一台在线分析仪同时控制二条线原料磨配料的改造实施

原料配料的质量控制是生熟料质量控制和系统高产优质低耗运行之关键。山东东华水泥公司有2条5000t/d熟料生产线,其中#2线采用跨皮带式在线分析仪对进磨原料进行实时、在线、连续检测和快速调整,而#1线采用"自动取样器+荧光分析仪"的质控系统,生料质量明显差于#2线。为提高#1线生料质量,实施了利用#2线一台跨皮带式在线分析仪同时控制两台ATOX50原料磨配料的技术改造,取得了优质、低耗、稳定的生产运行效果,并有效降低了#1线的生料配料成本和系统检修费用等。     

生产锅炉高压电动机微机综合保护测控装置的改造

1#、2#生产锅炉的高压电动机,在运行、保护校验中,因控制和保护系统使用元件较多,接线复杂、引线过多,加上保护装置元件性能变差,会使元器件问的时间、性能配合误差较大和准确性差,造成拒动、误动情况的发生,直接影响生产锅炉的长周期稳定运行。经过多方分析验证,决定利用2007年度设备大检修机会,对1#、2#牛产锅炉高压电动机采用微机综合保护测控装置的改造,从根本上解决高压电动机控制和保护系统的的问题,以免影响1#、2#生产锅炉长周期稳定运行。     

不同基质结合镁碳砖对炉渣的抗侵蚀性研究

为了研究不同基质镁碳砖对炉渣的抗侵蚀性,实验选用炉渣A对3种不同配方的坩埚试样进行了抗渣实验,同时采用扫描电子显微镜、X射线能谱仪、X射线衍射等手段进行了微观分析.结果表明1#电熔尖晶石坩埚试样的性能指标最好.结合岩相分析知,1#坩埚试样抗侵蚀性最好,其渣蚀层最薄,为 20.58 mm.2#和3#镁钙砂试样发生了难以控制的水化现象,其性能受到一定影响.     

成核剂对高光泽聚丙烯性能的影响

研究和对比了山梨醇类成核剂(NA-1#)和有机磷酸酯盐类成核剂(NA-2#)对高光泽聚丙烯(PP)的成核能力、光泽度和力学性能的影响.实验结果表明,成核剂NA-1#和NA-2#均有比较好的成核能力和增光能力,都可以在一定程度上提高样品的刚性和硬度;NA-2#的整体性能要优于NA-1#.     

毛细管气相色谱法测定6#抽提溶剂油馏程

针对6#抽提溶剂油馏程测定过程中,其结果滞后于生产控制的问题,利用毛细管气相色谱法对6#抽提溶剂油产品馏程进行检测,达到快速、准确控制馏程的目的.     

涤纶DTY油剂的应用性能

分别采用国产油剂1#,2#及进口油剂3#生产83 dtex/72 f涤纶DTY,对3种DTY油剂的应用性能进行了比较.结果表明:1#油剂的上油性能最好;1 #和3#油剂的抗静电性能优于2#油剂;1#和2#油剂的飞溅性能优于3#油剂;2#油剂有严重的刺激性气味.综合性价比,在涤纶DTY生产中,1#油剂的应用性能最优.     

NBH-2.7自然循环电解槽改膜极距相关工艺

新疆中泰化学股份有限公司氯碱厂第1期1#、2#装置的改造证明：膜极距电解槽改造可以降低电耗,是一种工期短、回收成本快的节能技术.对北化机NBH-2.7自然循环槽改膜极距后,在极化电流、气相压力、控制槽温工艺等方面进行了优化控制及改进,延长了膜的使用寿命,达到节能和降低生产成本的目的.     

韶关冶炼厂1~#系统硫酸干吸改造

介绍了韶冶1#系统硫酸装置的工艺流程及设备,主要介绍了1#系统硫酸干吸塔的改造情况,通过改造,改善了有关工艺指标的控制,有效的提高了系统生产能力,并进一步的改善了环保排放和节能减排。     

压缩机DCS控制系统的研究与应用

介绍了广东南方碱业股份有限公司压缩工段新压缩机DCS联锁控制及0#、1#~3#旧压缩机引入DCS控制的研究与应用。着重介绍如何解决0#压缩机的PLC与DCS的通讯和控制。     

浅谈燃煤粒度对锅炉热效率的影响

通过查阅锅炉专业书籍,简要介绍了煤的种类和燃煤粒度的关系,即燃煤挥发分高,入炉燃煤小粒度份额可相应减少;锅炉不同燃料、不同类型锅炉对燃煤粒度的要求,即高循环倍率的循环流化床锅炉对入炉煤的粒径要求比较细.低循环倍率的循环流化床锅炉对入炉煤的粒径要求比较粗.链条锅炉因属于固定床层状燃烧方式,要求入炉煤的粒径应成块分布,粒径小于3 mm的份额小于30%以及燃煤粒度对锅炉运行的影响.并结合我厂锅炉的实际情况--流化床锅炉分离器结焦、床层越烧越低,运行中不放料、飞灰含碳量偏高,链条锅炉炉渣含碳量偏高,热效率偏低问题.通过理论联系实际,分析出问题产生的主要原因是燃煤质量发生较大偏差,且燃煤粒度太细,不符合锅炉完全燃烧的要求.为此,车间通过将榆煤系统1#概率筛网孔由30mm×30mm扩大到40mm×40 mm,1#碎煤机筛板直径由30mm扩大到40mm,将2#概率筛网孔由10mm×10mm扩大到20mm×20mm,1#煤机筛板直径由10 mm扩大到20 mm,并通过加大车间小指标考核力度,控制燃煤湿度的方法满足煤的完全燃烧要求,同时通过控制燃料粒度来解决生产问题,并提高锅炉热效率的,最后对车间通过控制燃煤粒度所带来的经济效益进行分析.     

环保型杀菌剂(DBNPA)的绿色合成

二溴次氮基丙酰胺(DBNPA)是一种环保型杀菌灭藻剂和水处理剂.通过实验,发现了合成它的最佳氧化剂,即在H2O的作用下,Br2与氰基乙酰胺(CAA)溶液一起加热回流。可制备高产率的二溴次氮基丙酰胺，H2O2的作用是使反应中产生的HBr氧化为Br2而被循环利用。同时，还对合成工艺及污染控制技术进行了研究，找到了最佳的反应条件，使DBNPA的产率达95％以上。并且控制了污染问题，基本无三废排放，为实现DBNPA的绿色生产技术，提供了参考依据。     

委内瑞拉常压渣油萃取窄馏分催化裂化反应性能及产物中硫氮组成

以正戊烷为溶剂,采用超临界溶剂萃取分馏装置将委内瑞拉常压渣油分离为15个窄馏分和一个脱油残渣。采用LHO-1催化剂,在温度500 ℃、剂油质量比4和空速30 h^-1条件下,在小型固定流化床上对不同窄馏分进行催化裂化反应。结果表明,随着窄馏分的变重,干气产率从1.84%升至4.98%,液化气产率从12.18%升至14.47%,汽油产率则从37.49%降至16.73%,柴油产率由23.12%降至17.33%,焦炭产率由9.34%升至20.08%。窄馏分1^＃~4^＃具有良好的裂化性能,窄馏分5^＃~9^＃裂化性能中等,窄馏分10^＃~15^＃裂化性能较差。催化裂化汽油中硫化物主要以噻吩硫为主,尤其是短侧链烷基噻吩,约占90%。催化裂化柴油中硫化物主要为苯并噻吩,约为70%,其次是二苯并噻吩。催化裂化柴油中的含氮化合物主要为苯胺类、 喹啉类、吲哚类和咔唑类,其中,吲哚及其衍生物约占总氮含量的50%,而一甲基、二甲基和三甲基的氮化物含量占氮化物总量的70%以上。     

Structure and functional complementation of engineered fragments from yeast phosphoglycerate kinase

Previous studies have shown that, although the isolated structuraldomains of yeast phosphoglycerate kinase recover a quasi-nativestructure in vitro as well as in vivo, they do not reassociatenor generate a functional enzyme. The aim of this work was firstto study the folding of complementary fragments different fromstructural domains and second to determine the requirementsfor their reassociation and functional complementation. Themethod used for producing rigorously defined fragments consistsof the introduction of a unique cysteinyl residue in the proteinfollowed by a specific cleavage by 5'5'-dithiobis(2-nitrobenzoate)/potassiumcyanide at this residue. Two pairs of complementary fragmentswere thus obtained, 1–96/97–415 and 1–248/249–415.The structure and stabilities of the different fragments werestudied. The short fragments, i.e. 1–96 and 249–415were found to contain some secondary structure, but to havea low stability. Each large fragment has a high structural contentand a stability close to that of the corresponding domain. Incontrast to that observed with the isolated domains, a weakbut significant complementation was observed for the two pairsof fragments; the pair of fragments 1–248/249–415recovered 8% of the activity of the native enzyme upon complementation.An independent refolding of the complementary fragments beforereassociation decreased the yield of complementation for thepair of fragments 1–96/97–415, but did not affectthe complementation for the other pair (1–248/249–415).From the present data and previous work on the isolated domains,it appears that the correct folding of the isolated fragmentsis not a prerequisite for their complementation.     

Impurities in vegetable oil refining soapstock

Summary The nature of the impurities in vegetable oil foots renders them resistant to treatment by acids as in normal acidulation. Strong caustic was found to attack the gums and make them at least partially soluble in a 5 to 10% aqueous caustic solution. At this concentration a soap phase of 45–60% TFA could be centrifugally separated, and the majority of the impurities or their degraded products were discharged in the lye. The ratio of Oxidized Acids and Insoluble Impurities to the TFA was much lower in the soap than in the raw soapstock; the Oxidized Acids/Black Acids ratio could generally be reduced to 5% or less. This reduction in impurities was found to improve laboratory still yields markedly without the necessity of Twitchell- or pressure- splitting the black acids from treated stocks. Distillate yields of 86–89% were obtained from treated stocks, compared to 69–70% from untreated stocks.     

Cholesterol content of human parotid saliva

Free and esterifed cholesterol were determined in parotid fluid collected from 19 individuals by encapsulation of Stenson's duct in the oral 16.7±7.1 (SD) μg/100 ml and cholesterol esters averaged 13.2±8.0 (SD) μg/100 ml. Two assays are described for the measurement of cholesterol in parotid saliva. Lipophilic material was extracted with ether-ethanol (3∶1). In assay 1, the solid residue of the extract was separated into its components by thin layer chromatography. Substances on the chromatogram were made to fluoresce and the spots were photographed. Cholesterol was determined by densitometry of its black image on film. In assay 2, the ether-ethanol residue was subjected to quantitative gas chromatography. Both methods yield similar data.     

碱减量废水残渣甲酯化反应动力学研究

为实现碱减量废水残渣有效利用,对碱减量废水残渣甲酯化反应条件与反应动力学规律进行了系统考察。论文首先考虑洗涤干燥等预处理方法对碱减量废水残渣组成的影响,然后通过改变醇酸比、初始水分含量及反应温度条件,进行了碱减量废水残渣甲酯化反应动力学实验研究。结果表明,预处理可有效去除残渣中的无机盐杂质提高对苯二甲酸纯度,但预处理会明显降低后续残渣甲酯化产物对苯二甲酸二甲酯(DMT)的收率以及对苯二甲酸(TA)甲酯化反应的转化。TA甲酯化两步反应均对温度敏感,采用典型的可逆平衡反应模型对实验数据进行拟合,得到动力学模型参数,并在此基础上对动力学模型进行检验,结果表明所建立的动力学模型是可靠的,能很好的预测各组分的浓度。研究所得可为碱减量废水残渣甲酯化工艺放大与设计提供依据。     

Effect of the integrated use of legume residue,poultry manure and inorganic fertilizers on maize yield,nutrient uptake and soil properties

Identification of a sustainable integrated soil fertility management option in the tropics will not only salvage the degraded soils but also enhances the attainment of the goal of food security. This study was conducted in 2004 and 2005 on a degraded tropical Alfisol in south western Nigeria to evaluate the effect of legume residue, poultry manure and inorganic fertilizers on maize yield, nutrient uptake and soil properties. The treatments consisted of two rates of poultry manure (0 and 5 t ha⁻¹), three rates of N fertilizer (0, 50 and 100 kg N ha⁻¹ applied as urea), three rates of P fertilizer (0, 30 and 60 kg P ha⁻¹ applied as single super phosphate) and two soybean treatments (with or without incorporation of legume residue) in various combinations as a factorial experiment in Randomized Complete Block design with three replicates. Results showed that poultry manure alone led to significant increase in maize yield (60%) and soil organic matter (45%). In contrast, legume residue incorporation gave significantly lower increase in yield (7%) and soil organic matter (11%). However, the combined application of poultry manure and legume incorporation led to 72% increase in maize yield as opposed to 63 and 10% increase recorded when manure alone or legume alone were incorporated, respectively. Optimal maize yield was achieved when manure application was integrated with P fertilizer application. The interaction of P fertilizer and legume incorporation indicated that soil phosphorus and maize P concentration were significantly increased with the application of the P fertilizer and legume incorporation. Hence, the application of P fertilizer alone is most likely to be economical compared with its integration with legume incorporation.     

新型聚醚酮熔体过滤装置的设计与应用

聚醚酮合成反应时产生细小胶体杂质,原料、精制及干燥过程会带入诸如灰尘等杂质,另外熔体挤出造粒中,聚醚酮因长时间塑化和加热产生碳化。这些杂质进入挤出模具中,会造成流道堵塞或制品残缺,不同程度地影响聚醚酮的应用范围。采用挤出机熔融、加压,经熔体泵加压,再经过高目数过滤网,成功实现了聚醚酮熔体的连续过滤。由于产量扩大,原有过滤设备已满足不了生产需要。经过放大原有设备,生产运行表明:由于网片区域空间过大,难控制网片表面的温度。温度过高会使物料出现变性;网片面积大易变形,杂质逃逸,不能实现聚醚酮预定过滤目标。根据已成功实现过滤的经验,设计一种新型过滤装置,采用双柱,每柱双网。过滤条件为:加料速度175 kg/h;挤出机加热温度375℃;出口压力12 MPa;熔体泵出口压力22～40 MPa;过滤网304材质;网块直径200 mm、网区直径180 mm、网孔最小直径5μm;换网次数1次/55分针。测试结果为过滤后杂质粒径小于5μm,纯物料收率91.4%。     

Yield response of maize (Zea mays L.) to crop residue management on two major soil types Of Alemaya, Eastern Ethiopia: I. Effects of varying rates of applied and residual N and P fertilizers

Field trials were conducted on two soil types for seven years (1988–1994) to investigate grain yield response of maize to crop residue application as influenced by varying rates of applied and residual N and P fertilizers. Yearly application of N and P fertilizers at both one-half and full recommended rates resulted in grain yield increases of more than 500 and 1100 kg ha-1, respectively over application of only crop residue. Moreover, grain yield responses due to residual N and P fertilizers applied only during the first year were found to be comparable to the yearly applications of these fertilizers. Rainfall and soil type have exerted considerable influences on the grain yield response obtained in this study. Grain yield exhibited a corresponding decrease with decreasing rainfall. Grain yield increases on Typic Pellustert were relatively higher than on Typic Ustorthent.     

Conservation tillage,local organic resources and nitrogen fertilizer combinations affect maize productivity,soil structure and nutrient balances in semi-arid Kenya

Smallholder land productivity in drylands can be increased by optimizing locally available resources, through nutrient enhancement and water conservation. In this study, we investigated the effect of tillage system, organic resource and chemical nitrogen fertilizer application on maize productivity in a sandy soil in eastern Kenya over four seasons. The objectives were to (1) determine effects of different tillage-organic resource combinations on soil structure and crop yield, (2) determine optimum organic–inorganic nutrient combinations for arid and semi-arid environments in Kenya and, (3) assess partial nutrient budgets of different soil, water and nutrient management practices using nutrient inflows and outflows. This experiment, initiated in the short rainy season of 2005, was a split plot design with 7 treatments involving combinations of tillage (tied-ridges, conventional tillage and no-till) and organic resource (1 t ha⁻¹ manure + 1 t ha⁻¹ crop residue and; 2 t ha⁻¹ of manure (no crop residue) in the main plots. Chemical nitrogen fertilizer at 0 and 60 kg N ha⁻¹ was used in sub-plots. Although average yield in no-till was by 30–65% lower than in conventional and tied-ridges during the initial two seasons, it achieved 7–40% higher yields than these tillage systems by season four. Combined application of 1 t ha⁻¹ of crop residue and 1 t ha⁻¹ of manure increased maize yield over sole application of manure at 2 t ha⁻¹ by between 17 and 51% depending on the tillage system, for treatments without inorganic N fertilizer. Cumulative nutrients in harvested maize in the four seasons ranged from 77 to 196 kg N ha⁻¹, 12 to 27 kg P ha⁻¹ and 102 to 191 kg K ha⁻¹, representing 23 and 62% of applied N in treatments with and without mineral fertilizer N respectively, 10% of applied P and 35% of applied K. Chemical nitrogen fertilizer application increased maize yields by 17–94%; the increases were significant in the first 3 seasons (P < 0.05). Tillage had significant effect on soil macro- (>2 mm) and micro-aggregates fractions (<250 μm >53 μm: P < 0.05), with aggregation indices following the order no-till > tied-ridges > conventional tillage. Also, combining crop residue and manure increased large macro-aggregates by 1.4–4.0 g 100 g⁻¹ soil above manure only treatments. We conclude that even with modest organic resource application, and depending on the number of seasons of use, conservation tillage systems such as tied-ridges and no-till can be effective in improving crop yield, nutrient uptake and soil structure and that farmers are better off applying 1 t ha⁻¹ each of crop residue and manure rather than sole manure.