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31.
    
This paper proposes a three-phase approach to forecast a competitive price for a notebook computer as a function of constituent features. Phase I uses regression analysis to relate computer price to constituent features in each of a series of time periods. Phase II involves a time series analysis of each regression coefficient to quantify how trends in market conditions (e.g., the evolution of component technology) affect the market value of each feature. Phase III uses the time series analysis to forecast future market values of each feature and combines these results to forecast a competitive selling price for a notebook model that is composed of a selected set of features. The approach can be used in support of management decisions related to prescribing when to upgrade a notebook model and what features to include in each upgrade. The approach can be used, for example, to forecast notebook model price at introduction, and the rate at which price will erode over the model’s life cycle. Computational results indicate that the approach can forecast the price of a notebook computer model up to four months in advance of its introduction to within 10%. It can also forecast the rate of price erosion to within 10% for up to seven months after introduction — the length of the life cycle of a typical notebook model. Since this approach uses only publicly available data, it can be used easily in industry.  相似文献   
32.
  总被引:1,自引:0,他引:1  
BACKGROUND: The stage of maturity at harvest has a major effect on the fatty acid (FA) content and composition of forage plants consumed by dairy cows. The present study investigated the dynamics of FA content and composition in stover (leaves and stem) and ears (cob, shank and husks) of two maize genotypes (G2 and G6) grown on sandy and clay soils and harvested at 14, 42, 56, 70 and 84 days after flowering (DAF). In addition, the FA content and composition of six maize genotypes (G1‐G6) grown on the two soil types were compared at the normal harvest time of early genotypes in the Netherlands (70 DAF). RESULTS: The contents of total FAs and major individual FAs in both stover and ears changed significantly (P < 0.001) during the grain‐filling period (14‐84 DAF). In stover the contents of C16:0, C18:2, C18:3 and total FAs declined (P < 0.001) while those of C18:0 and C18:1 increased (P < 0.001) with progressive grain filling. The rate of decline in C18:3 and total FA contents was slower during 14‐56 DAF as compared with 56‐84 DAF. In ears, the contents of C16:0, C18:1, C18:2 and total FAs increased up to 56 DAF and then remained more or less constant until 84 DAF. At 70 DAF the content of polyunsaturated fatty acids (PUFAs) in both stover and ears did not differ among the six genotypes. However, the average contents of C16:0, C18:3 and total FAs in stover were higher (P < 0.05) on clay soil, whereas those of C18:0 and C18:1 were higher on sandy soil. CONCLUSION: The results demonstrate that the maximum PUFA content in silage maize is harvested around 56 DAF, in the present study at a Tsum of 927 °C.d or at an ear dry matter content of 440 g kg?1, which is before the onset of rapid senescence. Any further delay in harvesting will cause a rapid decline in C18:3 content in maize silages. Copyright © 2011 Society of Chemical Industry  相似文献   
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Knowledge of digesta passage kinetics in ruminants is essential to predict nutrient supply to the animal in relation to optimal animal performance, environmental pollution and animal health. Fractional passage rates (FPR) of feed are widely used in modern feed evaluation systems and mechanistic rumen models, but data on nutrient‐specific FPR are scarce. Such models generally rely on conventional external marker techniques, which do not always describe digesta passage kinetics in a satisfactory manner. Here the use of stable isotope‐labelled dietary nutrients as a promising novel tool to assess nutrient‐specific passage kinetics is discussed. Some major limitations of this technique include a potential marker migration, a poor isotope distribution in the labelled feed and a differential disappearance rate of isotopes upon microbial fermentation in non‐steady state conditions. Such limitations can often be circumvented by using intrinsically stable isotope‐labelled plant material. Data are limited but indicate that external particulate markers overestimate rumen FPR of plant fibre compared with the internal stable isotope markers. Stable isotopes undergo the same digestive mechanism as the labelled feed components and are thus of particular interest to specifically measure passage kinetics of digestible dietary nutrients. © 2013 Society of Chemical Industry  相似文献   
34.
Norman R. F. Maier was born in a small town in Michigan on November 27, 1900. He was educated in the Michigan public schools and received his BA from the University of Michigan in 1923. After a year of graduate work at the University of Berlin (1925-1926) he completed his PhD in 1928 at the University of Michigan. Following a year of teaching, Dr. Maier was for two years a National Research Council Fellow in Zoology at the University of Chicago, where he worked with Professor K. S. Lashley. In 1931 he joined the faculty of the University of Michigan, where he worked for the rest of his life, dying of a heart attack on September 24, 1977. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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A supramolecular approach was undertaken to create functionally activatable cell‐penetrating peptides. Two tetra‐arginines were assembled into an active cell‐penetrating peptide by heterodimerizing leucine zippers. Three different leucine‐zipper pairs were evaluated: activation was found to depend on the association constant of the coiled‐coil peptides. The weaker‐binding peptides required an additional disulfide linkage to induce cell‐penetrating capability, whereas for the most‐stable coiled‐coil no additional stabilization was needed. The latter zipper pair was used to show that the induced formation of the coiled coils allows control over the uptake of an oligoarginine CPP‐conjugated cargo protein.  相似文献   
38.
A standard product which provides a highly available programmable controller is described. The system has no impact on the application programmer and features the ability to have a failed portion of the system replaced without stopping its operation.  相似文献   
39.
Presents the minutes of the 1970 American Psychological Association (APA) Council of Representatives. The Council of Representatives met in Miami Beach, Florida on September 6, 1970 at the APA Annual Convention, and again in Washington, D.C., on October 3 and 4. These minutes constitute the official record of actions of the Association taken during the year. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
40.
Presents a new method of inferring students' cognitive structures and their development in a college course. The method, a modification of J. S. Reitman and H. H. Rueter's (see record 1980-31828-001) ordered tree technique, generates a unique structure that displays important relationships assumed to be in a student's memory about concepts taken from a specific field of study. The usefulness of this method was assessed in 2 studies that used subject matter from a university course in which 253 students were enrolled. Results show that the technique differentiated between Ss with different levels of achievement. In addition, the 4 measures produced by the method—grouping, hierarchical structure, directionality of the structure, and similarity to the instructor—showed development throughout the course and were related to academic performance. The characteristics of the method are discussed in light of other ways of inferring cognitive structure. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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