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971.
Response of atmospheric particulate matter to changes in precursor emissions: a comparison of three air quality models 总被引:1,自引:0,他引:1
Pun BK Seigneur C Bailey EM Gautney LL Douglas SG Haney JL Kumar N 《Environmental science & technology》2008,42(3):831-837
Three mathematical models of air quality (CMAQ, CMAQ-MADRID, and REMSAD) are applied to simulate the response of atmospheric fine particulate matter (PM2.5) concentrations to reductions in the emissions of gaseous precursors for a 10 day period of the July 1999 Southern Oxidants Study (SOS) in Nashville. The models are shown to predict similar directions of the changes in PM2.5 mass and component (sulfate, nitrate, ammonium, and organic compounds) concentrations in response to changes in emissions of sulfur dioxide (SO2), nitrogen oxides (NO(x)), and volatile organic compounds (VOC), except for the effect of SO2 reduction on nitrate and the effect of VOC reduction on PM2.5 mass. Furthermore, in many cases where the directional changes are consistent, the magnitude of the changes are significantly different among models. Examples are the effects of SO2 and NO(x) reductions on nitrate and PM2.5 mass and the effects of VOC reduction on organic compounds, sulfate and nitrate. The spatial resolution significantly influences the results in some cases. Operational model performance for a PM2.5 component appears to provide some useful indication on the reliability of the relative response factors (RRFs) for a change in emissions of a direct precursor, as well as for a change in emissions of a compound that affects this component in an indirect manner, such as via oxidant formation. However, these results need to be confirmed for other conditions and caution is still needed when applying air quality models for the design of emission control strategies. It is advisable to use more than one air quality model (or more than one configuration of a single air quality model) to span the full range of plausible scientific representations of atmospheric processes when investigating future air quality scenarios. 相似文献
972.
Catering businesses continue to be the most common setting for foodborne disease outbreaks. In a study of catering businesses in England and Wales, operational practices relating to the supply, preparation, and service of food in 88 businesses associated with outbreaks were compared with those practices at 88 control businesses. Operational practices did not differ significantly between case and control businesses but larger small medium-size enterprise (SME) businesses were more likely to be associated with foodborne disease outbreaks than were micro-SME businesses. Businesses associated with outbreaks of Salmonella infection were less likely to use local or national suppliers but instead used regional suppliers, especially for eggs. This practice was the only significantly independent operational practice associated with outbreaks of Salmonella infection. Regional egg suppliers also were more likely to be used by businesses associated with outbreaks attributed to food vehicles containing eggs. Businesses associated with egg-associated outbreaks were less likely to use eggs produced under an approved quality assurance scheme, suggesting that the underlying risk associated with using regional suppliers may relate to the use of contaminated eggs. 相似文献
973.
Vaishali Bane Sharon Hutchinson Aisling Sheehan Brid Brosnan Paul Barnes Mary Lehane 《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2016,33(11):1728-1740
Tetrodotoxin (TTX), often referred to as the ‘puffer fish’ poison, is a marine toxin and it has been identified as the agent responsible for many food poisoning incidents around the world. It is a neurotoxin that blocks voltage-gated sodium channels, resulting in respiratory paralysis and even death in severe cases. It is known to occur in many different species of fish and other organisms. The toxin is mainly found in the Southeast Asia region. Worryingly, TTX is starting to appear in European waters. It is suspected that this is a consequence of Lessepsian migration, also known as the Erythrean invasion. Therefore, straightforward and reliable extraction and analytical methods are now urgently required to monitor seafood of European origin for TTX. This paper provides a versatile, dependable and robust method for the analysis of TTX in puffer fish and trumpet shellfish using LC-MS/MS. A three-stage approach was implemented involving: (1) the screening of samples using fast multiple reaction monitoring (MRM) mass spectral analysis to identify quickly positive samples on a triple quadrupole mass spectrometer (QqQMS/MS), the API 3000; (2) a Fourier-transform (FT)-MS full-scan analysis of positive samples to collect qualitative data; and (3) a method with a longer chromatography run to identify and quantitate the positive samples using the QqQMS. The quantitative LC-QqQMS method delivered excellent linearity for solvent-based standards (0.01–7.5 µg ml–1; R2 ≥ 0.9968) as well as for matrix-matched standards (0.05–37.50 µg g–1; R2 ≥ 0.9869). Good inter-day repeatability was achieved for all the relevant analytes with %RSD values (n = 9) ranging from 1.11% to 4.97% over a concentration range of 0.01–7.5 µg ml–1. A sample clean-up procedure for the puffer fish and trumpet shellfish was developed to ensure acceptable and reproducible recoveries to enable accurate and precise determination of TTX in a myriad of tissues types. Blank mackerel matrix was used for the TTX standard spiking studies in order to calculate the recoveries of the toxin during the extraction procedure. The recovery was 61.17% ± 5.42% for the extraction protocol. MS/MS studies were performed on a linear-trap quadruple-Orbitrap mass spectrometer (LTQ-Orbitrap) to obtain high-mass-accuracy data of the target analytes and their characteristic fragment ions in the puffer fish and trumpet shellfish samples. This facilitated identification of TTX and its associated analogues. These high-mass-accuracy studies facilitated the development of a rapid MRM-based quantitative method for TTX determination on the LC-QqQMS. 相似文献
974.
Hanevold C Lu S Yonekawa K 《Hemodialysis international. International Symposium on Home Hemodialysis》2010,14(Z1):S2-S6
Dialysis concentrate acidified with citrate as opposed to acetate has been reported to prevent clotting in hemodialysis circuits, and improve dialysis efficiency in adults. There is no information on its use in children. The purpose of the study was to evaluate the utility of citrate dialysate for renal replacement therapy in a pediatric population with acute kidney injury. We performed a retrospective review of our experience using Citrasate® concentrate from December 2007 to August 2009. All treatments were provided using the Fresenius 2008 dialysis machine. Citrasate® was utilized in 7 children aged 60.3±51.0 months (mean±SD), range 13 months to 12 years. The number of treatments varied from 4 to 31 (mean 12±8 treatments) for a total of 89 treatments. Rare sporadic mild hypocalcemia was noted but could not be definitively linked with the use of Citrasate®. Four children also required low‐dose heparin (3.6–15 U/kg/h) due to clotting. Activated clotting times (when checked) were not affected by this low‐dose heparin therapy. Some degree of clotting occurred in 21 of 89 (23.5%) treatments. Early termination of treatment due to thrombosis was required in 7 of 89 (7.8%) treatments. In summary, use of Citrasate® dialysis concentrate was well tolerated in critically ill children with acute kidney injury. Citrasate® reduced but did not completely eliminate the need for heparin in our population. Further study in a more diverse population would be helpful. 相似文献
975.
Manne Sharon; Winkel Gary; Zaider Talia; Rubin Stephen; Hernandez Enrique; Bergman Cynthia 《Canadian Metallurgical Quarterly》2010,78(2):236
Objective: Little attention has been paid to the role of nonspecific therapy processes in the efficacy of psychological interventions for individuals diagnosed with cancer. The goal of the current study was to examine the three constructs from the generic model of psychotherapy (GMP): therapeutic alliance, therapeutic realizations, and therapeutic openness/involvement in the treatment outcome of women with gynecological cancers attending either a 7-session supportive counseling intervention or a coping and communication skills intervention. Method: Two hundred and three women completed measures of alliance, realizations, and openness after Intervention Sessions 2, 3, and 6, as well as measures of depressive symptoms after these sessions and 6 months after the pre-intervention assessment (posttreatment). Results: Consistent with the GMP, in early sessions, therapeutic bond predicted openness in terms of positive affect experienced during sessions, and both aspects of openness (positive and negative affect), in turn, predicted more therapeutic realizations. Therapeutic realizations predicted perceptions of greater session progress, and greater therapeutic bond predicted more therapeutic realizations. When early session GMP variables were used to predict later GMP processes and outcomes and posttreatment outcomes, early therapeutic bond predicted later session therapeutic realizations directly and indirectly via emotional arousal, emotional arousal predicted session progress, session progress predicted lower postsession depressive symptoms, and depressive symptoms as rated after Session 6 predicted depressive symptoms 3 months posttreatment. However, a number of additional associations among GMP processes were found. Conclusions: Our results suggest that therapy processes played a role in predicting both short- and long-term treatment outcomes. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
976.
This study estimated normative reading trajectories for the population of English-proficient language minority students attending U.S. public elementary schools. Achievement of English-language learners (ELLs) was evaluated in terms of native English speakers' progress, and estimates were adjusted for the effects of socioeconomic status (SES). The ELL group was disaggregated into native Spanish speakers and native speakers of Asian languages. Multilevel latent variable growth modeling indicated that achievement trends of Asian-language ELLs are more similar to those of native English speakers than to those of Spanish ELL groups. Spanish ELLs had lower initial reading achievement than both Asian-language ELLs and native English speakers, and Asian students had higher initial achievement than did the native English speaking group. Additionally, Spanish ELLs had statistically significantly less growth over time than did Asian ELLs, with differences being most notable on reading evaluation–related tasks. Language-related differences in total reading were minimized when SES effects were specifically modeled, suggesting that SES may be the more significant factor explaining the lower achievement rates of English-proficient native Spanish speakers. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
977.
Aten Jamie D.; Topping Sharon; Denney Ryan M.; Bayne Tania G. 《Canadian Metallurgical Quarterly》2010,41(2):167
The purpose of this qualitative study was to explore how mental health professionals and African American pastors and their churches could collaborate to overcome minority disaster mental health disparities. Forty-one African American pastors of churches located in south Mississippi, in counties directly affected by Hurricane Katrina, participated in semi-structured interviews approximately 1 year after the storm. The majority of participants reported being interested in collaborating with mental health professionals to: (a) develop educational and outreach opportunities, (b) lead assessment procedures, (c) offer consultation activities, (d) provide clinically focused services, and (e) utilize spiritual resources and support. Participants provided further insight into how these collaborative activities could be modified to meet post-disaster needs and offered novel applications. Following from these discussions, the article provides a number of recommendations that can be used to aid in the development of disaster collaborative activities between African American pastors and churches and mental health professionals to serve minority communities while also decreasing disparities. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
978.
Five studies indicate that conceptualizations of power are important elements of culture and serve culturally relevant goals. These studies provide converging evidence that cultures nurture different views of what is desirable and meaningful to do with power. Vertical individualism is associated with a conceptualization of power in personalized terms (i.e., power is for advancing one's personal status and prestige), whereas horizontal collectivism is associated with a conceptualization of power in socialized terms (i.e., power is for benefiting and helping others). Cultural variables are shown to predict beliefs about appropriate uses of power, episodic memories about power, attitudes in the service of power goals, and the contexts and ways in which power is used and defended. Evidence for the cultural patterning of power concepts is observed at both the individual level and the cultural-group level of analysis. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
979.
Development of delayed bitterness and effect of harvest date in stored juice from two complex citrus hybrids
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980.
Studied the presence and magnitude of menstrual-cycle-related mood changes using standardized measures of depression and anxiety. 158 females aged 15–16 yrs completed the Menstrual Distress Questionnaire and reported the actual date of onset of their next 2 menstrual periods. These Ss and their male classmates were later given the Depression Adjective Check List, Forms A and D, and the State-Trait Anxiety Inventory twice, 2 wks apart, in an unrelated classroom setting. This study assessed the magnitude of anxiety and depression experienced by the 29 Ss who were tested within 4 days preceding the onset of menstruation and the 23 Ss who were tested during the first 4 days of menstruation. Premenstrual and menstrual test scores were compared with those obtained during the intermenstrual phase of the cycle. No significant differences in mood attributable to cycle phase were found. A control group of males also showed no significant difference in mood. Adolescent women appear to be different from women over 30 who have been reported to show significantly increased state anxiety and depression during the premenstrual phase of the menstrual cycle. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献