Modified Atmosphere Maintains Quality of Fresh-cut Cantaloupe (Cucumis melo L.)

ABSTRACT: Fresh-cut cantaloupe cubes were placed in film-sealed containers in which the internal gas mixture was attained naturally (nMAP), was flushed with 4 kPa O₂ plus 10 kPa CO₂ (fMAP), or was maintained near atmospheric levels by perforating the film (PFP). While both nMAP and fMAP maintained the salable quality of melon cubes for 9 d at 5°C, fMAP maintained quality better than nMAP. The benefit of fMAP was indicated by better color retention, and by reduced translucency, respiration rate, and microbial population compared with nMAP. Shelf life of cubes in PFP was only 5 to 7 d at 5°C, and its rapid decline was due to tissue translucency and/or off-odor development.     

柴油机动力总成异常振动试验分析

对某SUV车柴油机动力总成产生的异常振动进行了试验分析研究.在介绍柴油机动力总成振动基本分析方法的基础上,开展了整车道路及转鼓试验,进行了整车及台架条件下动力总成的振动模态试验.通过对动力总成的振动特性分析,找到了引起动力总成操纵手柄异常振动的原因:飞轮壳刚度偏低,动力总成系统固有频率落入柴油机工作转速的激励频率区间,...     

Stagnation Points in Flows about Solid Bodies

A possible first step in determining the flow about a steadily advancing ship is to consider the ship plus its mirror image in the undisturbed free surface. If the ship has a bulbous bow, the question may be asked whether a stagnation point can be expected not only at the intersection of the stem and the undisturbed surface, but also at some point on the stem near the bulb. In analogous two-dimensional situations the latter could not happen. That it can happen in three dimensions is shown here by the example of two dipoles situated perpendicularly to an oncoming flow. Both two- and three dimensional versions are considered. The conditions under which these stagnation points can occur in three dimensions are determined and the reason why this does not happen in two dimensions is explained.     

2009年一季度工程机械行业发展状况

对2009年一季度工程机械行业整体运行状况以及进出口进行了综合介绍.并重点分析了五大细分产品的销售情况,最后介绍了龙头企业的发展状况.     

提高柴油十六烷值RICH工艺技术的工业应用

石油化工科学研究院针对催化裂化柴油提高十六烷值的需要，开发了RICH技术，采用兼具好的加氢精制性能和开裂化性能的新型催化剂及相应的工艺技术，于2001年初在洛阳石化总厂800kt/a催化裂化柴油加氢装置上成功地实现了首次工业应用，工业应用结果与中试结果基本吻合，催化裂化柴油原料除十六烷值可提高10个单位左右外，密度及硫、氮等杂质含量也得到大幅度降低，柴油收率在97％左右。     

Authentication of the 31 species of toxic and potent Chinese Materia Medica by light microscopy,part 3: Two species of T/PCMM from flowers and their common adulterants

Toxic and potent Chinese Materia Medica (T/PCMM) has become a hot and sensitive topic as more and more people around the world are interested in the safety of herbal medicines. T/PCMM is irreplaceable in treating some diseases; but it can easily cause serious problems if confused with other herbal medicines. Accurate identification is essential to ensure their safe use, but up to now, the literature on the authentication of T/PCMM is scant. Thus, we are undertaking a study of 31 T/PCMM originating from plants, animals, minerals, and secreta. Our previous study established microscopic observation as a simple, fast, accurate, and convenient method for identifying and authenticating animal and seed T/PCMM. This study focused on the authentication of flower T/PCMM as a part of the whole study. The flower T/PCMM studies were derived from two species, Datura metel L. (Flos Daturae) and Rhododendron molle G. Don (Flos Rhododendri Mollis). Other species easily confused with these two were also examined and characterized. Using the microscope camera, normal light and polarized light microscopy, we determined the macroscopic and microscopic features of the flowers; in addition, the oil immersion lens was used to study the pollen grain characteristics. The results demonstrated that flower T/PCMM can be identified and authenticated using a light microscope equipped with an oil immersion lens. This same equipment can be easily used to characterize other herbal flower medicines. Microsc. Res. Tech., 2009. © 2009 Wiley-Liss, Inc.     

非对称复式断面明渠中污染物输移扩散的大涡模拟

运用大涡模拟计算了两个非对称复式断面明渠内的水流运动和污染物扩散，其中由亚格子尺度涡运动引起的亚格子应力与物质扩散通过Smagorinsky-Lilly亚网格模型模拟。预测结果与Shiono等使用激光多普勒流速计(LDA)和激光诱导荧光技术(LIF)测量的实验数据进行了对比，计算得到的流场结构和污染物浓度分布均较好地吻合于测量结果。成功地再现了在其中一个复式断面明渠中观测到的横向浓度分布呈现显著双峰值的现象，根据计算的流场得出复式断面明渠中流向交替变化的强烈横向流动是产生这种现象的主要原因。     

多层岩盐矿爆破切割压裂工艺

多层岩盐矿（含芒硝矿）的开采，普遍采用分层建井回采工艺，即每回采一层盐，均需分别建一组回采井，回采费用高。该文介绍一种新的回采工艺－爆破切割全程裸露盐层，其特点是建一组回采井，采用爆破切割方法，将所有盐层裸露并予以回脂，大大降低回采费用，提高回采速度。