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171.
The relation between inflation and RPV plays a prominent role in explaining the costs of inflation. This study investigates whether the CPI subcategories drift apart more over a period of high inflation rates than during one of low inflation. The wider dispersion of the subcategories is reflected in an increasing number of common stochastic trends in the system of sub price indices. The results for US data as well as for cross-country comparisons indicate that the influence of inflation on the dispersion of relative prices cannot be revealed by counting cointegrating relations. Thus, the number of stochastic trends or cointegrating relations is not a reliable indicator for the distorting effect of inflation on the dispersion of relative prices.  相似文献   
172.
高等教育正经历着重大的变革,英语作为高等教育中不可缺少的组成部分,日益成为跨世纪人才的基本素质之一。因此素质教育成了摆在广大英语工作者面前的一项艰巨任务。英语由应试教育向素质教育转变,教师素质的提高是关键。  相似文献   
173.
This paper proposes a model of decision under ambiguity deemed vector expected utility, or VEU. In this model, an uncertain prospect, or Savage act, is assessed according to (a) a baseline expected‐utility evaluation, and (b) an adjustment that reflects the individual's perception of ambiguity and her attitudes toward it. The adjustment is itself a function of the act's exposure to distinct sources of ambiguity, as well as its variability. The key elements of the VEU model are a baseline probability and a collection of random variables, or adjustment factors, which represent acts exposed to distinct ambiguity sources and also reflect complementarities among ambiguous events. The adjustment to the baseline expected‐utility evaluation of an act is a function of the covariance of its utility profile with each adjustment factor, which reflects exposure to the corresponding ambiguity source. A behavioral characterization of the VEU model is provided. Furthermore, an updating rule for VEU preferences is proposed and characterized. The suggested updating rule facilitates the analysis of sophisticated dynamic choice with VEU preferences.  相似文献   
174.
Book Reviews     
Cameron, Deborah Verbal hygiene
Eco, Umberto The search for the perfect language
Caldas-Coulthard, Carmen Rosa and Coulthard, Malcom (eds) Texts and practices: Readings in critical discourse analysis
Peräkylä, Anssi, Aids counselling: Institutional interaction and clinical practice
Williams, Colin H. Called unto liberty: On language and nationalism
Besnier, Niko Literacy, emotion and authority: Reading and writing on a Polynesian atoll
Firth, Alan (ed.) The discourse of negotiation: Studies of language in the workplace
Holmes, Janet Women, men and politeness
Aitchison, John and Carter, Harold A Geography of the Welsh language 1961–1991 .
Williams, Rhian Huws, Williams, Hywel and Davies, Elaine (eds) Gwaith Cymdeithasol a'r Iaith Gymraeg/Social work and the Welsh language  相似文献   
175.
Although the parameters for contaminant bioaccumulation models most likely vary over time, lack of data makes it impossible to quantify this variability. As a consequence, Monte Carlo models of contaminant bioaccumulation often treat all parameters as having fixed true values that are unknown. This can lead to biased distributions of predicted contaminant concentrations. This article demonstrates this phenomenon with a case study of selenium accumulation in the mussel Mytilus edulis in San Francisco Bay. "Ignorance-only" simulations (in which phytoplankton and bioavailable selenium concentrations are constant over time, but sampled from distributions of field measurements taken at different times), which an analyst might be forced to use due to lack of data, were compared with "variability and ignorance" simulations (sampling phytoplankton and bioavailable selenium concentrations each month). It was found that ignorance-only simulations may underestimate or overestimate the median predicted contaminant concentration at any time, relative to variability and ignorance simulations. However, over a long enough time period (such as the complete seasonal cycle in a seasonal model), treating temporal variability as if it were ignorance at least gave a range of predicted concentrations that enclosed the range predicted by explicit treatment of temporal variability. Comparing the temporal variability in field data with that predicted by simulations may indicate whether the right amount of temporal variability is being included in input variables. Sensitivity analysis combined with biological knowledge suggests which parameters might make important contributions to temporal variability. Temporal variability is potentially more complicated to deal with than other types of stochastic variability, because of the range of time scales over which parameters may vary.  相似文献   
176.
The variability of the grade sizes in Markovian manpower systems in continuous time is considered. The differential equations describing the evolution of the variance-covariance matrix are derived and the associated generator is determined in a closed form. The limiting variability of an expanding system is studied via two theorems which provide conditions for the limit to exist independently of the initial distribution and for the rate of convergence to be exponentially fast. A numerical illustration of the theory is given.  相似文献   
177.
Following a comprehensive evaluation of the health risks of radon, the U.S. National Research Council (US-NRC) concluded that the radon inside the homes of U.S. residents is an important cause of lung cancer. To assess lung cancer risks associated with radon exposure in Canadian homes, we apply the new (US-NRC) techniques, tailoring assumptions to the Canadian context. A two-dimensional uncertainty analysis is used to provide both population-based (population attributable risk, PAR; excess lifetime risk ratio, ELRR; and life-years lost, LYL) and individual-based (ELRR and LYL) estimates. Our primary results obtained for the Canadian population reveal mean estimates for ELRR, PAR, and LYL are 0.08, 8%, and 0.10 years, respectively. Results are also available and stratified by smoking status (ever versus never). Conveniently, the three indices (ELRR, PAR, and LYL) reveal similar output uncertainty (geometric standard deviation, GSD approximately 1.3), and in the case of ELRR and LYL, comparable variability and uncertainty combined (GSD approximately 4.2). Simplifying relationships are identified between ELRR, LYL, PAR, and the age-specific excess rate ratio (ERR), which suggest a way to scale results from one population to another. This insight is applied in scaling our baseline results to obtain gender-specific estimates, as well as in simplifying and illuminating sensitivity analysis.  相似文献   
178.
Whether and to what extent contaminated sites harm ecologic and human health are topics of considerable interest, but also considerable uncertainty. Several federal and state agencies have approved the use of some or many aspects of probabilistic risk assessment (PRA), but its site-specific application has often been limited to high-profile sites and large projects. Nonetheless, times are changing: newly developed software tools, and recent federal and state guidance documents formalizing PRA procedures, now make PRA a readily available method of analysis for even small-scale projects. This article presents and discusses a broad review of PRA literature published since 2000.  相似文献   
179.
Shaping functional vocal language is difficult when an individual has not yet acquired an echoic repertoire and does not emit sufficient phonemes (i.e., speech sounds) for shaping. Few studies have evaluated interventions to increase the frequency and breadth of phonemes. The current study extended Esch, Esch, and Love (2009) by evaluating the effects of a Lag 1 reinforcement schedule on vocal variability and limiting the definition of variability to responses that incorporated a novel phoneme. For 2 of the 3 participants, the cumulative number of novel phonemes, the percentage of trials with variability, and the number of different phonemes emitted per session increased during the Lag 1 intervention phase.  相似文献   
180.
为了对大学生学习成绩的长期变动性进行研究,将某专业299名学生按第一学期成绩排名分为1个5等分组,再将他们按大学毕业成绩排名分为第2个5等分组,观察2个5等分组间人员的流动情况并据此构建大学期间学生在2个5等分组间的成绩转移矩阵;在此基础上分析了每个等分组的成绩转移情况;计算了平均5等分组间的流动率、停留在同一5等分组的比率;与“数学意义上的完美转移矩阵”指标进行比较的结论是该专业学生大学期间成绩变动性不大。  相似文献   
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