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排序方式: 共有1016条查询结果,搜索用时 15 毫秒
111.
Salvador Barber M. José Torner M. Antonia Martínez-Anaya Carmen Benedito de Barber 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1989,189(1):6-11
Summary Changes in mono- and disaccharides and acetic and lactic acid production of six different straight doughs elaborated with combinations of pure strains of yeastsSaccharomyces cerevisiae andCandida boidinii and lactic acid bacteriaLactobacillus plantarum andStreptococcus sp have been investigated, as well as the baking quality of the resulting breads. The type and proportion of the fermentative microorganisms were found to influence the biochemical activity of the doughs. The sugar levels after mixing reached different proportions, depending on the type of sugar and the type of microorganisms used. After proofing, the glucose and fructose content of the doughs decreased to 0.01%–0.02% db and maltose decreased to 0.45%–0.11 % db. Acetic and lactic acids underwent variable changes during fermentation, depending on the type of dough. Lactic acid showed higher levels than acetic acid. Bread made from these doughs had different sensory characteristics, texture, edibility and overall acceptance, as well as different lactic and acetic acid contents, depending on the mixture of microorganisms inoculated.
Presented at the 8th International Cereal and Bread Congress, Lausanne, Switzerland, June 1988.
This paper is a part of a doctoral thesis 相似文献
Biochemische Merkmale und Leistungsfahigkeit der mit Mischungen reiner Mikroorganismen hergestellten Weizenbackteige
Zusammenfassung Die Forschungsaufgabe befaßte sich mit den Veranderungen der Mono- und Disaccharide, mit der Entstehung von Essig- und Milchsaure in sechs Teigen, die mit Kombinationen reiner HefekulturenSaccharomyces cerevisiae undCandida boidinii und MilchsäurebakterienLactobacillus plantarum undStreptococcus sp hergestellt waren und mit den sich daraus ergebenden Qualitätsmerkmalen der Brote. Die Art und Anteile der Mikroorganismen übten einen entscheidenden Einfluß auf die biochemische Aktivität der Teige aus. Nach dem Knetvorgang konnten unterschiedliche Gehalte gemäß der eingesetzten Saccharide und Mikroorganismen festgestellt werden. Der Glucose- und Fructoseanteil der fermentierten Teige verringerte sich auf 0,01–0,02% t. g., der Maltoseanteil auf 0,45-0,11% t.g. In den einzelnen Teigen veranderten sich wahrend der Garung die Essig-und Milchsauregehalte unterschiedlich. Bei der Milchsaure konnte eine grbBere Zunahme und somit höhere Endgehalte als bei der Essigsaure festgestellt werden. Die mit diesen Teigen hergestellten Brote erreichten verschiedene Textureigenschaften (Weichheit der Krume) und sensorische Merkmale, insbesondere Kaufahigkeit und Geschmack Bowie einen, entsprechend der Mikroorganismenmischung, höheren oder geringeren Milch- und Essigsäuregehalt.
Presented at the 8th International Cereal and Bread Congress, Lausanne, Switzerland, June 1988.
This paper is a part of a doctoral thesis 相似文献
112.
113.
Piedad N. De Aza Carmen M. López Francisco Guitián Salvador De Aza 《Journal of the American Ceramic Society》1993,76(4):1052-1054
A reexamination of the system CaO·SiO2 –ZrO2 has been conducted in order to use this system to obtain ZrO2 -toughened wollastonite materials. The results have shown that CaO·SiO2 –ZrO2 is a pseudobinary system with an invariant peritectic point at 1467°± 2°C, which is in disagreement with previously reported results. 相似文献
114.
A new voltammetric method for a direct determination of gold nanoparticles, based on adsorption and electrochemical detection of colloidal gold, is described. In this protocol, the absorption of gold nanoparticles onto the rough surface of graphite-epoxy composite electrode is followed by their electrochemical oxidation in 0.1 M HCl medium at a potential of +1.25 V. The resulting tetrachloroaurate ions generated near the electrode surface are detected by differential pulse voltammetry (DPV). The DPV response is linear in the range from 4.7 × 108 to 4.7 × 1011 nanoparticles cm−3 with a limit of detection of 1.8 × 108 gold nanoparticles cm−3. The surface characteristics of the composite electrode are investigated and the parameters that affect the complete analytical detection process of gold nanoparticles are optimized. 相似文献
115.
Mario Gonzalez-de la Parra Pilar Rodriguez-Loaiza Salvador Namur 《Quality Engineering》2003,16(2):321-328
A case study from the chemical and pharmaceutical industries is used to show the value of the repeated measures design in developing processes for drug substances. This article advocates the use of the repeated measures design in situations that commonly arise in the chemical and pharmaceutical industries when repeated measurements are taken on the same experimental unit, instead of the common practice of comparing only individual conditions, a procedure that is inappropriate in many cases. One of the most important advantages of applying the repeated measures design is the abundance of data that can be obtained by taking into account the entire response curve instead of only isolated individual points on it. 相似文献
116.
This paper proposes a parameter fitting procedure using Markov Modulated Poisson Processes (MMPPs) that leads to accurate estimates of queuing behavior for network traffic exhibiting long-range dependence behavior. The procedure matches both the autocovariance and marginal distribution of the counting process. A major feature is that the number of states is not fixed a priori, and can be adapted to the particular trace being modeled. The MMPP is constructed as a superposition of L 2-MMPPs and one M-MMPP. The 2-MMPPs are designed to match the autocovariance and the M-MMPP to match the marginal distribution. Each 2-MMPP models a specific time-scale of the data. The procedure starts by approximating the autocovariance by a weighted sum of exponential functions that model the autocovariance of the 2-MMPPs. The autocovariance tail can be adjusted to capture the long-range dependence characteristics of the traffic, up to the time-scales of interest to the system under study. The procedure then fits the M-MMPP parameters in order to match the marginal distribution, within the constraints imposed by the autocovariance matching. The number of states is also determined as part of this step. The final MMPP with M2
L
states is obtained by superposing the L 2-MMPPs and the M-MMPP. We apply the inference procedure to traffic traces exhibiting long-range dependence and evaluate its queuing behavior through simulation. Very good results are obtained, both in terms of queuing behavior and number of states, for the traces used, which include the well-known Bellcore traces. 相似文献
117.
Salvador Barber Rosario Báguena Carmen Benedito de Barber M. Antonia Martínez-Anaya 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1991,192(1):46-52
Summary The evolution of some biochemical (acetic and lactic acid contents, fermentation quotient and changes in mono-, di-, and trisaccharides), rheological and fermentative characteristics (extensigram, maturogram and impulsogram) and bread quality (volume, density, texture, and degree of acidification) during a multistage wheat sour dough process have been investigated. Acetic acid contents of sour doughs (SD), bread doughs (BD) and breads (B) increased with the increase in number of processing stages. Lactic acid followed similar trends in SD, but in BD and B it reached maximum levels during the third stage. SD contained higher amounts of acids than BD and B. Dynamics of sugars followed patterns according to the fermentative activity and microflora evolution in the different steps. An improvement as the number of SD stages increased was observed in rheological and fermentative properties of BD, such as in oven spring. A positive effect on B characteristics (volume, density, texture, and acidity) was also observed. The last stage of the SD process led to the best final product, with noticable differences in relation to those occurring with a smaller number of stages.
Paper presented in part at the 7th World Congress of Food Science and Technology, Singapore (Singapore), September–October, 1987 相似文献
Entwicklung biochemischer und rheologischer Eigenschaften und des Backverhaltens während einer mehrstufigen Weizensauerteigführung
Zusammenfassung Es wurde die Entwicklung biochemischer Daten (Essigsäure- und Milchsäuregehalt, Gärungsquotient und Veränderungen an Mono-, Di- und Trisacchariden, rheologischer und Gäreigenschaften (Extensograph, Maturograph und Ofentrieb) und der Brotqualität (Volumen, Dichte, Textur und Säuregrad) während einer mehrstufigen Weizensauerteigführung untersucht. Die Essigsäuregehalte von Sauerteigen, Brotteigen und Broten stiegen mit der Zahl der Führungsstufen an. Beim Milchsäuregehalt ergaben sich ähnliche Tendenzen, jedoch beim Brotteig und Brot wurde das Maximum erst in der dritten Stufe erreicht. Veränderungen des Zuckergehaltes stimmten mit der Gäraktivität und der Mikrofloraentwicklung in den verschiedenen Stufen überein. Es ergab sich eine Verbesserung in den rheologischen und Gäreigenschaften von Brotteigen sowie im Ofentrieb, wenn die Zahl von Sauerteigstufen anstieg. Es wurde auch ein positiver Einfluß auf die Broteigenschaften (Volumen, Dichte und Säuregrad) beobachtet. Die letzte Stufe der Sauerteigführung ergab das beste Endprodukt mit deutlichen Unterschieden, wenn mit einer geringeren Zahl von Stufen hergestellt.
Paper presented in part at the 7th World Congress of Food Science and Technology, Singapore (Singapore), September–October, 1987 相似文献
118.
Isolated diastolic hypertension is not officially recognized as a form of hypertension. It is currently defined as a diastolic pressure greater than 90 mm Hg with systolic pressure < 140 mmHg. It implies an elevation of vascular resistance in the arteriolar sector and small arteries, and persistence of distensibility of the aorta and large vessels. It therefore predominantly affects young patients with relatively recent HT, without any accentuation of aging of the vessel wall by smoking, diabetes, or atheroma. It is responsible for a reduction of pulse pressure, and does not appear to be associated with deterioration of the prognosis. The demonstration of diastolic HT indicates the presence of excess adrenergic tone with predominance of alpha tone, or raised plasma renin, in the absence of any alteration of myocardial function capable of reducing systolic pressure. Monotherapy with angiotensin converting enzyme inhibitors, which reduce stimulation of growth of smooth muscle fibres, and calcium channel blockers, whose effects increase with increasing vasoconstrictor tone, would be preferable to diuretics and non-selective beta-blockers. 相似文献
119.
Understanding thermal energy distribution is essential to interpret skin temperature for diagnosing various pathological and experimental conditions. The present paper investigates temperature data measurements acquired with an infrared thermometer system and in vivo temperature measurements on the backs of New Zealand rabbits. Local differences in skin temperature are significant around bony structures and in visceral areas. The results suggest that the location of experimental sites must be considered when interpreting data which use local temperature as an indicator of microvascular phenomena on the skin surface. Our techniques have proven valuable for quantifying thermal effects on small fields or skin lesions of experimental animals, and can be used noninvasively to measure the onset and transient vascular effects caused by noxious insults including laser radiation. 相似文献
120.