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991.
James G. Taylor 《Journal of The Franklin Institute》1981,311(3):151-170
New important battle-outcome-prediction conditions are developed for combat between two homogeneous military forces modelled by variable-coefficient Lanchester-type equations for area fire. Such conditions are very significant in modern operations research for developing important insights into the dynamics of combat. However, similar differential-equation models do arise in other fields of science and technology such as mathematical ecology and epidemiology, and consequently our new mathematical results may also find application there. These new important “simple approximate” battle-outcome-prediction conditions depend on not only the combat-attrition model but also the battle-termination model, and they are developed for two different types of battle-termination conditions (fixed-force-level-breakpoint battles and fixed-force-ratio-breakpoint battles). They are sufficient (but not necessary) to determine the outcome of battle without having to explicitly compute the force-level trajectories, and a generalization of Lanchester’s famous linear law to variable-coefficient combat is involved in their development. Certain integrability properties of the Lanchester attrition-rate coefficients figure prominently in these results, and an important physical interpretation (relating to logistics considerations) is given for these properties. 相似文献
992.
In recent years it has become clear that a firm's competitive position is significantly influenced by its capacity to innovate. This paper explores the hypothesis that if there are factors operating at the regional level which inhibit this capacity, then firms located in particular regions may suffer. One such factor might be a lack of centralized scientific services. Regions under-represented in terms of a viable scientific infrastructure may find difficulty in attrating new science-based firms, and firms already in the region may find themselves at a comparative disavantage compared with firms located elsewhere. Social forces of this kind might be playing an important part in enhancing the social and economic problems of underdeveloped regions. 相似文献
993.
Anthony G. Wilhelm 《The Information Society》2003,19(4):279-286
Bridging the digital divide between information and technology haves and have-nots has waned from the top of the national policy agenda in the United States during a time in which the sunken investments of the 1990s need to be leveraged. A national information network now exists yet this infrastructure--largely hardware--needs to be continually modernized and parlayed with commitments to building human capacity, developing relevant content, and scaling socially beneficial technology applications, such as telemedicine, in order to optimize these initial multi-billion-dollar outlays. This article makes the case that sidestepping public-private initiatives aimed at accelerating digital opportunity is imprudent, given the mounting empirical evidence highlighting the payoffs of information and communications technologies, when properly integrated and applied, especially in enhancing the life chances of underserved Americans. Policy next steps should advance the goals of expanding universal service initiatives, including hastening broadband deployment to homes and learning institutions, and deepening programs which leverage the utility of the existing infrastructure, such as expanding human-capital development, producing relevant content, and innovating socially beneficial technology applications. 相似文献
994.
The diffusion of the magnetic field due to a step current in an infinitely long ideal conductor, through infinite media is discussed. An analytical solution of the field diffusion through two concentric cylinders of different conductivity is derived using a generalized Ohm's law which considers both solid and fluid conductors. A rigorous mathematical treatment which can be generalized to any number of conducting cylinders is presented.The limiting case of an external superconducting medium is discussed and it is shown that with all the other parameters fixed it represents a lower limit in diffusion time. 相似文献
995.
The paper describes the edition, on computer output microfiche, of the supplement to the 1965 Union catalogue of foreign periodicals in Belgian and Luxemburgian libraries and documentation centers. The microfiches contain location information of 28,000 periodicals in 300 libraries and are edited in a rich typography. The paper discusses the coding of the bibliographic fields, the computer processing and formulates some forecasts for the near and further future. 相似文献
996.
James Hartley 《中国科技期刊研究》2004,15(2):127-129
参考文献表的编排有多种体例形式,并且不同体例中参考文献各著录项的表达也不尽相同。由于期刊大都倾向于采用自己所特定的参考文献著录格式,因而目前已有的参考文献软件并不能给予作者很多帮助,即作者如果将其稿件由某期刊改投到另一种期刊,通常需要改动其中的参考文献表格式和正文中的相关部分。在众多的参考文献表格式中,有两种最为主要。其一是在人文科学中较为常用的哈佛体系(即著者一出版年体系),该体系规定正文中给出引文的作者和出版年,文献书目中的引文按著者姓名的字母顺序和出版年的先后排列。另外一种主要的参考文献表是数字体系(顺序编码制),即正文中给出引文的序号,参考文献表中的各篇文献按其在正文中出现的先后顺序排列。科技论文和医学论文多采用该种体例。本文列举了上述两种体例的格式,并对比了二者的优缺点,认为著者.出版年体系可以使学术论文的读者很方便地了解作者所引用的工作是由谁完成的,而数字体系(顺序编码制)因为简洁,从而可以使读者更为通畅地阅读论文。 相似文献
997.
A. A. Momin M. P. Bankar G. M. Bhoite 《Indian journal of clinical biochemistry : IJCB》2016,31(3):286-293
Elevated plasma triglyceride and non-esterified fatty acid concentrations may cause insulin resistance and type 2 diabetes mellitus. Lipoprotein lipase (LPL) is a rate-determining enzyme in lipid metabolism. A variant in the LPL gene has been identified which alters the penultimate amino acid Serine at 447 to a stop codon (S447X), and results in a truncated LPL molecule lacking the C-terminal dipeptide Ser–Gly. The present study was designed to evaluate the frequency of S447X variant in the LPL gene and its effect on the lipid and lipoprotein levels in type 2 diabetic subjects. The genotype frequency distributions of type 2 diabetes patients and controls were in Hardy–Weinberg equilibrium. Comparison of the genotype and allelic frequencies of S447X in subjects with type 2 diabetics compared to controls demonstrated no significant difference. In subjects with type 2 diabetics having hypertriglyceridemia (TG ≥ 150 mg/dl) compared to diabetics with TG level <150 mg/dl, significant difference in genotype frequency was found among these groups, while allelic frequency of X was significantly differed. Logistic regression analysis showed the negative association of LPL S447X variant with TG and VLDL cholesterol, while no association with total cholesterol, HDL cholesterol and LDL cholesterol was found. The lipid levels except for HDL cholesterol were found to be significantly lower in carriers for S447X than wild type in diabetes group. The decreased level of TG and TG rich lipoprotein in subjects with SNP S447X in LPL, predicts anti-atherogenic activity of carriers for S447X variant in general population as well as type 2 diabetic patients. 相似文献
998.
G. A. Alabi 《Information processing & management》1985,21(6):525-533
This paper presents the results of a comparative cost study of the manual circulation system and experimental automated system in a university library in Nigeria. Two sets of data were collected: one on the existing manual circulation system and the other on the experimental automated system on an Apple II microcomputer. Eight different circulation activities were identified for evaluation for which the direct labor cost of circulating a book on each system was calculated. The experimental automated system was found to be less labor intensive than the manual system, although overall unit cost of book circulation on the automated system was higher than on the manual system ($0.59 and $0.49, respectively). Factors attributed to the higher unit cost on the automated system were the cost of equipment and the low circulation figure. However, the automated system was found to be more effective in providing up-to-date and accurate data required for the monitoring of the library stock. 相似文献
999.
James L. Dolby 《Information processing & management》1977,13(1):69-77
One of the fundamental problems in information science is to distinguish various objects (such as books or journal articles) on the basis of associated values (such as authors and titles). Where the values fail to distinguish two distinct objects we say that the objects are ambigious under the given value assignment. To obtain a measure of ambiguity, it is only necessary to count the number of ways that the objects can be arranged for each set of ambiguous objects, multiply these counts and take logarithms. It is shown that such an approach leads to a measure in the formal sense and that the measure depends only on the definition of equality of values so that it can be simply extended to sets of values and ordered sets of values. It is also shown that it is possible to construct a function of ambiguity that one can call “information” and that the information loss that occurs when distinct values are grouped into equivalence classes (as in the use of search and sort keys) is also a measure. Finally, it is shown that ambiguity and information as here defined are directly related to Shannon's definition of “information” thus tieing this approach to that portion of information theory associated with the derivation of optimal distributions frequently used in information science models. 相似文献
1000.