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141.
Interval Time Series Analysis with an Application to the Sterling-Dollar Exchange Rate 总被引:2,自引:0,他引:2
Traditional econometrics has long employed "points" to measure time series data. In real life situations, however, it suffers the loss of volatility information, since many variables are bounded by intervals in a given period. To address this issue, this paper provides a new methodology for interval time series analysis. The concept of "interval stochastic process" is formally defined as a counterpart of "stochastic process" in point-based econometrics. The authors introduce the concepts of interval stationarity, interval statistics (including interval mean, interval variance, etc.) and propose an interval linear model to investigate the dynamic relationships between interval processes. A new interval-based optimization approach for estimation is proposed, and corresponding evaluation criteria are derived. To demonstrate that the new interval method provides valid results, an empirical example on the sterling-dollar exchange rate is presented. 相似文献
142.
Abstract: A radiation hard phase-locked loop (PLL) is designed at 2.5 GHz using silicon on sapphire complementary metal-oxide-semiconductor process. Radiation hardness is achieved through improving circuit design without sacrificing real estate. Stability is guaranteed by a fully self-bias architecture. The lock time of PLL is minimized by maximizing the loop bandwidth. Frequency tuning range of voltage controlled oscillator is significantly enhanced by a novel load configuration. In addition, multiple bias stages, asynchronous frequency divider, and silicon on sapphire process jointly make the proposed PLL more radiation hard. Layout of this PLL is simulated by Cadence Spectre RF under both single event effect and total induced dose effect. Simulation results demonstrate excellent stability, lock time < 600 ns, frequency tuning range [1.57 GHz, 3.46 GHz], and jitter < 12 ps. Through comparison with PLLs in literatures, the PLL is especially superior in terms of lock time and frequency tuning range performances. 相似文献
143.
ORGANIZATIONAL LEARNING AND VENDOR SUPPORT QUALITY BY THE USAGE OF APPLICATION SOFTWARE PACKAGES: A STUDY OF ASIAN ENTREPRENEURS 总被引:2,自引:0,他引:2
In this paper we study how organizational learning impacts organizational behavior, and howvendor support quality enhances product adoption and usage behavior.These constructs were verifiedusing Application Software Packages(ASP)-a prewritten, precoded, commercially available set ofprograms that eliminates the need for individuals or organizations to write their own softwareprograms for certain functions. The relationship between ASP usage, usage outcomes and useprocesses were also investigated. Two hundred and ninety-five Chinese, Indian, and Malayentrepreneurships were studied. It was found that usage outcome strongly determines usage, while useprocess has only an indirect relationship (via outcome) on usage. The impact of organizational learningand vendor service quality on usage, usage outcome, and use process were robust. Theoretical andpractical implications of the research are discussed. 相似文献
144.
This paper proposes an interval method to explore the relationship between the exchange rate of Australian dollar against US dollar and the gold price,using weekly,monthly and quarterly data.With the interval method,interval sample data are formed to present the volatility of variables. The ILS approach is extended to multi-model estimation and the computational schemes are provided. The empirical evidence suggests that the ILS estimates well characterize how the exchange rate relates to the gold price,both in the long-run and short-run.The comparison between the interval and point methods indicates that the difference between the OLS and the ILS estimates is increasing from weekly data to quarterly data,since the lowest frequency point data lost the most information of volatility. 相似文献
145.
Childbearing outside marriage in western Europe 总被引:1,自引:0,他引:1
Kiernan K 《Population trends》1999,(98):11-20
Across most European states in recent decades there have been significant increases in childbearing outside marriage. This article examines the extent to which women have their first child in one of four settings: prior to any partnership; in their first cohabiting partnership; in first marriage; and after a first partnership. Temporal changes in these behaviours and variation according to background characteristics of the women are also examined. For the women who had a child outside any partnership, we examine the extent to which they go on to form partnerships and how long after the birth this happens. For those who had their first child within a cohabiting union, we examine the extent to which they marry and how long after the birth this occurs. Finally, we investigate whether children born within cohabiting unions that do and do not convert into marriages are more or less likely than those born within marriage to see their parents separate. 相似文献
146.
The very low fertility experienced in several European countries in recent decades in the presence of higher intended family sizes has renewed interest in fertility intentions data. While the overall level of childbearing in Britain over the past few decades has remained relatively stable and high in comparison with many other European countries, we have seen sizeable increases in the age at which childbearing starts. This study uses data from the 1991 to 2007 General Household Surveys to examine trends in family intentions data in an attempt to arrive at a better understanding of these recent fertility developments. First, time trends in intended family size are compared with trends in observed fertility. Next, aggregate changes in intentions regarding the level and timing of fertility across the life course for cohorts are investigated together with the extent to which these aggregate intentions are matched by the subsequent childbearing of cohorts. Finally, both change across the life course and uncertainty in family intentions are examined. We conclude by discussing what these findings might tell us about contemporary reproductive decision making. 相似文献
147.
Power-Based Arbitrary Decisional Actions in the Resolution of MIS Project Issues: A Project Manager's Action Research Perspective 总被引:1,自引:0,他引:1
As a management information systems (MIS) project manager and an action researcher, the author examined, over time, the influence on information system development (ISD) of the informal sociopolitical organizational actions. The paper reports two cases of action research findings concerning the effect on ISD project implementation processes of power-based arbitrary decisional actions in bureaucratic environments. The research focused on the relationship of such unilateral actions to the interconnected subprocesses of deliberate and conscious attempts by the ISD project members to define and resolve system implementation issues. A suggested conceptual framework for the issue-resolution processes (IRP's) and obstacle-coping processes (OCP's) is based on the author's IRP/OCP-related behavioral constructs and theoretical models dealing with soft-systems issues, especially appreciative system theory and soft-systems methodology, and innovative flexible, "complementarist" (Sinn, 1998) or pluralist problem-solving approaches. 相似文献
148.
Daniel S. Yeung Wing W. Y. Ng Aki P. F. Chan Patrick P. K. Chan Michael Firth Eric C. C. Tsang 《系统科学与系统工程学报(英文版)》2007,16(2):166-180
Company bankruptcies cost billions of dollars in losses to banks each year. Thus credit risk prediction is a critical part of a bank's loan approval decision process. Traditional financial models for credit risk prediction are no longer adequate for describing today's complex relationship between the financial health and potential bankruptcy of a company. In this work, a multiple classifier system (embedded in a multiple intelligent agent system) is proposed to predict the financial health of a company. In our model, each individual agent (classifier) makes a prediction on the likelihood of credit risk based on only partial information of the company. Each of the agents is an expert, but has limited knowledge (represented by features) about the company. The decisions of all agents are combined together to form a final credit risk prediction. Experiments show that our model out-performs other existing methods using the benchmarking Compustat American Corporations dataset. 相似文献
149.
S. K. MISHRA Shouyang WANG K. K. LAI 《系统科学与复杂性》2007,20(3):344-349
In this paper, we introduce a new class of generalized convex function, namely, a-pseudounivex function, by combining the concepts of pseudo-univex and α-invex functions. Further, we establish some relationships between vector variational-like inequality problems and vector optimization problems under the assumptions of α-pseudo-univex functions. Results obtained in this paper present a refinement and improvement of previously known results. 相似文献
150.
Stanley N. Salthe 《Foundations of Science》2010,15(4):357-367
I distinguish Nature from the World. I also distinguish development from evolution. Development is progressive change and
can be modeled as part of Nature, using a specification hierarchy. I have proposed a ‘canonical developmental trajectory’
of dissipative structures with the stages defined thermodynamically and informationally. I consider some thermodynamic aspects
of the Big Bang, leading to a proposal for reviving final cause. This model imposes a ‘hylozooic’ kind of interpretation upon
Nature, as all emergent features at higher levels would have been vaguely and episodically present primitively in the lower
integrative levels, and were stabilized materially with the developmental emergence of new levels. The specification hierarchy’s
form is that of a tree, with its trunk in its lowest level, and so this hierarchy is appropriate for modeling an expanding
system like the Universe. It is consistent with this model of differentiation during Big Bang development to view emerging
branch tips as having been entrained by multiple finalities because of the top-down integration of the various levels of organization
by the higher levels. 相似文献