全文获取类型
收费全文 | 1870篇 |
免费 | 69篇 |
国内免费 | 47篇 |
专业分类
管理学 | 179篇 |
民族学 | 7篇 |
人才学 | 2篇 |
人口学 | 55篇 |
丛书文集 | 90篇 |
理论方法论 | 43篇 |
综合类 | 856篇 |
社会学 | 107篇 |
统计学 | 647篇 |
出版年
2024年 | 1篇 |
2023年 | 6篇 |
2022年 | 7篇 |
2021年 | 17篇 |
2020年 | 25篇 |
2019年 | 41篇 |
2018年 | 48篇 |
2017年 | 96篇 |
2016年 | 41篇 |
2015年 | 60篇 |
2014年 | 73篇 |
2013年 | 361篇 |
2012年 | 117篇 |
2011年 | 111篇 |
2010年 | 88篇 |
2009年 | 102篇 |
2008年 | 102篇 |
2007年 | 93篇 |
2006年 | 97篇 |
2005年 | 51篇 |
2004年 | 79篇 |
2003年 | 46篇 |
2002年 | 58篇 |
2001年 | 40篇 |
2000年 | 42篇 |
1999年 | 42篇 |
1998年 | 18篇 |
1997年 | 17篇 |
1996年 | 13篇 |
1995年 | 13篇 |
1994年 | 17篇 |
1993年 | 11篇 |
1992年 | 7篇 |
1991年 | 9篇 |
1990年 | 5篇 |
1989年 | 3篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 4篇 |
1981年 | 3篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
排序方式: 共有1986条查询结果,搜索用时 15 毫秒
1.
《Journal of Policy Modeling》2022,44(1):147-162
Using an ARDL model for a panel of 15 OECD countries, this work analyses the impact that FDI, both jointly and by sector, has on CO2 emissions. The findings reveal that these countries are yielding to the pressure on the trade sector. Unexpectedly, gross fixed capital formation shrink pollution, excluding in the mining sector. With findings supporting the Pollution Haven Hypothesis, policymakers must pay attention to FDI inflows, ensuring that FDI place high importance on the transfer of green technologies to improve the efficiency. These goals could be achieved through an increase in the stringency of environmental laws within the host countries, especially the ones related to FDI. 相似文献
2.
Supporting healthy lifestyle behaviours is a key aspect of preventing type 2 diabetes which disproportionately affects disadvantaged groups from a younger age. Formative participatory research was undertaken to design a program for young Aboriginal people in a remote town in North West Australia with a high level of health needs and relatively few prevention initiatives. Focus groups and advisory discussions with Aboriginal community members were used to determine the nature of the program. The need for a comprehensive program was consistently expressed and limited healthy lifestyle knowledge and difficulties with healthy eating influenced by food environments were noted to be important. With guidance from the Derby Aboriginal Health Service, findings were integrated with previous international research evidence to develop a program tailored to local Aboriginal people aged 15–25 years and refine it after piloting. This 8-session program, ‘Maboo wirriya, be healthy’ involved an education component consistent with the US Diabetes Prevention Program and practical activities including group exercise. Changes to program structure and documentation were made after piloting for future use. The community-directed approach used in this study is vital to ensure relevance of localised chronic disease prevention programs in a range of settings. 相似文献
3.
In a special paired sample case, Hotelling’s T2 test based on the differences of the paired random vectors is the likelihood ratio test for testing the hypothesis that the paired random vectors have the same mean; with respect to a special group of affine linear transformations it is the uniformly most powerful invariant test for the general alternative of a difference in mean. We present an elementary straightforward proof of this result. The likelihood ratio test for testing the hypothesis that the covariance structure is of the assumed special form is derived and discussed. Applications to real data are given. 相似文献
4.
Uniform designs are widely used in various scientific investigations and industrial applications. By considering all possible level permutation of the factors, a connection between average centered L2-discrepancy and generalized wordlength pattern for asymmetrical fractional factorial designs is derived. Moreover, we present new lower bounds to the average centered L2-discrepancy for symmetrical and asymmetrical U-type designs. For illustration of the theoretical results, the lower bounds for symmetrical and asymmetrical U-type designs are tabulated, and numerical results indicate that our lower bounds behave well and can be recommended for use in practice. 相似文献
5.
AbstractThis paper considers the optimization problems for a consecutive-2-out-of-n:G system where n is considered to be fixed or random. When the number of components is constant, the optimal number of components and the optimal replacement time are discussed by minimizing the expected cost rates. Furthermore, we focus on the above discussions again when n is a random variable. We give an approximate value of MTTF and propose the preventive replacement policy, respectively. 相似文献
6.
Factors associated with early cessation of breastfeeding in women with gestational diabetes mellitus
《Women and birth : journal of the Australian College of Midwives》2015,28(2):143-147
AimTo determine factors associated with early cessation of breastfeeding (≤3 months) in women with recent gestational diabetes mellitus (GDM).MethodsA cross-sectional online survey of women aged ≥18 years, diagnosed with GDM in 2010 and registered with the National Diabetes Services Scheme in Australia. The 59 questions examined breastfeeding duration, intention, attitudes, exclusivity and support.Results738 women completed the survey (15% response rate). Data was analysed for 729 eligible respondents. Of these 97% reported ‘ever’ breastfeeding and 19% had breastfed for ≤3 months. Cessation of breastfeeding at or before 3 months was associated with breastfeeding problems at home [adjusted odds ratio 8.01, 95% confidence interval (4.57, 14.05)], return to work prior to three months [OR 3.39 (95% CI 1.53, 7.55)], inadequate breastfeeding support [OR 1.88 (95% CI 1.10, 3.22)], caesarean delivery [OR 1.70 (95% CI 1.04, 2.76)], low socioeconomic status (SEIFA 1 unit increase) [OR 0.89 (95% CI 0.81, 0.97)] and BMI (2 unit increase) [OR 1.08 (95% CI 1.01, 1.57)]. Being married or de facto [OR 0.14 (95% CI 0.03, 0.62)] was a protective against early cessation of breastfeeding.ConclusionStrategies to improve breastfeeding duration in women with GDM need to address those most at risk of early cessation and provide appropriate postpartum breastfeeding support in this group. 相似文献
7.
四川盆地卤水分布广泛,资源丰富, 早为世人所瞩目,中三叠统雷口坡组是四川盆地最早开采天然气和盐卤的层系之一。根据盆地雷口坡组大量钻井资料研究表明,盆地雷口坡组主要成盐期分别为雷三2 期和雷四2 期,在盆地东部和南部由于受到古隆起的影响,盐岩地层已被剥蚀难以保存,现今盐岩主要分布在开江古隆起和泸州古隆起的西部以及天井山古隆起的南部(华蓥山以西—龙门山以东的川西—川中地区)。印支运动对盆地雷口坡组盐岩在平面的迁移起着十分重要的作用,根据不同时期盐岩统计数据看,两期盐盆在平面上具有向西迁移、叠加的特征,其中川中的GS1 井就钻遇了这两期的盐岩。 相似文献
8.
9.
电子商务市场蓬勃发展的同时,也存在严重的信息不对称现象,给消费者带来极大的购物风险。文章基于信息不对称理论,利用淘宝网交易数据对 C2C 市场上消费者的从众决策行为进行研究。研究发现 C2C 市场上店铺的日销量在店铺间存在二八分布的特征,说明网络消费者在购买商品时有从众行为。基于面板模型对店铺市场份额的研究表明,店铺历史销量信息对消费者选择店铺的决策有显著正向影响,而店铺信用对消费者决策的影响并不显著。因此,建议 C2C 交易平台增加退货量指标、动态销量图以及销量和价格的相互对应信息等,以促进消费者理性购物。 相似文献
10.
罗明高 《西南石油大学学报(社会科学版)》2018,14(3):9-13
本文对传统的石油地质理论定义的含油气面积提出了异议,用倒转背斜油气藏、断层下盘油气藏和不整合面下油气藏的实例阐明在传统定义下确定含油气面积存在的问题,指出用这种方法确定的含油气面积小于实际面积。笔者将含油气面积定义为含油气体在水平面上的投影区域,并推荐了三种正确的确定方法、 相似文献