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1.
The use of time for child care and housework among Swedish families is investigated. We allow the effect of children on child care and housework to vary by age of the child and also by whether the child is cared for outside the home or not. Our estimates allow us to compute the total cost of children in the form of the cost of time, and the cost of goods, services and housing.The result shows that time used for child care decreases sharply with the age of the child but this is not the case for time used for other housework. Considerable economies of scale is found to prevail for time used for child care. Child care outside the home reduces time use for other housework but the effect on time used for child care is quite small. For the average family time use cost make up more than half of total child cost. Our estimates indicate that decreased time use cost for children caused by care outside the home are not very different from a typical parental fee for public day care.This research was supported by a grant from the Swedish Council of Social Research (SFR). We thank Lennart Flood for useful comments on an earlier version.  相似文献   
2.
We experimentally compare fast and slow decisions in a series of experiments on financial risk taking in three countries involving over 1700 subjects. To manipulate fast and slow decisions, subjects were randomly allocated to responding within 7 seconds (time pressure) or waiting for at least 7 or 20 seconds (time delay) before responding. To control for different effects of time pressure and time delay on measurement noise, we estimate separate parameters for noise and risk preferences within a random utility framework. We find that time pressure increases risk aversion for gains and risk taking for losses compared to time delay, implying that time pressure increases the reflection effect of Prospect Theory. The results for gains are weaker and less robust than the results for losses. We find no significant difference between time pressure and time delay for loss aversion (tested in only one of the experiments). Time delay also leads to less measurement noise than time pressure and unconstrained decisions, and appears to be an effective way of decreasing noise in experiments.  相似文献   
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In competitive swimming, suits have become more important. These suits influence friction, pressure and wave drag. Friction drag is related to the surface properties whereas both pressure and wave drag are greatly influenced by body shape. To find a relationship between the body shape and the drag, the anthropometry of several world class female swimmers wearing different suits was accurately defined using a 3D scanner and traditional measuring methods. The 3D scans delivered more detailed information about the body shape. On the same day the swimmers did performance tests in the water with the tested suits. Afterwards the result of the performance tests and the differences found in body shape was analyzed to determine the deformation caused by a swimsuit and its effect on the swimming performance. Although the amount of data is limited because of the few test subjects, there is an indication that the deformation of the body influences the swimming performance.  相似文献   
5.
Performance of certain cognitive tasks either during physical load or in rest pauses between boosts might lead to slowing of muscle fatigue and fatigue related decline in performance. Seventeen right-handed healthy volunteers (age 24 ± 1.4, 8 males) participated in this study, aiming to investigate the effect of the level of the cognitive information processing - 1) passive perception of audio stimuli, 2) active stimuli discrimination, 3) active stimuli discrimination following motor response - on motor task performance (handgrip test 30% and 7% of MVC) and muscle fatigue development. Cognitive tasks show the following effects on motor work: i) Perceived fatigue during 30 % MVC (fatiguing) condition developed slower if participant pressed button in response to deviant acoustic stimuli, as compared to passive listening. Counting task, an active task without motor component, took the intermediate position and did not differ significantly from two other cognitive tasks. ii) MVC after 30% MVC (fatiguing) condition tended to decrease stronger when accompanied with passive listening in comparison with both active tasks. iii) Motor task performance during 30% MVC (fatiguing) condition was better for active cognitive task with motor component than for passive task. Active task without motor component took the intermediate position and did not differ significantly from both the other cognitive tasks.  相似文献   
6.
This article examines the existing contractual arrangements and industry standards in private equity. It shows that investors are, in principle, capable of structuring their particular investments according to their own preferences, there are a range of governance problems and risks that could be potentially hazardous for some classes of investors. We examine the circumstances where existing industry codes and legal tools can be used to address the problems that arise in relation to private equity and buyout activity.  相似文献   
7.
What drives infants’ attention in complex visual scenes? Early models of infant attention suggested that the degree to which different visual features were detectable determines their attentional priority. Here, we tested this by asking whether two targets—defined by different features, but each equally salient when evaluated independently—would drive attention equally when pitted head‐to‐head. In Experiment 1, we presented 6‐month‐old infants with an array of Gabor patches in which a target region varied either in color or spatial frequency from the background. Using a forced‐choice preferential‐looking method, we measured how readily infants fixated the target as its featural difference from the background was parametrically increased. Then, in Experiment 2, we used these psychometric preference functions to choose values for color and spatial frequency targets that were equally salient (preferred), and pitted them against each other within the same display. We reasoned that if salience is transitive, then the stimuli should be iso‐salient and infants should therefore show no systematic preference for either stimulus. On the contrary, we found that infants consistently preferred the color‐defined stimulus. This suggests that computing visual salience in more complex scenes needs to include factors above and beyond local salience values.  相似文献   
8.
The purpose of the study was to extend the literature on verbal self-regulation by using the “silent dog” method to evaluate the role of verbal regulation over nonverbal behavior in 2 individuals with autism. Participants were required to talk-aloud while performing functional computer tasks.Then the effects of distracters with increasing demands on target behavior were evaluated as well as whether self-talk emitted by Participant 1 could be used to alter Participant 2''s performance. Results suggest that participants'' tasks seemed to be under control of self-instructions, and the rules generated from Participants 1''s self-talk were effective in teaching computer skills to Participant 2. The silent dog method was useful in evaluating the possible role of self-generated rules in teaching computer skills to participants with autism.  相似文献   
9.
Economists have long conceptualized and modeled the inherent interdependent relationships among different sectors of the economy. This concept paved the way for input-output modeling, a methodology that accounts for sector interdependencies governing the magnitude and extent of ripple effects due to changes in the economic structure of a region or nation. Recent extensions to input-output modeling have enhanced the model's capabilities to account for the impact of an economic perturbation; two such examples are the inoperability input-output model( 1 , 2 ) and the dynamic inoperability input-output model (DIIM).( 3 ) These models introduced sector inoperability, or the inability to satisfy as-planned production levels, into input-output modeling. While these models provide insights for understanding the impacts of inoperability, there are several aspects of the current formulation that do not account for complexities associated with certain disasters, such as a pandemic. This article proposes further enhancements to the DIIM to account for economic productivity losses resulting primarily from workforce disruptions. A pandemic is a unique disaster because the majority of its direct impacts are workforce related. The article develops a modeling framework to account for workforce inoperability and recovery factors. The proposed workforce-explicit enhancements to the DIIM are demonstrated in a case study to simulate a pandemic scenario in the Commonwealth of Virginia.  相似文献   
10.
We study the effect of railroad access on urban population growth. Using GIS techniques, we match triennial population data for roughly 1,000 cities in 19th‐century Prussia to georeferenced maps of the German railroad network. We find positive short‐ and long‐term effects of having a station on urban growth for different periods during 1840–1871. Causal effects of (potentially endogenous) railroad access on city growth are identified using propensity score matching, instrumental variables, and fixed‐effects estimation techniques. Our instrument identifies exogenous variation in railroad access by constructing straight‐line corridors between nodes. Counterfactual models using pre‐railroad growth yield no evidence to support the hypothesis that railroads appeared as a consequence of a previous growth spurt.  相似文献   
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