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141.
Advances in wired and wireless networking technologies are making networked computing the most common form of high performance computing. Similarly, software like Mosaic and Netscape have not only unified the networked computing landscape, but they have made it available to the masses in a simple, machine independent way. These developments are changing the way we do computational science, learn, research, collaborate, access information and resources, and maintain local and global relations. We envision a scenario where large scale computational science and engineering applications like virtual classrooms and laboratories are ubiquitous, and information resources are accessible on-demand from anywhere. In this paper we present the design of a user interface that will be appropriate to this scenario. We argue that interfaces modeled on the pen and paper paradigm are suited in this context. Specifically, we present the software architecture of a notebook interface. We lay down the requirements for such an interface and present its implementation using the World Wide Web. A realization of the notebook model is presented for a problem solving environment (PDELab) to support the numerical simulation of PDE based applications on a network of heterogeneous high performance machines. © 1997 John Wiley & Sons, Ltd.  相似文献   
142.
A polymer‐anchored nickel(II)–phenanthroline complex [polyNi(II)–phen] was synthesized and used effectively as a reusable catalyst in various oxidation reactions in the presence of tert‐butylhydroperoxide as an oxidant in acetonitrile medium. The catalyst was characterized with elemental analysis, atomic absorption spectrometry (AAS), thermogravimetric analysis, scanning electron microscopy, and spectrometric methods such as diffuse reflectance spectroscopy, ultraviolet–visible spectroscopy, and Fourier transform infrared spectroscopy. The study of the effects of the time, temperature, oxidant, catalyst concentration, molar ratio of substrate to oxidant, and solvent in the oxidation of styrene individually gave the optimized reaction conditions. Under optimized conditions, the catalyst exhibited good conversions for the oxidation reactions of various olefins, alkanes, aromatic alcohols, and thioethers. The catalyst was easily recovered by simple filtration and reused for more than five times with consistent catalytic activity. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012  相似文献   
143.
144.
A new polymer anchored copper(II) azo complex has been synthesized and characterized by using scanning electron microscope (SEM), thermogravimetric analysis (TGA), elemental analysis, atomic absorption spectroscopy (AAS) and spectrometric methods like diffuse reflectance spectra of solid (DRS) and Fourier transform infrared spectroscopy (FTIR). The immobilized Cu(II) catalyst shows excellent catalytic activity in oxidation of cyclohexene, styrene, benzyl alcohol and ethylbenzene in presence of tert-butylhydroperoxide (TBHP) as an oxidant. The effects of different solvents, oxidants, temperature, substrate oxidant ratio and amount of catalyst were also studied. The catalytic results reveal that the polymer-anchored Cu(II) azo complex catalyst can be recycled more than five times without appreciable loss in the catalytic activity.  相似文献   
145.
Raman spectra of several minerals and organics were obtained from a small portable instrument at a distance of 10 m in a well-illuminated laboratory with a single 532 nm laser pulse with energy of 35 mJ/pulse. Remote Raman spectra of common minerals (dolomite, calcite, marble, barite, gypsum, quartz, anatase, fluorapatite, etc.) obtained in a short period of time (1.1 mus) clearly show Raman features that can be used as fingerprints for mineral identification. Raman features of organics (benzene, cyclohexane, 2-propanol, naphthalene, etc.) and other chemicals such as oxides, silicates, sulfates, nitrates, phosphates, and carbonates were also easily detected. The ability to identify minerals from their Raman spectra obtained from a single laser pulse has promise for future space missions where power consumption is critical. Such a system could be reduced in size by minimizing the cooling requirements for the laser unit. The remote Raman system is also capable of performing time-resolved measurements. Data indicate that further improvement in the performance of the system is possible by reducing the gate width of the detector (ICCD) from 1.1 mus to approximately 20 ns, which would significantly reduce the background signal from daylight or a well-illuminated laboratory. The 1.1 mus signal gating was effective in removing nearly all background fluorescence with 532 nm excitation, indicating that the fluorescence in most minerals is probably from long-lifetime inorganic phosphorescence.  相似文献   
146.
Breast cancer is the leading cause of cancer-related deaths for women in the United States and the rest of the world. About 8% of women develop breast cancer during the course of their lives. Dietary habits are closely associated with both the risk and progression of breast cancer. Dietary agents have accumulated increasing importance with regards to the prevention and treatment of breast cancer. One such manner by which these compounds can target breast cancer development and progression is through interference with the angiogenic pathways. Angiogenesis is an intricate process that involves the development of new capillaries from previously existing blood vessels. Disruption of this pathway, therefore, provides a novel and effective avenue for therapeutic intervention of breast cancer. Various phytochemicals found in the diet kill breast cancer cells in vitro and prevent as well as suppress breast cancer progression in various preclinical animal models. This review examines the value of dietary phytoconstituents in the prevention and treatment of breast cancer through modulation of the intricate and complex process of angiogenesis. In addition, the potential benefits, challenges, and future directions of research on anti-angiogenic dietary phytochemicals in the prevention and intervention of breast cancer are also addressed.  相似文献   
147.
EED process for HI concentration was studied for the effect of individual operating parameters such as I2/HI ratio, concentration of HI(xHI/H2O)HI(xHI/H2O), temperature and pressure. Studies were conducted in an asymmetric system where the effects of operating parameters were varied for anolyte and the catholyte separately. Open circuit voltage (OCV) was found to be a contributor toward the net potential drop across the EED cell. Ohmic resistance was found to decrease with increase in I2/HI ratio in catholyte and was found to increase with increase in I2/HI ratio in anolyte. Increase in xHI/H2OxHI/H2O decreased the resistance for anolyte section whereas caused an increase in resistance for catholyte section. Increase in temperature reduced the voltage drop and the resistance across the EED cell. A non-zero differential pressure between the two compartments of the cell increased the resistance across the cell without affecting the OCV value. Electrode potential studies at the graphite electrodes showed an increase in the electro potential with increase in the iodine concentration and decrease with the increase in the HI concentration. Energy required for concentrating acid increased linearly with current density favoring operation at low current densities. Energy consumed in overcoming OCV contributed substantial fraction of the total energy consumed in EED process at lower current densities.  相似文献   
148.
The development of luminescent mercury sulfide quantum dots (HgS QDs) through the bio‐mineralization process has remained unexplored. Herein, a simple, two‐step route for the synthesis of HgS quantum dots in bovine serum albumin (BSA) is reported. The QDs are characterized by UV–vis spectroscopy, Fourier transform infrared (FT‐IR) spectroscopy, luminescence, Raman spectroscopy, transmission electron microscopy (TEM), X‐ray photoelectron spectroscopy (XPS), circular dichroism (CD), energy dispersive X‐ray analysis (EDX), and picosecond‐resolved optical spectroscopy. Formation of various sizes of QDs is observed by modifying the conditions suitably. The QDs also show tunable luminescence over the 680–800 nm spectral regions, with a quantum yield of 4–5%. The as‐prepared QDs can serve as selective sensor materials for Hg(II) and Cu(II), based on selective luminescence quenching. The quenching mechanism is found to be based on Dexter energy transfer and photoinduced electron transfer for Hg(II) and Cu(II), respectively. The simple synthesis route of protein‐capped HgS QDs would provide additional impetus to explore applications for these materials.  相似文献   
149.
The worldwide transition to lead-free electronics has increased the usage of several lead-free pad finishes for electronic assembly manufacturers, including immersion silver, immersion tin, electroless nickel-immersion gold, and organic solderability preservatives. This study assesses and compares immersion silver as a circuit board finish in terms of its ease of use, wettability, solderability, shelf life, appearance, solder joint strength, intermetallic and void formation, reliability, and costs.  相似文献   
150.
Several compositional forms of simulation-based security have been proposed in the literature, including Universal Composability, Black-Box Simulatability, and variants thereof. These relations between a protocol and an ideal functionality are similar enough that they can be ordered from strongest to weakest according to the logical form of their definitions. However, determining whether two relations are in fact identical depends on some subtle features that have not been brought out in previous studies. We identify two main factors: the position of a “master process” in the distributed system and some limitations on transparent message forwarding within computational complexity bounds. Using a general computational framework, called Sequential Probabilistic Process Calculus (SPPC), we clarify the relationships between the simulation-based security conditions. Many of the proofs are carried out based on a small set of equivalence principles involving processes and distributed systems. These equivalences exhibit the essential properties needed to prove relationships between security notions and allow us to carry over our results to those computational models which satisfy these equivalences.  相似文献   
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