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1.
Business Modelling has evolved as a key activity to reflect new business venture strategy by framing the way a firm will operate and how it will function in achieving its goals (e.g., profitability, growth, innovation, social impact). However, scholars and practitioners have criticized the adoption of a too static perspective in the design and use of conventional Business Model representations. Such a static perspective prevents nascent entrepreneurs experimenting with their Business Models and, as a result, identifying the most effective strategies, especially in terms of business sustainability and profitability. In this paper, we argue that combining conventional Business Model schemas with System Dynamics modelling results in a strategy design tool that may overcome several limitations related to a static view of Business Model representation. Mapping the different key elements underlying value creation processes into a system of causal interdependencies – through the use of simulation – allows strategy analysts and entrepreneurs to experiment and learn how the business reacts to strategic and organizational changes in terms of performance, innovation and value creation. As such, Dynamic Business Models provide useful insights to strategy formulation and business venturing by capturing how critical Business Model elements interact to produce enduring competitive advantages over time. 相似文献
2.
David J. Sharrow Jessica Godwin Yanjun He Samuel J. Clark Adrian E. Raftery 《Population studies》2018,72(1):1-15
In 2015, the United Nations (UN) issued probabilistic population projections for all countries up to 2100, by simulating future levels of total fertility and life expectancy and combining the results using a standard cohort component projection method. For the 40 countries with generalized HIV/AIDS epidemics, the mortality projections used the Spectrum/Estimation and Projection Package (EPP) model, a complex, multistate model designed for short-term projections of policy-relevant quantities for the epidemic. We propose a simpler approach that is more compatible with existing UN projection methods for other countries. Changes in life expectancy are projected probabilistically using a simple time series regression and then converted to age- and sex-specific mortality rates using model life tables designed for countries with HIV/AIDS epidemics. These are then input to the cohort component method, as for other countries. The method performed well in an out-of-sample cross-validation experiment. It gives similar short-run projections to Spectrum/EPP, while being simpler and avoiding multistate modelling. 相似文献
3.
《Risk analysis》2018,38(9):1988-2009
Harbor seals in Iliamna Lake, Alaska, are a small, isolated population, and one of only two freshwater populations of harbor seals in the world, yet little is known about their abundance or risk for extinction. Bayesian hierarchical models were used to estimate abundance and trend of this population. Observational models were developed from aerial survey and harvest data, and they included effects for time of year and time of day on survey counts. Underlying models of abundance and trend were based on a Leslie matrix model that used prior information on vital rates from the literature. We developed three scenarios for variability in the priors and used them as part of a sensitivity analysis. The models were fitted using Markov chain Monte Carlo methods. The population production rate implied by the vital rate estimates was about 5% per year, very similar to the average annual harvest rate. After a period of growth in the 1980s, the population appears to be relatively stable at around 400 individuals. A population viability analysis assessing the risk of quasi‐extinction, defined as any reduction to 50 animals or below in the next 100 years, ranged from 1% to 3%, depending on the prior scenario. Although this is moderately low risk, it does not include genetic or catastrophic environmental events, which may have occurred to the population in the past, so our results should be applied cautiously. 相似文献
4.
Feng Xinghai 《佛山科学技术学院学报(社会科学版)》1992,(4)
根据机械振动和积木式传递矩阵法的原理,提出了用于估算单、双转子系统一阶临界转速的实用方法,从而得到的“K3表”可方便地使用于产品的方案设计阶段或现场排故,并可得到满意的工程精度。 相似文献
5.
宋晓杰 《吉林工程技术师范学院学报》2005,(6)
利用SPSS软件,对我国31个省、直辖市的大中型工业企业的总资产贡献率、成本费用利润率、资本保值增值率、流动资产周转次数、全员劳动生产率、产品销售率、资产负债率、总资产周转率、净资产收益率、销售利润率等十个经济效益指标进行了因子分析,并将这十个指标归结为盈利、销售、运营、发展等多个因子。最后,根据每个因子得分情况将所有地区归为六类,进而做出综合评价。 相似文献
6.
李久昌 《宝鸡文理学院学报(社会科学版)》2003,23(3):10-17
三门峡上村岭虢国墓地车马坑是迄今为止发现的西周春秋时期规模较大、等级齐全、排列有序的贵族墓祔葬车马坑。虢国车马坑葬继承和沿用商周车马殉葬制,又适应和迎合社会进步及变革需要,对车马坑的殉葬内容和形式进行变通与革新,摒弃车葬坑和同穴葬,整车葬成为主流形式,并盛行车马葬和异穴葬,车马排列有序,殉葬性质更加明确,是象征性、明器化殉葬的滥觞,殉人制消失,显示出传统车马坑葬制开始出现瓦解的苗头。大量车马坑葬在虢国墓地出现,反映了虢国生产力发展水平和崇勇尚武世风,更反映了车马坑主人的身份等级,它与列鼎制紧密配合,形成了一个不可分割的整体。 相似文献
7.
逆系统方法是以非线性控制为目的,以直接分析为途径,以动态系统的逆概念为核心。该文将逆系统方法应用于刚体动力学中,运用非线性控制的逆系统方法设计Euler动力学方程的控制器,通过对一个陀螺的外力矩进行实施控制,使刚体在动坐标系下的角速度稳定跟踪指令,来实现对刚体转动的渐进跟踪控制。 相似文献
8.
Gaussian Markov random field (GMRF) models are commonly used to model spatial correlation in disease mapping applications. For Bayesian inference by MCMC, so far mainly single-site updating algorithms have been considered. However, convergence and mixing properties of such algorithms can be extremely poor due to strong dependencies of parameters in the posterior distribution. In this paper, we propose various block sampling algorithms in order to improve the MCMC performance. The methodology is rather general, allows for non-standard full conditionals, and can be applied in a modular fashion in a large number of different scenarios. For illustration we consider three different applications: two formulations for spatial modelling of a single disease (with and without additional unstructured parameters respectively), and one formulation for the joint analysis of two diseases. The results indicate that the largest benefits are obtained if parameters and the corresponding hyperparameter are updated jointly in one large block. Implementation of such block algorithms is relatively easy using methods for fast sampling of Gaussian Markov random fields ( Rue, 2001 ). By comparison, Monte Carlo estimates based on single-site updating can be rather misleading, even for very long runs. Our results may have wider relevance for efficient MCMC simulation in hierarchical models with Markov random field components. 相似文献
9.
10.
Orsenigo Luigi Pammolli Fabio Riccaboni Massimo Bonaccorsi Andrea Turchetti Giuseppe 《Journal of Management and Governance》1997,1(2):147-175
The paper moves a step forward in the direction of establishing a connection between the structure and evolution of knowledge
bases and the structure and evolution of organizational forms in innovative activities in a science-intensive industry. The
paper has an explicit focus on the dynamics of the network of collaborative agreements in R&D in the pharma/biotech industry
after the “molecular biology revolution”. Using a comprehensive dataset, built by the authors integrating several sources
in the industry, the dynamics of the network over time is extensively analyzed. With regards to network structure, it is found
that, while the size of the network increases over time due to net flows of entry, its topological properties remain relatively
unchanged. The evolution of the network has occurred without relevant deformations in the core-periphery profile. With regards
to age-dependent propensity to collaborate, the paper finds that the extent of inter-generational collaboration is much more
significant than intra-generational collaboration. In addition, the propensity of firms of a given generation to enter into
collaboration with firms of a different generation increases with the distance between the two, while the total number of
intra-generational collaborations decreases over time and, moreover, tends to decrease for most recent generations. In the
paper a unitary and coherent explanation of the evidence is developed, coming to reveal the existence of a striking isomorphism
between structural properties of the dynamics of knowledge and of the evolution of network structure.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献