全文获取类型
收费全文 | 1149篇 |
免费 | 122篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 12篇 |
综合类 | 1篇 |
化学工业 | 287篇 |
金属工艺 | 11篇 |
机械仪表 | 24篇 |
建筑科学 | 51篇 |
矿业工程 | 1篇 |
能源动力 | 43篇 |
轻工业 | 260篇 |
水利工程 | 9篇 |
石油天然气 | 7篇 |
无线电 | 88篇 |
一般工业技术 | 164篇 |
冶金工业 | 131篇 |
原子能技术 | 10篇 |
自动化技术 | 173篇 |
出版年
2024年 | 1篇 |
2023年 | 14篇 |
2022年 | 27篇 |
2021年 | 47篇 |
2020年 | 25篇 |
2019年 | 36篇 |
2018年 | 50篇 |
2017年 | 48篇 |
2016年 | 52篇 |
2015年 | 39篇 |
2014年 | 64篇 |
2013年 | 84篇 |
2012年 | 72篇 |
2011年 | 97篇 |
2010年 | 70篇 |
2009年 | 61篇 |
2008年 | 64篇 |
2007年 | 50篇 |
2006年 | 36篇 |
2005年 | 38篇 |
2004年 | 36篇 |
2003年 | 21篇 |
2002年 | 24篇 |
2001年 | 13篇 |
2000年 | 18篇 |
1999年 | 10篇 |
1998年 | 45篇 |
1997年 | 31篇 |
1996年 | 13篇 |
1995年 | 19篇 |
1994年 | 13篇 |
1993年 | 10篇 |
1992年 | 4篇 |
1991年 | 3篇 |
1990年 | 1篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1979年 | 2篇 |
1977年 | 2篇 |
1976年 | 7篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1971年 | 2篇 |
排序方式: 共有1272条查询结果,搜索用时 15 毫秒
61.
Alex Augusto Gonçalves Candido Santiago Guidobono Gindri Junior 《Journal of food engineering》2009,90(2):285-290
Ice-glazing is applied to protect the frozen shrimp from undesirable quality changes during frozen storage. Effects of initial frozen shrimp temperature on glaze uptake; glazing time on glaze uptake; and different glaze percentage on physical and chemical changes of frozen shrimp during storage were investigated. Shrimps were frozen in a spiral freezing machine (?35 °C/15 min); transferred to the air blast freezer until the core temperature reached ?18 °C, ?25 °C and ?30 °C; submitted to glazing process; and stored at ?18 °C for 180 days. The glazing percentage, pH and N-TVB levels were monitored every 45 days. This study has demonstrated the effectiveness of the glazing process as a protecting agent for frozen shrimp. A reasonable range of water uptake could be between 15% and 20% to guarantee the final quality. Therefore, it is important to prevent temperature fluctuations during transportation and storage to maintain the quality of the frozen shrimps. 相似文献
62.
San Miguel Montes Liza E.; Allen Daniel N.; Puente Antonio E.; Neblina Cris 《Canadian Metallurgical Quarterly》2010,22(2):465
The Wechsler Intelligence Scale for Children (WISC) is the most commonly used intelligence test for children. Five years ago, a Spanish version of the WISC–IV was published (WISC-IV Spanish; Wechsler, 2005), but a limited amount of published information is available regarding its utility when assessing clinical samples. The current study included 107 children who were Spanish speaking and of Puerto Rican descent that had been administered the WISC–IV Spanish. They were subdivided into a clinical sample of 35 children with diagnoses of various forms of brain dysfunction (primarily learning disability, attention-deficit/hyperactivity disorder, and epilepsy) and a comparison group made up of 72 normal children who were part of the WISC–IV Spanish version standardization sample. Comparisons between these groups and the standardization sample were performed for the WISC–IV Spanish index and subtest scores. Results indicated that the clinical sample performed worse than the comparison samples on the Working Memory and Processing Speed Indexes, although findings varied to some extent depending on whether the clinical group was compared with the normal comparison group or the standardization sample. These findings provide support for the criterion validity of the WISC–IV Spanish when it is used to assess a clinically referred sample with brain dysfunction. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
63.
A. Santiago L. Martin J.J. Iruin M.J. Fernández-Berridi A. González L. Irusta 《Progress in Organic Coatings》2014
Polyurethane–siloxane thermoset copolymers were obtained from Isophorone diisocyanate trimer, Polycaprolactone triol and 10% of hydroxy terminated Polydimethyl siloxane. The copolymers showed a phase separated structure that depended on the conversion of the reaction and casting temperature. The different samples obtained had water contact angles higher than 90°. Moreover the contact angle values presented a maximum at intermediate reaction conversion. Although FTIR measurements showed that siloxane concentration at the surface increased with reaction time, the maximum contact angle value was related to the higher roughness calculated from AFM images. DMTA results confirmed that the phase separation was higher at intermediate conversions. 相似文献
64.
Fernanda Lopes Aldina Santiago Luís Simões da Silva Tim Heistermann Milan Veljkovic José Guilherme da Silva 《钢结构国际杂志》2013,13(3):459-472
The reverse channel connection appears to have the best combination of desirable features under fire loading: moderate construction cost, ability to develop catenary action and extremely high ductility through deformation of the web channel (Ding and Wang, 2007). This paper presents the results of an experimental investigation of a reverse channel component conducted at the University of Coimbra as part of the European RFCS COMPFIRE Project, the main focus of which is to characterise the behaviour of steel joints that connect steel beams to concrete-filled tubular columns under natural fire loading. A series of tensile and compressive tests at ambient and elevated temperatures was conducted. The purposes of the experimental tests were to characterise the strength, stiffness and ductility of this joint component and to establish a relationship between force, displacement and temperature. 相似文献
65.
Santiago A. Pighin Bruno Coco Horacio Troiani Facundo J. Castro Guillermina Urretavizcaya 《International Journal of Hydrogen Energy》2018,43(15):7430-7439
This paper presents a comparative study of H2 absorption and desorption in MgH2 milled with NbF5 or NbH0.9. The addition of NbF5 or NbH0.9 greatly improves hydriding and dehydriding kinetics. After 80 h of milling the mixture of MgH2 with 7 mol.% of NbF5 absorbs 60% of its hydrogen capacity at 250 °C in 30 s, whereas the mixture with 7 mol.% of NbH0.9 takes up 48%, and MgH2 milled without additive only absorbs 2%. At the same temperature, hydrogen desorption in the mixture with NbF5 finishes in 10 min, whereas the mixture with NbH0.9 only desorbs 50% of its hydrogen content, and MgH2 without additive practically does not releases hydrogen. The kinetic improvement is attributed to NbH0.9, a phase observed in the hydrogen cycled MgH2 + NbF5 and MgH2 + NbH0.9 materials, either hydrided or dehydrided. The better kinetic performance of the NbF5-added material is attributed to the combination of smaller size and enhanced distribution of NbH0.9 with more favorable microstructural characteristics. The addition of NbF5 also produces the formation of Mg(HxF1-x)2 solid solutions that limit the practically achievable hydrogen storage capacity of the material. These undesired effects are discussed. 相似文献
66.
Optimisation of rancidity stability in long‐chain PUFA concentrates obtained from a rainbow trout (Oncorhynchus mykiss) by‐product
下载免费PDF全文
![点击此处可从《International Journal of Food Science & Technology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Mª Macarena Berríos Alicia Rodriguez Matías Rivera Mª Elsa Pando Mª Antonieta Valenzuela Santiago P. Aubourg 《International Journal of Food Science & Technology》2017,52(6):1463-1472
This research was focused on the production of polyunsaturated fatty acid concentrates from a farmed rainbow trout (Oncorhynchus mykiss) by‐product (i.e. belly muscle). The effect of different process variables (urea/fatty acids (FA) contents ratio, crystallisation time and temperature and stirring speed of the urea/FA mixture) on the lipid oxidation development during the urea complexation process was investigated. For this purpose, an experimental design (26 runs) following the response‐surface methodology was developed. As a result, peroxide value and TOTOX index showed to be dependent on the crystallisation time and temperature and the urea/FA ratio, while no influence of the crystallisation stirring speed was detected on both indices; additionally, polyene index was affected by the urea/FA ratio and its interaction with the crystallisation time. An optimised desirability score near 1.0 was attained provided values of 2.8 °C, 3.05 h and 3.57 were applied for crystallisation temperature, crystallisation time and urea/FA ratio, respectively. 相似文献
67.
We have applied particle tracking techniques to obtain spatially resolved velocity measurements in electrokinetic flow devices. Both micrometer-resolution particle image velocimetry (micro-PMV) and particle tracking velocimetry (PTV) techniques have been used to quantify and study flow phenomena in electrokinetic systems applicable to microfluidic bioanalytical devices. To make the flow measurements quantitative, we performed a series of seed particle calibration experiments. First, we measure the electroosmotic wall mobility of a borosilicate rectangular capillary (40 by 400 microm) using current monitoring. In addition to this wall mobility characterization, we apply PTV to determine the electrophoretic mobilities of more than 1,000 fluorescent microsphere particles in aqueous buffer solutions. Particles from this calibrated particle/ buffer mixture are then introduced into two electrokinetic flow systems for particle tracking flow experiments. In these experiments, we use micro-PIV, together with an electric field prediction, to obtain electroosmotic flow bulk fluid velocity measurements. The first example flow system is a microchannel intersection where we demonstrate a detailed documentation of the similitude between the electrical fields and the velocity fields in an electrokinetic system with uniform zeta potential, zeta. In the second system, we apply micro-PIV to a microchannel system with nonuniform zeta. The latter experiment provides a simultaneous measurement of two distinct wall mobilities within the microchannel. 相似文献
68.
69.
E Arzoz A Santiago F Esnal R Palomero 《Canadian Metallurgical Quarterly》1996,54(7):847-50; discussion 851-2
PURPOSE: This article describes a technique of salivary gland endoscopy using a 2.1-mm endoscope with a 1-mm working channel. The technique allows intracorporeal lithotripsy under endoscopic control. Two types of energy to produce calculi fragmentation were analyzed. PATIENTS AND METHODS: Of 39 patients who presented with obstructive sialoadenitis, endoscopic treatment was possible in 27. Eighteen had a diagnosis of sialolithiasis. Intracorporeal lithotripsy was done under endoscopic control in these patients. Laser energy was used to produce fragmentation in 3 cases and pneumobalistic energy in 9. In 6 cases, the calculi were extracted with forceps. RESULTS: Fifteen patients are free of stones and symptoms after a 6-month follow-up. Fragmentation and extraction of the calculi were not possible in 3 patients. Two of these patients required open surgery. The other patient is under observation. CONCLUSIONS: The use of endoscopes with a working channel allows irrigation to improve visibility during exploration. Both extraction of calculi and lithiasis fragmentation using different energies can be carried out through the channel. In this series, pneumoballistic energy (Lithoclast) has been shown to produce calculus fragmentation with more efficiency than lasertripsy (Dornier Impact). When dilation and placement of a cannula (Abocath 16 G) was done 2 days preoperatively, endoscopy was performed more easily. Postoperative drainage has proven effective in avoiding complications. 相似文献
70.
CR González FR Noriega S Huerta A Santiago M Vega J Paniagua V Ortiz-Navarrete A Isibasi MM Levine 《Canadian Metallurgical Quarterly》1998,16(9-10):1043-1052
Attenuated Salmonella typhi are attractive for use as live vector vaccines to express protozoal antigens and deliver them to the human immune system. The gene encoding the mature form of Leishmania mexicana mexicana gp63 under control of tac promoter was integrated into the delta aroC locus of the chromosome of attenuated delta aroC, delta aroD S. typhi strain CVD 908. After oral immunization of BALB/c mice with two 1 x 10(9) colony forming unit doses given 21 days apart, CVD 908 omega (delta aroC::Ptac-gp63) elicited a broad T cell-mediated immune response against L. m. mexicana gp63 as demonstrated by: (1) lymphoproliferative response to fixed whole L. m. mexicana promastigotes; (2) activation of IL-2 (but not IL-4)-producing lymphocytes; (3) appearance of cytotoxic T cells against mouse mastocytoma cells expressing gp63. This T-cell mediated immune response was associated with significant protection in F1 (BALB/cXC57Bl/6) mice challenged in their footpads with a wild type strain of L. m. mexicana. 相似文献