全文获取类型
收费全文 | 154篇 |
免费 | 7篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 22篇 |
金属工艺 | 3篇 |
机械仪表 | 4篇 |
建筑科学 | 2篇 |
矿业工程 | 2篇 |
能源动力 | 12篇 |
轻工业 | 18篇 |
水利工程 | 2篇 |
无线电 | 8篇 |
一般工业技术 | 38篇 |
冶金工业 | 4篇 |
原子能技术 | 1篇 |
自动化技术 | 44篇 |
出版年
2023年 | 2篇 |
2022年 | 10篇 |
2021年 | 2篇 |
2020年 | 6篇 |
2019年 | 5篇 |
2018年 | 6篇 |
2017年 | 4篇 |
2016年 | 10篇 |
2015年 | 4篇 |
2014年 | 7篇 |
2013年 | 12篇 |
2012年 | 11篇 |
2011年 | 13篇 |
2010年 | 6篇 |
2009年 | 15篇 |
2008年 | 12篇 |
2007年 | 5篇 |
2006年 | 5篇 |
2005年 | 1篇 |
2004年 | 4篇 |
2003年 | 2篇 |
2002年 | 4篇 |
2001年 | 1篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1982年 | 2篇 |
1981年 | 2篇 |
排序方式: 共有161条查询结果,搜索用时 0 毫秒
51.
John E. Daskalakis 《国际能源研究杂志》1993,17(8):689-695
We examine the steady incompressible laminar boundary layer flow along a vertical cylinder with isothermal walls. The mixed free and forced convection regime is studied while injection/suction of fluid can take place through the cylinder surface. The two-dimensional boundary layer equations are solved using an efficient finite difference scheme, and velocity and temperature profiles, as well as skin friction, heat transfer and pressure coefficients, are calculated. It is proved that fluid injection can considerably reduce the skin friction and heat transfer at the wall. Also, significant differences are reported when the present results are compared with published results for the zero mass transfer case. 相似文献
52.
A Antsaklis G Daskalakis N Papantoniou S Michalas 《Canadian Metallurgical Quarterly》1998,18(9):934-940
The aim of this study, was to determine the fetal loss rate after fetal blood sampling (FBS) in relation to the indication. In total, 1981 FBS procedures (1878 pregnancies) were included, of which 117 were performed for the detection of congenital infection (group 1), 1437 for the detection of haemoglobinopathy (group 2), 233 for prenatal diagnosis with normal ultrasound findings (group 3), 121 for rapid karyotyping in cases with abnormal sonographic findings (group 4) and 73 for severe growth retardation (group 5). All the procedures were performed with a free-hand technique under continuous ultrasound guidance. Pregnancy losses occurring within two weeks of FBS were considered procedure-related losses. 343 pregnancies were terminated. Of the remaining 1535 continuing pregnancies, 73 (4.8 per cent) were lost, of which 39 (2.5 per cent) were lost within two weeks of the procedure. The procedure-related losses were 3 in 103 (2.9 per cent), 17 in 1090 (1.6 per cent), 2 in 191 (1 per cent), 11 in 84 (13.1 per cent) and 6 in 67 (8.9 per cent) in groups 1, 2, 3, 4 and 5, respectively. The differences in procedural loss between the five groups were highly significant, suggesting that the method entails a much higher risk when the fetus is structurally abnormal, or severely growth retarded. Patients should therefore be counselled before the procedure accordingly. 相似文献
53.
The first-order diffraction efficiency eta1 of surface-stabilized ferroelectric liquid-crystal (SSFLC) phase gratings is calculated for device thicknesses in the range d = 1 to 5 microm and for pitches p of 5 to 20 microm assuming incident light at 633 nm. The peak value of eta1 as a function of d has negligible dependence on the incoming polarization when p = 20 microm. For smaller pitch values the peak value of eta1 decreases and becomes increasingly dependent on the orientation of the incoming polarization owing to the influence of the domain walls that occur between the SSFLC pixels. 相似文献
54.
Ventikos NP Vergetis E Psaraftis HN Triantafyllou G 《Journal of hazardous materials》2004,107(1-2):51-58
This paper presents an operational synthesis of major oil spill response methods (mechanical, chemical, etc.) and the corresponding oil response equipment for sea context (booms, skimmers, etc.). We focus on important features of oil spill response, in order to formulate a decision-based database, capable of supporting the development of a complete oil spill response operation. Moreover, we classify these findings and introduce simple formatting and standards to supply predictive tools for oil spill models. The actual goal of this paper is to come up with a decision-driven process, which can provide for a realistic choice of oil spill response equipment in the design of the primary oil response phase. This is intended to lead to a prompt, logical, and well-prepared oil spill response operation satisfying time and cost criteria and protecting the marine environment. 相似文献
55.
Ha KS Jo SH Kang BH Apostolidis E Lee MS Jang HD Kwon YI 《Journal of food science》2011,76(8):H188-H193
During the heat processing of raw ginseng to produce red ginseng, amino acid derivatives such as arginyl-fructose (AF) and arginyl-fructosyl-glucose (AFG) are formed at high levels, through amadori rearrangement, the early step of Maillard reaction, from arginine and glucose or maltose, respectively. However, very limited information is available about the effect of the structural difference between AF and AFG on various biological activities. This is the first report of the mode of action and effect of AF and AFG on the type 2 diabetes management related inhibition of postprandial hyperglycemia in vitro and in animal model. In our previous study, standards AF and AFG were chemically synthesized and in this study their inhibitory activities against rat intestinal α-glucosidases and porcine pancreatic α-amylase were investigated in vitro. The IC(50) value of the in vitro inhibitory activity of AF and AFG on rat intestinal sucrase was high and in similar levels (6.40 and 6.20 mM, respectively). Additionally, a mild pancreatic α-amylase inhibitory activity was observed, with IC(50) values 36.30 and 37.60 mM for AF and AFG, respectively. The effect of AF and AFG on the postprandial blood glucose increase after meal was investigated in Sprague Dawley rats fed on starch or sucrose meals. Both amadori compounds significantly reduced the postprandial blood glucose levels after starch or sucrose loading. These results indicate that AF and AFG, Maillard reaction products, may have antidiabetic effect by suppressing carbohydrate absorption in the gastrointestinal level, and thereby reducing the postprandial increase of blood glucose. 相似文献
56.
Viguier B Zór K Kasotakis E Mitraki A Clausen CH Svendsen WE Castillo-León J 《ACS applied materials & interfaces》2011,3(5):1594-1600
This article describes the combination of self-assembled peptide nanofibrils with metal electrodes for the development of an electrochemical metal-ion biosensor. The biological nanofibrils were immobilized on gold electrodes and used as biorecognition elements for the complexation with copper ions. These nanofibrils were obtained under aqueous conditions, at room temperature and outside the clean room. The functionalized gold electrode was evaluated by cyclic voltammetry, impedance spectroscopy, energy dispersive X-ray and atomic force microscopy. The obtained results displayed a layer of nanofibrils able to complex with copper ions in solution. The response of the obtained biosensor was linear up to 50 μM copper and presented a sensitivity of 0.68 μA cm?2 μM?1. Moreover, the fabricated sensor could be regenerated to a copper-free state allowing its reutilization. 相似文献
57.
Emmanouil Liandris Maria Gazouli Styliani Taka Margarita Andreadou Anna Vaiopoulou Nikolaos Tzimotoudis Ioannis Kasampalidis Dionysis Mpaseas George Fyliousis Palmiro Poltrionieri Nigel Cook John Ikonomopoulos 《Journal of food science》2014,79(3):M362-M368
Foodborne illness is a major cause of morbidity and mortality especially for children, even in the developed world. The aim of this study was to assess the microbial safety of food of animal origin intended for consumption by children in Greece. Sampling involved 8 categories of retail products and was completed with a collection of 850 samples. These were tested by PCR and/or culture for Listeria monocytogenes, Campylobacter spp., Escherichia coli O157, Salmonella spp., Cronobacter sakazakii, Brucella spp., and Mycobacterium avium subsp paratuberculosis (MAP). The number of positive results recorded collectively for the pathogens under investigation over the total number of samples tested was 3.52% and 0.12% by PCR and culture, respectively. The most frequently detected pathogen was enterohemorrhagic E. coli (1.29%) followed by Brucella (0.82%) and Listeria (0.82%). DNA belonging to MAP was detected in 0.35% of samples, which was also the percentage of positivity recorded for Campylobacter. The percentage for Salmonella was 0.12%. It can be concluded from the results that there is no indication of noncompliance for the tested food samples. However, detection of DNA belonging to pathogens that are transmissible to humans through food is indicative that constant vigilance regarding food safety is an absolute necessity. 相似文献
58.
Papageorgiou GZ Bikiaris D Kanaze FI Karavas E Stergiou A Georgarakis E 《Drug development and industrial pharmacy》2008,34(3):336-346
Formulations of the drug Fluconazole with different release characteristics were prepared by dispersing the active pharmaceutical ingredient (API) in various polymeric carriers, and especially in polymer blends. Fluconazole was tested as a model drug with low solubility in water. First solid dispersions in pure polymers were studied. Use of pure polyvinylpyrrolidone (PVP) as carrier even for high drug load (30 wt%) resulted in rapid release. The drug release rates decreased by increasing the API content. The dissolution rate enhancement was attributed to drug amorphization, particle size reduction, and possible improvement of the drug wetting characteristics. Hydroxypropyl methylcellulose (HPMC) gave solid dispersions, from which the release rates of the drug varied from immediate to sustaining. As the drug amount increased, the rates became higher. Similar behavior also was found when Chitosan was used as carrier, with much more controlled rates close to those for sustained release. These differences were mainly attributed to the limited solubility and swelling of HPMC and Chitosan in aquatic media. To study the effectiveness of polymer blends in adjusting the release rates of the drug, solid dispersions in PVP/HPMC and PVP/Chitosan miscible blends were studied. The release rates of Fluconazole were adequately adjusted by differentiating the weight ratio of the polymers in the blends. PVP/HPMC blends with high PVP content can be used for immediate release formulations but PVP/Chitosan blends are inappropriate for such formulations and can only be used for controlled release. 相似文献
59.
Dimitrakakis E Janz A Bilitewski B Gidarakos E 《Journal of hazardous materials》2009,162(2-3):913-919
The study of cementitious activity of chromium residue (CR) was carried out to formulate the properties of chromium residue-cement matrices (CRCM) by blending CR with Ordinary Portland Cement (OPC). The particle size distribution, microstructures of CR were investigated by some apparatuses, and physical properties, leaching behavior of hexavalent chromium [Cr(VI)] of CRCM were also determined by some experiments. Three types of commonly used superplasticizers (sulphonated acetone formaldehyde superplasticizer (J1), polycarboxylate-based superplasticizer (J2) and naphthalene superplasticizer (J3)) were chosen to investigate their influences on the physical properties and the Cr(VI)-immobilisation in the leachate of the CRCM hardened pastes. The results show that the CR has a certain cementitious activity. The incorporation of CR improves the pore size distribution of CRCM. The Cr(VI) concentrations in the leachate of CRCM significantly decrease by incorporation of J2. Among three superplasticizers, J2 achieves lowest Cr(VI) leaching ratio. Based on this study, it is likely to develop CR as a potential new additive used in cement-based materials. 相似文献
60.
Emmanouil MAZONAKIS Catherine STIRLING Karen L. BOOTH Jenny McCLENAHAN Neil HERON Colin C. GEDDES 《Hemodialysis international. International Symposium on Home Hemodialysis》2009,13(1):6-10
Access-related bacteremia is an important cause of morbidity in chronic hemodialysis patients. The incidence of bacteremia is higher in patients dialyzing through a tunneled central venous catheter (TCVC) compared with an arteriovenous fistula (AVF). Our aim was to explore if this is explained by patient comorbidity. Two groups of chronic hemodialysis outpatients were compared: all patients who dialyzed through a TCVC at any time during 2003 and were fit enough to subsequently have a functioning AVF or renal transplant even if it was after 2003 (Group 1; n=93); and all patients who dialyzed through a TCVC in 2003 and were not fit enough to have a functioning AVF or renal transplant (Group 2; n=119). Episodes of bacteremia (n=71) were identified and those not related to access were excluded. Patients in Group 1 were younger than Group 2 (57.5 years vs. 64.8 years; P=0.001). The incidences of bacteremia in Groups 1 and 2 were, respectively, 0.31 and 0.44 episodes per 1000 patient days while dialyzing through an AVF (P=0.77), and 2.21 and 2.27 per 1000 days while dialyzing through a TCVC (P=0.91). The 3-year actual survival from January 1, 2003 to January 1, 2006 was significantly higher in Group 1 than in Group 2 (80.6% vs. 26.1%; P<0.0001) confirming the higher comorbidity of the patients in Group 2. Patients dialyzing through a TCVC (compared with an AVF) have a significantly higher risk of access-related bacteremia, irrespective of comorbidity. 相似文献