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141.
The future of power grids is expected to involve an increasing level of intelligence and integration of new information and communication technologies in every aspect of the electricity system, from demand-side devices to wide-scale distributed generation to a variety of energy markets. This paper provides a general outlook of the definition of this future in the US and the European Union and compares two approaches—GridWise™ and SmartGrid. It describes the contexts in both the worlds, as they influence the two visions of the future intelligent power grid, and as they form foundations at each respective federal level for supporting research in this field. The similarities and complementarities of the two research programs are examined. Within the framework of a solid precedence for trans-Atlantic co-operation in energy research, the time would seem optimal to set in motion active collaboration and educational exchange on GridWise and SmartGrid research. 相似文献
142.
G Brambilla M Fiori E Pierdominici G Antonucci P Giorgi V Ramazza M Zucchi 《Canadian Metallurgical Quarterly》1998,22(7):457-465
The frequency of lumbar disc hemiation amounts to 5.1% with the male and 3.7% with the female population. Because of the often long-time pain-conditional impairment of the patients as well as the varied therapy-possibilities, the treatment of the ruptured lumbar intervertebral disc represents a special challenge. The indication to the operation for the lumbar disk-herniation results from the malfunctions of the nerve roots, the pains, as well as the temporal course of the symptoms. New and important developments have given the introduction of micro-surgical operation-techniques into the orthopedics. This development has led to it that many orthopedists and neurosurgeons the micro-surgical operation-technique prefers. Important for the micro-surgical lumbar discectomy is the operation-microscope, a good preoperative diagnostics as well as a particular micro-surgical operation-instrument. Through the different enlargement-possibilities of the operation-microscope, all anatomical structures can increase and are done visibly for the surgeon as well as the assistant. Intraoperative injuries of the dura as well as the spinal-nerves are certainly avoided hereby. The micro-surgical discectomie requires no longer time like the conventional operation of the disk. The postoperative stay in the hospital as well as the time of the work-incompetence is reduced. Postoperative inflammations of the disk-area as well as renewed operations are rarer with the microchirurgischen technique. If an operation is necessary, so this should not be out-hesitated too long in order to avoid bed results. 相似文献
143.
The world of energy has lately experienced a revolution, and new rules are being defined. The climate change produced by the greenhouse gases, the inefficiency of the energy system or the lack of power supply infrastructure in most of the poor countries, the liberalization of the energy market and the development of new technologies in the field of distributed generation (DG) are the key factors of this revolution. It seems clear that the solution at the moment is the DG. The advantage of DG is the energy generation close to the demand point. It means that DG can lower costs, reduce emissions, or expand the energy options of the consumers. DG may add redundancy that increases grid security even while powering emergency lighting or other critical systems and reduces power losses in the electricity distribution. After the development of the different DG and high efficiency technologies, such as co‐generation and tri‐generation, the next step in the DG world is the interconnection of different small distributed generation facilities which act together in a DG network as a large power plant controlled by a centralized energy management system (EMS). The main aim of the EMS is to reach the targets of low emissions and high efficiency. The EMS gives priority to renewable energy sources instead of the use of fossil fuels. This new concept of energy infrastructure is referred to as virtual utility (VU). The VU can be defined as a new model of energy infrastructure which consists of integrating different kind of distributed generation utilities in an energy (electricity and heat) generation network controlled by a central energy management system (EMS). The electricity production in the network is subordinated to the heat necessity of every user. The thermal energy is consumed on site; the electricity is generated and distributed in the entire network. The network is composed of one centralized control with the EMS and different clusters of distributed generation utilities and heat storage tanks. Each of these clusters is controlled by a local management station (LMS). Every LMS has information about the requirements (heat, cold and electricity) of the users connected to its cluster and the state of the utilities and water level of the storage tanks in its cluster. The EMS receives the information from the LMSs and sets the electricity input or output of every cluster in the network. With the information ordered by the EMS, the LMS set the run or stand‐by of the utilities of its cluster. The benefits of the VU are the optimization of the utilization yield of the whole network, the high reliability of the electricity production, the complete control of the network for achieving the main aim of the EMS, the high velocity for assuming quick changes in the demand of the system and high integration of renewable energy sources, plus the advantages of the DG. This paper indicates the state of the art of the VU concept, analyses the projects that are being developed in this field and considers the future of the VU concept. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
144.
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146.
Túlio M. Nunes Izabel C. C. Turatti Norberto P. Lopes Ronaldo Zucchi 《Journal of chemical ecology》2009,35(10):1172-1180
Chemical compounds on the cuticle are a rich source of information used during interactions among social insects. Despite
the multitude of studies on these substances and their function in ants, wasps, and honeybees, little is known about this
subject in stingless bees (Hymenoptera: Apidae, Meliponini). We studied the chemical composition of the cuticle of the stingless
bee, Frieseomelitta varia, by gas chromatography-mass spectrometry (GC-MS), to investigate potential chemical variation among castes, gender, age,
and reproductive status. We found differences in the cuticular hydrocarbon composition among workers, males, and queens, recording
both qualitative and quantitative differences among individuals of different ages and gender. The cuticle of physogastric
queens presented a chemical profile that was distinct from all other groups in the analysis, with high relative abundances
of alkenes and alkadienes with 27, 29, and 31 carbon atoms. We discuss the possibility that these compounds signal a queen’s
presence to the colony, thereby initiating all vital worker-queen interactions. 相似文献
147.
Debora Fabbri Alessandra Bianco Prevot Edmondo Pramauro 《Applied catalysis. B, Environmental》2004,49(4):233-238
The effect of sodium dodecyl sulphate (SDS) on the photocatalytic degradation of 2,4,5-trichlorophenol (2,4,5-TCP) in aqueous TiO2 dispersions under irradiation with simulated AM1 solar light was investigated. A peculiar kinetic behaviour was observed, with increasing inhibition of the substrate degradation as a function of SDS concentration below the critical micellar concentration (cmc), followed by a subsequent faster degradation around this concentration range and a further degradation rate decrease above the cmc. The role of surfactant adsorption onto the suspended semiconductor and the disaggregation of TiO2 microparticles seems to be crucial. The complete degradation of the investigated substrate, still achievable in the presence of SDS without relevant changes in the reaction mechanism, was confirmed suggesting the possible application of photocatalysis for the treatment of surfactant-containing wastes. 相似文献
148.
Francesco Bonchi Carlos Castillo Debora Donato Aristides Gionis 《Data mining and knowledge discovery》2009,19(2):227-244
Given a taxonomy of events and a dataset of sequences of these events, we study the problem of finding efficient and effective
ways to produce a compact representation of the sequences. We model sequences with Markov models whose states correspond to
nodes in the provided taxonomy, and each state represents the events in the subtree under the corresponding node. By lumping
observed events to states that correspond to internal nodes in the taxonomy, we allow more compact models that are easier
to understand and visualize, at the expense of a decrease in the data likelihood. We formally define and characterize our
problem, and we propose a scalable search method for finding a good trade-off between two conflicting goals: maximizing the
data likelihood, and minimizing the model complexity. We implement these ideas in Taxomo, a taxonomy-driven modeler, which we apply in two different domains, query-log mining and mining of moving-object trajectories.
The empirical evaluation confirms the feasibility and usefulness of our approach. 相似文献
149.
The soot combustion process, promoted by some promising diesel particulate combustion catalysts based on Cs and V oxides (Cs2O, Cs3VO4, Cs4V2O7, Cs2O · V2O5, CsVO3, Cs2V4O11, V2O5), is discussed on the grounds of an experimental test campaign involving reaction runs in micro-reactors (temperature-programmed conditions) and in a differential scanning calorimeter apparatus. Such investigations led to define the roles of the Cs and V species in these catalysts as well as to identify the Cs3VO4 catalyst as the most active. 相似文献
150.
Posttransplant monitoring of anti-HLA antibodies with routine techniques gives unsatisfactory results due to a variety of technical limitations. We investigated how a new alternative technique correlates with posttransplant clinical events. A total of 313 nonselected serum samples from 136 patients were screened by an ELISA utilizing captured soluble HLA class I antigens. We observed the absence of anti-HLA antibody production in acute rejection cases responding to standard antirejection therapy. On the other hand, we showed a clear presence of these antibodies in acute rejection episodes not responding to standard therapy (P<0.0001) and in chronic rejection (P<0.001). We conclude that routine posttransplant monitoring by ELISA offers early risk assessment that is crucial for proper immunosuppression and for antirejection therapy choice. 相似文献