铁路列车风挡位移试验台的研制

以铁路列车折棚式风挡的质量检验为背景,研制一种风挡位移实验台,能够模拟列车运动时的晃动、上下坡、转弯等状况,包括实现铁路部门要求的风挡最小曲线通过能力试验。运用模块化设计思想,根据风挡在列车运动过程中受到6个自由度方向力而产生的形变,设计三坐标直角位移平台和三坐标转动端组成的试验台模拟其运动状态,并采用PLC控制系统进行操作完成检验。风挡位移试验台的工作结果表明,它显著提高了风挡检验的效率,同时降低了检验需要的经济成本,为六自由度方向检测的试验平台提供了一个设计方向。     

AW系列新型捕收剂的性能与选矿实践

由于在烃链上引入表面活性分子，使捕收剂溶解性能好，利于在矿浆中的分散，在改善浮选行为，降低浮选温度，消除钙镁离子的影响方面起到重要作用，为实现无碱或少碱的常温浮选奠定了基础。ＡＷ系列捕收剂适用于选别磷灰石类型和沉积变质磷灰岩型的磷矿石，选别矾山磷矿石、甜水磷矿石、江淮磷矿石、肥东磷矿石都取得了较好指标。     

32P isotopic techniques for evaluating the agronomic effectiveness of rock phosphate materials

Tropical soils are often low in available P and therefore require inputs of P fertilizer for optimum plant growth and production of food and fiber. The cost of applying imported or locally produced, water-soluble, P fertilizers is often greater than utilizing indigenous phosphate rock. Therefore quantifying the P availability of soils amended with phosphate rock-based products in a variety of crop management and environmental conditions in developing countries is desirable for making recommendations on best type and rate of fertilizers to use to obtain maximum agronomic and economic benefits. One adequate approach for evaluating the agronomic effectiveness of rock phosphate materials is through the use of³²P/³³P isotopic tracers. The present paper describes the principles and assumptions of the³²P isotopic techniques commonly used in the field and greenhouse for the agronomic evaluation of rock phosphate materials. An overview of the applications of these techniques is also given.     

Agronomic evaluation of fertilizer products derived from Sukulu Hills phosphate rock

Partial acidulation of phosphate rock (PR) or compaction of PR with soluble P fertilizers can improve the usefulness of unreactive PR for use as P fertilizer. A greenhouse study was conducted to evaluate nonconventional phosphate fertilizers derived from a low reactive Sukulu Hills PR from Uganda. Raw PR (which contained 341.0 g kg^–1 Fe₂O₃), beneficiated or concentrate PR, partially acidulated PR (PAPR) and PR compacted with triple superphosphate (TSP) were evaluated. Compacted materials had a P ratio of PR:TSP = 50:50. PAPR materials were made by 50% acidulation with H₂SO₄. TSP was used as a reference fertilizer. Fertilizers were applied to an acidic (pH = 5.4) Hiwassee loam (clayey, kaolinitic, thermic Rhodic Kanhapludults) at rates of 0, 50, 100, 200, 300 and 400 mg P kg^–1 soil. Two successive corn (Zea mays L.) crops were grown for 6 weeks. Compacted concentrate PR + TSP and raw PR + TSP were 94.4 and 89.7% as effective as TSP, respectively, in increasing dry-matter yields for the first corn crop. PAPR from the concentrate was 54.8% as effective as TSP. Raw PR, concentrate PR and the PAPR from the raw PR were ineffective in increasing dry-matter yields. The same trends were obtained when P uptake was used to compare effectiveness. Ineffectiveness of the raw PR and its corresponding PAPR was attributed to a high Fe₂O₃ content in the raw PR. Bray I and Pi paper were found to be nearly equally suitable at estimating available P in the soils treated with responsive fertilizer materials. Mehlich 1 overestimated available P in soil treated with raw PR, concentrate PR or the PAPR from the raw PR.     

Long-term residual value of North Carolina and Queensland rock phosphates compared with triple superphosphate

The effectiveness of large single applications of North Carolina reactive rock phosphate, Queensland non-reactive rock phosphate, and Calciphos, were compared to the effectiveness of superphosphate in field experiments in south-western Australia for up to 11 years after application. As measured using plant yield, superphosphate was the most effective fertilizer in the year of application, and relative to freshly-applied superphosphate, the effectiveness of the superphosphate residues declined to be about 15 to 65% as effective in the year after application, and 5 to 20% as effective 9 to 10 years after application. Relative to freshly-applied superphosphate, all the rock phosphates were 10 to 30% as effective in the year of application, and the residues remained 2 to 20% as effective in the 10 years after application. The bicarbonate soil test reagent predicted a more gradual decrease in effectiveness of superphosphate of up to 70% 10 years after application. For rock phosphate, the reagent predicted effectiveness to be always lower than for superphosphate, being initially 2 to 11% as effective in the year after application, and from 10% to equally as effective 10 years later. Therefore rock phosphates are unlikely to be economic alternatives to superphosphate in the short or long term on most lateritic soils in south-western Australia.     

普通过磷酸钙工艺技术之我见

普通过磷酸钙的生产工艺技术，因矿的品质不同而各异。磷矿粉是生产的物质基础，应抓好这一环节。这里着重介绍云南的磷矿干法生产工艺技术。     

球墨铸铁摇臂铸件常见缺陷的防止

分析了球墨铸铁摇臂碳化物和硬度偏高、皮下气孔以及试棒伸长率偏低等常见缺陷的产生原因，并提出解决措施。主要有：提高浇注温度，控制浇注时间、型砂水分、锰量和残余镁量，强化孕育，延长试棒开型时间等。     

Wear and cutting performance of diamond composite material-a comparison with tungsten carbide

A series of wear and rock cutting tests were undertaken to assess the wear and cutting performance of a thermally stable diamond composite (TSDC). The wear tests were conducted on a newly designed wear testing rig in which a rotating aluminium oxide grinding wheel is turned (also known as machined) by the testing tool element.The rock cutting tests were performed on a linear rock-cutting planer. The thrust and cutting forces acting on the tool were measured during these tests. A tungsten carbide element was also studied for comparative purposes. The wear coefficients of both materials were used to evaluate wear performance while cutting performance was assessed by tool wear and the rates of increase in forces with cutting distance.     

云锡塘子凹矿体矿岩物理力学参数研究

通过对 31- 1#矿体矿岩物理力学参数的研究 ,对矿岩特性及稳固性进行了科学、合理地评价 ,为矿体开采过程中采矿方法的选择、采场结构参数的确定及回采过程中 ,地压的管理提供了科学依据 ,从而保证了矿山生产的安全可靠性     

岩石非定常蠕变模型辨识

在页岩蠕变试验数据基础上,分析岩石黏弹性变形随应力水平不同和时间发展的变化规律.通过反分析方法建立一维情况下非定常黏弹性模型的蠕变方程,通过应变的理论计算结果与试验结果的对比发现,不考虑参数的时间相关性将引起较大的误差,而考虑参数的时间相关性的非定常黏弹性模型比定常黏弹性模型可更为准确地反映岩石的黏弹性变形性能.在软岩巷道二维非定常蠕变模型辨识的工程实例中,事先假定围岩为黏弹性和黏弹塑性两种不同力学模型,并分别考虑参数为定常和非定常两种情形,在已知现场量测位移条件下,利用位移反分析并根据一定的准则函数求其不同模型中的参数及相应的准则函数值,由各个模型相应的准则函数值大小,判定最佳模型.在假定的一组模型里,发现非定常黏弹塑性模型为最佳模型.