日粮中添加不同水平稀土对肉鸡生长影响的研究

30日龄Star肉用仔鸡180只,随机分成6组.每组30只。5个试验组在基础日粮中添加不同水平的稀土,对照组喂基础日粮。经5周的饲喂结果表明,除150ppm硫酸铈组外.日粮中添加50ppm硫酸铈和100、200、250ppm硝酸稀土分别较对照提高增重17.4%(P<0.05)、12.2%(P<0.05)、18.4%(P<0.01)和27.6%(P<0.01),并在提高饲料转化率和屠宰率方面呈现出良好作用。因此,在肉鸡日粮中添加适量的稀土化合物,不仅可以促进生长,而且能降低饲养成本,提高经济效益。     

双相不锈钢中相变对力学性能和腐蚀性能的影响

1 前言 双相不锈钢（DSS）的用量增加是由于它们在力学强度和各种环境中的耐腐蚀性能方面具有诱人的综合性能，以及可焊接性能。由于点腐蚀被认为在DSS用途中具有关键性的作用，因此有必要依据其耐点蚀性能对DSS进行分类。按照其耐点蚀性能对DSS进行排序的通常方法一直是采用计算PRE。数值的经验公式：[第一段]     

有机硅对钛白粉颜料性能和应用性能的影响

研究不同官能团的有机硅对锆铝包膜的金红石型钛白粉包结料进行表面处理,通过高温保温后考察钛白粉的白度变化来分析不同种类有机硅对钛白粉热稳定性的影响;研究了有机硅对钛白粉颜料性能和应用性能的影响。试验结果表明,不同功能基团对钛白粉的热稳定性、吸油量、分散性等颜料性能,以及分散性和遮盖力等应用性能影响的对应关系不同,而有机硅的种类和功能基团的不同对钛白粉的白度和亮度影响不大。     

钛合金中氧富集对显微组织和性能的影响

１前言 钛及钛合金中的氧富集造成的冶金、组织缺陷是钛材生产者和飞机发动机制造者共同关心的问题,也是目前钛材生产中最普遍存在的质量问题之一。通常钛材中氧富集区表现为单相α和富α该区的抗拉强度、塑性以及断裂韧性明显低于正常区。有人还证实氧富集区就是材料发生脆性断裂的断裂源。因此,航空用钛材绝对不允许氧富集区存在。国内外对航空用钛材半成品和成品的氧富集问题都作了严格限定,并要求钛材生产部门进行严格的检验。本文就氧富集区形成原因、组织特征,以及对材料性能的影响进行讨论。２试验材料及过程 试验材料为工业 Ｔ…     

铈对工业纯铝冲压性能和耐蚀性能的影响

研究了添加不同量铈对工业纯铝板的冲压性能、耐蚀性能及铸态硬度的影响．试样经轧制退火后在室温条件下作技力试验，取得常规条件下的屈强比σ0.2／σb、加工硬化指数n、板厚方向性系数γ、均匀延伸率εb和板平面方向性系数△γ，找出了稀土金属铈含量对工业纯铝板冲压性能的影响规律．     

钢中硫化物夹杂物球化和对钢性能的影响

本文叙述了钢液凝固中,硫化物夹杂球化的条件,钢在压力加工中硫化物不易变形的原因,以及硫化物变形后再加热时的行为,举例说明了硫化物球化对钢性能的影响;以便通过相应的措施来改善钢的性能。     

稀土对3Cr8Si2钢的耐热性能和耐腐蚀性能的影响

研究了在相同的试验条件下,于3Cr8Si2钢中添加微量稀土元素和不加稀土元素情况下的耐热性能和耐腐蚀性能的情况。结果表明,在3Cr8Si2钢中添加微量稀土元素后,可使其耐热性能提高2.5倍以上,耐腐蚀性能提高约2倍。将添加稀土元素的3Cr8Si2钢制成的工业炉烟道转动闸门,经批量的工业性试验证明,其使用寿命长,经济效益显著。     

硅对铝黄铜组织和性能的影响

研究了硅含量对Ｃｕ－６Ａ１－４Ｎｉ－２８～３２Ｚｎ合金组织和性能的影响。结果表明，硅的加入促进γ相析出，使合金具有效强化效果。硅含量越高，强效果越大，但合金脆性增加，难以成型，在该合金中，硅首先溶解在块状相中，使块状相强化，当硅含量较高时才部分溶于基体中，使基体硬度提高。     

烧结法粗液脱硅节能技术的改进

以节能降耗为出发点 ,阐述了烧结法粗液脱硅工艺的发展过程。从蒸汽直接加热连续脱硅到蒸汽间接加热连续脱硅 ,通过多方面的试验探索及验证 ,提出了烧结法粗液脱硅的改进方法 :一段脱硅运用常压脱硅技术、钠硅渣彻底分离后二段脱硅使用HCAC添加剂等 ,可以从根本上改变高能耗的脱硅现状 ,在提高精液A/S的前提下 ,尽可能降低Al2 O3 的损失     

钢铁企业投入产出模型及吨钢能耗和环境负荷分析

同时考虑钢铁生产过程中资源消耗、产品生产和污染物排放等问题,构造了一张能源—环境负荷投入产出表.应用物质平衡理论,建立了钢铁企业产品生产过程和能量转换过程数学模型;给出了工序能耗、产品能值和吨钢能耗表达式,以及工序、产品和吨钢环境负荷计算公式;分析了影响上述指标的各种因素,以及能流、物流和污染物流三者间的相互关系;总结了20年来我国钢铁工业吨钢能耗和环境负荷的变化与进步.     

氧化剂对粗铅熔化渣提锡的影响

以高锰酸钾、双氧水、次氯酸钠和氧气为氧化剂,研究了碱法提取粗铅熔化渣中的锡时氧化剂种类对锡浸出率的影响。结果表明,加入氧化剂可以明显提高锡浸出率,其中高锰酸钾对锡浸出率影响最大,双氧水、次氯酸钠的影响次之,鼓风通入氧气有一定作用,但效果不明显。每千克原料较适宜的氧化剂用量分别为:高锰酸钾20g、双氧水600mL、次氯酸钠400mL。     

泵与风机的性能分析及其节能技术

文章详细分析了泵与风机的闸阀节流特性曲线，分析了目前泵与风机广泛使用的各种调速系统，就其节能的选择方面，详述了各种调速方式的优劣，并以实例分析了变频调速优良的节能效果，同时说明了变频调速也有负面作用。     

Effects of Nutrient Source and Supply on Crude Oil Biodegradation in Continuous-Flow Beach Microcosms

Ammonium and nitrate were used as nitrogen sources to support microbial biodegradation of crude oil in continuous-flow beach microcosms to determine whether either nutrient was more effective in open systems, such as intertidal shorelines. No differences in the rate or extent of oil biodegradation were observed, regardless of whether these nutrients were provided continuously or intermittently. Nutrients were provided once every two weeks to intermittent-input microcosms and washed out within four to five days. In continuous-input microcosms, ammonium and nitrate were assimilated as quickly as they were provided during the first week, but both accumulated to greater than 10?mg?N/L thereafter. The sensitivity of the oil mineralization rate to nutrient input decreased rapidly as the extent of oil degradation increased, and after about two weeks the rate of oil-mineralization appeared to be independent of nutrient input. Therefore, there may be little value in maintaining a long-term supply of nutrients in contact with oil-contaminated sediments. The rates of microbial assimilation of ammonium and nitrate followed similar trends. Both compounds were assimilated more slowly as the extent of oil biodegradation increased, and the nitrate uptake rates approached zero after about two weeks. Ammonium assimilation continued at a low rate throughout the six-week experiment, but this did not appear to affect the rate of oil mineralization. Assimilation of ammonium resulted in a sharp decrease in the pH of the synthetic seawater that was pumped continuously through the microcosms, but nitrate had a much smaller effect on pH. The magnitude of the ammonium-associated pH change was never as large as was observed in previous studies involving oil biodegradation in batch reactors, however, and did not affect the oil-biodegradation rate.     

2002年全国炼铁生产技术会议暨炼铁年会在马钢召开

为贯彻落实中央经济工作会议和全国经贸工作会议的精神,落实冶金工业“十五”规划,促进我国炼铁科技进步和生产技术发展,提高钢铁企业的市场竞争力,中国金属学会于2002年6月26～28日在马钢召开了“2002年全国炼铁生产技术会议暨炼铁年会”。会议的主题是:节能降耗、降成本、炼铁环境友好。参加会议的有中国钢铁工业协会党委书记、副会长吴     

Project Performance versus Use of Technologies at Project and Phase Levels

Lack of information regarding technology benefits along with uncertain competitive advantage from new technology have resulted in industry reluctance to implement new technologies. An industry-wide survey was used to collect project data from more than 200 capital facility projects on the issue of technology usage and overall project success. Twenty-two research hypotheses are presented and analyzed according to five different data class variables: industry sector, total installed cost, public versus private, greenfield versus expansion versus renovation, and typical versus advanced projects. Findings pertaining to associations between project success and technology usage at the project and phase level are discussed. The results of this research indicate that several technologies may contribute significantly to project performance in terms of cost and schedule success, particularly for certain types of projects. In addition, project schedule success is more closely associated with technology utilization than is project cost success. Findings from this study can provide companies with information on technology benefits and whether to use certain technologies.     

转炉炼钢工序能耗实绩剖析

报导了宝钢炼钢厂降低转炉工序能耗的一系列措施，宝钢连铸７年实现负能炼钢１９９５年创造了吨钢－７．９７ｋｇ标煤的优异成绩，取得可观的经济效益，同时，进一步提出了保持和提高负能炼钢水平的基本设计。     

Effects of Schedule Pressure on Construction Performance

Accelerating a project can be rewarding. The consequences, however, can be troublesome if productivity and quality are sacrificed for the sake of remaining ahead of schedule, such that the actual schedule benefits are often barely worth the effort. The tradeoffs and paths of schedule pressure—and its causes and effects—are often overlooked when schedule decisions are being made. This paper analyzes the effects that schedule pressure has on construction performance, and focuses on tradeoffs in scheduling. A research framework has been developed using a causal diagram to illustrate the cause-and-effect analysis of schedule pressure. An empirical investigation has been performed by using survey data collected from 102 construction practitioners working in 38 construction sites in Singapore. The results of this survey data analysis indicate that advantages of increasing the pace of work—by working under schedule pressure—can be offset by losses in productivity and quality. The negative effects of schedule pressure arise mainly by working out of sequence, generating work defects, cutting corners, and losing the motivation to work. The adverse effects of schedule pressure can be minimized by scheduling construction activities realistically and planning them proactively, motivating workers, and by establishing an effective project coordination and communication mechanism.     

高能球磨对Al-Fe-V-Si耐热铝合金微观组织及压缩性能的影响

采用惰性气体雾化法制备了Al-7.8Fe-1.3V-2.0si合金粉末,通过高能球磨和粉末冶金工艺制备了Al-Fe-V-Si合金棒材,研究了材料的微观组织和在25,250,315℃下合金的压缩强度,结果表明,高能球磨可以使合金中Al12(Fe,V)3Sj析出相分布更加弥散均匀,能使合金在25,250和315℃下的压缩强度得到大幅度提高.