全文获取类型
收费全文 | 1122篇 |
免费 | 106篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 8篇 |
化学工业 | 402篇 |
金属工艺 | 26篇 |
机械仪表 | 34篇 |
建筑科学 | 31篇 |
能源动力 | 73篇 |
轻工业 | 185篇 |
水利工程 | 25篇 |
石油天然气 | 12篇 |
无线电 | 83篇 |
一般工业技术 | 161篇 |
冶金工业 | 20篇 |
原子能技术 | 5篇 |
自动化技术 | 167篇 |
出版年
2024年 | 3篇 |
2023年 | 24篇 |
2022年 | 48篇 |
2021年 | 112篇 |
2020年 | 105篇 |
2019年 | 87篇 |
2018年 | 115篇 |
2017年 | 110篇 |
2016年 | 89篇 |
2015年 | 45篇 |
2014年 | 94篇 |
2013年 | 112篇 |
2012年 | 79篇 |
2011年 | 62篇 |
2010年 | 47篇 |
2009年 | 30篇 |
2008年 | 23篇 |
2007年 | 13篇 |
2006年 | 7篇 |
2005年 | 8篇 |
2004年 | 4篇 |
2003年 | 1篇 |
2002年 | 2篇 |
2001年 | 1篇 |
1995年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1988年 | 1篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1982年 | 1篇 |
排序方式: 共有1232条查询结果,搜索用时 15 毫秒
91.
Hakim Ghalfi Noreddine Benkerroum Marc Ongena Maryam Bensaid Philippe Thonart 《Food research international (Ottawa, Ont.)》2010,43(1):33-39
Three novel bioactive peptides (BAP1–3) from Lactobacillus curvatus CWBI-B28 were isolated and purified using de Man, Rogosa and Sharp (MRS) broth by a three-step protein purification protocol including ammonium sulfate precipitation, hydrophobic C18 Sep-Pak column and reverse-phase high performance liquid chromatography (RP-HPLC). This procedure allowed the recovery of chromatographically pure antimicrobial peptides with the yields of 19%, 10% and 15% of BAP1, BAP2 and BAP3, respectively. The respective apparent molecular masses as determined by tricine-SDS-polyacrilamide gel electrophoresis were 6365, 3426 and 3496. N-terminal amino acid sequencing of the BAPs and comparison of their sequences with those of international data bases indicated that BAP1 is more likely to be a casein-derived bioactive protein produced upon hydrolysis of the tryptone present in MRS broth by Lb. curvatus CWBI-B28 during active growth. However, the identity of BAP2 and BAP3 could not be determined with certainty; yet, they would be novel bacteriocins not fitting in any of the known classes of bacteriocins. Therefore, this strain would have the ability to produce intrinsic antimicrobial substances and also release bioprotective peptides from milk-proteins upon cultivation in milk or casein-containing food products due to its proteolytic activity. Thus, Lb. curratus CWBI-B28 possesses a good potential to be used in food preservation and safety. 相似文献
92.
Mohammad Taraz Mohammad‐Reza Khatami Maryam Hajiseyedjavadi Amir Farrokhian Mohsen Amini Hossein Khalili Alireza Abdollahi Simin Dashti‐Khavidaki 《Hemodialysis international. International Symposium on Home Hemodialysis》2013,17(3):382-390
Elevated proinflammatory cytokines have been attributed to poor sleep quality in patients receiving hemodialysis. This is the first investigation about the relationship between sleep quality and circulating levels of antiinflammatory markers in these patients. A total of 72 patients who were receiving maintenance hemodialysis were enrolled in this cross‐sectional study. The Pittsburgh Sleep Quality Index (PSQI) was used to measure sleep quality. Patients were divided into two groups: good sleepers (PSQI score < 5) and poor sleepers (PSQI score ≥ 5). Assessments were made for serum biochemical parameters (albumin, parathyroid hormone), inflammatory (interleukin [IL]‐6, tumor necrosis factor‐alpha [TNF‐α], and high‐sensitivity c‐reactive protein [hs‐CRP] ) and antiinflammatory (IL‐10) markers. Fifty‐four patients (75%) were classified as poor sleepers. Poor sleepers showed significantly lower levels of serum IL‐10 and higher serum triglyceride and parathyroid hormone concentrations. These patients were more likely to have more comorbidities. The global PSQI score was significantly correlated with serum IL‐10 (p = 0.03) and triglyceride levels (p = 0.01). Multivariate logistic regression analysis showed a direct correlation between PSQI and having comorbidities (p = 0.011, odds ratio [OR] = 3.918; confidence interval 95% [CI] = 2.742–19.031), between PSQI and serum triglyceride (p = 0.027, OR = 1.027 [95% CI = 1.007–1.048] ), and an inverse correlation between PSQI and serum IL‐10 level (p = 0.021, OR = 0.424 [95% CI = 0.195–0.922]). Reduced circulating levels of the antiinflammatory cytokine IL‐10 were significantly associated with poor sleep quality in hemodialysis patients. Factors including serum IL‐10 and triglyceride concentrations and having comorbidities may predict patients prone to poor sleep quality. 相似文献
93.
Masoud Ghanei-Motlagh Mohammad Ali Taher Vahid Saheb Maryam Fayazi Iran Sheikhshoaie 《Electrochimica acta》2011,56(15):5376
A novel ion-selective poly(vinyl chloride) (PVC) membrane sensor for Cu2+ ions based on N,N′-(2,2-dimethylpropane-1,3-diyl)-bis(dihydroxyacetophenone) (NDHA) as a new ionophore was prepared and studied. The best performance was observed for the membrane composition, including 30:65:1:4 (wt%) = PVC:DBP:KTpClPB:NDHA. The electrode showed a good Nernstian slope of 30.0 ± 0.5 mV/decade in a wide linear range activity of 3.0 × 10−7 to 1.0 × 10−2 mol dm−3 Cu(NO3)2 with limit of detection 2.5 × 10−7. Sensor exhibited a fast response time (t95% < 10 s) and could be used for about 4 months in the pH range of 3.0–7.4. The proposed potentiometric sensor was found to work satisfactorily in partially non-aqueous media up to 30 (vol%) content of methanol, ethanol and acetone. Applications of this electrode for the determination of copper in real samples, and as an indicator electrode for potentiometric titration of Cu2+ ion using EDTA, were reported. In order to predict the extraction ability of NDHA for different metallic ions, the complexes [M(NDHA)] and [M(H2O)6] (where M = Cu2+, Co2+, Hg2+, Pb2+, Ag+, Mg2+, Ca2+, Mn2+, Zn2+, Cd2+, K+ and Al3+) were investigated using ab initio theoretical calculations. The metal binding capability was evaluated using the binding energy. Results of our study could be useful for prediction of the extraction power of this Schiff base and could play a guiding role in planning experiments. 相似文献
94.
95.
Julien Fatisson Sania Mansouri Daniel Yacoub Yahye Merhi Maryam Tabrizian 《Journal of the Royal Society Interface》2011,8(60):988-997
Platelet adhesion and activation rates are frequently used to assess the thrombogenicity of biomaterials, which is a crucial step for the development of blood-contacting devices. Until now, electron and confocal microscopes have been used to investigate platelet activation but they failed to characterize this activation quantitatively and in real time. In order to overcome these limitations, quartz crystal microbalance with dissipation (QCM-D) was employed and an explicit time scale introduced in the dissipation versus frequency plots (Df–t) provided us with quantitative data at different stages of platelet activation. The QCM-D chips were coated with thrombogenic and non-thrombogenic model proteins to develop the methodology, further extended to investigate polymer thrombogenicity. Electron microscopy and immunofluorescence labelling were used to validate the QCM-D data and confirmed the relevance of Df–t plots to discriminate the activation rate among protein-modified surfaces. The responses showed the predominant role of surface hydrophobicity and roughness towards platelet activation and thereby towards polymer thrombogenicity. Modelling experimental data obtained with QCM-D with a Matlab code allowed us to define the rate at which mass change occurs (A/B), to obtain an A/B value for each polymer and correlate this value with polymer thrombogenicity. 相似文献
96.
97.
Maryam Aliei Azam Sazvar Bozorgmehr Ashrafi 《The International Journal of Advanced Manufacturing Technology》2012,63(1-4):215-223
Evolutions rooted in technology in market arena, business, and demands reforms in supply chain and consequently more demands for created value by end user are among factors causing reforms on management of supply chain. Integrity of supply chain activities and utilized technologies is an essential factor to survive competitions in the market. Organizations, therefore, need to adopt policies to coordinate themselves with new arena in market and electronic commerce. Despite bad news from Iran tail industries about unplanned production, the industry is still in growing path. In addition to easy access to mineral resources and low-energy costs, which have made it quite reasonable to invest in the industry, state tariff policies for imported tail products have made new investment chances in the industry. As a result, Iran recently won a position among five leading counties in world tail industry. However, knowing about high profit margin in tail industries, many countries have stepped into the market and through producing high-quality products have intensified competition in the market. This study tries to identify and assess IT indexes in Iran tail industry’s supply chain and hopes to take a step forward to gain better market position in international market by prioritizing the indexes using fuzzy logic. 相似文献
98.
Maryam BahramParvar Seyed M.A. Razavi Mostafa Mazaheri Tehrani 《International Journal of Food Science & Technology》2012,47(12):2655-2661
Mixture design was used to determine the optimum ratio as well as concentration of basil seed gum (BSG), guar gum (GG) and carboxymethyl cellulose (CMC) in the formulation of ice cream stabilisers. Predicted equations and contour plots of physicochemical responses were also generated. Generally, increasing the ratio of BSG in gums mixture increased the apparent viscosity of ice cream mixes and decreased the melting rate. Increasing the proportion of GG at concentration of 0.35% enhanced overrun of samples. High ratios of BSG at concentration of 0.35% and CMC at concentration of 0.15% increased the fat destabilisation in ice creams. Combination of 84.31% BSG and 15.69% CMC at concentration of 0.35% proposed as optimum formulation which verified in practice. Introducing BSG as a novel source of stabiliser could be promising as alternative and improve the quality and diversity of ice cream and related products. 相似文献
99.
100.
S. Mojtaba Taghizadeh Hamid Mirzadeh Mehdi Barikani Maryam Yousefi 《International Journal of Adhesion and Adhesives》2009,29(3):302-308
In this study, miscibility and tack of blends of poly (vinylpyrrolidone) (PVP)/acrylic pressure-sensitive adhesive (PSA) were evaluated. For this purpose, appropriate amounts of PVP (2–30% w/w) were added to an acrylic PSA to obtain visually homogeneous solution. The resulting solution was evenly applied on a polyethylene terephthalate (PET) film with final specific thicknesses of 10, 40, and 70 μm by using a film applicator and miscibility as well as tack values were evaluated. With the addition of 2% (w/w) PVP the tack value decreased and increased in 5% (w/w) PVP and then continuously decreased up to 30%(w/w). It was found that the tack value was related to miscibility as well as to viscosity and the free functional group such as hydroxyl group of the blend. By the morphological analysis performed through scanning electron microscopy (SEM) and also by the study of thermal analysis using the differential scanning calorimetry (DSC) behavior of blends, it was found that the two distinct phases constituted after adding 5% (w/w) of PVP. This resulted in the acrylic PSA forming the continuous phase, and by increasing the concentration of PVP a dispersed phase was developed. The dispersed phase has a higher viscosity than the continuous phase and therefore cannot wet the adherent and hence result in lowering the tack values. 相似文献