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531.
Vascular access (VA) is the lifeline for patients with end‐stage renal disease on regular hemodialysis (HD). Tunneled catheters have been associated with increased risk of luminal thrombosis, infection, hospitalization, and high cost. Our aims were to follow the “Fistula First Initiative,” avoid or reduce the rate of catheter insertion, improve the rate of arteriovenous fistula (AVF) use, and study the effect of increased AVF use on quality of dialysis and patient's outcome. A VA program has been established in collaboration with an enthusiastic and professional vascular surgery team to manage 358 patients who have been on regular HD treatment for a period ranging from 1 to 252 months. The mean ± standard deviation age of patients was 52 ± 15 years with 62% male patients. Over a period of 2 years, 408 procedures were performed. These include 293 AVFs and 56 arteriovenous grafts (AVGs). Other procedures include 39 permanent catheter insertions, 8 AVF aneurysmectomy, removal of 6 AVGs, embolectomy of 4 AVGs, excision of 1 AVG lymphocele, and ligation of 1 AVF. This program resulted in significant increase in AVF rate from 35% to 82%; reduction in catheter rate from 62% to 10.9%; infection rate down from 6.6% to 0.6%; VA clotting down from 5.1% to 1.0%; and increase in average blood flow rate from 214 ± 32 to 298 ± 37 mL/min (P < 0.01). These results have been associated with improved average single pool Kt/V from 0.88 ± 0.19 to 1.28 ± 0.2 (P < 0.01); increased hemoglobin from 9.2 ± 1.2 to 10.9 ± 0.9 g/dL (P < 0.01); improved serum albumin from 3.2 ± 0.5 to 3.7 ± 0.4 g/dL (P < 0.05); reduction in administered erythropoietin dose by 19%; and significant drop in hospitalization rate from 6.1% to 3.8%. These results confirm the great benefits of AVF on quality of HD and patient outcome, and clearly affirm that AVF should always be considered first.  相似文献   
532.
The aim of this study was to develop fluconazole in an ultrapure polyvinyl alcohol (PVA) hydrogel able to deliver the drug in a sustained release pattern for local treatment of skin fungal infections. The topical fluconazole hydrogels were prepared using PVA hydrogels physically cross-linked by freeze-thaw technique. Polyethylene glycol (PEG) was added as a hydrophilic excipient as a release enhancer of fluconazole. The effects of PVA molecular weight, PEG molecular weight, and PEG concentration were studied using a 2 x 4 x 2 factorially designed experiment. The selected fluconazole hydrogel proved to be physically stable over a period of 6 months and to be effective in the topical treatment of cutaneous candidiasis. Therefore, it could be concluded that the formula composed of 10% PVA 205000 and 1.5% PEG 4000 and 2% fluconazole and prepared by three cycles of freezing, and thawing is very promising in the local treatment of skin fungal infection as an alternative to the systemic use of fluconazole.  相似文献   
533.
Tested the hypotheses that interpretations increase clients' motivation to change and that interpretations identifying causal factors clients can directly control lead to greater client change than interpretations identifying causes clients cannot directly control. 36 students who were experiencing problems with procrastination were assigned to 1 of 12 conditions defined by 3 interview conditions and 4 interviewers. Ss received 2 interviews 1 wk apart. In one interpretation condition the interviewers worked from a causal framework of procrastination as caused by a lack of effort, poor self-discipline, and ambiguous goals. In the other interpretation condition the interviewers saw procrastination as a symptom of underlying conflicts and resentments stemming from unresolved conflict with parents. In the 3rd condition the interviewers refrained from any statements of opinion but reflected the students' ideas about the nature and causes of their procrastination. The results generally support the hypotheses. (9 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
534.
It is not economically viable to connect remote areas to the national electric grid, so pumping systems based on photovoltaic energy sources are suitable for these areas. The induction motor is more rugged, reliable, and maintenance free than d.c. motors. In this paper, a pumping system based on an induction motor driven by a voltage source inverter is investigated. Two control strategies are considered. First, the system is controlled to operate on the maximum power line of the PV array, with variable water discharge Q. Second, the induction machine is controlled to operate at maximum efficiency. The operating characteristic of the array is thus controlled to match the voltage and current required by the motor. Comparison is carried out between the two operating schemes.  相似文献   
535.
This article presents a synthesis of research on the relative effectiveness of women and men who occupy leadership and managerial roles. Aggregated over the organizational and laboratory experimental studies in the sample, male and female leaders were equally effective. However, consistent with the assumption that the congruence of leadership roles with leaders' gender enhances effectiveness, men were more effective than women in roles that were defined in more masculine terms, and women were more effective than men in roles that were defined in less masculine terms. Also, men were more effective than women to the extent that leader and subordinate roles were male-dominated numerically. These and other findings are discussed from the perspective of social-role theory of sex differences in social behavior as well as from alternative perspectives. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
536.
The evolution of chiral spin structures is studied in ferrimagnetic Ta/Ir/Fe/GdFeCo/Pt multilayers as a function of temperature using scanning electron microscopy with polarization analysis (SEMPA). The GdFeCo ferrimagnet exhibits pure right-handed Néel-type domain wall (DW) spin textures over a large temperature range. This indicates the presence of a negative Dzyaloshinskii–Moriya interaction that can originate from both the top Fe/Pt and the Co/Pt interfaces. From measurements of the DW width, as well as complementary magnetic characterization, the exchange stiffness as a function of temperature is ascertained. The exchange stiffness is surprisingly more or less constant, which is explained by theoretical predictions. Beyond single skyrmions, it is identified by direct imaging a pure Néel-type skyrmionium, which due to the expected vanishing skyrmion Hall angle, is a promising topological spin structure to enable applications by next generation of spintronic devices.  相似文献   
537.
    
Metabolomics is a dynamically evolving field, with a major application in identifying biomarkers for drug development and personalized medicine. Numerous metabolomic studies have identified endogenous metabolites that, in principle, are eligible for translation to clinical practice. However, few metabolomic‐derived biomarker candidates have been qualified by regulatory bodies for clinical applications. Such interruption in the biomarker qualification process can be largely attributed to various reasons including inappropriate study design and inadequate data to support the clinical utility of the biomarkers. In addition, the lack of robust assays for the routine quantification of candidate biomarkers has been suggested as a potential bottleneck in the biomarker qualification process. In fact, the nature of the endogenous metabolites precludes the application of the current validation guidelines for bioanalytical methods. As a result, there have been individual efforts in modifying existing guidelines and/or developing alternative approaches to facilitate method validation. In this review, three main challenges for method development and validation for endogenous metabolites are discussed, namely matrix effects evaluation, alternative analyte‐free matrices, and the choice of internal standards (ISs). Some studies have modified the equations described by the European Medicines Agency for the evaluation of matrix effects. However, alternative strategies were also described; for instance, calibration curves can be generated in solvents and in biological samples and the slopes can be compared through ratios, relative standard deviation, or a modified Stufour suggested approaches while quantifying mainly endogenous metabolitesdent t‐test. ISs, on the contrary, are diverse; in which seven different possible types, used in metabolomics‐based studies, were identified in the literature. Each type has its advantages and limitations; however, isotope‐labeled ISs and ISs created through isotope derivatization show superior performance. Finally, alternative matrices have been described and tested during method development and validation for the quantification of endogenous entities. These alternatives are discussed in detail, highlighting their advantages and shortcomings. The goal of this review is to compare, apprise, and debate current knowledge and practices in order to aid researchers and clinical scientists in developing robust assays needed during the qualification process of candidate metabolite biomarkers. © 2019 John Wiley & Sons Ltd. Mass Spec Rev  相似文献   
538.
    
Recently, there has been a considerable rise in the number of diabetic patients suffering from diabetic retinopathy (DR). DR is one of the most chronic diseases and makes the key cause of vision loss in middle-aged people in the developed world. Initial detection of DR becomes necessary for decreasing the disease severity by making use of retinal fundus images. This article introduces a Deep Learning Enabled Large Scale Healthcare Decision Making for Diabetic Retinopathy (DLLSHDM-DR) on Retinal Fundus Images. The proposed DLLSHDM-DR technique intends to assist physicians with the DR decision-making method. In the DLLSHDM-DR technique, image preprocessing is initially performed to improve the quality of the fundus image. Besides, the DLLSHDM-DR applies HybridNet for producing a collection of feature vectors. For retinal image classification, the DLLSHDM-DR technique exploits the Emperor Penguin Optimizer (EPO) with a Deep Recurrent Neural Network (DRNN). The application of the EPO algorithm assists in the optimal adjustment of the hyperparameters related to the DRNN model for DR detection showing the novelty of our work. To assuring the improved performance of the DLLSHDM-DR model, a wide range of experiments was tested on the EyePACS dataset. The comparison outcomes assured the better performance of the DLLSHDM-DR approach over other DL models.  相似文献   
539.
    
This article examines some of the basic questions about silicon module recycling: (1) What can be recovered from silicon modules? (2) What recycling technologies are needed? (3) What are the potential revenues for different recycling scenarios? And (4) what are the major challenges for different recycling scenarios? Three recycling scenarios are considered: module reuse, component extraction, and material extraction. Recycling process sequences for different scenarios are outlined. The discussions conclude that module reuse generates the highest revenue with the fewest processing steps, while material extraction leads to the lowest revenue with the most processing steps. It is suggested that gentle and clean separation of silicon solar cells from the glass pane is a critical technology for silicon module recycling. It is also argued that two low‐concentration metals must be recovered from silicon modules: silver as a scarce material and lead as a toxic material. Their recovery requires chemical methods, while bulky materials including glass cullet, aluminum frame, and copper wiring can be recovered with physical methods. The silicon in the cells can be extracted with different qualities: ferro‐silicon, metallurgical‐grade silicon, or solar‐grade silicon, with a higher revenue and more complicated recycling process for purer silicon. Markets outside the solar industry for the recovered silicon should be explored. The biggest challenge for module reuse is to find a large and sustained market for hundreds of gigawatts peak of decommissioned modules a year, and the biggest challenge for component extraction is the many different module and cell structures on the market and cell efficiency variability. For all the three scenarios, the cost of collecting and processing waste modules is a common challenge.  相似文献   
540.
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