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31.
Quantifying change after large habitat restoration efforts is critical to assessing the effort's success. After river restoration activities, fish abundance is expected to increase and also fluctuates naturally by season and with environmental conditions. A side‐looking hydroacoustic system was used to estimate fish abundance in the Penobscot River, ME, from 2010 to 2016 during predam (2010–2013) and postdam (2014–2016) removal years during nonice periods. Automated data processing enabled continuous abundance estimates from fish tracks. A threefold increase in mean fish abundance was recorded after dam removal. A fourfold increase in median fish abundance occurred in the fall relative to spring and summer of the same year, regardless of dam presence. Interannual fish abundance in every season monitored increased at least twofold after dam removal. We related variability in fish abundance to tide, discharge, temperature, diurnal cycle, daylength, moon phase, and restoration activities (focusing on dam presence). Daylength corresponding to the fall and summer was the most important indicator for higher fish abundance. Fish abundance was generally greatest in the fall during outgoing tides at night, with lesser peaks occurring during the month of June at night. Before dam removal, fish abundance peaked when water temperature was less than 9.25°C, at night, during outgoing tides. After dam removal, fish abundance peaked when daylength was less than 11.3 hr, at night, during outgoing tides, when water temperature was above 4.56°C and no full moon was present. Peak fish abundance occurred during only 0.02–2.3% of the total time sampled. The threefold increase in fish abundance recorded after dam removal was observed despite yearly stocking efforts of adult alewife increasing 24% in postdam removal years. Finally, parallel studies of fish presence in the Penobscot River were used to compare the utility of this method as an indicator of fish abundance in response to dam removal.  相似文献   
32.
The paper reviews the current state of knowledge regarding European emissions of mercury and presents estimates of European emissions of mercury to the atmosphere from anthropogenic sources for the year 2000. This information was then used as a basis for Hg emission scenario development until the year 2020. Combustion of coal in power plants and residential heat furnaces generates about half of the European emissions being 239 tonnes. The coal combustion is followed by the production of caustic soda with the use of the Hg cell process (17%). Major points of mercury emission generation in the mercury cell process include: by-product hydrogen stream, end box ventilation air, and cell room ventilation air. This technology is now being changed to other caustic soda production technologies and further reduction of Hg emissions is expected in this connection. The third category on the list of the largest Hg emitters in Europe is cement production (about 13%). The largest emissions were estimated for Russia (the European part of the country), contributing with about 27% to the European emissions, followed by Poland, Germany, Spain, Ukraine, France, Italy and the United Kingdom. Most of these countries use coal as a major source of energy in order to meet the electricity and heat demands. In general, countries in the Central and Eastern Europe generated the main part of the European emissions in 2000. Emission reductions between 20% and 80% of the 2000 emission amounts can be obtained by the year 2020, as estimated by various scenarios.  相似文献   
33.
We report a simple model describing the solubility of rods in solvents, expressing the final result explicitly in terms of the surface entropy and the enthalpy of mixing. This model can be combined with any expression for the mixing enthalpy depending on the requirements. For example, in one instance it predicts the dispersed concentration of rods to decrease exponentially with the Flory-Huggins parameter of the dispersion. Using a different enthalpy function, it predicts a Gaussian peak when concentration is plotted versus solvent surface energy. The model also suggests specific solvent-rod interactions to be important and shows the dispersed concentration to be very sensitive to ordering at the solvent-rod interface. We have used this model to describe experimental results for the concentration of dispersed nanotubes in various solvents. Qualitative agreement with these predictions is observed experimentally. However, we suggest that the fact that quantitative agreement is not found may be explained by solvent ordering at the nanotube surface.  相似文献   
34.
Rethinking Project Management: Researching the actuality of projects   总被引:2,自引:0,他引:2  
This paper puts forth the somewhat controversial position that what is needed to improve project management in practice is not more research on what should be done or the frequency and/or use of traditional project management practices. We argue that while a great deal is written about traditional project management we know very little about the “actuality” of project based working and management. This paper formulates a research approach that takes seriously practitioner’s lived experience of projects. We explore the ontological, epistemological and methodological assumptions underlying this kind of research and provide examples of some project management research originating from this perspective. We conclude by summarizing the findings from these studies and providing insights into the map ahead for future such research. In this kind of work the attention is refocused on praxis, on context-dependent judgement, on situational ethics and on reflexivity which enables social actors to see how power actually functions in context.  相似文献   
35.
A considerable proportion of cases of myeloproliferative and lymphoproliferative disorders exhibit renal involvement. However, it is unclear whether the cytologic features, immunophenotype or grade of malignancy of the cells infiltrating the kidney differ from those of the primary tumor. This study was performed on 120 autopsy cases with the following diagnoses: acute myelogenous leukemia (AML, n = 22; subtypes M1 + M2, n = 12, subtype M4, n = 10), chronic myelogenous leukemia (CML, n = 7), agnogenic myeloid metaplasia/myelofibrosis (AMM/MF, n = 6), acute lymphocytic leukemia (ALL, n = 6), chronic lymphocytic leukemia (CLL, n = 9), other low-grade non-Hodgkin's lymphomas (low-grade NHL, n = 24), high-grade NHL (n = 21) and multiple myeloma (MM, n = 25). Renal involvement was investigated by light microscopy and immunohistochemistry. It was found in 34% of the cases, and was most common in ALL (83%) and low-grade NHL (50%) and least common in high-grade NHL (10%) and MM (12%). Dense infiltration of almost the entire kidney was most commonly seen in AML, low-grade NHL and ALL. Infiltration was bilateral and involved both the cortex and medulla in the majority of cases. When involvement of other organs was compared with that of the kidney, the lung was found to be involved in approximately the same number of cases, but liver involvement was more common and heart involvement less common. Reactive lymphocytic infiltration of the kidney was found in 18 of the 120 cases (15%), and was distinguished from scanty tumorous infiltration by immunohistochemical staining. No major phenotypical differences were found between the tumor cells infiltrating the kidney and those of the primary tumors in the bone marrow or lymph nodes. However, in one case of CML, the cells infiltrating the kidney were negative for KP1 and chloroacetate esterase, but could be identified by reactivity for CD34. The grade of malignancy in NHL was similar in both the nodal and renal manifestations.  相似文献   
36.
Boron cluster-conjugated antisense oligonucleotides (B-ASOs) have already been developed as therapeutic agents with “two faces”, namely as potential antisense inhibitors of gene expression and as boron carriers for boron neutron capture therapy (BNCT). The previously observed high antisense activity of some B-ASOs targeting the epidermal growth factor receptor (EGFR) could not be rationally assigned to the positioning of the boron cluster unit: 1,2-dicarba-closo-dodecaborane (0), [(3,3′-Iron-1,2,1′,2′-dicarbollide) (1-), FESAN], and dodecaborate (2-) in the ASO chain and its structure or charge. For further understanding of this observation, we performed systematic studies on the efficiency of RNase H against a series of B-ASOs models. The results of kinetic analysis showed that pyrimidine-enriched B-ASO oligomers activated RNase H more efficiently than non-modified ASO. The presence of a single FESAN unit at a specific position of the B-ASO increased the kinetics of enzymatic hydrolysis of complementary RNA more than 30-fold compared with unmodified duplex ASO/RNA. Moreover, the rate of RNA hydrolysis enhanced with the increase in the negative charge of the boron cluster in the B-ASO chain. In conclusion, a “smart” strategy using ASOs conjugated with boron clusters is a milestone for the development of more efficient antisense therapeutic nucleic acids as inhibitors of gene expression.  相似文献   
37.
The absorbed dose to water is the reference physical quantity for the energy absorbed in tissue when exposed to beams of ionizing radiation in radiotherapy. The SI unit of absorbed dose to water is the gray (Gy = 1 J/kg). Ionization chambers are used as the dosimeters of choice in the clinical environment because they show a high reproducibility and are easy to use. However, ionization chambers have to be calibrated in order to convert the measured electrical charge into absorbed dose to water. In addition, protocols require these conversion factors to be SI traceable to a primary standard of absorbed dose to water. We present experimental results where the ionization chamber used for the dosimetry for the scanned proton beam facility at PSI is compared with the direct determination of absorbed dose to water from the METAS primary standard water calorimeter. The agreement of 3.2% of the dose values measured by the two techniques are within their respective statistical uncertainties.  相似文献   
38.
The demands on the neutral beam heating and current drive system of a DEMO device exceed those of existing fusion experiments by several orders of magnitude. By predicting possible power waveforms it is possible to analyse the technological advances necessary to achieve a system relevant to deployment on a power plant. Achieving the necessary efficiency will require simultaneous improvements in beam current density, neutralization efficiency and beam transmission. Considering the deployment on the tokamak vessel shows no major disruption to the tritium breeder blanket and no requirement to reach a high packing density of injectors. The thermal management of components subjected to low heat flux for many hours is considered and it is shown that radiation cooling can be exploited to control the temperature of such items.  相似文献   
39.
The study presents a comparative evaluation of emptiness (lacunarity) in model structures with different types of inhomogeneity of dispersed particle distributions. The research on emptiness (lacunarity) as a measure of the degree of space filling and, at the same time, of the internal characterization of a set has been based on the optimal covering and gliding-box methods.  相似文献   
40.
OBJECTIVE: In women who use oral contraceptives with low estrogen doses, a quiescent endometrium is frequently produced. Further reduction of the estrogen dose would not be expected to alter this effect. In this open-label study, the effects on the endometrium of a monophasic oral contraceptive containing 75 micrograms gestodene and 20 micrograms ethinylestradiol were assessed. METHOD: Biopsies were performed on 25 women on therapy. The biopsies were performed during the late luteal phase (last 7 days) in the pretreatment cycle and during days 15-21 in cycle 6 for 13 subjects (Group A) and during days 15-21 in cycle 3 and during the late luteal phase (last 7 days) in the post-treatment cycle for 12 subjects (Group B). RESULTS: All subjects completed six cycles of treatment. Nine of 13 subjects pretreatment and nine of 12 subjects at cycle 3 were characterized by the pathologist as having a secretory endometrium. Four of 13 subjects at cycle 6 and ten of 11 subjects post-treatment also demonstrated a secretory endometrium. Pre-decidual changes were seen in one, two, two and zero subjects at pretreatment, after three cycles, six cycles, and post-treatment, respectively. Six subjects had an atrophic endometrium at cycle 6. CONCLUSIONS: With monophasic gestodene/ethinylestradiol 75 micrograms/20 micrograms, a secretory or inactive endometrium was present in most subjects. Thus, the effects on the endometrium of this oral contraceptive containing a reduced estrogen dose are consistent with those produced by other low-estrogen-dose combination oral contraceptives.  相似文献   
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