淀粉的化学改性研究

简要介绍了淀粉的结构及其化学改性的原理和方法;综述了国内外淀粉化学改性的研究工作;详细介绍了非离子淀粉、阴离子淀粉、阳离子淀粉以及两性淀粉的合成方法.淀粉通过化学改性改善了水溶性、大大降低了水不溶物的含量、增加了黏度的稳定性、从而扩大了淀粉的应用领域,使得改性淀粉广泛应用于食品、纺织、造纸、油田和医药等众多领域.     

助磨剂对普通硅酸盐水泥性能的影响及作用机理

研究了助磨剂对普通硅酸盐水泥的流动性、颗粒分散度及其砂浆性能的影响并对作用机理进行了探讨。结果表明 ,助磨剂加强了水泥的流动性、提高了水泥细度、增加了细粉量、对勃氏比表面积无明显改变、增加了水泥3d、2 8d强度 ;助磨剂的作用机理是减小了粉碎阻力、防止团聚和糊磨、提高流动性而加强了料和球的作用频率和效率 ,从而提高了粉磨效率。     

我国聚氯乙烯行业现状与发展趋势

介绍了近年我国PVC树脂生产能力、产量、消费量、进出口，列出了主要企业产能，并与世界和日本、德国、美国的一些情况进行了比较。总结了我国PVC行业的特点，并提出了几点看法。     

丁二烯装置溶剂精制系统污染源控制及其工艺改进

介绍了丁二烯装置溶剂精制工艺流程,分析了溶剂精制系统中产生的焦油、丁二烯二聚物及废水三大污染源及其危害。制定并实施了工艺改进措施,经过改进排焦工艺、丁二烯二聚物脱除工艺、溶剂精制系统脱水工艺,实现了排焦作业密闭操作、减少了作业过程带来的现场异味污染、消除了焦油池内人工开挖焦油带来的高风险作业、减少了装置废渣生成量、COD排放总量得到了控制,达到了净化溶剂品质、规避环保风险、节约资源、环境友好的生产目标,提高了装置运行质量,同时丁二烯二聚物污染源转化为副产品销售,增加了装置的经济效益。     

"十三五"期间中国PVC产业回顾和展望(续完)

从生产、进出口、市场、应用等方面分析了国内PVC行业现状.介绍了国家有关PVC行业的政策.阐述了"十三五"期间国内PVC产业受国际环保、能源、低碳公约及国家环保、能源、产业政策等规范,产业升级改造逐步走向正轨.回顾了"十三五"期间PVC行业发生的重大生产、安全、环保、技术事件,并展望了"十四五"期间PVC产能增长的预期.列举了"十三五"期间PVC行业的主要实用生产技术,并分析了国内PVC行业存在的主要问题.     

影响醚化反应因素的探讨

主要介绍了醚化反应的机理,明确了反应温度、反应压力、醇烯比、空速等参数对异丁烯与甲醇反应生成甲基叔丁基醚(MTBE)这一个可逆放热反应的影响。从而优化了操作条件,该善了MTBE产品及醚后碳四产品质量、降低了生产成本、提高了经济效益。     

航煤加氢运行分析及改进措施

对航煤加氢生产中遇到的收率低、质量不稳定、低压排放量大、能耗高等问题进行了分析,并通过完善工艺流程、更换催化剂、提高反应压力等措施稳定了产品质量、减少了低压排放、降低了装置能耗。     

邻氯苯甲醛合成中氯化工序的技术改进

介绍了在邻氯苯甲醛合成中 ,采用的双釜串联氯化技术 ,改善了反应条件、提高了氯气利用率、降低了消耗、解决了环境污染问题。     

1998～1999年国外塑料工业进展

收集了 1998年 7月到 1999年 6月国外塑料工业相关期刊资料 ,介绍了 1998～ 1999年国外塑料工业进展。提供了日本、美国、加拿大、德国、法国、比利时、意大利、英国、西班牙、匈牙利、马来西亚等国通用热塑性树脂、工程塑料、通用热固性树脂、特种工程塑料的产量和增长率 ,提供了美国、日本、德国、韩国、法国、比利时、荷兰、意大利和其他国家以及亚洲、欧洲、北美洲、中南美洲、非洲和大洋洲等地域的树脂产量及构成比 ,此外还提供了中国台湾的树脂产量。按通用热塑性塑料、通用热固性塑料、通用工程塑料和特种工程塑料分类 ,对其合成工艺、树脂品种延伸、新的应用开发等工业技术作了详尽的介绍     

冷却塔淋水填料研究进展

本文介绍了冷却塔淋水填料的应用及其作用,总结了不同类型和结构淋水填料的特点,分析了不同材质淋水填料的动态发展。对比了塑料、金属、木材、竹材、水泥和陶瓷等材质的淋水填料在耐腐蚀性、冷却性能、使用寿命、加工成型和结构等方面的特点和不同。此外,本文还总结归纳了国内外对淋水填料的研究进展及展望了淋水填料的发展趋势,为淋水填料的研究和改进提供了重要参考价值。     

气固两相流动的LDV测试技术研究与实施

介绍了气固两相流动的ＬＤＶ测试方法和有关技术。并对方管内网栅后气固两相流动进行了测量，固相颗粒平均粒径Ｄｐ＝９００μｍ，颗粒质量分数α＝０．２０５％、０．３０％。试验给出了管内不同断面上气流及颗粒速度分布情况，通过与纯气流条件下的试验结果比较，分析了不同质量分数的颗粒对气流速度结构的影响，并对同样条件下的颗粒与气流速度分布进行了比较。     

Gas management in flow field design using 3D direct methanol fuel cell model under high stoichiometric feed

This study presents a 3D CFD model for modeling gas evolution in anode channels of a DMFC under high stoichiometric feed. The improved two-phase model includes a new submodel for mass source and interphase transfer in anode channels. Case studies of typical flow field designs such as parallel and serpentine flow fields illustrate applications of the CFD model. Simulation results reveal that gas management of typical flow fields is ineffective under certain operating conditions. The CFD-based simulations are used to visualize and to analyze the gas evolution and flow patterns in anode channels. The developed CFD model is useful in flow field design for improving gas management in DMFC.     

筛板上两相流的检测——热膜流速仪的应用

介绍了用热膜流速仪对精馏筛板上气液两相流的检测工作,讨论了适合于筛板上气液两相流测定的热膜流速仪检测信号的识别和标定方法,给出了筛板上两相流流场和气含率的测定结果。     

气体穿过筛板上固液两相流层时的阻力特性

对气体穿过筛板上固液两相流层的流动特性进行了研究,关联出了气体穿过筛板上固液两相流层时泡沫工况下的筛板压降公式,为工程应用提供实验基础。     

陶瓷过滤器脉冲反吹系统引射性能的实验测定(Ⅰ)──喷吹气体流量的测定和分析

采用热线风速仪测量陶瓷过滤器脉冲反吹喷嘴出口的流场得到了喷吹气体流量，分析了喷吹压力和脉冲宽度对喷吹气体流量的影响。实验结果表明，喷吹气体流量随喷吹压力的增加而显著增加，而脉冲宽度的增加对喷吹气体流量的影响较小，只是增加了气体喷吹持续时间。同时证明由热线风速仪测得的一次脉冲反吹的压缩气体耗量与将储气罐排气过程简化为绝热排气过程所计算出的结果非常吻合，推荐采用绝热排气过程估算压缩气体耗量。     

油气水三相节流阀的流通能力研究

油、气、水三相混合物的流动规律较单相或气液两相流动更为复杂,然而目前主要采取单相流方法来计算三相节流阀的流通能力。为了更精确地对油气水三相节流阀流通能力进行计算,以油气水三相介质流过节流阀时的能量守恒方程为基础,考虑节流时的临界流动和亚临界流动两种状态,建立了油气水三相节流阀流通能力计算模型;采用二分法对模型进行了求解,并编制了相应的计算软件。以此为基础,结合番禺35-1气田的实际油气生产数据,分析对不同开度,不同节流前压力和不同节流后压力下流经阀门的总质量流量,验证了方法的准确性。     

Identification of Flow Regimes in a Concurrent Gas Liquid Upflow through Packed Beds

The flow regimes bubble flow, pulse flow, and spray flow were identified by visual observation in a packed column. Three gas‐liquid systems (air/water, air/56 % glycerol, and air/monoethanolamine) and four column packings (Raschig rings, Intalox saddles, and two sizes of spheres) were investigated to cover wide ranges of physical properties of gas liquid systems and characteristics of column packings affecting the flow regime transition. Criteria for the flow regime transition were developed in terms of system and operating variables.     

Validation of Gas Flow Measurement During Ozone Generator Performance Testing

Key measurements for ozone generator efficiency testing include generator power, ozone concentration, and gas flow rate. Accurate gas flow measurement must address numerous issues such as: meter precision, meter calibration, gas density changes due to variations in molecular composition, and gas compression and expansion changes due to variation in temperature and pressure. Preferably, the gas flowmeter for performance testing is one that can be field-verified for accuracy. Orifice-plate, flow-tube and venturi differential pressure flowmeters have these characteristics and have been frequently used to obtain gas flow readings of record during ozone generator performance tests. This paper discusses the importance of field-verification, provides reference equations and example calculations, and presents issues and considerations for quality assurance.     

Flow direction when fan shaped geometry is applied in gas-assisted injection molding: 2. Development of flow model and its predictions

In part 2 of the paper simplified unsteady-mass (and momentum-) balance equations of melt polymer resin in the cavities of GAIM were proposed, as a time-dependent rule of thumb, to constitute a novel flow model in GAIM under the configuration of two fan-shaped geometries connected with a gas nozzle. Upon performing a simulation on them with commercial software (MOLDFLOW), we compared the time evolution of simulated gas penetration lengths with the those of unsteady trajectory on the gas flow in GAIM by the suggested novel flow model in the fan-shaped cavities in order to check the precision of model-predicted gas penetration lengths as well as the consistency of its predicted direction. The results by the suggested novel flow model were satisfactory to fit the trajectory simulated with commercial software (MOLDFLOW).     

Prediction of Two‐Phase Frictional Pressure Drop for the Concurrent Gas and Newtonian Liquids Upflow through Packed Beds

Correlations were developed to predict frictional pressure drop for concurrent gas‐liquid upflow through packed beds covering all the three identified flow regimes, i.e. bubble flow, pulse flow and spray flow. The observation that the gas and liquid flow rates have different influences on the two‐phase pressure drop in different flow regimes, was taken into consideration in the development of these correlations. More than 600 experimental pressure drop data from the present study and literature covering a wide range in gas‐liquid systems, flow rates and column packing were used.