共查询到20条相似文献,搜索用时 140 毫秒
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萜类化合物具有可观的经济价值,但是目前的生产过程复杂、产量低。酿酒酵母甲羟戊酸途径为萜类化合物的合成提供直接前体,因此酿酒酵母细胞具有合成异源萜类化合物的天然优势。对酿酒酵母甲羟戊酸途径的清晰认识是对其进行有效利用的基础,本文从代谢途径、关键酶的特点和全局调控机制3个方面对该途径进行了介绍。从代谢途径的构建和优化、模块与底盘细胞的适配、模块构建及组装方式的角度概述了酿酒酵母细胞异源合成单萜、倍半烯萜、二萜、三萜类化合物的研究进展。指出实现酿酒酵母高效合成萜类化合物所需要解决的基础问题是对酿酒酵母甲羟戊酸途径进行更为全面了解和对萜类化合物的天然代谢途径进行明确解析;另外,合成生物学的进一步发展也将为此提供应用基础。 相似文献
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1胶原纤维巴西Novaprom胶原纤维是以精选的牛皮内剖层(真皮)组织提取的,它不同于明胶或明胶的衍生物。它的生产是在严格控制的时间和温度范围内进行的,从而确保其主要成分──胶原蛋白的活性不变,并以天然纤维的形式存在。它在肉制品中的结构呈纤维状而不是一般的胶冻,因而这种结构是非常稳定的,是不可逆的。它是很好的功能性动物纤维蛋白,在肉制品及鱼糜制品等相关的食品中得到广泛的应用。2胶原纤维的性能及相关指标(1)蛋白质含量:胶原纤维中的动物蛋白质(M×6.25)高达98%,含有人体必需的氨基酸。(2)吸水、持水性:胶原纤维结构良好,呈矩… 相似文献
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玻璃纤维池窑拉丝生产线配合料的制备中,原料是形成优质玻璃液的基础,因此可以说配合料的稳定性、均匀性和准确性对玻璃纤维的质量起着决定的作用.生产实践证明:组分和粒度均匀的配合料,不但能强化玻璃液的熔化和澄清过程,而且还能减少或消除影响玻璃质量的各种弊病.所以认真拟定玻璃纤维原料的成分和选择玻璃纤维的种类和化学性质:严格控制进厂原料化学成分、粒度和水份;做好原料的分堆、存放、加工、称量、混合、输送是优质配合料制备不可缺少的手段,这也是做好玻璃纤维池窑配合料的基本任务. 相似文献
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1前言 随着池窑生产的发展,原有的浸润剂在快速浸润性和快速浸透性方面无法得到满足.意大利DSM公司聚酯乳液是公认的喷射纱浸润剂最好的成膜剂.本项目的目的是研制出能工业化生产的与DSM公司产品质量相当的聚酯乳液,替代进口,节约外汇,满足我国池窑发展需要,争创良好的经济社会效益. 相似文献
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利用撞击流和平推流的优点,开发出一种新型的撞击流吸收器。对该吸收器进行了停留时间分布实验研究。利用清水吸收空气中CO2,对该吸收器的吸收性能进行了研究,实验结果表明,“全混流 平推流”流动特点的撞击流吸收器的吸收率明显高于鼓泡式吸收器,具有一定的推广与应有价值。 相似文献
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An absorber plate is an essential component of some solar energy devices. As a primary energy conversion component, useful energy loss is not desired. The interactions and interrelationship between the parameters for use, insulation thermophysical properties, and ambient parameters are pertinent in the design of solar air heaters. A 2D finite element analysis was used to quantify the influence of edge convection heat loss on a simple absorber plate model. Results showed that the performance of the air heater can be significantly affected by edge heat loss from the absorber. The average temperature of the absorber, computed from the nodal temperature profile of the absorber, rose with superior edge insulation for low values of the heat transfer coefficient of the working fluid. However, when the ambient temperature was high, the average temperature of the absorber increased with poor edge insulation, although this condition is irregular due to fluctuations in the ambient condition. For low values of the heat transfer coefficient of the working fluid and low ambient temperature, the nondimensional edge loss flux was negligible for the absorber with superior edge insulation, and for high values of the heat transfer coefficient of the working fluid and low ambient temperature, the nondimensional edge loss flux was high for a poorly insulated absorber. 相似文献
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针对氨汽提法尿素生产过程中中压吸收塔液位难以控制的问题,介绍了中压吸收塔工作原理;分析了吸收塔各点温度与液位、组分之间的关系以及液位控制影响因素;从稳定中压吸收塔的负荷着手,论述了液位调节方法和控制措施;提出了根据温度的变化确定液位高低的液位判定方法。 相似文献
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介绍美丰100kt/a合成氨装置搬迁改造项目整体更换CO2吸收塔的实例,对新CO2吸收塔的主要参数进行了确认计算。生产实践表明,CO2吸收塔各主要设备参数的选择、内件及填料的选型是符合实际要求的。 相似文献
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The 123 oxide conductor incorporated with short brass fibers was used as the absorber matrix in the double layer design of the microwave absorber paint. The absorber layer was covered with another layer of transforming paint that contain a ferrite - resin mixture for efficient microwave absorption. Enhanced microwave absorption of about 10-20 dB was observed with the 123 oxide conductor in the absorber matrix at ambient temperature. The absorption was ascribed to the possibility of a rotational mode arising out of the rotation of the group of octahedra surrounding the Barium site in the perovskite lattice. 相似文献
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Power generation from fossil fuel-fired power plants is the largest single source of CO2 emissions. Post combustion capture via chemical absorption is viewed as the most mature CO2 capture technique. This paper presents a study of the post combustion CO2 capture with monoethanolamine (MEA) based on dynamic modelling of the process. The aims of the project were to compare two different approaches (the equilibrium-based approach versus the rate-based approach) in modelling the absorber dynamically and to understand the dynamic behaviour of the absorber during part load operation and with disturbances from the stripper. A powerful modelling and simulation tool gPROMS was chosen to implement the proposed work. The study indicates that the rate-based model gives a better prediction of the chemical absorption process than the equilibrium-based model. The dynamic simulation of the absorber indicates normal absorber column operation could be maintained during part load operation by maintaining the ratio of the flow rates of the lean solvent and flue gas to the absorber. Disturbances in the CO2 loading of the lean solvent to the absorber significantly affect absorber performance. Further work will extend the dynamic modelling to the stripper for whole plant analysis. 相似文献