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201.
From the electrical point of view, the body and the anode of high power gyrotrons behave as capacitive loads. A highly dynamic power supply is, therefore, hard to achieve. The MAGY concept (Modulator for the Anode of a triode type GYrotron) embodies an innovative solution to manage the capacitive current ensuring a very low ripple on the output voltage. It consists of a series of independent, bi-directional and regulated DC sources. Compared to existing topologies, this solution requires a smaller number of power modules. It avoids internal high frequency modulation and simultaneously offers high resolution of the output voltage and a wide range of operating scenarios.  相似文献   
202.
An integrated facility-wide system for nuclear physics data acquisition is described. Four PDP-11/45's connected via a SYSTEM/7 to an IBM/370-168 are used in the system. User programs specifying spectrum definition and analysis logic are written using macros and are expanded into PL11 or PL/1, depending on the subsystem into which the program is to be linked. Both subsystems also use a common command set.  相似文献   
203.
节省时间的组合式密炼机Dipl-LingJuergenPohletal.著刘倩怡译吴秀兰校90年代密炼机的设计应适应目前经济、环保、安全及易于维护保养的需要。鉴于密炼机的平均寿命约为30年,Werner&Pflei-derer公司已研制出一种组合式密...  相似文献   
204.
The results of a pluridisciplinary epidemiological study carried out on a series of 225 adults from rural areas, in whom the prevalence of arterial hypertension disease (AHTD) and borderline (AHTB) was of 19.0% and 14.4%, respectively, are presented. In 19.0% of the carriers of over five associated risk factors for cardiovascular disease, the classical lipid constants (triglycerides-TG. total lipids-TL. total cholesterol-TC. HDL-cholesterol-HDL-c), plasma (PML) and erythrocyte magnesium level (EML), as compared to the degree of drinking water mineralization were determined. The environmental conditions, also expressed in water hardness (21.650 G) or magnesium water intake (85.13 mg/l) correlate in 41.0% of the subjects with a decrease in PML (1.8 mg/l) and in 70.48 with a decrease in EML (4.8 mg/l) through the association of some behavioral or metabolic risk factors: stress, consumption of atherogenic foods, excess alcohol and lipid dysmetabolism (TG: 130-140 mg/l = 59.5%; TL: 8 g%-30.9%; TC: 220 mg/l = 19%; HDL-c: 35 mg/l + 1.9%).  相似文献   
205.
Microfluidic devices have become more and more important in the field of thermal or chemical process engineering within the last years (by Schubert et al. Microscale Thermophys Eng 5:17–39, 2001). Cooling is one point of research where microchannels and other microstructured geometries provide significant advantages compared to conventional devices as they offer much higher possible surface to volume ratios and short characteristic distances. Therefore, an intense amount of heat can be transferred by these devices, which can be significantly increased by phase transition. Thus, evaporation of a fluid flow in microchannels allows very compact, fast, and powerful cooling devices. In this research study a novel microstructured evaporator geometry consisting of curved microchannels was evaluated on its evaporation properties compared to previous studies dealing with evaporation of R134a (Tetrafluoroethane) in straight microchannels (by Wibel et al. Chem Eng J 167:705–712, 2011). This novel evaporator design takes advantage of the strong centrifugal forces acting on the (evaporating) two phase flow in the curved microchannels. Due to the feasibility of very small radii of curved microchannels, strong centrifugal forces can be obtained for the fluid flow inside the microstructures. Additionally, those forces are boosted as flow velocities within the channels become higher due to the volume increase induced by evaporation. Therefore, a phase separation could take place inside the microstructure with a higher liquid fraction of evaporating coolant near one side of the curved channels during the transition to vapor. A high liquid fraction inside the evaporator is aimed by an intended removal of the evaporated gas phase from the microstructure. Experimental results of the evaporation of water and R134a as coolants demonstrate the potential of this curved geometry in comparison to evaporation in straight channels. Optical investigations of the new micro evaporator concept by high-speed videography (by Maikowske et al. Appl Therm Eng 30:1872–1876, 2010) are carried out for further improvements of the design. Various bubble formations and movements of the evaporating fluid flow were studied for various vapor fractions by using different fluids. These investigations show how the separation and extraction of the vapor fraction of the novel microstructure concept could be improved.  相似文献   
206.
Software Quality Journal - The globalization of the software industry has led to an emerging trend where software systems depend increasingly on the use of external open-source external libraries...  相似文献   
207.
This work presents a highly flexible mixed-signal CMOS image sensor suitable for smart camera applications. These systems need to fit different constraints regarding power consumption, speed and quality, and the optimal compromise may differ depending on the application. Moreover, the best implementation of a desired image processing task may be in the analog or the digital domain, or even a combined computation. Different aspects starting from the image sensor and signal acquisition up to the pre-processing in analog and digital domain are investigated in this paper to optimize not just one part of the system, but the whole system altogether. Moreover, it is shown that analog processing algorithms can improve signal quality, processing speed and latency while being able to save power, which is important for real-time systems. In order to be able to carry out spatial operations, the state-of-the-art sensor is modified to be able to read out multiple pixels at the same time. This allows analog spatial filter operations which consume significantly less power. As an example, an averaging filter is described which needs less than 5.3 % of the power–time product of a digital implementation for one computation. To enhance data throughput and flexibility, 3D chip stacking is proposed to partition the sensor in smaller units and enable massively parallel processing.  相似文献   
208.
209.
TTCN-3 has gained increasing significance in recent years. It was originally developed to fit the needs of testing software-based applications and systems in the telecommunication industry and has shown its applicability to a wide range of other industrial domains in the mean time. TTCN-3 provides platform-independent, universal and powerful concepts to describe tests, especially for discrete, interactive systems. However, TTCN-3 addresses systems with discrete input and output characteristics only. The lack of powerful means that reasonably allow specifying and evaluating continuous data flow makes TTCN-3 sufficient neither for the automotive industry nor for other industries that deal with highly complex software-based control systems. This paper introduces the notion of streams, stream ports and stream templates to TTCN-3. It revises the initial design of continuous TTCN-3, a TTCN-3 extension for testing continuous or hybrid systems [20,21] and demonstrates the applicability for a case study that is typical for testing embedded control systems in the automotive industry.  相似文献   
210.
Zusammenfassung Um die Frage zu beantworten, ob Aflatoxine im Käse vorkommen können, mußten käsereitechnische Erfahrungen über toxinproduzierende Mikroorganismen gesammelt werden. Zunächst wurden 169 Käseproben des Handels auf das mögliche Vorkommen von Aflatoxin B1 geprüft. Bei keiner der 19 Käsesorten, in der Hauptsache Tilsiter, Edamer, Romadur und Camembert, konnte dieses Toxin nachgewiesen werden.Bei Modelluntersuchungen zur Entwicklung von Aflatoxin B1 wurden einzelne Käse mit aflatoxinbildenden Schimmelpilzen künstlich infiziert, das Toxin nach der Mycelbildung isoliert und quantitativ bestimmt.Der Kulturschimmel des Camembertkäses (Penicillium candidum) verhindert das Wachstum B1-Aflatoxin bildender Pilze, so daß kein Aflatoxin B1 nachweisbar war. Auch beim Romadur kann das Vorkommen von Aflatoxin B1 wegen der Pilzwachstumshemmung, vermutlich durch die Schmierenbildung, ausgeschlossen werden.Dagegen gelang es, auf Tilsiterkäse mitAspergillus flavus undAspergillus parasiticus bei 18–30° C und mitPenicillium puberulum bei 5–20° C größere Mengen von Aflatoxin B1 anzureichern. Hierbei muß die relative Luftfeuchtigkeit mehr als 79% betragen. 18 bzw. 5° C sind die unteren Grenzwerte für das Wachstum der betreffenden Schimmelpilze auf dem Käse. Unter optimalen Einflüssen (Temp. 26° C; rel. Luftfeuchtigkeit 99%) ist das Aflatoxin B1 bereits 3–4 Tage nach Pilzbefall durchAspergillus flavus im Käse vorhanden. Durch Vergleiche der gefundenen Ergebnisse mit den Verhältnissen in Käsereien kann eine Bildung von Aflatoxin B1 in Käse durch die genannten Organismen nicht ausgeschlossen werden, so daß weitere Untersuchungen erforderlich sind.
About the formation of aflatoxin B1 in cheese
Summary In order to answer the question whether aflatoxins can be present in cheese, observations on toxin-producing micro-organisms during manufacture of cheese had to be undertaken. 169 cheese samples, taken from the market, were tested for possible presence of aflatoxin B1. In none of the 19 cheese varities, mainly Tilsiter, Edamer, Romadur, and Camembert, toxins could be found.By artificial infection of cheese with aflatoxin-producing fungi, the toxin was isolated after mycel-formation and quantitatively determined.The starter fungus of Camembert cheese (Penicillium candidum) pevents the growth of aflatoxin B1 forming fungi so that no aflatoxin B1 was detected. Also in Romadur cheese the presence of aflatoxin B1 can be excluded due to growth prevention, probably by smear formation.It was possible, however, to obtain larger amounts of aflatoxin B1 on Tilsiter cheese by growth ofAspergillus flavus andAspergillus parasiticus at 18–30° C. The relative humidity has to be more than 79%. 18° C resp. 5° C are the lower tolerance values for the growth of these fungi on cheese. Under optimal conditions (temperature: 26° C, relative humidity: 99%) aflatoxin B1 is present in cheese 3–4 days after infection byAspergillus flavus. By comparing these results with the conditions in cheese factories, the formation of aflatoxin B1 in cheese, caused by the organisms mentioned, cannot be excluded, so that further investigations are necessary.


Auszug aus der Dissertation Lebensmittelchemiker Dieter Groll: Zur Aflatoxin-Entwicklung in Käse. Dissertation TH München 1969.

Für die Unterstützung dieser Arbeit durch das Bundesministerium für Gesundheitswesen sei an dieser Stelle herzlich gedankt.  相似文献   
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