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61.
Energy efficiency and greenhouse gas emissions are closely linked. This paper reviews agricultural options to reduce energy
intensities and their impacts, discusses important accounting issues related to system boundaries, land scarcity, and measurement
units and compares agricultural energy intensities and improvement potentials on an international level. Agricultural development
in recent decades, while increasing yields, has led to lower average energy efficiencies when comparing the 1960s and the
mid 1980s. In the two decades thereafter, energy intensities in developed countries increased, but with little impact on greenhouse
gas emissions. Efficiency differences across countries in the year 2000 suggest a maximum improvement potential of 500 million
tons of CO2 annually. If only below average countries would increase their energy efficiency to average levels of the year 2000, the
resulting emission reductions would be below 200 million tons of CO2 annually.
相似文献
Pete SmithEmail: URL: http://www.abdn.ac.uk/biologicalsci/staff/details/pete.smith |
62.
Campbell Barbara K.; Fuller Bret E.; Lee Eun Sul; Tillotson Carrie; Woelfel Tiffany; Jenkins Lindsay; Robinson James; Booth Robert E.; McCarty Dennis 《Canadian Metallurgical Quarterly》2009,23(2):260
A multisite, randomized trial within the National Drug Abuse Treatment Clinical Trials Network (CTN) was conducted to test 3 interventions to enhance treatment initiation following detoxification: (a) a single session, therapeutic alliance intervention (TA) added to usual treatment; (b) a 2-session, counseling and education, HIV/HCV risk reduction intervention (C&E), added to usual treatment; and (c) treatment as usual (TAU) only. Injection drug users (n = 632) enrolled in residential detoxification at 8 community treatment programs were randomized to 1 of the 3 study conditions. TA participants reported entering outpatient treatment sooner and in greater numbers than TAU participants. Reported treatment entry for C&E fell between TA and TAU with no significant differences between C&E and the other conditions. There were no differences among the interventions in retention, as measured by weeks of outpatient treatment for all participants who reported treatment entry. Alliance building interventions appear to be effective in facilitating transfer from detoxification to outpatient treatment, but additional treatment engagement interventions may be necessary to improve retention. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
63.
Enhancing the carbon sink in European agricultural soils: including trace gas fluxes in estimates of carbon mitigation potential 总被引:7,自引:0,他引:7
Pete Smith Keith W. Goulding Keith A. Smith David S. Powlson Jo U. Smith Pete Falloon Kevin Coleman 《Nutrient Cycling in Agroecosystems》2001,60(1-3):237-252
The possibility that the carbon sink in agricultural soils can be enhanced has taken on great political significance since
the Kyoto Protocol was finalised in December 1997. The Kyoto Protocol allows carbon emissions to be offset by demonstrable
removal of carbon from the atmosphere. Thus, forestry activities (Article 3.3) and changes in the use of agricultural soils
(Article 3.4) that are shown to reduce atmospheric CO2levels may be included in the Kyoto emission reduction targets. The European Union is committed to a reduction in CO2 emissions to 92% of baseline (1990) levels during the first commitment period (2008–2012). We have shown recently that there
are a number of agricultural land-management changes that show some potential to increase the carbon sink in agricultural
soils and others that allow alternative forms of carbon mitigation (i.e. through fossil fuel substitution), but the options
differ greatly in their potential for carbon mitigation. The changes examined were, (a) switching all animal manure use to
arable land, (b) applying all sewage sludge to arable land, (c) incorporating all surplus cereal straw, (d) conversion to
no-till agriculture, (e) use of surplus arable land to de-intensify 1/3 of current intensive crop production (through use
of 1/3 grass/arable rotations), (f) use of surplus arable land to allow natural woodland regeneration, and (g) use of surplus
arable land for bioenergy crop production. In this paper, we attempt for the first time to assess other (non-CO2) effects of these land-management changes on (a) the emission of the other important agricultural greenhouse gases, methane
and nitrous oxide, and (b) other aspects of the ecology of the agroecosystems. We find that the relative importance of trace
gas fluxes varies enormously among the scenarios. In some such as the sewage sludge, woodland regeneration and bioenergy production
scenarios, the inclusion of trace gases makes only a small (<10%) difference to the CO2-C mitigation potential. In other cases, for example the no-till, animal manure and agricultural de-intensification scenarios,
trace gases have a large impact, sometimes halving or more than doubling the CO2-C mitigation potential. The scenarios showing the greatest increase when including trace gases are those in which manure
management changes significantly. In the one scenario (no-till) where the carbon mitigation potential was reduced greatly,
a small increase in methane oxidation was outweighed by a sharp increase in N2O emissions. When these land-management options are combined to examine the whole agricultural land area of Europe, most of
the changes in mitigation potential are small, but depending upon assumptions for the animal manure scenario, the total mitigation
potential either increases by about 20% or decreases by about 10%, shifting the mitigation potential of the scenario from
just above the EU's 8% Kyoto emission reduction target (98.9 Tg C y−1) to just below it. Our results suggest that (a) trace gas fluxes may change the mitigation potential of a land management
option significantly and should always be considered alongside CO2-C mitigation potentials and (b) agricultural management options show considerable potential for carbon mitigation even after
accounting for trace gas fluxes.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
64.
Shahid Bokhari Benjamin Rutt Pete Wyckoff Paul Buerger 《Concurrency and Computation》2006,18(15):1929-1950
Mass storage systems (MSSs) play a key role in data‐intensive parallel computing. Most contemporary MSSs are implemented as redundant arrays of independent/inexpensive disks (RAID) in which commodity disks are tied together with proprietary controller hardware. The performance of such systems can be difficult to predict because most internal details of the controller behavior are not public. We present a systematic method for empirically evaluating MSS performance by obtaining measurements on a series of RAID configurations of increasing size and complexity. We apply this methodology to a large MSS at Ohio Supercomputer Center that has 16 input/output processors, each connected to four 8 + 1 RAID5 units and provides 128 TB of storage (of which 116.8 TB are usable when formatted). Our methodology permits storage‐system designers to evaluate empirically the performance of their systems with considerable confidence. Although we have carried out our experiments in the context of a specific system, our methodology is applicable to all large MSSs. The measurements obtained using our methods permit application programmers to be aware of the limits to the performance of their codes. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
65.
66.
OBJECTIVE: Previous studies indicate that low resting heart rate is probably the best-replicated biological correlate of childhood antisocial and aggressive behavior. Nevertheless, there have been few longitudinal tests of this relationship, little control over potential confounds and mediators, and no test of its cross-cultural generalizability. This study tests the hypothesis that low resting heart rate at age 3 years predicts aggression at age 11 years. METHOD: Resting heart rate at age 3 years was assessed in 1,795 male and female children from Mauritius. Aggressive and nonaggressive forms of antisocial behavior were assessed at age 11 years using the Child Behavior Checklist. RESULTS: Aggressive children had lower heart rates than nonaggressive children (p < .001). Conversely, those with low heart rates were more aggressive than those with high heart rates (p < .003). There were no interactions with gender or ethnicity. Evidence was found for specificity of low heart rate to aggressive forms of antisocial behavior. Group differences in heart rate were not attributable to 11 biological, psychological, and psychiatric mediators and confounds. CONCLUSIONS: It is concluded that low resting heart rate, a partly heritable trait reflecting fearlessness and stimulation-seeking, is an important, diagnostically specific, well-replicated, early biological marker for later aggressive behavior. 相似文献
67.
Cross-fostering spontaneously hypertensive rat (SHR) pups to Wistar-Kyoto (WKY) normotensive mothers influenced physical development, resting mean arterial pressure and heart rate, open-field behavior, and sympathetic-adrenal medullary responses to stressors. Cross-fostering WKY pups to SHR mothers at birth, however, did not affect these developmental processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
68.
Pitman D. L.; Natelson B. H.; Ottenweller J. E.; McCarty R.; Pritzel T.; Tapp W. N. 《Canadian Metallurgical Quarterly》1995,109(4):767
For 5 days, rats were exposed to shocks that were signalled by a light 0, 33, 66, or 100% of the time. Basal hormone levels and responses to a light-shock pair were measured daily. Greater predictability was associated with higher basal plasma corticosterone and norepinephrine levels indicative of chronic stress. Habituation of the corticosterone response was also less in the groups with greater predictability. However, predictability did not affect plasma prolactin or epinephrine responses. Because the endocrine systems responded differently, it is unlikely that the changes were due to a unitary process. Greater predictability appeared to be more stressful in this paradigm. Both associative and nonassociative factors have major roles in determining the hormonal responses to repeated presentation of stressors. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
69.
This paper presents a method of joint rehabilitation utilizing the principals of active motion and CPM (continuous passive motion) and joint unloading. Most true intra-articular disorders appear to be a progression of both chemical and mechanical alterations. The physiological sound principals of joint mobilization are used both as post surgical rehabilitation and as definitive therapy. When used as nonsurgical therapy, the benefits appear to be as a result of a reversal, lessening, or a favorable adaptive response of the chemical and mechanical alterations. 相似文献
70.
Determination of the crystal structure of the human TBP-associated factor (hTAF(II))28/hTAF(II)18 heterodimer shows that these TAF(II)s form a novel histone-like pair in the TFIID complex. The histone folds in hTAF(II)28 and hTAF(II)18 were not predicted from their primary sequence, indicating that these TAF(II)s define a novel family of atypical histone fold sequences. The TAF(II)18 and TAF(II)28 histone fold motifs are also present in the N- and C-terminal regions of the SPT3 proteins, suggesting that the histone fold in SPT3 may be reconstituted by intramolecular rather than classical intermolecular interactions. The existence of additional histone-like pairs in both the TFIID and SAGA complexes shows that the histone fold is a more commonly used motif for mediating TAF-TAF interactions than previously believed. 相似文献