冷轧酸碱废水处理工艺及其重要参数的设定和分析

介绍了本钢浦项冷轧薄板有限责任公司酸碱废水处理工艺并详细分析了各工艺点控制参数的设定。该工艺按照这些控制参数进行设定后运行,出水水质指标可以达到或优于国家规定排放标准。     

论大学生压力管理与和谐校园的构建

随着社会竞争日益激烈,大学生因学业、经济、就业、人际交往等问题,正面临越来越大的压力。这些压力严重影响了大学生的身心健康,使得校园不和谐因素增多。高校要大力开展大学生压力管理教育,营造良好的教育环境,帮助大学生对自身的压力进行正确的管理,通过压力管理有效地对大学生的生理、心理产生积极的作用,在潜移默化中促进其自身和谐,进而推进校园以及社会的和谐。     

四并联镍氢/镍镉智能快速充电器设计

设计一种镍氢-镍镉智能快速充电器,四节电池独立控制,可单独充电.综合应用O△V电压及温度控制策略,为保护电池使用寿命,充电过程中及时检测是否存在温度过高或过低等异常,并自动停止充电.为防止过冲,采用高灵敏度的O△V检测策略,能及时检测电池是否充满,一旦电池充满便转为涓流充电.     

容城农田土壤的速效磷养分状况及供磷能力

为给冬小麦高产提供合理施用磷肥的科学依据,采用田间试验法,以容城轻壤质潮土为研究对象,对农田土壤速效磷的养分状况及冬小麦田间试验进行分析,探讨了土壤的供肥能力。结果表明,容城土壤含磷水平较高,高、中水平占60%之多,但差异性较大,冬小麦土壤磷素贡献率高、中、低产田分别达到82.37%9、0.36%和84.82%,土壤的供磷能力分别为67.646、3.75和57.11kg/hm2,推算出了高、中、低产田冬小麦经济最佳施肥量分别为1191、11和109kg/hm2。     

基于ARM的高频开关电源数字控制系统设计

随着新型功率器件的日趋成熟,更灵活可靠的数字控制是开关电源的发展方向。基于此,采用了先进精简指令集运算机（ARM）处理器来实现脉宽调制（PWM）移相控制信号的输出,以实现软开关电源PWM反馈回路的数字控制。实验结果表明,设计能达到预期的性能要求。     

论后勤社会化改革背景下的高校安全稳定舆论导向工作

后勤社会化改革的深化给高校安全稳定舆论导向工作提出了新的挑战。面对安全舆论导向工作出现的新特点．我们有必要探索一下高校安全稳定舆论导向工作的新走向。     

南溪井水位对气压动态过程的响应

对四川南溪井的水位和气压进行了相关性分析,得到了该井气压系数的背景值,目的在于搞清气压对该井水位的干扰程度及其规律,找出排除气压干扰的方法,为分析预报提供科学依据。     

试析高职教育教学改革中教师的压力

高职院校必须关注影响教师的各种压力,与传统的"以教师为中心"的教学模式相比,在"以学生为中心"的教学模式的实施过程中,教师教学工作量的大幅增加、教学难度相应提高以及对教师综合素质的要求,使教师承受着较大的压力,这不仅会抑制教师对教学改革的热情,还会影响高职院校教育教学改革的效果。     

Applications of water sensitivity in situ remediation at saltwater-freshwater interface

Based on the laboratory experiments with the saltwater and freshwater replacing each other in the level sand column, taking the kaolin, illite, smectite, bivalent hydrargyrum ion (Hg²⁺) and phenol (C₆H₅OH) as examples, this paper studies the applications of water sensitivity in situ remediation in saltwater-freshwater transition zone. In the water sensitivity process, the release and migration of clay minerals can make the hydraulic conductivity (HC) decrease and pollutants remove. A new type of low penetrable or impenetrable purdah can be built by adding clay minerals into the sand media to replace the underground concrete impenetrable wall to prevent seawater intrusion, and a number of the heavy metals and organic pollutants in the sand media can be removed by in situ remediation. The results show that the content of kaolin and illite influences the water sensitivity process slightly, and HC of the sand columns descends from 0.011 cm/s to 0.001 4 cm/s and 0.001 2 cm/s respectively even if the content reaches 12% (weight ratio, sic passim). However, for smectite, HC descends sharply to about 1×10⁻⁸ cm/s when its content reaches 4%, and no water can flow through the sand columns beyond 5%. The particle release and migration processes can remove the Hg²⁺ and C₆H₅OH out of the sand columns efficiently, the removing rate of Hg²⁺ is 31.68% when the freshwater and saltwater are filtered through the sand columns polluted by Hg²⁺, while it is 67.55% when the water sensitivity occurs. With the same method, the removing rates of C₆H₅OH under the fluid flow and water sensitivity are 55.71% and 43.43% respectively. Supported by National Natural Science Foundation of China (No. 40572142). HAN Zhiyong, born in 1976, male, Dr, associate Prof.     

Bridge pressure flow scour at clear water threshold condition

Bridge pressure flow scour at clear water threshold condition is studied theoretically and experimentally. The flume experiments reveal that the measured scour profiles under a bridge are more or less 2-dimensional; all the measured scour profiles can be described by two similarity equations, where the horizontal distance is scaled by the deck width while the local scour by the maximum scour depth; the maximum scour position is located just under the bridge about 15% deck width from the downstream deck edge; the scour begins at about one deck width upstream the bridge while the deposition occurs at about 2.5 deck widths downstream the bridge; and the maximum scour depth decreases with increas-ing sediment size, but increases with deck inundation. The theoretical analysis shows that: bridge scour can be divided into three cases, i.e. downstream unsubmerged, partially submerged, and totally submerged. For downstream unsubmerged flows, the maximum bridge scour depth is an open-channel problem where the conventional methods in terms of critical velocity or bed shear stress can be applied; for partially and totally submerged flows, the equilibrium maximum scour depth can be described by a scour and an inundation similarity number, which has been confirmed by experiments with two decks and two sediment sizes. For application, a design and field evaluation procedure with examples is presented, including the maximum scour depth and scour profile.