阿魏酸酯酶功能特性及应用概述

阿魏酸酯酶(ferulic acid esterase,FAE)广泛存在于自然界,属于羧酸酯水解酶的一个亚类。经过一系列反应,其能将天然半纤维素和果胶中的酚酸、阿魏酸(ferulic acid,FA)及对香豆酸等释放出来,是一种具有应用潜力的酶。因此,各行业通过相关科学技术来利用FAE,以获得如人畜食品、纸浆和纸张、燃料乙醇和药物制剂等产品。该文对阿魏酸酯酶的酶学特性、生产研究、结构解析及生物技术中的潜在应用等方面进行综述,旨在工业需求的推动下,加快阿魏酸酯酶的科学研究发现,进行知识转移,对该类物质实现高效利用,并致力于植物生物质转化和生产高附加值分子的生物合成。     

稻花香馫香型白酒风味特征分析

为了研究一种三香结合工艺的馫香型白酒,对其和其他5种香型(浓香型、清香型、酱香型、兼香型、馥郁香型)进行定性定量分析。将得到的数据进行相关性分析、主成分分析(PCA)和聚类分析。结果表明,馫香型白酒在化合物种类上接近酱香型白酒;在某些风味化合物上与浓香型白酒相似度较高,都与己酸乙酯、己酸己酯、己酸异丁酯、庚酸乙酯、己酸乙酯、己酸丁酯、戊酸乙酯、己酸戊酯和乙酸己酯等化合物存在较高的相关性;与小曲清香型白酒中的β-苯乙醇、乙酸异戊酯、异戊醇的绝对含量接近,且明显高于其他香型,尤其是乙酸异戊酯含量突出,两种白酒含量分别达到了10.35 mg/L和13.07 mg/L。最终确定了馫香型白酒融合了浓、清、酱三种香型的部分特点,形成了具有复合香气的独特风格。     

高压静电场用于烟叶陈化处理的研究

利用高压静电场直接处理经打叶复烤后未陈化的烟叶，对处理后的烟叶进行致香成分、理化指标等的分析结果表明，不同强度的高压静电场具有提高和抑制烟叶中酶活力的作用，并对烟叶的香气质量及吸味有明显的改善作用。在实验的基础上，根据物理学和生物学的理论，初步探讨 了利用高压静电场加速烟叶陈化的微观机理。     

增产液化石油气和柴油的催化剂CMOD-200的工业应用

介绍一种增产液化石油气和柴油的新型裂化催化剂CMOD 2 0 0在武汉分公司Ⅱ套重油催化裂化装置的应用情况。该剂通过对载体和分子筛的改性及合理调配 ,具有良好的产品分布 ,与CC 16催化剂相比 ,在总的目的产品收率提高 1.2 7个百分点的情况下 ,液化石油气收率提高 4.5 6个百分点 (其中丙烯体积分数提高 1.36个百分点 ) ,并能保持较高的柴油收率和柴气比 ;且焦炭选择性好 ,抗重金属污染能力强 ;经济效益显著 ,适合于加工重油并欲多产液化石油气和柴油的催化裂化装置。     

航空压气机叶片理论型面数学建模研究

提出了NURBS节点因子法理论,研究了基于节点因子法的航空压气机叶片理论型面数学建模方法,通过实例分析,证明了该方法比传统方法更加精确可行。     

The physical reason for the apparently low deposition rate during high-power pulsed magnetron sputtering

In high-power pulsed magnetron sputtering, a large power density is applied giving rise to a high degree of ionization. From an application point of view, the major drawback of this technology is the considerably lower deposition rate as compared to DC magnetron sputtering. Using transport-of-ions-in-matter simulations, we show that the apparently low deposition rate can be understood based on the non-linear energy dependence of the sputtering yields. Our calculations are consistent with deposition-rate measurements on Cu films as well as with published deposition-rate data for Ti [Konstantinidis S, Dauchot JP, Ganciu M, Ricard A, Hecq M. J Appl Phys 2006;99:013307].     

覆岩组合运动特征及关键层位置研究

把煤矿覆岩的组合运动视为以坚硬岩层为依托的复合关键层的运动，运用弹性薄板理论和复合材料力学的层合板理论讨论了复合关键层的应力，从而为计算复合关键层的整体强度提供了途径；并且采用结构塑性极限分析方法解析得出了关键层失稳时的极限荷载，依据此极限荷载可以近似判断出覆岩中关键层的位置。     

基于专利地图的纺织品抗菌技术分析

运用专利情报分析方法分析纺织品抗菌技术的发展趋势,以期为纺织品抗菌技术的研究提供专利信息支撑.以IncoPat数据库中纺织品抗菌技术的专利文献为数据源,采用专利地图分析方法,从时间、地域、专利权人和技术等维度对该领域进行态势分析.研究发现:纺织品抗菌技术专利申请和公开数量总体呈上升趋势;我国是纺织品抗菌技术专利分布最多...     

基于可达性与服务度的城市避震减灾绿地规划布局研究——以遵化市为例

传统的避震减灾绿地指标包括总面积、人均面积等,这些指标只能应避震减灾绿地的量,而不能反应其质,更不能反应其在灾害发生及灾后救援中与灾民需求的关系,出现了避震减灾绿地方面的"不公平"现象。自"防灾避险实施率"提出以后,绿地的可达性分析与评价逐渐被重视。针对这些问题,本文从避震减灾绿地的可达性与服务度概念入手,提出基于可达性与服务度的避震减灾绿地布局规划的方法。并以遵化市为例,以可达性作为避震减灾绿地定位的依据,服务度作为避震减灾绿地规划定量的依据,给出了遵化市规划建成区的避震减灾绿规划布局方案。通过此方法以期对未来避震减灾绿地体系规划提供可借鉴理论及方法。     

Development and experimental study of beryllium window for ITER radial X-ray camera

Radial X-ray camera (RXC) is a diagnostic device planned to be installed in the ITER Equatorial Port #12. Beryllium window will be installed between the inner and outer camera of RXC, which severs as the transmission photocathode substrate and also the vacuum isolation component. In this paper the design and manufacture process of two types of beryllium windows were introduced. Although 50 μm thickness of beryllium foil is the best choice, the 80 μm one with X-ray threshold of 1.34 keV was selected for safety consideration. Using the intermediate layer (low purity of beryllium) between the beryllium foil and the stainless steel base flange is an effective strategy to limit the welding thermal deformation and thermal stress of the thin foil caused by bonding between different materials. By using ANSYS software, the feasibility of the aperture design was analyzed and validated. Metal sealing ring was applied in the mechanical clamped beryllium window for its good stability under high temperature and neutron radiation. Although both of the hollow metal sealing ring with 0.03 mm silver coating and the pure silver sealing ring can satisfy the sealing requirement, the later one was chosen to produce the final product. Two hours 240 °C high temperature baking test, two hours 3.3 Hz vibration test and fatigue test were performed on the two types of beryllium windows. Based on the tests results, the two types of beryllium windows could stand the high temperature baking during the wall conditioning phase of ITER tokamak and the vibration during transportation without causing large leakage. Both of the two types of beryllium windows could bear impact load (0.1 MPa pressure difference) for many times without failure.