集中供暖室内温度控制系统的硬件设计

介绍了室内温度控制系统的功能及整体结构,分析了主、从控制器的硬件结构。主控制器采用液晶显示模块及键盘模块进行温度、时间的设定与各个房间温度、电磁阀工作状态的监测。从控制器采用数字温度传感器作为温度采集元件,通过驱动双稳态电磁阀的开闭实现温度控制。     

融合开放与传统实践教学管理模式的研究

当前,高校的实践教学管理普遍存在传统的相对集中和开放两种实践教学管理模式,它们各自存在优缺点,而且具有一定的互补性。提出探索建立一种全新的、相对独立的实验教学管理模式,以实现传统与开放二者间的优势互补,进而推动高校实践教学质量的进一步提高。     

铬在铁合金厂周边土壤-蔬菜系统中的迁移转化及健康风险

分析湖南省某铁合金厂附近重金属铬在土壤中的分布及迁移特征,在土壤-植物系统中的迁移转化规律,以及铬污染蔬菜对人体的健康风险。结果表明：铁合金厂外排污口、污灌区和对照区土壤的铬含量平均值分别为2239.5,995.33和104.9mg/kg。总铬在排污口附近土壤中主要富集在地表下200-400mm;在污灌区,主要富集于地表下0-200mm;而在对照区,铬浓度从上至下逐渐降低且各层之间富集浓度相差不大。结果也表明芹菜、莴苣和白菜均能够把土壤中吸收的致毒性较强的六价铬转化成低毒的三价铬,且蔬菜中的铬含量平均值为11.95mg/kg。铬在土壤–蔬菜中的生物富集因子大小依次为：白菜〉莴苣〉芹菜。居民每天摄入的铬含量严重超过食物中最大铬允许摄入量,表明铬污染对当地居民存在一定的健康风险。     

Spatial distribution of chromium in soils contaminated by chromium-containing slag

To evaluate the metal chromium (Cr) contamination of soil at a chromium-containing slag site by ferrochromium production, the contaminated sites, under slag heap, in the vicinity of slag heap and arable soils near the outlet of sewer channel, and unpolluted site 5 km away from one ferroalloy plant in Hunan Province, China, were selected. The concentrations of total Cr and water soluble Cr in bulk soil samples and profile depth samples were determined. The results show that the soils in the vicinity of slag heap have the highest total Cr content followed by the soils under the slag heap and near the outlet of sewer channel of the factory. The mean concentrations of total Cr in the top soils at above three contaminated locations exceed the critical level of Secondary Environmental Quality Standard for Soil in China by 3.5, 5.4 and 1.8 times. In most Cr polluted soils, total Cr has a relative accumulation in soil depth of 40-60 cm, but this trend is not found in unpolluted soils. The average concentrations of water soluble Cr (Ⅵ) in top soils under slag heap and in the vicinity of slag heap are 176.9 times and 52.7 times higher than that in the uncontaminated soils, respectively. However, water soluble Cr (Ⅵ) contents in soils near sewer channel are all low and the values are close to that in the uncontaminated soils. Although water soluble Cr (Ⅵ) content in soil profiles decreases with soil depths, it in soils under slag heap maintains a high level even at a depth of 100-150 cm. The results imply that the transportation of Cr (Ⅵ) can result in a potential risk of groundwater system in this area.     

蒙乃尔合金的氩弧焊工艺研究

通过对蒙乃尔合金氩弧焊工艺的可行性研究结果表明：焊接规范必须控制在恰当的范围内，热输入太强则易产生热裂纹，太弱则易出现熔合不良和夹渣缺陷，增加操作难度。接头ＨＡＺ存在一低度，低塑性，低强度区，热裂纹及拉伸断裂多出现于该区。     

结构式团体心理治疗在精神分裂症康复期的应用研究

目的：研究结构式团体心理治疗对康复期精神分裂症患者整体社会功能的影响。方法将120例康复期精神分裂症患者按简单随机方法分成2组,每组60例。研究组在原有药物治疗及康复训练基础上实施结构式团体心理治疗,每周1次,每次1 h,共10次;对照组则维持原有药物治疗及康复训练。分别在治疗前后及随访12周时,使用住院慢性精神病患者社会功能评定量表（SSSI）、自尊量表（SES）、自我和谐量表（SCCS）进行评估。结果研究组治疗后 SES 总分高于治疗前,SSSI、SCCS 总分低于治疗前（均 P ＜0．05）。对照组治疗后 SES 总分低于治疗前（P ＜0．05）,而治疗前后 SSSI 和 SCCS 总分差异无统计学意义（均 P ＞0．05）。2组治疗后 SSSI、SES、SCCS总分差异均有统计学意义（均 P ＜0．05）。研究组12周随访时与治疗后 SSSI、SES、SCCS 总分比较差异均无统计学意义（均 P ＞0．05）。结论结构式团体心理治疗可以明显改善康复期精神分裂症患者的社会功能,且治疗效果相对稳定、持久。     

关于工程公司走向国际市场的几点思考

介绍了国内工程公司向国际市场开拓过程中,应引起重视的一些问题及解决方法。     

Selective leaching of chromium-containing slag by HCl

A batch of column experiments was carried out to investigate the change of Cr（Ⅵ） concentration leached out from chromium-containing slag with HCI as leaching agent, and to study influences of pH, ratio of solid mass to solution volume, flow velocity and temperature on Cr（Ⅵ） leaching. The optimal parameters were obtained for Cr（Ⅵ） leaching and a fitting model was established to describe the procedure of Cr（Ⅵ） leaching. The results show that Cr（Ⅵ） concentration in leachate increases with decreasing pH and increasing flow velocity and temperature. Moreover, Cr（Ⅵ） leaching percentage increases with increasing ratio of solid mass to solution volume. The optimal parameters for Cr（Ⅵ） selective leaching are as follows： pH=3.0, 1：5 of ratio of solid mass to solution volume, 180 mL/min of flow velocity and 40 ℃ of temperature. The procedure of Cr（Ⅵ） leaching fits well with the model： v= 1.87t^-0.54, indicating that the leaching rate of Cr（Ⅵ） declines in an exponential order of-0.54.     

Inhibitory effect of Cr（Ⅵ） on activities of soil enzymes

To evaluate the influence of various Cr(VI) concentrations (0.05, 0.25, 0.50, 1.00 and 2.00 g/kg) on the activity of soil enzymes, the activities of catalase, polyphenol oxidase, dehydrogenase, alkaline phosphatase in soils were investigated in the incubation experiment with a period of 35 d. The results indicate that all the tested Cr(VI) concentrations significantly inhibit dehydrogenase activity by over 70% after 35 d. The activity of alkaline phosphatase is slightly inhibited during the whole experiment except for on the day 7. Cr(VI) has no obvious effect on the activity of catalase in soil. On the contrary, Cr(VI) stimulates the activity of polyphenol oxidase. The results suggest that dehydrogenase activity can be used as an indicator for assessing the severity of chromium pollution. Foundation item: Projects(2006AA06Z374, 2007AA021304) supported by the National High-Tech Research and Development Program of China; Project(2008SK2007) supported by the Key Program of Science and Technology of Hunan Province, China     

浅谈岩土工程勘察质量在工程建设中的重要性

通过某大型工程建设实例阐述了岩土工程勘察资料的准确性对工程建设的影响 ,及其在工程建设中的重要性。