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151.
Kimberly F. Sellers Derek S. Young 《Journal of Statistical Computation and Simulation》2019,89(9):1649-1673
While excess zeros are often thought to cause data over-dispersion (i.e. when the variance exceeds the mean), this implication is not absolute. One should instead consider a flexible class of distributions that can address data dispersion along with excess zeros. This work develops a zero-inflated sum-of-Conway-Maxwell-Poissons (ZISCMP) regression as a flexible analysis tool to model count data that express significant data dispersion and contain excess zeros. This class of models contains several special case zero-inflated regressions, including zero-inflated Poisson (ZIP), zero-inflated negative binomial (ZINB), zero-inflated binomial (ZIB), and the zero-inflated Conway-Maxwell-Poisson (ZICMP). Through simulated and real data examples, we demonstrate class flexibility and usefulness. We further utilize it to analyze shark species data from Australia's Great Barrier Reef to assess the environmental impact of human action on the number of various species of sharks. 相似文献
152.
In recent decades, quantile regression has received much more attention from academics and practitioners. However, most of existing computational algorithms are only effective for small or moderate size problems. They cannot solve quantile regression with large-scale data reliably and efficiently. To this end, we propose a new algorithm to implement quantile regression on large-scale data using the sparse exponential transform (SET) method. This algorithm mainly constructs a well-conditioned basis and a sampling matrix to reduce the number of observations. It then solves a quantile regression problem on this reduced matrix and obtains an approximate solution. Through simulation studies and empirical analysis of a 5% sample of the US 2000 Census data, we demonstrate efficiency of the SET-based algorithm. Numerical results indicate that our new algorithm is effective in terms of computation time and performs well for large-scale quantile regression. 相似文献
153.
F. Prataviera J. C. S. Vasconcelos G. M. Cordeiro E. M. Hashimoto 《Journal of applied statistics》2019,46(10):1792-1821
We define the exponentiated power exponential distribution and propose a regression model with different systematic structures based on the new distribution. We show that the new regression model can be applied to dispersion data since it represents a parametric family of models that includes as sub-models some widely-known regression models. It then can be used more effectively in the analysis of real data. We use maximum likelihood estimation and derive the appropriate matrices for assessing local influence on the parameter estimates under different perturbation schemes. Some global-influence measurements are also investigated and simulation studies are performed to evaluate the accuracy of the estimates. We provide an application of the regression model with four systematic structures to nursing activities score data in the Unit of the Medical Clinic of University of São Paulo (USP) Hospital. 相似文献
154.
Björg Thordardottir Agneta Malmgren Fänge Carlos Chiatti 《Journal of Housing for the Elderly》2019,33(1):41-55
Housing adaptation aims to enable clients to live independently in their own homes. Studies focusing on participation in everyday life following a housing adaptation are lacking and needed. This study aimed to explore housing adaptation clients' experiences of participation in everyday life before and after a housing adaptation, through the lens of a housing adaptation, using a qualitative follow-up design, with 11 participants. It was found that when the housing adaptation met the participants' needs, performance of activities improved and the housing adaptation opened doors to engagement and participation in everyday life. Thus, focus on performance and engagement in everyday life at the onset of the housing adaptation process, combined with regular follow-ups, may enhance participation. 相似文献
155.
Les auteurs s'intéressent aux disparités salariales entre les différents groupes de migrants qualifiés qui travaillent en grand nombre pour le secteur privé dans les États du Conseil de coopération du Golfe. Ils se demandent notamment si la prime salariale des Occidentaux (par rapport aux travailleurs venus d'Asie ou d'autres États arabes) découle d'éventuels a priori des employeurs. L'analyse, qui repose sur des données de 2012–2014 et sur deux méthodes de décomposition classiques, infirme l'hypothèse: les caractéristiques observables relatives à la productivité expliquent entre un tiers et trois quarts des écarts; le coût d'opportunité de la migration, supérieur pour les Occidentaux, explique la portion restante. 相似文献
156.
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158.
Maria Fatima Ruiz Paiva Félix Neto María Teresa Muñoz Sastre Nadine Laumond-Salvatore Sheila Rivière Etienne Mullet 《Social indicators research》2009,94(1):173-181
The study was aimed at replicating on a Portuguese sample the seven-factor model of life appraisal (physical autonomy, love
life, family life, social life, occupational life, finances, and leisure life) that was suggested by Salvatore and Munoz Sastre
Social Indicators Research 53:229–255 (2001). A sample of 1,111 Portuguese participants, aged 17–85, was presented with the Appraisal of Life Questionnaire. The “domain” model of life appraisal satisfactorily accounted for the data gathered on the Portuguese sample. Regarding
finances and occupational life, Portuguese scores were lower than French scores. Regarding the occupational score and the
leisure score, a clear linear decrease as a function of age was evidenced in the Portuguese sample. Finally, regarding the
family score and the financial score, a non-linear relationship with age was found. An increase was observed from young adult
age to adult age, and a decrease was observed from adult age to older age. A strong decrease in the physical autonomy scores
among Portuguese females was also observed. 相似文献
159.
Robert D. Crutchfield Martie L. Skinner Kevin P. Haggerty Anne McGlynn Richard F. Catalano 《Race and social problems》2009,1(4):218-230
Criminologists have long reported the existence of racial disparity in the criminal justice system, but the important question
is why. While some argue that observed differences are a consequence of more criminal behavior among minorities, the weight
of the evidence indicates that this is but a partial explanation. In this paper, we study data from a sample of juveniles
to examine how racial differences in early police contact, and important social environments—family, school, and neighborhoods—affect
later contact and arrests, controlling for self-reported delinquency. We find that early (in middle school) contact with police
is an important predictor of later (high school) arrests. Also we found that, in addition to being male and living in a low-income
family, children who have parents who have a history of arrest, who have experienced school disciplinary actions, who have
delinquent peers, and who are in networks with deviant adults are more likely to have problems with law enforcement. These
factors help to explain racial differences in police contacts and arrests. 相似文献
160.
Joseph F. Wyer 《Economic inquiry》2018,56(3):1777-1787
Commuters' lives have become more complicated with rising income. In my model, transportation mode choices are made simultaneously with the choice of whether to make multiple stops. Using travel behavior data, I estimate the model using an error components logit (ECL) specification to account for commuters' unobserved preferences for particular modes and find that omitting unobserved preferences underestimates value of travel time relative to the crossing‐components ECL. The estimated model predicts that increased trip complexity causes substitution away from public transit to automobiles, with the exception that bicyclists transition only to more complex trips and do not change transportation modes. (JEL R41, C25) 相似文献