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41.
Mild-Heat and High-Pressure Inactivation of Carrot Pectin Methylesterase: A Kinetic Study 总被引:2,自引:0,他引:2
B. Ly-Nguyen A.M. Van Loey C. Smout S. ErenÖzcan D. Fachin I. Verlent S. Vu Truong T. Duvetter M.E. Hendrickx 《Journal of food science》2003,68(4):1377-1383
ABSTRACT: Pectin methylesterase (PME) was extracted from carrots and purified by affinity chromatography. The thermal high-pressure inactivation of the PME was investigated in a model system. Under these conditions, the (thermo) stable fraction is not inactivated and the isobaric-isothermal inactivation followed a fractional-conversion model. At lower pressures (< 300 MPa) and higher temperatures (> 50°C), an antagonistic effect of pressure and heat was observed. A 2nd- and 3rd-degree polynomial model (derived from available thermodynamic model) was successfully used to describe the heat pressure dependence of the inactivation rate constants. From the purified carrot PME sample, the thermostable PME fraction was isolated. The thermal inactivation of this fraction followed first-order kinetics. 相似文献
42.
目的:探讨薛荔籽果胶对去势雌性大鼠矿物质吸收的影响。方法:将30只SD成年雌鼠随机分为5组。4组大鼠做双侧卵巢切除手术,一周后分为空白组和薛荔籽果胶高、中、低剂量组;用伪切除同龄大鼠作对照(Sham组)。喂养4周后解剖,测定盲肠内容物pH值、短链脂肪酸、骨钙、骨磷含量及矿物质元素的表观吸收等指标。结果:去势雌性大鼠对钙、镁、磷、锌和铁元素的表观吸收率及骨钙和骨磷含量显著低于正常大鼠(P<0.05)。薛荔籽果胶能显著增加去势雌性大鼠短链脂肪酸含量和盲肠面积(P<0.05),降低盲肠pH值,并且在一定程度上抑制钙、镁、磷、锌和铁元素的表观吸收率。结论:薛荔籽果胶能降低去势雌性大鼠矿物质的表观吸收率。 相似文献
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M. MARANGON M. LUCCHETTA D. DUAN V.J. STOCKDALE A. HART E.J. WATERS 《Australian Journal of Grape and Wine Research》2012,18(2):194-202
Backgrounds and Aims: Bentonite is commonly added to white wines to remove the grape proteins responsible for haze formation. Despite being effective, this technique has drawbacks; thus, new solutions are desirable. The ability of carrageenan and pectin to remove heat‐unstable grape proteins, and the impact that such addition has on the physicochemical and sensorial profile of a wine were assessed. Methods and Results: Carrageenan and pectin were added separately or in combination to a Chardonnay juice prior to fermentation. Both adsorbents removed proteins (up to 75%), thus increasing wine protein stability. Carrageenan was more effective than pectin at increasing wine protein stability. Conclusions: Pectin and carrageenan removed protein and partially stabilized the samples of the wine. Significance of the Study: Pre‐fermentation addition of pectin or carrageenan may provide the wine industry with an alternative protein stabilization procedure. 相似文献
46.
Oni Yuliarti Lara Matia‐Merino Kelvin T. Goh John Mawson Charles Brennan 《International Journal of Food Science & Technology》2012,47(3):633-639
Pectin was extracted from gold kiwifruit by four commercial enzyme preparations (Celluclast 1.5 L, Cytolase CL, Cellulyve TR 400 and NS33048). The chosen enzymes were used either in single or in combination, with and without protease addition. The recovered pectin was characterised and compared for the yield, total nonstarch polysaccharide and neutral sugar composition, protein and ash, pectin, molecular weight distribution and the viscosity. Results indicated that enzyme‐extracted gold kiwifruit pectin was rich in galacturonic acid. Purified pectin yield, and their physicochemical composition and rheological property (viscosity), was significantly affected by the type of enzyme used. The pectin extracted by Celluclast 1.5 L demonstrated to be the most viscous and recorded the highest in molecular weight (Mw) (1.65 × 106 g mol–1) compared with the other extracts. The extract Mw and their distribution were discussed and related to their viscosity behaviour. 相似文献
47.
采用超滤浓缩后乙醇沉淀的方法制备南瓜果胶.通过单因素试验,确定优化超滤条件为:超滤膜截留分子量50 kD,压力0.08 MPa,温度25 ℃,溶液pH 7.0;在该条件下,将南瓜果胶提取液浓缩至原体积1/5,再加入80%乙醇溶液沉淀果胶并洗涤果胶1次,所得的南瓜果胶纯度为80.08%,得率为8.50%,凝胶度为120.25,酯化度为31.82,干燥失重为4.26%,总灰分为3.22%,半乳糖醛酸为88.10%,pH为2.7,铅及砷含量分别为1.2 mg/kg和0.036 mg/kg,各项指标均达到国家质量标准QB 2484--2000. 相似文献
48.
从柠檬皮中分离提取果胶的研究 总被引:3,自引:0,他引:3
本文探讨了酸水解法从柠檬皮中提取果胶的工艺,通过分析提取果胶的影响因素,并由正交实验法确定提取柠檬果胶的最佳工艺条件. 相似文献
49.
酰胺化果胶的特性、应用及研究现状 总被引:1,自引:0,他引:1
本文将酰胺化果胶与普通低酯果胶以及高酯果胶进行了多方面的比较,重点介绍酰胺化果胶的特性。结合国内外对酰胺化果胶生产和研究的状况,及其在食品工业和医疗方面的应用现状,对酰胺化果胶生产的开发前景进行了分析。 相似文献
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