全文获取类型
收费全文 | 202篇 |
免费 | 21篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 83篇 |
金属工艺 | 3篇 |
机械仪表 | 3篇 |
建筑科学 | 4篇 |
能源动力 | 9篇 |
轻工业 | 54篇 |
水利工程 | 1篇 |
无线电 | 9篇 |
一般工业技术 | 30篇 |
冶金工业 | 2篇 |
原子能技术 | 2篇 |
自动化技术 | 23篇 |
出版年
2024年 | 4篇 |
2023年 | 5篇 |
2022年 | 7篇 |
2021年 | 11篇 |
2020年 | 11篇 |
2019年 | 9篇 |
2018年 | 14篇 |
2017年 | 14篇 |
2016年 | 7篇 |
2015年 | 9篇 |
2014年 | 7篇 |
2013年 | 24篇 |
2012年 | 17篇 |
2011年 | 23篇 |
2010年 | 11篇 |
2009年 | 7篇 |
2008年 | 5篇 |
2007年 | 8篇 |
2006年 | 12篇 |
2005年 | 5篇 |
2004年 | 6篇 |
2003年 | 1篇 |
2002年 | 2篇 |
2000年 | 1篇 |
1995年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有224条查询结果,搜索用时 31 毫秒
31.
John F. Scamehorn Edwin E. Tucker Hatice Gecol Napaporn Komesvarakul Lorena K. Serventi Kirk H. Raney Stephen F. Capps 《Journal of surfactants and detergents》2007,10(4):287-299
This study presents a method to develop an efficient and economical system for cleaning home laundry on a commercial scale
with both water and chemical (detergent) reuse. The experiments were done using an industrial-type horizontal-axis machine,
two leading consumer heavy-duty liquid laundry detergents, one I&I detergent formulation, and chlorine bleach. The technical
feasibility of reusing laundry water at high levels without significant deterioration in detergency was established in this
study. Warm water (40 °C) was used in the wash cycle, and cold water (29 °C) was used for three rinse cycles. In the integrated
process, waters from wash and rinse steps were treated using tubular microfiltration units with 0.1 μm pore size to remove
particles and emulsion droplets. These recovered waters were recycled to be reused. In addition, water recycled from the wash
step contains surfactants that can be reused. In order to simulate a large-scale industrial laundry operation at steady-state,
the batch process used here was operated six times in sequence; wash and rinse waters were filtered after each cycle and reused
in the next wash cycle. The surfactant recovery is over 40%. Soiled test strips were used to measure the percentage of soil
removal after the wash/filtration sequence for stains and various liquid or particulate soils. The soil removal remained practically
constant under simulated steady-state conditions even with water recoveries of nearly 90%. Softness of towels remained unchanged
when recycled water was used in this process. Chlorine carry-over from white laundry to the wash process was shown to be minimal.
This is important to avoid color fading in mixed loads upon reuse since water is not segregated for colored laundry versus
white laundry. Hardness ions can precipitate fatty acids which reduce flux during filtration and decrease surfactant recovery.
Preliminary analysis of the different formulations used indicates that an all-nonionic formulation may be best suited to this
recycling process.
相似文献
John F. ScamehornEmail: |
32.
The impacts of water and ethanolic extracts of propolis at a dose of 0.4 or 0.8% on vacuum packaged sardine fillets inoculated with Morganella psychrotolerans DSM 17886 during storage at 3 ± 1°C for 15 days were investigated. All fish groups were inoculated with M. psychrotolerans (108 cfu/ml) at a rate of 1%. Sensory, colorimetric, chemical analysis (total volatile basic nitrogen, thiobarbituric acid, peroxide values, and free fatty acids), pH value, and microbiological analysis (viable mesophilic and psychrophilic bacteria, coliform, and lactic acid bacteria count) were carried out. An enhance in L* values was found in the group treated with 0.8% ethanolic extracts of propolis on the seventh day of the storage. Application of propolis extract on fish fillets significantly inhibited bacterial growth during storage and extended shelf life of sardine for 4 and 6 days by the use of water extract and for 8 days by the use of ethanolic extract at doses of 0.4 and 0.8%, respectively. The result of the study revealed that application of propolis extracts, mainly ethanolic propolis extracts on sardine fillets resulted in lower lipid oxidation and bacterial growth, therefore, could be natural food additive for preservation of fish fillets. 相似文献
33.
Hydrogels in the form of rods with varying crosslink densities and three‐dimensional network structures were prepared from Poly(N‐vinyl‐2‐pyrrolidone) (PVP)/water and PVP/water/persulfate systems by irradiation with γ rays at ambient temperature. Average molecular weights between crosslinks, percent swelling, swelling equilibrium values, diffusion/swelling characteristics (i.e., the structure of network constant, the type of diffusion, the initial swelling rate, swelling rate constant), and equilibrium water content were evaluated for both hydrogel systems. Water diffusion to the hydrogel is a non‐Fickian type diffusion and diffusion coefficients vary from 6.56 × 10−7 to 2.51 × 10−7cm2min−1 for PVP and 6.09 × 10−7 to 2.14 × 10−7 cm2min−1 for PVP/persulfate hydrogel systems. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 994–1000, 2000 相似文献
34.
A new approach to the electricity generation expansion problem is proposed to minimize simultaneously multiple objectives, such as cost and air emissions, including CO2 and NOx, over a long term planning horizon. In this problem, system expansion decisions are made to select the type of power generation, such as coal, nuclear, wind, etc., where the new generation asset should be located, and at which time period expansion should take place. We are able to find a Pareto front for the multi-objective generation expansion planning problem that explicitly considers availability of the system components over the planning horizon and operational dispatching decisions. Monte-Carlo simulation is used to generate numerous scenarios based on the component availabilities and anticipated demand for energy. The problem is then formulated as a mixed integer linear program, and optimal solutions are found based on the simulated scenarios with a combined objective function considering the multiple problem objectives. The different objectives are combined using dimensionless weights and a Pareto front can be determined by varying these weights. The mathematical model is demonstrated on an example problem with interesting results indicating how expansion decisions vary depending on whether minimizing cost or minimizing greenhouse gas emissions or pollutants is given higher priority. 相似文献
35.
Hatice Begüm Murathan Gülay Özkan Meryem Sena Akkuş Derya Öncel Özgür Göksel Özkan 《International Journal of Hydrogen Energy》2018,43(23):10728-10733
The aim of this study is to enable high hydrogen production yield from catalytic methanolysis of ammonia borane (AB) in the presence of a cordierite type ceramic monolithic. The monolithic channel surfaces were coated with Al2O3 by wash-coating method and then this layer was impregnated with 1 wt%Pd-2 wt%Co bimetallic catalyst. SEM-EDX and multi-point BET analysis were used in order to characterize the catalyst. The experimental studies were conducted in a continuous flow type reactor, which was used for the first time in this study. The reactions were carried on low temperature (40 °C), and with various AB feed concentrations and flow rates. It was found that the highest hydrogen production yield (88.5%) was obtained from AB flow rate of 3.3 mL/min, and AB feed concentration of 0.1 wt%. It was concluded that Pd-Co/Al2O3 coated monolithic, which is a stable, active and low-cost catalyst, was a very promising catalyst for on-board hydrogen production from the methanolysis of ammonia borane. 相似文献
36.
Hasene Keskin Derya Koçak Yanık Hatice Neval Mucuk Fahrettin Göğüş Sibel Fadıloğlu 《Journal of food science》2016,81(4):C841-C848
2‐Monoacylglycerols (2‐MAG) with a high content of oleic acid at sn‐2 position was synthesized by enzymatic ethanolysis of refined olive pomace oil, which is a byproduct of olive oil processing. Six lipases from different microbial sources were used in the synthesis of 2‐MAG. Immobilized lipase from Candida antarctica gave the highest product yield among the selected lipases. Response surface methodology was applied to optimize reaction conditions; time (4 to 10 h), temperature (45 to 60 °C), enzyme load (10 to 18 wt%), and ethanol:oil molar ratio (30:1 to 60:1). The predicted highest 2‐MAG yield (84.83%) was obtained at 45 °C using 10 (wt%) enzyme load and 50:1 ethanol:oil molar ratio for 5 h reaction time. Experiments to confirm the predicted results at optimum conditions presented a 2‐MAG yield of 82.54%. The purification yield (g 2‐MAG extracted/100 g of total product) was 80.10 and 69.00 for solvent extraction and low‐temperature crystallization, respectively. The purity of the synthesized 2‐MAG was found to be higher than 96%. 相似文献
37.
The synthesis, characterization and voltammetric and spectroelectrochemical properties of newly synthesized lead phthalocyanines bearing tetra-(1,1-(dicarbpenthoxy)-2-(4-biphenyl)-ethyl), tetra-(1,1-(dicarbpenthoxy)-2-(1-naphthyl)-ethyl and tetra-((1,1,2-(tricarbopentoxyethyl)) substituents have been presented in this work for the first time. The characterization of the complexes was made by elemental analysis, 1H NMR, FT-IR, UV-vis and Maldi-TOF. The solution redox properties and spectroelectrochemical investigation of the complexes are studied using various electrochemical techniques in DCM on a platinum electrode. Cyclic voltammetry and differential pulse voltammetry studies show that the complexes give three one-electron ligand-based reductions and two one-electron oxidation couples having diffusion-controlled mass transfer character. Assignments of the redox couples were confirmed by spectroelectrochemical measurements. Spectroelectrochemical studies reveal that all complexes are demetallized during the spectroelectrochemical measurement under the applied potentials at the first reduction and oxidation potentials of the complexes. Different ring substituents of the complexes affect the easy demetallization processes of the complexes. 相似文献
38.
The crystallization of highly isotactic polypropylene confined in self-ordered nanoporous alumina is studied by differential scanning calorimetry. A transformation from a predominantly heterogeneous to predominantly homogeneous nucleation takes place if the pore diameter is smaller than 65 nm. Crystallization is suppressed with decreasing pore size, and the absence of nucleation below 20 nm pores indicates the critical nucleus size. The results reported here might enhance the understanding of nanocomposites containing semicrystalline polymers and reveal design criteria for polymeric nanofibers with tailored mechanical and optical properties. 相似文献
39.
Knoll W Caminade AM Char K Duran H Feng CL Gitsas A Kim DH Lau A Lazzara TD Majoral JP Steinhart M Yameen B Zhong XH 《Small (Weinheim an der Bergstrasse, Germany)》2011,7(10):1384-1391
This contribution summarizes efforts in designing, assembling/synthesizing, and structurally and functionally characterizing nanostructured materials using anodized aluminum oxide (AAO) as a thin-film template. Optical waveguide spectroscopy, using a nanoporous template as the guiding structure, is a particularly powerful analytical tool. The layer-by-layer approach for the fabrication of multilayer assemblies is shown to allow the fabrication of nanotube arrays. In addition to using dendrimers as building blocks, semiconducting nanomaterial (e.g., quantum dot) hybrid architectures with very interesting photophysical properties can be assembled. These can be employed, for example, in biosensing applications. Other strategies for using the AAO layers as templates include the growth of polymeric nanorod arrays from different functional monomers, which, after the dissolution of the template, are still able to guide light. This opens up novel concepts for integrated optics platforms with nanostructured materials. 相似文献
40.
Antioxidant activities of organic grape, pomace, juice, must, wine and their correlation with phenolic content 总被引:2,自引:0,他引:2
Hatice K. Yldrm Yasemin D. Akçay Ulgar Güvenç Ahmet Altndili & Eser Y. Sözmen 《International Journal of Food Science & Technology》2005,40(2):133-142
The highest values of antioxidant activity (AOA), inhibition of low‐density lipoproteins (LDL‐diene, LDL‐MDA) and total phenols were determined in pomace (82.30 and 82.60%), grapes (68.91%) and must [2750 mg L?1 gallic acid equivalents (GAE)], respectively. For all parameters (AOA, iLDL‐diene, iLDL‐MDA, total phenols) the highest values were obtained in Cabernet Sauvignon and Merlot grape varieties. Positive correlations were determined between AOA and iLDL‐diene (r = 0.809); AOA and total phenols (r = 0.528); total phenols and iLDL‐diene (r = 0.451) with significance of P < 0.005. The results of principal component analysis demonstrated that the location of iLDL‐diene and AOA is the same for pomace, must and red wines. The total phenols are found in the same place in red wines, red grapes, pomace and must. The results emphasize the importance of must, pomace and red wine for inhibiting LDL‐oxidation. 相似文献