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71.
Abstract Not all commodities are things, nor are all things available in society commodities. Then, what are commodities? Using the case of rapeseed and its products in China, this paper examines the role of grades and standards (G&S) in simultaneously determining the life of things as commodities and the position of humans as market participants. In the first section, we summarize our conceptual understandings of commodities. Next, the paper examines tests and trials to which rapeseed in China were subjected by the mid 1990s. We then discuss how G&S represent political processes among commodity chain actors for creating, legitimizing and maintaining the social relations between things and people. Lastly, we discuss our conclusion that the analysis of tests and trials helps us understand the process of commodification as simultaneous transformations of humans and things in a commodity chain while reorganizing linkages among these actors. 相似文献
72.
In two-parameter family of distribution, conditions for a modified maximum likelihood estimator to be second-order admissible are given. Applying these results to two-parameter logistic regression model, it is shown that the maximum likelihood estimator is always second-order inadmissible and the Rao-Blackwellized minimum logit chi-squared estimator is second-order admissible if and only if the number of the doses is greater than or equal to 6. 相似文献
73.
An axiomatization of the Kalai-Smorodinsky solution when the feasible sets can be finite 总被引:1,自引:0,他引:1
We axiomatize the Kalai-Smorodinsky solution (1975) in the Nash bargaining problems if the feasible sets can be finite. We
show that the Kalai-Smorodinsky solution is the unique solution satisfying Continuity (in the Hausdorff topology endowed with payoffs space), Independence (which is weaker than Nash's one and essentially equivalent to Roth (1977)'s one), Symmetry, Invariance (both of which are the same as in Kalai and Smorodinsky), and Monotonicity (which reduces to a little bit weaker version of the original if the feasible sets are convex).
Received: 4 November 1999/Accepted: 6 June 2001 相似文献
74.
Akito Yoshiko Aya Tomita Ryosuke Ando Madoka Ogawa Shohei Kondo Akira Saito Noriko I. Tanaka Teruhiko Koike Yoshiharu Oshida Hiroshi Akima 《European review of aging and physical activity》2018,15(1):13
Background
Older individuals have been shown to present muscle atrophy in conjunction with increased fat fraction in some muscles. The proportion of fat and connective tissue within the skeletal muscle can be estimated from axial B-mode ultrasound images using echo intensity (EI). EI was used to calculate the index of muscle quality. Walking, home-based weight-bearing resistance training, and its combinations are considered simple, easy, and practical exercise interventions for older adults. The purpose of this study was to quantify the effects of walking and walking with home-based resistance training on muscle quality of older individuals.Methods
Thirty-one participants performed walking training only (W-group; 72?±?5?years) and 33 participants performed walking and home-based resistance training (WR-group; 73?±?6?years). This study was a non-randomized controlled trial with no control group. All participants were instructed to walk 2 or 3 sets per week for 10?weeks (one set: 30-min continuous walking). In addition, the WR-group performed home-based weight-bearing resistance training. EI was measured as a muscle quality index using axial B-mode ultrasound images of the rectus femoris and vastus lateralis of the mid-thigh. We further averaged these parameters to obtain the EI of the quadriceps femoris (QF). Participants further performed five functional tests: sit-ups, supine up, sit-to-stand, 5-m maximal walk, and 6-min walk.Results
QF EI was significantly decreased in both groups after training (W-group 69.9?±?7.4?a.u. to 61.7?±?7.0?a.u., WR-group 64.0?±?9.5?a.u. to 51.1?±?10.0?a.u.; P?<?0.05), suggesting improved muscle quality. QF EI was further decreased in the WR-group compared with the W-group. The sit-up test in both groups and the sit-to-stand and 5-m maximal walk tests in the W-group were significantly improved after training.Conclusion
These results suggest that training-induced stimulation is associated with a decrease in EI in some thigh regions. Furthermore, the addition of home-based resistance training to walking would be effective for a greater reduction of EI.75.
Using data from the first wave of the Millennium Cohort Study, covering a large birth cohort of children in the UK at age 8 to 12 months, this paper examines the effects of leave-taking and work hours on fathers’ involvement in four specific types of activities: being the main caregiver; changing diapers; feeding the baby; and getting up during the night. We also investigate the effects of policies on fathers’ leave-taking and work hours. We find that taking leave and working shorter hours are related to fathers being more involved with the baby, and that policies affect both these aspects of fathers’ employment behaviour. Thus, we conclude that policies that provide parental leave or shorter work hours could increase fathers’ involvement with their young children. 相似文献
76.
K. Tanaka T. Watanabe H. Higuchi K. Miyamoto Y. Yusa T. Kiyonaga H. Kiyota Y. Suzuki T. Wada 《Researches on Population Ecology》1999,41(3):253-262
To examine density dependence in the survival, growth, and reproduction of Pomacea canaliculata, we conducted an experiment in which snail densities were manipulated in a paddy field. We released paint-marked snails of
15–20 mm shell height into 12 enclosures (pens) of 16 m2 at one of five densities – 8, 16, 32, 64, or 128 snails per pen. The survival rate of released snails was 95% and was independent
of snail density. The snail density had a significant effect on the growth and egg production of individual snails. This density
dependence may have been caused by reduced food availability. The females at high density deposited fewer and smaller egg
masses than those at low density, and consequently produced fewer eggs. The females at densities 8 and 16 deposited more than
3000 eggs per female, while the females at density 128 oviposited only 414 eggs. The total egg production per pen was, however,
higher at higher snail density. The survival rates of juvenile snails were 21%–37% and were independent of adult density.
The juvenile density was positively correlated with the total egg production per pen and hence was higher at higher adult
density. However, the density of juveniles larger than 5 mm in shell height, i.e., juveniles that can survive an overwintering
period, was not significantly different among density treatments. These results suggest that snail density after the overwintering
period is independent of the density in the previous year. Thus, density dependence in growth and reproduction might regulate
the population of P. canaliculata in paddies.
Received: October 23, 1998 / Accepted: July 16, 1999 相似文献
77.
Yukata Tanaka 《统计学通讯:理论与方法》2013,42(9):3157-3175
The problem of detecting influential observations in principalcomponent analysis was discussed by several authors. Radhakrishnan and kshirsagar ( 1981 ), Critchley ( 1985 ), jolliffe ( 1986 )among others discussed this topicby using the influence functions I(X;θs)and I(X;Vs)of eigenvalues and eigenvectors, which wwere derived under the assumption that the eigenvalues of interest were simple. In this paper we propose the influence functionsI(X;∑q s=1θsVsVs T)and I(x;∑q s=1VsVs t)(q<p;p:number of variables) to investigate the influence onthe subspace spanned by principal components. These influence functions are applicable not only to the case where the edigenvalues of interst are all simple but also to the case where there are some multiple eigenvalues among those of interest. 相似文献
78.
Yutaka Tanaka 《统计学通讯:理论与方法》2013,42(11):3991-4010
Tanaka(1988) derived two influence functions related to an ordinary eigenvalue problem (A–λs I)vs = 0 of a real symmetric matrix A and used them for sensitivity analysis in principal component analysis. One of these influence functions was used to develop sensitivity analysis in factor analysis (see e.g. Tanaka and Odaka, 1988a). The present paper derives some additional influence functions related to an ordinary eigenvalue problem and also several influence functions related to a generalized eigenvalue problem (A–θs A)us = 0, where A and B are real symmetric and real symmetric positive definite matrices, respectively. These influence functions are applicable not only to the case where the eigenvalues of interest are all simple but also to the case where there are some multiple eigenvalues among those of interest. 相似文献
79.
The present paper deals with sensitivity analysis in maximum likelihood factor analysis. To investigate the influence of a small change of data we derive theoretical influence functions I(x; LLT ) and I(x; Δ) for a common variance matrix T= LLT and a unique variance matrix Δ respectively. Numerical examples are shown to illustrate our procedure. 相似文献
80.
The influence function of the covariance matrix is decomposed into a finite number of components. This decomposition provides a useful tool to develop efficient methods for computing empirical influence curves related to various multivariate methods. It can also be used to characterize multivariate methods from the sensitivity perspective. A numerical example is given to demonstrate efficient computing and to characterize some procedures of exploratory factor analysis. 相似文献