mozambique and South Africa. Its dried leaf is often used in traditional medicine for the treatment of infectious and inflammatory diseases. Hereby, we present results of studies carried out according to the pharmacopoeia standards for the identification of herbal drugs, in the whole, fragmented, and powdered plant material. These results were complemented with scanning electron microscopy and histochemical techniques. The leaf microscopic analysis revealed a typical dorsiventral mesophyll with a corresponding spongy parenchyma–palisade parenchyma ratio of 0.60, anomocytic and paracytic stomata, papillate cells with a diameter of 4.00 ± 0.40 µm, multicellular uniseriate nonglandular trichomes with a length of 27.00 ± 4.10 µm and cristalliferous idioblasts containing calcium oxalate cluster crystals with a diameter of 23.04 ± 5.84 µm. The present findings demonstrate that the G. arenicola leaf has both nonglandular trichomes and hypoderm, features not previously described in the corresponding botanical section (Gymnosporia sect. Buxifoliae Jordaan). The establishment of these new botanical markers for the identification of G. arenicola leaf is essential for quality, safety and efficacy reasons. Microsc. Res. Tech. 78:1001–1009, 2015. © 2015 Wiley Periodicals, Inc.  相似文献   
90.
Dimethyl phthalate esters (DMPE) can easily be released into the environment from plastic products. As endocrine disruptors, DMPE mimic estrogenic activities in animals and humans. The metabolites of DMPE are suspected to cause even more serious health problems. Among the common sterilization techniques adopted in the study of DMPE degradation, the average loss of the parent DMPE compounds after autoclaving was as high as 21.26%. In contrast, the loss after 0.2 microm filtration was significantly lower at 2.28%. It is suggested that filtration should be used over autoclaving for sterilizing DMPE. The environmental fate of DMPE under sulfate-reducing condition was simulated and studied in microcosm system. It was observed that dimethyl phthalate (DMP), dimethyl isophthalate (DMI) and dimethyl terephthalate (DMT) could not be mineralized over an extended period of 6 months, but with the transformation to the respective monomethyl phthalate and/or phthalic acid. The dominant species of microorganisms utilizing individual DMPE isomer as the sole carbon source were isolated and identified as facultative anaerobe Thauera sp., Xanthobacter sp. and Agrobacterium sp. for DMP, DMI and DMT, respectively. This study illustrates that the detrimental DMPE and their natural metabolites may accumulate in the sulfate-reducing environment. Accordingly, proper surveillance program should be devised to monitor both the parent compounds and degradation intermediates of DMPE in order to protect the aquatic ecosystem and human health.  相似文献   
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