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991.
Examined the relationships among sociodemographic characteristics, family processes, and the initiation of health risk behaviors in early adolescence. Ss were 189 6th and 7th graders from a public middle school. A path-analytic model was used to analyze data. Results showed that students who received autonomy support from parents were less likely to initiate sexual intercourse. Students who were emotionally detached from their parents were more likely to fight and use substances. Those who were emotionally detached tended to come from families with low levels of cohesion and acceptance. Sociodemographic variables, such as family structure, gender, and ethnicity, had both direct and indirect effects on health risk behaviors, but the indirect effects were quite small. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
992.
The authors argue that people's tendency to diversify their allocations of money and consumption choices over alternatives gives rise to decisions that vary systematically with the subjective grouping of available options. These subjective groupings are influenced by subtle variations in the presentation of options or elicitation of preferences. Studies 1-4 demonstrate such "partition dependence" in allocations of money to beneficiaries, consumption experiences to future time periods, and choices to a menu of consumption options. Study 5 documents weaker partition dependence among individuals with greater relevant experience discriminating among options, and Study 6 shows that the effect is attenuated among participants with stronger or more accessible intrinsic preferences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
993.
This study compared the behavioral effects of 3 anticonvulsants in impulsive aggressive men. In a double-blind, placebo-controlled, parallel groups design, participants were randomly assigned to 1 of 4 6-week treatments: phenytoin (n = 7), carbamazepine (n = 7), valproate (n = 7), or placebo (n = 8). The efficacy measure was the average aggression score, a global severity index from the Overt Aggression Scale (J. M. Silver & S. C. Yudofsky, 1991). Analysis showed a significant reduction in impulsive aggression during all 3 anticonvulsant conditions compared with placebo. However, the treatment effect during carbamazepine administration was slightly delayed compared with phenytoin and valproate. These findings suggest that increased use of anticonvulsants could make a significant impact in the control of impulsive aggression in both mental health and criminal justice settings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
994.
Diffusion of tritiated water (referred to as tritium) and helium-3 between mobile and immobile regions in aquifers (mass transfer) can affect tritium and helium-3 concentrations and hence tritium-helium-3 (3H/3He) ages that are used to estimate aquifer recharge and groundwater residence times. Tritium and helium-3 chromatographically separate during transport because their molecular diffusion coefficients differ. Simulations of tritium and helium-3 transport and diffusive mass transfer along stream tubes show that mass transfer can shift the 3H/3He age of the tritium and helium-3 concentration ([3H + 3He]) peak to dates much younger than the 1963 peak in atmospheric tritium. Furthermore, diffusive mass-transfer can cause the 3H/3He age to become younger downstream along a stream tube, even as the mean water-age must increase. Simulated patterns of [3H + 3He] versus 3H/3He age using a mass transfer model appear consistent with a variety of field data. These results suggest that diffusive mass transfer should be considered, especially when the [3H + 3He] peak is not well defined or appears younger than the atmospheric peak. 3H/3He data provide information about upstream mass-transfer processes that could be used to constrain mass-transfer models; however, uncritical acceptance of 3H/3He dates from aquifers with immobile regions could be misleading.  相似文献   
995.
Aerosol-mediated transport of perfluorooctanoate (PFO) from a water body to the atmosphere and the subsequent emission of gas-phase perfluorooctanoic acid (PFOA) was investigated. The potential for this process to facilitate long-range transport of PFOA/PFO was assessed. In a laboratory experiment, aerosols were generated and collected from deionized, fresh, and ocean waters spiked with PFO and analyzed by LC-MS/MS. Gas-phase samples were also collected from the system and analyzed for PFOA. Aerosols were found to have significantly higher concentrations of PFO than the parent water body (< or = 80 times for ocean waters). The PFOA, at equilibrium with the PFO in the aqueous aerosol, partitioned rapidly (t 1/2 = 7.2 s) out of the aerosol droplet. This suggests that rainout rates are likely to be longer than previously hypothesized. These results imply that water bodies are not a permanent sink for atmospheric PFOA as previous studies have suggested. The occurrence of contamination in remote regions may not depend solely on the previously hypothesized indirect sources but also on the long-range transport, via the gas phase, of direct releases of PFOA to both the aquatic and atmospheric environments.  相似文献   
996.
As a result of increased harmful algal blooms and hypoxia in Lake Erie, the US and Canada revised their phosphorus loading targets under the 2012 Great Lakes Water Quality Agreement. The focus of this paper is the Detroit River and its watershed, a source of 25% of the total phosphorus (TP) load to Lake Erie. Its load declined 37% since 1998, due chiefly to improvements at the regional Great Lakes Water Authority Water Resource Recovery Facility (WRRF) in Detroit and phosphorus sequestered by zebra and quagga mussels in Lake Huron. In addition to the 54% of the load from Lake Huron, nonpoint sources contribute 57% of the TP load and 50% of the dissolved reactive phosphorus load, with the remaining balance from point sources. After Lake Huron, the largest source is the WRRF, which has already reduced its load by over 40%. Currently, loads from Lake Huron and further reductions from the WRRF are not part of the reduction strategy, therefore remaining watershed sources will need to decline by 72% to meet the Water Quality Agreement target - a daunting challenge. Because other urban sources are very small, most of the reduction would have to come from agriculturally-dominated lands. The most effective way to reduce those loads is to apply combinations of practices like cover crops, buffer strips, wetlands, and applying fertilizer below the soil surface on the lands with the highest phosphorus losses. However, our simulations suggest even extensive conservation on those lands may not be enough.  相似文献   
997.
Blue sucker (Cycleptus elongatus) populations occur in the Mississippi River and Gulf of Mexico drainages of North America and are negatively affected by habitat fragmentation and flow regime alteration caused by dams. During fish assemblage surveys in August of 2022, we collected five juvenile blue suckers (312–428 mm total length) in the Angelina River upstream of Sam Rayburn Reservoir in East Texas (46,335 ha surface area) where the occurrence of the species was previously unconfirmed. Given this unexpected finding, we (1) analyzed mesohabitat associations to compare habitats we sampled with reports in the literature and (2) reviewed blue sucker occurrences in state, national, and global databases across historical (1950–1980) and contemporary (1981–2022) time periods to assess occurrence across gradients of habitat fragmentation and streamflow regulation. The blue sucker population in the Angelina River upstream of Sam Rayburn Reservoir was previously unconfirmed but is within the native range. Mesohabitats occupied by blue suckers were consistent with literature reports, including fast velocity, shallow depth, and coarse substrates. The low degree of regulation (19% of natural runoff stored by upstream reservoirs) and a high degree of habitat connectivity (287 rkm of unfragmented mainstem habitat) for the Angelina River upstream of Sam Rayburn Reservoir matched range-wide patterns of persistence within relatively intact (unfragmented and unregulated) or remnant (fragmented but unregulated) riverscapes. Our review reveals that blue sucker populations might persist (1) in remnant river fragments where local habitat conditions are appropriate and (2) where effects of habitat fragmentation and flow regulation are not coupled.  相似文献   
998.
All U.S. states regulate face-to-face tobacco sales at retail outlets. However, the recent growth of delivery sales of tobacco products by Internet and mail-order vendors has prompted new state regulations focused on preventing youth access and tax evasion. To date, there are no comprehensive and systematic analyses of these laws. The objectives of this study were to: (a) document the historical enactment of the laws; (b) assess the nature and extent of the laws; and (c) examine the relationship between the presence of laws and state tobacco control policy and other contextual variables. Between 1992 and 2006, 34 states (67%) enacted a relevant law, with 27 states' laws (45%) effective between 2003 and 2006. Five states banned direct-to-consumer shipment of cigarettes. The remaining 29 states' laws included a combination of requirements addressing minimum age/ID, payment issues, shipping, vendor licensure and related issues, tax collection/remittance, and penalties/enforcement. States with delivery sales laws have stronger youth tobacco access policies and state tobacco control environments, as well as higher state cigarette excise tax rates and revenue, past-month cigarette use rates, and perceptions of risk of use by adolescents. This paper provides the policy context for understanding Internet and other cigarette delivery sales laws in the U.S. It also provides a systematic framework for ongoing policy surveillance and will contribute to future analyses of the impact of these laws on successfully reducing youth access to cigarettes and preventing tax evasion.  相似文献   
999.
Our case study explored a Local Resilience Forum's (LRF) civil contingency response to COVID-19 in the United Kingdom. We undertook 19 semistructured ethnographic longitudinal interviews, between March 25, 2020 and February 17, 2021, with a Director of a Civil Contingencies Unit and a Chief Fire Officer who both played key roles within their LRF. Within these interviews, we focused on their strategic level decision-making and how their relationship with national government impacted on local processes and outcomes. Using a form of grounded theory, our data describe the chronological evolution of an increasingly effective localized approach toward outbreak control and a growing resilience in dealing with concurrent emergency incidents. However, we also highlight how national government organizations imposed central control on aspects of the response in ways that undermined or misaligned with local preparedness. Thus, during emergencies, central governments can undermine the principle of subsidiarity and damage the ways in which LRFs can help scaffold local resilience. Our work contributes to the theoretical understanding of the social psychological factors that can shape the behaviour of responder agencies during a prolonged crisis. In particular, the implications of our analysis for advancing our conceptual understanding of strategic decision-making during emergencies are discussed.  相似文献   
1000.
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