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81.
Pavol Hanus Bernhard Goebel Janis Dingel Johanna Weindl Juergen Zech Zaher Dawy Joachim Hagenauer Jakob C. Mueller 《Electrical Engineering (Archiv fur Elektrotechnik)》2007,90(2):161-173
The DNA sequencing efforts of the past years together with rapid progress in sequencing technology have generated a huge amount
of sequence data available in public molecular databases. This recent development makes it statistically feasible to apply
universal concepts from Shannon’s information theory to problems in molecular biology, e.g to use mutual information for gene
mapping and phylogenetic classification. Additionally, the genetic information in the cell is continuously subject to mutations.
However, it has to be passed from generation to generation with high fidelity, raising the question of existence of error
protection and correction mechanisms similar to those used in technical communication systems. Finally, better understanding
of genetic information processing on the molecular level in the cell can be acquired by looking for parallels to well established
models in communication theory, e.g. there exist analogies between gene expression and frame synchronization. 相似文献
82.
Katrin Mackenzie Juergen Battke Robert Koehler Frank-Dieter Kopinke 《Applied catalysis. B, Environmental》2005,59(3-4):171-179
The hydrolysis reaction of 1,1,2,2-tetrachloroethane (TeCA) is significantly enhanced by sorption on activated carbon. TeCA is quantitatively transformed into trichloroethene (TCE) at moderate pH values. This transformation is exploited as the basic step of a site-adapted groundwater-cleanup technology. The volatility of TCE is a factor of 23 higher than that of TeCA such that the partially dehydrochlorinated product can be easily stripped out of the groundwater flow. The base-mediated and the neutral dehydrochlorination of TeCA were studied as a function of temperature and pH value in batch and column experiments. Surprisingly, it was found that despite high loadings of the sorbent with TeCA and TCE (≥20 wt.%) the TeCA remains available for the hydrolysis reaction. 相似文献
83.
In this publication, several stainless steel microstructure reactors specially designed to obtain rapid and periodic temperature changes are presented. Different microstructure reactor designs have been manufactured and tested for their thermal behaviour and equally by running a test reaction under stationary and non-stationary temperature conditions. The devices were continuously electrically heated and periodically cooled by a deionized water flow. The objective of the experimental measurements was to demonstrate that non-stationary temperature conditions may lead to an increase in the reaction rate compared to the stationary conditions. The heterogeneously catalysed oxidation of CO was chosen as the test reaction. The catalyst used was a dispersion of platinum on a porous alumina support generated by sol-gel technology. The experiments realized under non-stationary temperature conditions with a temperature oscillation amplitude of 41 K and a period duration of 21 s show an increase in the mean CO2 concentration of a factor 1.72 compared to the mean concentration under quasi-stationary temperature conditions. The simulations of a simple monomolecular reaction under non-stationary temperature conditions indicate that the presence of a transitional surface coverage generated by the temperature oscillations may be a possible explanation for the observed phenomenon. 相似文献
84.
Torsten Henning Juergen J. Brandner Lutz Eichhorn Klaus Schubert Martin Schreiber Martin Güngerich Hermann Günther Peter J. Klar Vivian Rebbin Michael Fröba 《Microfluidics and nanofluidics》2007,3(3):299-305
We have incorporated microspheres, from 50 to 80 μm in diameter, of periodic mesoporous organosilica (inner surfaces up to
1,000 m2/g and pore sizes in the nanometre range) with two types of organic functionalities (benzene and ethane bridges, respectively)
inside microstructured channels (each 200 μm wide and 100 μm deep) and, exemplarily, monitored by Raman microscopy (Raman
spectroscopy through microscope optics) that the temperature characteristics of the adsorption–desorption equilibria of benzene
and ethanol vary significantly with the type of organic functionality of the microspheres and the pore morphology. The integration
of this class of nanostructured material into devices by means of microchannels is a promising novel approach to, among others,
substance separation in analytics, micro process engineering, and micro chemistry. 相似文献
85.
Minimizing steel corrosion in liquid lead-alloys by addition of oxygen requires devices for efficient oxygen transfer and reliable oxygen sensors. The accuracy of electrochemical oxygen sensors is analyzed using theoretical considerations and results from experiments in stagnant lead–bismuth eutectic (LBE). Additionally, the feasibility of gas/liquid oxygen-transfer and the long-term performance of electrochemical sensors in flowing liquid metal are addressed on the basis of the operating experience of the CORRIDA loop, a facility for testing steels in flowing LBE. 相似文献
86.
Personnel planning is traditionally one of the last activities in the process of bringing a product to the market. This can lead to a lack of necessary knowledge, skills, and abilities (KSA) on the shop floor often causing delays at the start of production. In Concurrent Engineering (CE), planning activities are integrated and information is frequently exchanged to avoid such problems. As job design determines the requirements for personnel planning, this article presents a method for integrating job design and personnel planning. This method makes it possible to define personnel requirements in early phases as well as designing jobs to the availability of personnel. It is based on a tool for modeling the task structure in the early phases, when information is still poorly defined, continuously adapting the task model to increasing levels of detail, and a method of directly deducing from the task structure the necessary KSA. The method is well suited to deal with poorly defined information; it allows the design of jobs, and considers personnel selection, education, and training concurrently to other planning activities. A case study is presented to demonstrate its use. © 2000 John Wiley & Sons, Inc. 相似文献
87.
Reising K Meins J Bastian B Eckert G Mueller WE Schubert-Zsilavecz M Abdel-Tawab M 《Analytical chemistry》2005,77(20):6640-6645
Peritumoral edema, one of the major causes for neurological disorders in brain tumor patients, is mainly treated with steroids, which unfortunately have significant side effects and interfere with the efficacy of chemotherapy. Boswellic acids, the main active ingredients of Boswellia serrata, are antiinflammatory agents, inhibiting 5-lipoxygenase, the key enzyme of leukotriene biosynthesis and one of the pathophysiological mechanisms of peritumoral edema. Based on positive results in clinical trials and animal studies, B. serrata resin dry extract was designated an orphan drug by the European Commission for the treatment of peritumoral edema resulting from brain tumors. Thus boswellic acids may be alternative drugs to corticosteroids. However, the question of the availability of boswellic acids in brain has not been addressed until now. Accordingly, a highly sensitive LC/MS method has been developed for the simultaneous determination of KBA and AKBA, the most potent boswellic acids, in plasma and brain. This method involves matrix-assisted liquid-liquid extraction on Extrelut NT followed by separation on reversed-phase high-performance liquid chromatography and tandem mass spectrometry detection using atmospheric pressure chemical ionization. Excellent linearity was obtained for the entire calibration range from 5 to 1500 ng/mL KBA and AKBA in plasma and 5 to 1000 ng/mL KBA and AKBA in brain. Validation assays of the lower limit of quantification as well as for the intra- and interday precision and accuracy met the international acceptance criteria for bioanalytical method validation. Moreover, the interchangeability of calibration curves generated in pork and rat brain homogenates could be demonstrated. Using the developed analytical method, KBA and AKBA could be detected for the first time in brain up to a concentration of 99 and 95 ng/g of brain, respectively, 3 h after the single oral administration of 240 mg/kg of dry B. serrata resin extract to Wistar rats. The developed method represents an appropriate tool to further study the time-dependent distribution of KBA and AKBA in plasma and brain as well as the absolute brain concentration after multiple doses and contributes thus to the optimization of the dosage regimen and to a better understanding of the therapeutic effects of B. serrata. 相似文献
88.
Timothy Cassidy James R. Cordy Thomas R. Dean Juergen Dingel 《Electronic Notes in Theoretical Computer Science》2005,141(4):57
Concurrent programming poses a unique set of problems for quality assurance. These difficulties include the complexities of deadlock, livelock and divergence, which can be extremely difficult to detect and debug. A variety of tools have been developed to assist designers and developers of concurrent applications. Some of these tools, such as VeriSoft, are specific to particular implementation languages, such as C++.The Java Remote Method Invocation (Java RMI) package facilitates the implementation of concurrent applications, including those where processes reside on different hosts and communicate over networks. Unfortunately, it does not relieve the developer from the potential pitfalls of controlling concurrent access to remote objects, and may, in fact, make concurrency problems even more difficult to find.This paper presents an approach that allows the VeriSoft state exploration system to be used to analyze Java RMI programs for deadlock, livelock, divergence, and assertion violations. The system works by transforming Java RMI programs into C++ programs where Java syntax, structure, concurrency and memory management are replaced by C++ equivalents and Java RMI communication has been transformed to VeriSoft C++ inter-process communication. We present the details of this transformation and discuss preliminary results for a number of small examples. 相似文献
89.
Anja Henss Marcus Rohnke Thaqif El Khassawna Parameswari Govindarajan Gudrun Schlewitz Christian Heiss Juergen Janek 《Journal of the Royal Society Interface》2013,10(86)
Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is a well-established technique in material sciences but has not yet been widely explored for implementation in life sciences. Here, we demonstrate the applicability and advantages of ToF-SIMS analysis for the study of minerals and biomolecules in osseous tissue. The locally resolved analysis of fragment ions deriving from the sample surface enables imaging and differentiation of bone tissue and facilitates histology on non-stained cross sections. In a rat model, bilateral ovariectomy combined with either a multi-deficiency diet or steroid treatment was carried out to create osteoporotic conditions. We focused our study on the Ca content of the mineralized tissue and monitored its decline. Calcium mass images of cross sections show the progressive degenerative changes in the bone. We observed a decreased Ca concentration in the edge region of the trabeculae and a decline in the Ca/P ratio. Additionally, we focused on the non-mineralized matrix and identified fragment ions that are characteristic for the collagen matrix. We observed trabeculae with wide ranges of non-mineralized collagen for the diet group owing to an impaired mineralization process. Here, the advantage of coeval monitoring of collagen and minerals indicated an osteomalacic model rather than an osteoporotic one. 相似文献
90.
Parameter set selection for dynamic systems under uncertainty via dynamic optimization and hierarchical clustering 下载免费PDF全文
Wei Dai Loveleena Bansal Juergen Hahn Daniel Word 《American Institute of Chemical Engineers》2014,60(1):181-192
It is common that only a subset of the parameters of models can be accurately estimated. One approach for identifying a subset of parameters for estimation is to perform clustering of the parameters into groups based upon their sensitivity vectors. However, this has the drawback that uncertainty cannot be directly incorporated into the procedure as the sensitivity vectors are based upon the nominal values of the parameters. This article addresses this drawback by presenting a parameter set selection technique that can take uncertainty in the parameter space into account. This is achieved by defining sensitivity cones, where a sensitivity cone includes all sensitivity vectors of a parameter for different values, resulting from the uncertainty, in the parameter space. Parameter clustering can then be performed based upon the angles between the sensitivity cones, instead of the angle between sensitivity vectors. The presented technique is applied to two case studies. © 2013 American Institute of Chemical Engineers AIChE J, 60: 181–192, 2014 相似文献