全文获取类型
收费全文 | 498篇 |
免费 | 42篇 |
国内免费 | 10篇 |
专业分类
综合类 | 11篇 |
化学工业 | 72篇 |
金属工艺 | 12篇 |
机械仪表 | 7篇 |
建筑科学 | 5篇 |
能源动力 | 3篇 |
轻工业 | 409篇 |
石油天然气 | 1篇 |
一般工业技术 | 11篇 |
冶金工业 | 13篇 |
原子能技术 | 5篇 |
自动化技术 | 1篇 |
出版年
2024年 | 4篇 |
2023年 | 3篇 |
2022年 | 16篇 |
2021年 | 20篇 |
2020年 | 25篇 |
2019年 | 20篇 |
2018年 | 21篇 |
2017年 | 19篇 |
2016年 | 25篇 |
2015年 | 29篇 |
2014年 | 31篇 |
2013年 | 33篇 |
2012年 | 46篇 |
2011年 | 34篇 |
2010年 | 22篇 |
2009年 | 22篇 |
2008年 | 15篇 |
2007年 | 19篇 |
2006年 | 21篇 |
2005年 | 24篇 |
2004年 | 18篇 |
2003年 | 15篇 |
2002年 | 11篇 |
2001年 | 13篇 |
2000年 | 10篇 |
1999年 | 4篇 |
1998年 | 8篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1986年 | 1篇 |
1984年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
排序方式: 共有550条查询结果,搜索用时 31 毫秒
101.
本研究以木薯嫩梢(Cassava tender shoots,CTS)为对象,利用感官评价法、营养质量指数法(Index of nutritional quality,INQ)和主成分分析法(Principal component analysis,PCA),探究了传统泡菜、芽菜、酱菜、橄榄菜、烫泡菜和盐渍菜等制作工艺对CTS腌制菜基本化学和元素组成、抗营养因子和亚硝酸盐含量的差异,以筛选出CTS适合的腌制菜工艺。结果表明:腌制的不同工艺条件显著影响CTS腌制菜品质。其中,CTS芽菜蛋白质含量最高,为35.29 g/100 g;CTS盐渍菜大部分化学组成含量较低;CTS腌制菜所含的矿物质皆不同程度降低,其中CTS芽菜工艺减少最多(Mn、Zn、K和Mg含量分别减少71.91%、70.72%、59.20%和60.84%)。各CTS腌制菜氰化物含量在32.62~82.41 mg/kg;单宁含量较低,含量在1.07~2.33 g单宁酸/100 g;亚硝酸盐含量远低于国家标准,含量在0.37~1.02 mg/kg。感官评价表明,CTS泡菜具有较好鲜味、质感和品相等,大众认可度高;INQ评价结果显示CTS盐渍菜、CTS泡菜和CTS烫泡菜的营养价值较高;PCA发现前3个主成分的累计贡献率为83.949%,PCA综合得分结果显示,CTS泡菜、CTS橄榄菜和CTS烫泡菜综合分值较高。最后,综合感官评价、INQ评价和PCA分析评价结果,得出CTS腌制的最佳工艺为CTS泡菜制作工艺,其次是CTS烫泡菜和CTS盐渍菜制作工艺。
相似文献102.
103.
Dhananjay?Dendukuri Levente?L.?DiosadyEmail author 《Journal of the American Oil Chemists' Society》2003,80(3):287-294
New microfiltration (MF)-based aqueous processes for the extraction of oil-free protein isolates from full-fat, dehulled mustard
flour have been developed. The processes used hydrophilic MF membranes to separate oil and protein. The most successful processing
sequence consisted of alkaline extraction of oil and protein from the flour at pH 11, centrifugation to remove undissolved
solids, and an initial microfiltration step to separate oil and dissolved protein. This was followed by proteolytic enzyme
treatment of the retentate and a second-stage MF step to recover further protein. The proteolytic enzyme treatment was designed
to break aggregated proteins into smaller fractions to permit their passage through the MF membrane. The permeates from the
two microfiltration steps were ultrafiltered to concentrate the protein and remove antinutritional compounds and highly fragmented
peptides. With this process, 60% of the protein originally in the flour was separated from the oil phase. Approximately 40%
of the protein present in the flour was recovered in the form of two oil-free protein isolates—a soluble protein isolate containing
91% protein and a precipitated protein isolate containing 100% protein. The process proves the potential of MF as an effective
method of extracting oil-free protein isolates from oilseeds without the use of organic solvents.
Based on a presentation at the 16th Annual Meeting of the Canadian Section of AOCS held in Winnipeg, Manitoba, Canada, September
29–October 1, 2001. 相似文献
104.
An evaluation of supercritical fluid extraction as an analytical tool to determine fat in canola,flax, solin,and mustard 总被引:1,自引:0,他引:1
Véronique?J.?BarthetEmail author James?K.?Daun 《Journal of the American Oil Chemists' Society》2002,79(3):245-251
Supercritical fluid extraction (SFE) with carbon dioxide was used to extract oil from soft oilseeds (flax, solin, canola,
and mustard). Oil content determinations from the SFE method AOCS Am 3–96, with and without ethanol as a modifier, were compared
to results obtained with an exhaustive extraction using petroleum ether (FOSFA as in AOCS Am 2–93). Without the modifier,
oil recoveries using SFE were 10 to 15% lower than oil contents by the FOSFA method for the flax and canola samples. For mustard,
the oil recoveries by SFE were about 20 to 30% lower than oil contents by the FOSFA method. In the presence of the modifier,
oil recoveries for flax and canola were about 3% lower than the FOSFA recoveries. Varying the time, temperature, and amount
of modifier (ethanol) showed that recoveries increased with time, pressure, temperature, and amount of modifier independently
of the oilseeds tested. Kinetics of the SFE extraction showed that the oil recoveries increased with the extraction time and
reached a plateau after 60 min. Multiple extractions (2×30 min), however, gave better recoveries than a single extraction
for the same amount of time (60 min). The best results were obtained using multiple extractions without modifier or a combination
of multiple extractions first without and then with 15% modifier. Under these last two conditions, oil recoveries were close
to 100% for flax, solin, and canola, but mustard oil recoveries were still 10% lower than recoveries using the FOSFA method.
Mustard samples gave the lowest oil recovery from SFE when compared to FOSFA method recoveries whatever conditions were tested,
suggesting a matrix effect on the oil recovery. The acyl lipid content of the various extracts was studied using the sum of
all FA expressed as TAG as a measure of acyl lipid extraction. The acyl lipid contents of the extracts were close to 100%
when no modifier was used during the SFE. In the presence of modifier, the acyl lipid contents of the extracts were 10 to
15% lower than the results obtained without modifier. The amount of acyl lipid in the extract decreased as the quantity of
modifier increased. This suggests that increasing the ethanol modifier increased the amount of polar compounds extracted without
significantly increasing the total amount of lipids. The FA profiles were constant throughout the various extraction procedures. 相似文献
105.
Renwick JA Zhang W Haribal M Attygalle AB Lopez KD 《Journal of chemical ecology》2001,27(8):1575-1583
The host plants of the native American butterfly, Pieris napi oleracea, include most wild mustards. However, garlic mustard, Alliaria petiolata, a highly invasive weed that was introduced from Europe, appears to be protected from this insect. Although adults will oviposit on the plant, most larvae of P. n. oleracea do not survive on garlic mustard. We used feeding bioassays with different larval stages of the insect to monitor the isolation and identification of two bioactive constituents that could explain the natural resistance of this plant. A novel cyanopropenyl glycoside (1), alliarinoside, strongly inhibits feeding by first instars, while a flavone glycoside (2), isovitexin-6-D--glucopyranoside, deters later instars from feeding. Interestingly, the first instars are insensitive to 2, and the late instars are little affected by 1. Furthermore, differential effects of dietary experience on insect responses suggest that 1 acts through a mechanism of post-ingestive inhibition, whereas 2 involves gustatory deterrence of feeding. 相似文献
106.
Comparison of combustion and Kjeldahl methods for determination of nitrogen in oilseeds 总被引:1,自引:0,他引:1
James K. Daun Douglas R. DeClercq 《Journal of the American Oil Chemists' Society》1994,71(10):1069-1072
The recent development of combustion-type nitrogen analyzers capable of handling relatively large samples with semi automatic
operation offers a potential replacement for the Kjeldahl method for direct determination of nitrogen. Nitrogen analyses for
canola seed, flaxseed, sunflower seed, mustard seed and soybeans on a LECO (St. Joseph, MI) FP-428 Nitrogen Analyzer were
evaluated against results from the Grain Research Laboratory's (GRL) Kjeldahl system. The nitrogen analyzer gave significantly
higher values than the Kjeldahl method, resulting in a correction of low values in the GRL Kjeldahl, caused by the inability
to use mercury as catalyst. The standard error for results from the analyzer was comparable to that for the Kjeldahl method.
The nitrogen analyzer also was faster than the Kjeldahl method and had less environmental impact. The combustion method has
replaced the Kjeldahl method for routine nitrogen determinations in oilseed surveys conducted by the GRL.
Presented at the 84th AOCS Annual Meeting & Expo, April 27, 1993, Anaheim, California. 相似文献
107.
During commercial solvent extraction of oil from an oil-seed, it is necessary to determine oil content in the miscella, drawn
intermittently from the extractor, to obtain an overall extraction rate. We measured optical density, specific gravity, refractive
index and viscosity of miscella of different known oil concentrations. These four characteristics were measured by calculating
deviations from the actual values. The deviations were maximum for optical density, intermediate for specific gravity and
viscosity, and small for refractive index, suggesting the latter to be an appropriate rapid method of determining miscella
oil content. 相似文献
108.
The relationship between host plant glucosinolate profile and feeding and growth of the Bertha armyworm,Mamestra configurata Walker was investigated using eight cultivated rape and mustard varieties. Mean larval weights of neonates reared on intact rosette-stage plants were significantly different on the different species in the orderBrassica juncea <Sinapis alba <B. napus <B. campestris. WhileB. juncea was least preferred,S. alba was significantly more attractive to neonate larvae in choice tests. Relative consumption and growth rates of fourth-instar larvae were also reduced onB. juncea foliage. Other differences were dependent on the plant growth stage. Neonate preference was not correlated to total glucosinolate levels, but rather to the concentrations of isothiocyanate-releasing glucosinolates. However, the relationship between consumption and glucosinolate levels was inconsistent. Relative growth rate was negatively correlated to total glucosinolate content for stage 3 and 4 foliage—mainly due to the concentration of isothiocyanatereleasing glucosinolates. The relative importance of isothiocyanate-releasing glucosinolates was verified by rearing neonates on meridic diets containing equimolar concentrations of sinigrin, its metabolite, allyl isothiocyanate, and indole-3-carbinol, metabolite of 3-indolylmethyl glucosinolate. Sinigrin and allyl isothiocyanate in the diet produced virtually identical negative weight vs. concentration regression lines. No such dose-response effect was observed with indole-3-carbinol. The data suggest that foliar isothiocyanate-releasing glucosinolates may provide some degree of plant protection from polyphagous insects. 相似文献
109.
Factors influencing the efficiency of the photocatalytic oxygenation of two mustard simulants (2-chloroethyl methyl sulfide and 2-chloroethyl ethyl sulfide) on irradiated suspensions of TiO2 in aerated acetonitrile are described. Product analysis indicates that sulfoxide formation is the dominant process in acetonitrile and that TiO2 is a much better photocatalyst than SnO2, ZrO2, or ZnO. 相似文献
110.