共查询到20条相似文献,搜索用时 171 毫秒
1.
聚丁烯(PB)管道的生产和应用 总被引:6,自引:0,他引:6
本文从介绍聚丁烯(PB)原料性能入手,介绍了聚丁烯(PB)管材的特点和生产,应用技术,以及国内聚丁烯(PB)管材生产和聚丁烯(PB)管材生产设备发展的现状,特别介绍了聚丁烯(PB)管材生产设备可以不配备熔体泵。 相似文献
2.
氯化聚乙烯的发展现状及分析 总被引:2,自引:0,他引:2
刘轶 《现代塑料加工应用》2010,22(3)
论述了国内外氯化聚乙烯(CPE)的发展情况,分析了国内用于CPE生产的高密度聚乙烯(HDPE)原料的生产情况,并对HDPE原料的生产提出了建议。 相似文献
3.
《精细化工原料及中间体》2016,(9)
正本发明提供了加氢醋酸生产乙醛的方法,由此使有效地使用不经洗涤的原料,低成本地生产醋酸成为可能。本发明还提供了以甲醇为原料工业规模生产醋酸和乙醛的方法。根据本发明,方法是以甲醇和合成气为原料生产醋酸和乙醛的,方法以下述步骤为特征(1)生产合成气,(2)从合成气除去二氧化碳杂质,将合成气分离成一氧化碳和氢气,(3)以步骤(2)生产的一氧化碳和甲醇生产醋酸,(4)以步骤(2)生产的氢气和步骤(3)生产的醋酸为原料生产乙醛。 相似文献
4.
5.
引入免疫机理对化工园区安全生产预警预测模型进行了研究。基于生物免疫系统与化工园区安全生产管理体系的相似性,借鉴抗原(Ag)与抗体(Ab)相互作用的机制,构建了化工园区安全生产预警指标体系,应用改进的层次分析法得到各指标权重,结果表明,影响较大的Ag指标有AgⅤ(企业生产危险性状况)、AgⅥ(企业间相互影响状况)、AgⅣ(整体规划水平);影响较大的Ab指标有AbⅠ(安全生产监管机构与人员配置)、AbⅣ(安全生产监管力度)、AbⅡ(安全生产规章制度)。结合Mamdani模糊模型、Elman网络算法分别建立了化工园区安全生产现状预警和未来预测模型,选取典型化工园区进行应用,获得其事故免疫力值。应用表明,该模型可对化工园区安全生产现状进行预警,对未来状态进行预测,预警预测结果与实际情况相符,并可根据模型预测结果采取相应的措施预防安全生产事故,为化工园区安全生产管理提供一种新的预警技术和方法,提升重大事故的预防预警能力。 相似文献
6.
郭智臣 《化学推进剂与高分子材料》2008,6(2)
<正>BASF(巴斯夫)公司位于上海漕泾的四氢呋喃(THF)厂即将恢复生产。该厂现在装备了1套新的生产装置,除了使用丁烷外,也可用丁二醇(BDO)作原料生产四氢呋喃。THF主要用作生产聚四氢呋喃(PolyTHF)的原料。通过此举,BASF公司将大幅度提高为相邻的2005年第一季度投产的聚四氢呋喃厂提供本地工业原料的可靠性。另外,该公司还计划于2010年初实现同时生产用于市场销售的马来酸酐(MA)。 相似文献
7.
最近,已出现了可作为连续混炼机组材料的粉状和粒状橡胶材料。这类材料当中值得一提的是陶氏化学公司生产的三元乙丙橡胶(EPDM)和德固赛公司(赢创工业公司)生产的橡胶-填料复合材料(RFC)。采用特殊的RFC生产技术使橡 相似文献
8.
介绍了一种以液态食品磷酸与碳酸钙及处理后的石灰水(纯净氢氧化钙)反应生产无水磷酸氢钙(牙膏级、药品级、食品级)新工艺。同时提供了按此工艺生产无水磷酸氢钙的生产结果。 相似文献
9.
全国工业产品生产许可证办公室最近批准了胶带产品的生产许可证换(发)证工作。本次胶带产品实施生产许可证包括两大类产品。1.阻燃输送带。其申证单元分别为:(1)全塑(PVC)整芯织物阻燃输送带;(2)橡塑(PVG)整芯织物阻燃输送带;(3)钢丝绳芯(ST)阻燃输送带;(4)一般用途阻燃(YBY)输送带。2.汽车V带。其申证单元分别为:(1)包边式汽车V带;(2)切边式汽车V带。每一大类产品中的申证单元需单独申请生产许可证。汽车V带产品是首次实施生产许可证。为了保证换(发)证工作的顺利进行,日前全国工业产品生产许可证办公室橡胶制品审查部分别在青岛和杭… 相似文献
10.
对热法磷酸(TPA)、溶剂法净化磷酸(PPA)和联产新技术生产三聚磷酸钠的能耗进行了估算.溶剂法生产工业级w(H3PO4)85%磷酸的能耗与用新装置产的黄磷(P4)生产TPA的能耗上限值接近,为其97.5%;用PPA生产STPP的能耗是生产P4新装置TPA能耗上限值的91.9%,是联产新技术HPA的178.6%(1.7... 相似文献
11.
考察了添加剂CaB2O3对转炉铜渣中夹杂铜沉降效果的影响,并结合铜渣的粘度测试及红外光谱表征,研究其影响机理,采用FactSage软件计算了添加剂对铜渣液相线温度的影响。结果表明,随添加剂含量增大,铜渣中夹杂铜的沉降效果逐渐增强,添加剂含量由0增至6wt%时,底部渣含铜量由4.10wt%增至6.85wt%,这是由于添加剂可有效降低铜渣粘度。随添加剂含量增大,渣粘度降低,但降低效果随温度增大而趋于平缓。随添加剂含量增大,铜渣的硅酸盐结构趋于简化,添加剂通过破坏铜渣复杂的硅酸盐结构降低铜渣粘度。铜渣的液相线温度随添加剂含量增大而减小,添加剂通过减少渣中固体颗粒的方式降低铜渣粘度。 相似文献
12.
P. E. Tilden W. D. Bedard D. L. Wood K. Q. Lindahl P. A. Rauch 《Journal of chemical ecology》1979,5(4):519-531
Western pine beetles were caught on unbaited sticky traps placed near a source ofexo-brevicomin, frontalin, and myrcene. Size of trap, distance and direction from the source of attractant, and height from the ground were varied. Significant differences in trap catch were observed in relation to each of the variables. Traps close to the source of attractant caught more beetles than traps farther from the source. Traps downwind of the source of attractant caught more beetles than did upwind traps. More males than females were trapped close to the source of attractant.Based in part on a thesis submitted by the senior author to the University of California, Berkeley, California, in partial fulfillment of the requirements for the degree Master of Science in entomology, December 1976. These studies were supported by the U.S. Forest Service and in part by the Rockefeller Foundation and a joint grant (NSF GB-34718/BMS 75-04223) from the U.S. National Science Foundation and the U.S. Environmental Protection Agency to the University of California. The findings, opinions, and recommendations are not necessarily those of the University of California or the funding agencies.Trade names and commercial enterprises or products are mentioned solely for information and do not constitute endorsement by the U.S. Department of Agriculture or University of California. 相似文献
13.
为阻断瓦斯爆炸在管道方向上的传播,保护管道后方区域,本文采用氮气幕来进行阻爆,所设计的实验装置在爆炸发生后能自动喷出氮气。主要研究了氮气的喷气压力和喷气时刻对阻爆功能的影响。结果表明,在喷气压力为0.1MPa时,氮气幕仅起到抑制作用,爆炸火焰能穿过整个实验管道。在喷气压力为0.2MPa时,仅部分实验能够阻爆,氮气幕产生不稳定的阻爆效果。在喷气压力为0.3MPa时,阻爆位置均稳定在左喷头和右喷头之间区域,氮气幕产生稳定地阻爆效果。喷气压力超过0.4MPa后,阻爆位置稳定在右喷头附近。在较低氮气压力0.2MPa下,喷气时刻对阻爆效果产生显著影响。随着喷气时刻延迟,氮气喷出量减小,氮气幕由不稳定阻爆变为不阻爆。喷气时刻延迟到198ms后,氮气幕便丧失阻爆功能。在喷气压力超过0.3MPa后,氮气幕阻爆效果便不受喷气时刻的影响,喷气压力对能否阻爆起决定作用。 相似文献
14.
Technical control over dispersions with particles in the nanometer size realm should bring about a boost in innovations for some parts of industry. Requirements for the development of these new products is the accurate characterization of the various materials systems. A characterization should always include a determination of the particle size distribution, since it is coupled to the specific effects of these systems. Ultrasound measurement techniques and electroacoustics are two if the available techniques that allow determination of the size distribution and zeta potential of particles with dimensions up to 10 nanometers. A further fundamental advantage of the method is the possibility of carrying out measurements in high‐concentration materials systems. This report describes ultrasound spectroscopy for the measurement of fine‐ and very‐fine‐dispersion particles, and the known theoretical concepts for the interpretation of spectra. In addition, experiences in the use of currently available measurement techniques are presented. 相似文献
15.
Inorganic/organic hybrid materials have considerable promise and are beginning to become a major area of research for many
coating usages, including abrasion and corrosion resistance. Our primary approach is to prepare the inorganic phase in situ
within the film formation process of the organic phase. The inorganic phase is introduced via sol-gel chemistry into a thermosetting
organic phase. By this method, the size, periodicity, spatial positioning, and density of the inorganic phase can be controlled.
An important aspect of the inorganic/organic hybrid materials is the coupling agent. The initial task of the coupling agent
is to provide uniform mixing of the oligomeric organic phase with the sol-gel precursors, which are otherwise immiscible.
UV-curable inorganic/organic hybrid systems have the advantages of a rapid cure and the ability to be used on heat sensitive
substrates such as molded plastics. Also, it is possible to have better control of the growth of the inorganic phase using
UV curing. It is our ultimate goal to completely separate the curing of inorganic and organic phases to gain complete control
over the morphology, and hence optimization of “all” the coating properties. Thus far, it has been found that concomitant
UV curing of the inorganic and organic phases using titanium sol-gel precursors afforded nanocomposite coatings which completely
block the substrate from UV light while maintaining a transparent to visible light. Also, it has been found that the morphology
of the inorganic phase is highly dependent on the concentration and reactivity of the coupling agent.
Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004, in Chicago,
IL. 相似文献
16.
The effect of various pretreatments on drying kinetics as well as quality parameters of selected vegetables and fruits was studied experimentally in a convective dryer. The pretreatments tested include application of pinholes and drilled holes of different diameters and densities, blanching and freezing. Potato, cassava, dragon fruit and red chilli were used as the sample drying materials. As expected, increase of the diameter and density of the holes under fixed drying conditions increased the drying rate. Samples with drilled holes showed better drying performance than those with pinholes. The improvement of the drying rate was found to be dependent on the physical properties and the initial moisture content of the material. Results show that the drying performance of the products that possess a skin of low moisture diffusivity, such as chilli, can be improved significantly by blanching and making perforations in the skin. Overall changes of color and volume shrinkage during drying of the samples with and without holes were similar. The effect of different modes of heat input, such as convection, conduction and radiation, on the drying performance of the treated samples was also experimentally investigated. On-off type controllers were used to regulate the power of the heaters and maintain the product temperature within a range of pre-set values. Convection combined with radiation displayed the highest drying rate. 相似文献
17.
为揭示非水平表面上微小蒸发液滴的传热传质特性,本文在准稳态模型的假设下构造三维液滴模型,综合考虑了蒸气扩散、蒸发冷却以及气相域中的自然对流这3种传输机理,对水平以及竖直基底上液滴的蒸发过程进行数值研究。通过分析气液界面上温度分布、蒸发通量分布及总蒸发率的变化,重点探究了基底过热度以及重力的改变对液滴蒸发特性的影响。结果表明:与水平基底上温度的对称分布不同,竖直基底上气液界面温度分布表现出明显的非对称性,且非对称性随基底过热度的升高而增强,最低温度点不再位于液滴顶点,而向一侧偏移。此外,水平基底上气液界面局部蒸发通量呈对称分布,各截面分布相似,而竖直基底上局部蒸发通量分布则呈现出显著的非对称性以及各截面异性,非对称性随着基底过热度的升高而增强,这是重力改变后气相域自然对流发生改变的结果。与水平基底相比,竖直基底上蒸发率更高,总蒸发时间更少。最后,基底由水平变为竖直时,液滴内部流场由对称双涡转变为非对称单涡,单涡流速显著大于双涡流速,液滴内流速随基底过热度的上升而增大,单涡环流造成了气液界面温度分布的改变以及最低温度点的偏移。 相似文献
18.
Breakage patterns of agglomerates 总被引:4,自引:0,他引:4
The experimental information available in the literature regarding the patterns of breakage of agglomerate materials is scarce, particularly in dynamic loading. The primary objective of this paper is to present our findings on the breakage patterns of the agglomerates and the interparticle bond. A high-speed digital video imaging technique is used here to gain an insight into the impact behaviour of individual agglomerates against a target plate. Several breakage patterns are observed. Agglomerates may suffer localised damage only, with the disintegration of the damaged zone into very fine debris, or localised damage combined with fracture. The frequency of occurrence of these patterns depends on the impact velocity and agglomerate structure. The pattern of breakage affects significantly the size distribution of the impact product. An investigation of the breakage of individual interparticle bonds is also presented. Two forms of failure are observed, internal (cohesive) and interfacial (adhesive) failure. The morphology of the fractured surface depends greatly on the type of breakage. Internal breakage shows irregular surfaces due to crack jumping, whereas interfacial failure produces clean, smooth fracture surfaces. These observations should provide the necessary foundation for the development of a fundamental model of agglomerate breakage. 相似文献
19.
S. K. Karmee D. Chandna R. Ravi A. Chadha 《Journal of the American Oil Chemists' Society》2006,83(10):873-877
The kinetics of transesterification of Pongamia oil using methanol at 60°C were studied. The forward as well as the reverse rate constants of all three steps involved in
the transesterification of Pongamia oil are reported for the first time. Among the forward rate constants, the one governing the conversion of TG to DG was the
highest and the one for DG to MG was the lowest. A distinct feature of the present work is the direct estimation of the equilibrium
constants of all three steps by measuring the concentrations of TG, DG, and MG at very long reaction times. This reduced the
number of parameters to be, determined from the kinetic data by one-half, thereby leading to more accurate estimation of the
rate constants. The equilibrium constant of the final step involving the conversion of MG to methyl ester and glycerol was
at least an order of magnitude greater than that of the first two reaction steps. A detailed comparison was made with kinetic
parameters reported in literature. The trend in the relative magnitudes of the rate constants appears to be unique to Pongamia oil. 相似文献
20.
《Journal of Adhesion Science and Technology》2013,27(11):1243-1251
Knowledge of the adhesion properties of materials is necessary for many applications. When one has to cover a wall or a concrete pavement with mortar, it is necessary to pay attention to the adhesion between the two materials, otherwise one can have some problems such as the delamination of the two materials after application. We present here a study of the adhesion between hydraulic mortars and concrete. Mortars with permeability-reducing admixtures were used. This type of mortar is used to reduce the possibility of water infiltration in construction. Mortars should be impermeable but this should not affect the adhesion. To measure the adhesion, we used the pull-off test. The results show a decrease in the adhesion strength with increasing permeability-reducing admixture dosage, except for one of the admixtures used. We believe that this result is a consequence of the decrease in porosity caused by the use of a more waterproofing admixture and that a higher dosage contributes to the increase of admixture at the interface. To confirm this, we performed a microscopic analysis of the failure surfaces of the mortars. The decrease in porosity was well seen in this analysis. However, this characteristic of mortars is not the only one that affects adhesion. The composition of the admixture is very important as we found different adhesion strengths, for similar porosity, with different admixtures. 相似文献