响应面法优化杏仁蛋白酶解工艺及其抗氧化活性研究

研究了杏仁蛋白的酶解工艺及其抗氧化活性。在单因素试验基础上,通过Box－Behnken中心组合设计优化酶解条件,确定出最佳酶解条件为pH14．72、温度54℃、底物浓度2．8％、酶底比1．2％,在此最优条件下水解度（DH）为27．12％。杏仁蛋白酶解液对DPPH·自由基的清除能力最强,其次为0：一‘自由基,最弱的为·OH自由基,清除率分别为85．92％、73．97％和65．92％．     

抗静电尼龙6/氧化锌晶须复合材料结构及性能研究

用熔融共混法制备出尼龙6(PA6)／氧化锌晶须(ZnOw)复合材料，测试了PA6／ZnOw复合材料的电性能和力学性能，分析了影响机理，并借助傅立叶转换红外光谱(FT-IR)对复合材料的结构进行了表征。结果表明，随着ZnOw用量的增加，复合材料的表面电阻率和体积电阻率明显下降，下降幅度达到4个数量级；拉伸强度和硬度有所降低，而冲击强度出现先升后降的趋势。红外谱图显示，表面经处理过的ZnOw与尼龙基体发生了相互作用。     

浅析采用冷冻除湿方式的温湿度独立控制系统冷源节能的可行性

本文以一工程实例作为研究对象,分析了当温湿度独立控制系统采用冷冻除湿方式时其冷源部分节能的可行性.     

减胶剂对水泥混凝土性能及胶凝材料水化作用的影响

通过掺与不掺减胶剂对胶凝材料体系的影响试验,研究了减胶剂对混凝土工作性、强度及耐久性的影响,探明了减胶剂对胶凝材料早期电阻率及水化产物的影响和对不同原材料所配制胶砂的激发效果.结果 表明:掺入0.5％的减胶剂能显著提高混凝土的28 d强度和混凝土的抗碳化性能、抗渗性能,降低混凝土的电通量.在达到相同的混凝土性能标准下,...     

Grape Pectic Enzyme Treatment Effect on White Musts & Wines Composition

White grapes of three different cultivars (‘Macabeo’, ‘Xarel.lo’ and ‘Parellada’) were treated with the same commercial pectic enzyme preparation on an industrial scale. The effect of this treatment on must and wine composition was studied in three consecutive years (1991, 1992 and 1993). Twenty-one parameters were determined to evaluate effects of the pecticenzyme treatment. Turbidity, galacturonic acid, total and acid polysaccharides, total and nonflavonoid phenols, proteins and meth-anol were affected by the treatments, although this effect usually depended on the cultivar and/or year. Moreover, the effects of treatment were more marked in must than in wines. However, a considerable loss of glucosidic colloids was found on musts and wines from treated grapes. The loss of must polysaccharides depended on their initial content and were mainly due to the pectin losses. Pectin lysis was responsible for increases in galacturonic acid levels which could be used as an index in wines (within a cultivar and year) to indicate pectic enzyme treatment.     

纳米ZnO掺杂对ZrO2(8mol% Y2O3稳定)电性能的影响研究

采用纳米粉料,在单轴成型,无压烧结条件下,用交流阻抗谱技术对掺不同质量百分比ZnO的ZrO2(8mol% Y2O3稳定)烧结体的电性能进行了研究.研究发现ZnO掺杂对ZrO2(8mol% Y2O3稳定)的离子导电性能具有优化作用.     

微乳液法制备SiO_2超疏水性气凝胶粉体

以水玻璃为硅源,煤油为分散介质,采用微乳液法和常压干燥工艺制备出了高比表面积、颗粒均匀的Si O2超疏水性纳米粉体气凝胶,研究了微乳液形成所需表面活性剂的剂量范围、干燥时间及气凝胶粉体密度变化规律,并对制得气凝胶粉体的粒径分布、比表面积、微观形貌及疏水性进行了分析测试。结果表明,微乳液法制备所得气凝胶粉体粒径分布均匀,效率高,并具有良好的超疏水性能。     

制冷空调学科防"非典"科研立项思路的探讨

本文结合防治“非典”工作中的经验和需求,简要地提出了一些制冷空调学科的科研立项思路,提供给有关科研、院校和企业的科技人员参考。     

Two-dimensional correlation optimized warping algorithm for aligning GC x GC-MS data

A two-dimensional (2-D) correlation optimized warping (COW) algorithm has been developed to align 2-D gas chromatography coupled with time-of-flight mass spectrometry (GC x GC/TOF-MS) data. By partitioning raw chromatographic profiles and warping the grid points simultaneously along the first and second dimensions on the basis of applying a one-dimensional COW algorithm to characteristic vectors, nongrid points can be interpolatively warped. This 2-D algorithm was directly applied to total ion counts (TIC) chromatographic profiles of homogeneous chemical samples, i.e., samples including mostly identical compounds. For heterogeneous chemical samples, the 2-D algorithm is first applied to certain selected ion counts chromatographic profiles, and the resultant warping parameters are then used to warp the corresponding TIC chromatographic profiles. The developed 2-D COW algorithm can also be applied to align other 2-D separation images, e.g., LC x LC data, LC x GC data, GC x GC data, LC x CE data, and CE x CE data.     

金属卤化物对4MgH2/TiH2复合材料储氢性能的影响

在氢气保护下,采用机械合金化制备4MgH_2/TiH_2以及4MgH_2/TiH_2+5%A(质量分数,A=AlCl_3,LaCl_3,CeCl_3)复合材料,并通过PCT、XRD、SEM以及DTA等手段对复合材料进行表征。结果显示,4MgH_2/TiH_2以及4MgH_2/TiH_2+5A(A=AlCl_3,LaCl_3,CeCl_3)复合材料吸氢量均在4.5%(质量分数)左右,且在150s时间内吸氢即可达到饱和。添加CeCl_3后,复合材料的脱氢反应焓从添加前的72.7kJ/mol下降到65.1kJ/mol,而添加AlCl_3和LaCl_3后,复合材料的脱氢反应焓则分别增加到80.6kJ/mol和82.5kJ/mol。这表明CeCl_3能有效提高4MgH_2/TiH_2复合材料的热力学性能,而AlCl_3和LaCl_3的添加则会导致4MgH_2/TiH_2复合材料的热力学性能下降。