碱洗塔洗塔系统的优化

介绍了氯乙烯合成工段碱洗塔洗塔工艺流程,并针对存在的问题对其进行了优化升级,使碱洗塔自控洗塔、配碱,提高了系统的自动化控制水平,节约了水资源,也降低了废水处理系统的负荷,最大限度地提高了碱液的利用率,提高了工作效率,增加了经济效益,     

患者住院费用明细在临床中的应用

住院费用明细的实施,让患者真正明白了医疗费用的每一笔开支,增加了医院的透明度,密切了医患关系,维护了医患双方的利益,赢得了患者及家属的信任,减少了医疗纠纷,树立了医院良好的社会形象。     

国外某1000t/d项目风扫生料磨调试

本文介绍了风扫生料磨的调试经验,通过改造出磨风管,降低了磨机通风阻力,增加了磨内通风量,提高了磨机的烘干能力;通过改造中心圆尺寸,增加了填充率,提高了磨机的出力,从而提高了磨机的产量,顺利实现了达产目标。     

带式过滤机在多品种氢氧化铝生产中的应用

介绍了带式真空过滤机的工作原理及其在多品种氢氧化铝生产方面的应用情况,并对带式真空过滤机使用过程中存在的问题进行了改造。改造之后,提高了洗涤过滤效率,降低了滤饼水分,降低了能耗,提高了产量,确保了产品质量,取得了较好的经济效益。     

浆料槽机械密封技术的改造

利用机械密封的优点和特性,对原来的浆料槽填料密封结构进行了改造,消除了泄漏,降低了噪声,减少了振动,改善了环境,且便于维护和检修,降低了检修人员的劳动强度和检修费用,设备的技术含量得到了提升。     

橡胶行业形势和协会的任务──在中国橡胶工业协会第十五次秘书长工作会议闭幕时的讲话

同志们：第十五次秘书长工作会议经过几天紧张的活动,今天就要结束了。几天来,各专业分会和地方协会的秘书长同志们,聚集一堂,认真地总结了去年协会的工作,研究橡胶行业当前的形势,交流了今年协会工作的设想,讨论了协会工作中的一些实际问题。会议交流了经验,统一了认识,协调了工作,明确了方向,为今年协会工作的开展打下了良好的基础。会议开得很好,达到了预期的目的。各分会和地方协会工作人员尤其是秘书长,去年为缓解行业困难,促进行业发展,做了大量艰苦的工作,付出了辛勤的劳动,作出了很大的贡献,我代表总会对大家表示…     

MTBE装置催化精馏塔捆包催化剂的应用

催化蒸馏塔内的催化剂进行了更换,弃用了原有的散装催化剂,采用了捆包催化剂,抑制了催化剂的副反应,减少了催化剂对催化精馏塔的腐蚀,有效延长了催化精馏塔的使用周期,也进一步满足了扩能改造的要求。     

三工实施技术创新成效显著

今年以来,山东三工橡胶有限公司动员全体职工积极进行技术革新,大力开展小改小革活动,加快技术创新,减少了物耗,降低了生产成本,提高了产品质量,取得了显著成效。一是优化配方设计。公司技术部根据掌握的成熟配方技术,大胆进行创新,合理优化配方设计。经过试验,采用新配方后,不仅提高了产品的各项性能指标,而且降低了生产成本,取得了较好的经济效益。二是开发新材料。在经过试验的基础上,积极采用新材料、新产品,降低了生产成本,提高了产品质量。像增塑剂A应用于混炼胶中,不仅降低了生产成本,而且提高了混炼胶中炭黑的分散度,改善了胶料的…     

二步法三聚氰胺热气冷却单元的新工艺

在两步法三聚氰胺工艺生产中,由于热气过滤单元温度高,产出的粗品三聚氰胺纯度低,副产物多,需要在精制过程中利用蒸汽,重新加热溶解粗品三聚氰胺,并送入结晶塔降温结晶,得到纯度高的三聚氰胺成品,此过程消耗了大量的蒸汽,增加了生产成本。提出了一种新的生产工艺,首次在二步法三聚氰胺工艺中增加了热气冷却单元,降低了热气温度,并副产了部分蒸汽,分离出了高沸点反应副产物,净化了热气,得到了纯度高的粗品三聚氰胺,同时改变了精制工艺,极大地降低了蒸汽消耗,节约了生产成本,提高了产品市场竞争力。     

酒瓶顶盖注塑模具设计

分析了酒瓶顶盖的结构,提出了模具设计的关键点,设计了模具的整体结构。根据塑件分型面的位置,设计了推件板和推杆的二次推出机构,在型芯紧固螺钉中心钻孔,解决了推杆的安装问题。多个分型面处采用了锥面配合,解决了导向件磨损的问题,提高了模具的精度,延长了模具的寿命。经过生产验证,该摸具结构合理、动作可靠。     

四丁基锡化合物与腐殖酸相互作用的光谱研究

通过荧光光谱、紫外光谱研究了四丁基锡(TeBT)化合物与腐殖酸(HA)的相互作用。结果表明,四丁基锡可以有规律的猝灭腐殖酸的荧光,并降低腐殖酸的芳构化程度。计算了四丁基锡与腐殖酸作用的热力学参数,表明二者之间作用力主要为氢键或范德华力。通过三维荧光谱图进一步证实了二者之间的作用。     

腐植酸对高岭土吸附四价铀的影响

在土壤中,对放射性废物处理的安全性评估,要求评价放射性核素的迁移.PH值从4到8,腐植酸浓度从15 mg/kg到200 mg/kg条件下,腐植酸对高岭土吸附四价铀的影响试验表明,没有腐植酸的情况下,20%～40%的四价铀存在于溶液中,pH值越高,吸附作用越强.在腐植酸的存在下,随着腐植酸浓度和PH值的升高,四价铀的溶解...     

Effect of grinding on the hydration of hydratable alumina and properties of hydratable alumina-bonded castables

Hydratable alumina (HA) is a superior Ca-free refractory binder, but the quick hydration rate restricts the working time of castables bonded with HA. In this work, HA was grounded for 1 h and 6 h by a rotational ball mill to study the effect of grinding on the hydration of HA and properties of HA-bonded castables. HA samples with and without grinding were cured at 30 °C and then terminated by freeze-vacuum drying. The phase composition and microstructure of the dried HA samples were then examined. Moreover, flow ability and mechanical strength of castables containing ungrounded and grounded HA were also investigated. The results indicate that the specific area of HA particles were decreased by grinding as the micro-pores and micro-cracks on the surface of HA particles were blocked by smaller HA particles, thereby decreasing the hydration rate of HA and increasing the flow ability of castables.     

Hyaluronic Acid as a Carrier Supports the Effects of Glucocorticoids and Diminishes the Cytotoxic Effects of Local Anesthetics in Human Articular Chondrocytes In Vitro

The current study aimed to investigate the cytotoxicity of co-administrating local anesthetics (LA) with glucocorticoids (GC) and hyaluronic acid (HA) in vitro. Human articular cartilage was obtained from five patients undergoing total knee arthroplasty. Chondrocytes were isolated, expanded, and seeded in 24-well plates for experimental testing. LA (lidocaine, bupivacaine, ropivacaine) were administered separately and co-administered with the following substances: GC, HA, and GC/HA. Viability was confirmed by microscopic images, flow cytometry, metabolic activity, and live/dead assay. The addition of HA and GC/HA resulted in enhanced attachment and branched appearance of the chondrocytes compared to LA and LA/GC. Metabolic activity was better in all LA co-administered with HA and GC/HA than with GC and only LA. Flow cytometry revealed the lowest cell viability in lidocaine and the highest cell viability in ropivacaine. This finding was also confirmed by live/dead assay. In conclusion, HA supports the effect of GC and reduces chondrotoxic effects of LA in vitro. Thereby, the co-administration of HA to LA and GC offers an alternative less chondrotoxic approach for treating patients with symptomatic osteoarthritis of the knee.     

Enhancing the physical and mechanical properties of pellet-shaped hydroxyapatite by controlling micron- and nano-sized powder ratios

Hydroxyapatite (HA) was fabricated in microns as its basic size. The particle size distribution was controlled by mixing micron- and nano-sized HA to obtain the optimum amount of mixture to improve its properties. HA powder with a size of 2.5 μm was mixed with that with a size of 200 nm, with a variety of concentrations of up to 20 wt%. A green body was fabricated using the uniaxial pressing method at a pressure of 200 MPa. The sintering process was conducted at a temperature of 1200 °C, heating rate of 3 °C/min, and holding time of 2 h in air. The physical characteristics of the HA sintered body were determined using X-ray diffraction, scanning electron microscopy, linear shrinkage, and density testing. The mechanical properties of the HA sintered body were tested using compressive strength testing. The test results indicated that the mechanical properties of the HA sintered body increased with the addition of nano-sized HA. The mechanism of the increasing strength occurred because nano-sized HA particles filled the gaps between the micron-sized particles. In this study, the highest mechanical properties were obtained by adding 20 wt% nano-sized HA. The compressive strength in the sample without added nano-sized HA was 132.2 MPa and increased significantly to 208.6 MPa with the addition of nano-sized HA of 20 wt%. No change in the phase in HA was observed within a sintering temperature of 1200 °C.     

Effect of hydromagnesite on the hydration of hydratable alumina and properties of corundum-based castables

Hydratable alumina (HA) was premixed with hydromagnesite (BMC) to investigate the BMC impact on the hydration behavior of HA and the thermo-mechanical properties of HA bonded (HAB) castables. The phase composition, microstructure and mass changes of dried HA samples, were characterized by XRD, SEM, and TG, respectively. Flow ability, microstructure, and thermo-mechanical properties of HAB castables were studied. Results indicated that BMC effectively lowered HA hydration rate due to the decreased specific surface area. The hot modulus of rupture strength of castables was improved because the sintering of Al₂O₃ was enhanced by the MgO from BMC decomposition.     

Modeling the microbial production of hyaluronic acid

Modeling of hyaluronic acid (HA) production by fermentation of Streptococcus zooepidemicus was performed. An accurate determination of the growth curve of the cocoid cells was first discussed, which was relevant to the change of cell morphology after entry into the stationary phase. A delayed growth-associated model was then proposed for the HA production, which was in accordance with mechanisms of HA formation reported in the literature. The proposed model was employed satisfactorily not only for HA production, but also for poly-γ-glutamic acid production.     

干燥方法对化学沉淀法合成HA粉体团聚的影响

化学沉淀法合成羟基磷灰石粉体工艺简单,成本低廉,但这种方法得到的羟基磷灰石粉体极易团聚,限制了羟基磷灰石的广泛使用.本文研究了在羟基磷灰石粉体的合成过程中不同干燥方法对粉体团聚的影响.结果表明:在烘箱干燥得到的粉体团聚较严重,微波干燥使粉体的团聚程度有所减轻,冷冻干燥可有效地减弱粉体的团聚,所得到的粉体比表面积较高.同时,本文还讨论了粉体在干燥过程中团聚形成的机理.     

How the interactions with humic acids affect the mobility of ionic dyes in hydrogels – 2. Non-stationary diffusion experiments

Non-stationary diffusion of two cationic dyes (Methylene Blue and Rhodamine 6G) was studied in hydrogels with different content of agarose and humic acids (HA). A simple spectrophotometrical method was utilized in the in situ measurement of dye concentration in the gel samples at different distances from the boundary. The effect of temperature, pH and ionic strength was investigated. The results confirmed the considerable partitioning of both dyes in agarose gels as well as the strong immobilization of dyes caused by their sorption on HA. The apparent diffusion coefficients of both dyes decreased with increasing solid content in gels. In the case of agarose gels without the addition of HA, this decrease was attributed to increased tortuosity of diffusion caused by denser agarose network. The apparent equilibrium constant of the sorption of dyes on HA in agarose/HA gels was calculated from their apparent diffusion coefficients. The value of the equilibrium constant increased with the content of HA in gel and, surprisingly, also with decreasing pH inside gel.     

Influence of temperature,ripening time and calcination on the morphology and crystallinity of hydroxyapatite nanoparticles

Nano-sized hydroxyapatite (HA) particles were prepared by chemical precipitation through aqueous solutions of calcium chloride and ammonium hydrogenphosphate. The influence of temperature, ripening time and calcination on the crystallinity and morphology of the HA nanoparticles were investigated. It was found that the crystallinity and crystallite size increased with the increase of synthetic temperature and ripening time. XRD and TEM results showed that the morphology change of HA nanoparticles was related to their crystallinity. High crystallinity of HA led to regular shape and smooth surface of the nanoparticles. The crystallinity of HA powders increased greatly after calcination at 650 °C for 6 h but the change of the crystallite size after calcination was dependent on the crystallinity and crystallite size of “as prepared” HA nanoparticles.