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71.
Roger L. Creighton J. Douglas Carroll Jr. Graham S. Finney 《Journal of the American Planning Association. American Planning Association》2013,79(2):96-103
In city planning, data-processing machines permit the rapid handling and summarization of data in housing, renewal, land use, transportation, and basic urban research. Electronic computers. specifically, are exciting because they offer a means of solving complex city planning problems, especially in forecasting land use and travel demand. For most planning operations punched card data processing is superior to other processes. The functions of these machines are described herein and three examples of data processing are elaborated on. In future years, planning techniques may have to be altered considerably to take advantage of the potentials of data processing. 相似文献
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The problem of predicting adhesive bond performance for both surface preparation and undercure defects has been studied using an ultrasonic, experimental test bed system. This experimental test bed incorporates the ultrasonic and computer equipment necessary to acquire and process data from various types of adhesively bonded test specimens. The computer hardware and software has been developed to allow the design of reliable pattern recognition algorithms for the evaluation of surface preparation and bond cure. The specific problem studied is the inspection of the adhesive bond in an aluminum to aluminum step-lap joint whose strength could be affected by improper surface preparation or undercure. A set of 154 bond specimens was used to design an algorithm that is 91% reliable for separating the specimens into a good class, those bonds with no defects, or a weak class, bonds with poor surface preparation or undercured adhesive layer. A Fisher Linear Discriminant function was selected by the test bed as the best pattern recognition routine for this classification problem. 相似文献
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Peer nomination procedures were used to explore the development of academic achievement values and their relation to perceptions of barriers to opportunity. A total of 615 boys and girls across 3 grade levels (2nd, 4th, 7th) and 2 ethnic groups (African American, Latino) nominated peers who they admired, respected, and wanted to be like. Nominations were summed to create a value index. Girls in both ethnic groups and across grade levels were more likely to nominate high- or average-achieving same-gender classmates as those who they admired, respected, and wanted to be like. Second- and 4th-grade boys in both ethnic groups reported a nomination pattern similar to that of girls. However, 7th-grade boys in both ethnic groups showed a relative preference for low-achieving same-gender classmates as valued. Perceptions of barriers were related to increasing valuing of low achievers among African American 7th-grade boys. Implications of the findings for understanding the motivational challenges of ethnic minority male adolescents are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
77.
This study examined the possible effects of caffeine ingestion on muscle metabolism and endurance during brief intense exercise. We tested 14 subjects after they ingested placebo or caffeine (6 mg/kg) with an exercise protocol in which they cycled for 2 min, rested 6 min, cycled 2 min, rested 6 min, and then cycled to voluntary exhaustion. In each exercise the intensity required the subject's maximal O2 consumption. Eight subjects had muscle and venous blood samples taken before and after each exercise period. The caffeine ingestion resulted in a significant increase in endurance (4.12 +/- 0.36 and 4.93 +/- 0.60 min for placebo and caffeine, respectively) and resulted in a significant increase in plasma epinephrine concentration throughout the protocol but not in norepinephrine concentration. During the first two exercise bouts, the power and work output were not different; blood lactate concentrations were not affected significantly by caffeine ingestion, but during the exercise bouts muscle lactate concentration was significantly increased by caffeine. The net decrease in muscle glycogen was not different between treatments at any point in the protocol, and even at the time of fatigue there was at least 50% of the original glycogen concentration remaining. the data demonstrated that caffeine ingestion can be an effective ergogenic aid for exercise that is as brief as 4-6 min. However, the mechanism is not associated with muscle glycogen sparing. It is possible that caffeine is exerting actions directly on the active muscle and/or the neural processes that are involved in the activity. 相似文献
78.
Salmonella montevideo is a recognised cause of ovine abortion and can cause disease in other domestic animals and humans. The organism was isolated from the aborted fetuses of a bitch from a pack of foxhounds. The subsequent collection of rectal swabs from the foxhounds at approximately two week intervals over a 48-day period resulted in the isolation of S montevideo from 50 of the 61 hounds in the pack on one or more occasions. Some of the hounds had gained access to an open pit containing dead ewes and aborted fetuses on a farm where the housed ewe flock was experiencing S montevideo infection. The S montevideo isolates from both the ovine and canine samples had a plasmid of 120 kilobases with an identical restriction endonuclease fragmentation pattern. The only other isolate from a contemporary outbreak lacked this plasmid. It was concluded that this case offered further evidence of the potential for salmonella infection to be spread by the scavenging of carcasses. 相似文献
79.
OA Ayangbile JP Fontenot PP Graham DJ Kirk VG Allen 《Canadian Metallurgical Quarterly》1998,76(3):686-693
Exacerbations of asthma have been associated with exposure to ozone or particles with a 50% cut-off aerodynamic diameter of 10 microm (PM10). We postulated in this study that the association of summertime air pollution (i.e. ozone and PM10) with acute respiratory symptoms, medication use and peak expiratory flow differs among patients grouped according to asthma severity. During the summer of 1995, effects of ambient air pollution on these parameters were studied in a panel of 60 nonsmoking patients with intermittent to severe persistent asthma. These patients were recruited from our Pulmonary Out-patient Clinic. Subgroup analysis was performed on the degree of hyperresponsiveness and lung steroid use before the start of the study, as indictors for the severity of asthma. Associations of the parameters studied with ozone, PM10, nitrogen dioxide (NO2), sulphur dioxide (SO2) and black smoke were evaluated using time series analysis. Several episodes with increased summertime air pollution occurred during the 96 day study period. Eight hour average ozone concentrations exceeded the World Health Organization (WHO) Air Quality Guidelines (120 microg x m(-3)) on 16 occasions. Daily mean levels of PM10 were moderately elevated (range 16-98 microg x m(-3)). Levels of the other measured pollutants were low. There was a consistent, positive association of the prevalence of shortness of breath (maximal relative risk (RRmax) 1.18) with ozone, PM10, black smoke and NO2. In addition, bronchodilator use was associated with both ozone and PM10 levels (RRmax 1.16). Stratification by airway hyperresponsiveness and steroid use did not affect the magnitude of the observed associations. No associations with peak expiratory flow measurements were found. We conclude that the severity of asthma is not an indicator for the sensitivity to air pollution. 相似文献
80.
Whether late positive components of event-related potentials (ERPs) parallel changes in heart rate (HR) indicative of attention/orienting to rare stimuli has been debated. In the present study, a three-stimulus design was used, with rare target, rare nontarget, and frequent standard stimuli delivered under identical conditions except that instructions to subjects described the targets to which subjects should respond but did not describe the nontargets. In Experiment 1, stimuli varied among modalities; in Experiment 2, auditory stimuli were employed. Both ERPs and HR were consistent with automatic processing preceding two stages of controlled processing. Rare stimuli evoked larger parietal P300 and initial HR deceleration than standards. Presumably because of load-reducing effects of long interstimulus intervals, targets and nontargets were not distinguished before a late slow wave and a late phase of HR acceleration. Neither rare stimulus elicited a recognizable frontal P3a. 相似文献