基于“90后”大学生特点的高校辅导员工作方法

经济全球化和信息网络技术的发展,为高校大学生的思想政治工作既提供了机遇,也带来了诸多挑战。面对9"0后"思想叛逆、社会意识淡薄、功力倾向严重等现象,高校辅导员思想政治工作要引导学生融入校园精神文明建设,加大心里健康教育并正确运用网络。     

Severe drought and the vitamin A status of rural pre-school children in India

A community-based cross-sectional study was carried out in six drought-affected areas of India in 2003 to assess the impact of drought on the vitamin A status of 3,657 rural pre-school children. The prevalence of Bitot's spots was found to be significantly (p < 0.01) higher (1.8 per cent) during drought (odds ratio (OR) = 2.0; 95 per cent confidence interval: 1.6 -2.7). The dietary intake of vitamin A was lower during drought and in 81 per cent of households it was less than 50 per cent of the recommended rate. Severe drought has an adverse impact on the vitamin A status of rural pre-school children, particularly those with illiterate mothers and belonging to an older age group (p < 0.01). Communities need to be sensitised, therefore, to vitamin A deficiency through health and nutrition education, and there needs to be wider coverage of vitamin A supplementation, particularly among children in drought-affected and drought-prone areas.     

珠江三角洲土地利用变化空间自相关分析

通过对复杂土地利用地学现象的空间与时间上的综合表达和描述,可揭示土地利用时空结构演变的内在规律,可以为研究区土地资源的合理利用、优化配置和可持续发展提供科学依据。本文利用珠江三角洲1990-2005年的土地利用数据,采用空间自相关分析方法对珠江三角洲土地利用／覆盖变化的空间特征进行了实证研究。通过对研究区全域空间自相关、单变量区域空间自相关、双变量区域空间自相关的计算,表明研究区土地利用／覆盖的全域空间自相关较弱,土地利用和开发存在随机性。单变量区域空间自相关和双变量区域空间白相关在不同区域、不同时期显现不同形态,揭示了研究区内部发展的差异性。空间自相关分析方法可直观地显示分析结果,不失为一种深入理解区域土地利用格局和变化的重要和有益的方法。     

基于人工蜂群算法的边坡最危险滑动面搜索

将用于连续数值优化问题的人工蜂群算法引入边坡稳定分析临界滑动面搜索领域.该方法模拟了蜂群的群体协作采蜜过程,具有自适应收敛的特点,克服了传统方法容易陷入局部最优的缺点,是一种全局优化算法.为进一步改善其在复杂边坡搜索中的效果,将Hooke-Jeeves模式搜索操作引入人工蜂群算法,提出一种用于边坡临界滑动面搜索的模式搜...     

Repetitive Strain in Nonrepetitive Work: A Case Study

In a Québec factory, a woman in a nontraditional job suffered from epicondylitis whereas her male coworkers were unaffected. A study was undertaken in order to enumerate the operations at risk for epicondylitis. Workers were interviewed in order to identify difficult operations and systematic observations were done over 4 work days. Although tasks were extremely varied, certain movements at risk for epicondylitis were repeated many times. Fifty-three valves were turned against resistance as part of this job, and one valve requiring a particularly difficult movement was turned 20 times in one day. There were at least 61 operations at risk for epicondylitis per day over a 4-day period. Strain on the elbow joint was particularly intense for the woman worker because the design of the workplace gave an advantage to taller workers with larger hands. Although this case study does not permit us to conclude that the worker’s epicondylitis was due to her job, it enables us to suggest that it would be wise to adapt the dimensions of relevant equipment and worksites to a wider range of potential worker sizes. We also raise some questions about the definition of repetitive strain in epidemiological studies. We suggest that it may be necessary to consider not only the cycle time but also the total of forces exerted on a joint in order to study workplace injuries to the musculoskeletal system.     

染料废水的X射线粉末衍射分析

染料生产过程的废水，其中含有致癌，致畸的有毒物质，通常需经生化处理后才排放，但生化处理并不能使其毒性消除骀尽，所以对处理后排放废水的进一步分析是当今环保分析中的一个重要课题，分光光度法，高压液相色谱及色－质联用仪是作微量分析的常用方法，但难以分析难挥发物和悬浮物，我们尝试用Ｘ射线粉末衍射分析法对分离废水得到的固态难挥发物作了分析，证明此法准确，快捷，可推广，但对胶状物或含量过低的物质则不适用。     

Urinary multiple marker screening for down's syndrome

We have examined the possibility of using multiple markers in maternal urine rather than serum in order to screen for Down's syndrome. Urine samples were available from 36 cases (24 Down's syndrome, five Edwards' syndrome, three Turner's syndrome, one Klinefelter's syndrome, one triploidy, one triple-X, one twin discordant for Down's syndrome) and 294 controls, including three twins. Three markers were tested: the β-core fragment of human chorionic gonadotrophin (hCG), total oestrogen (tE) and the free a subunit of hCG. Levels were corrected for creatinine excretion and expressed as multiples of the gestation-specific median (MOM) level from the singleton controls. The median value for the singleton Down's syndrome cases was 6.02, 0.74, and 1.08 MOM for β-core-hCG, tE, and a-hCG, respectively. The increases in β-core-hCG and the reduction in tE levels were highly significant (P<0.0001 and 0.005, respectively; Wilcoxon rank sum test) but the increase in free a-hCG was not (P=0.40). On the basis of a mathematical model, the expected detection rate for a 5 per cent false-positive rate was 79.6 per cent for β-core-hCG alone, which increased to 82.3 per cent when combined with tE. Aneuploidies other than Down's syndrome were characterized by low levels of tE and either low or high β-core-hCG.     

对硝基苯胺－H酸分光光度法测定水中亚硝酸盐

为提高光度法测定水中亚硝酸盐的分析灵敏度，利用亚硝酸离子在盐酸介质中与对硝基苯胺发生重氮化反应，然后在碱性介质中与Ｈ酸偶联，生成紫红色偶氮化合物。对实验条件进行了试验，提出了污染水中亚硝酸盐的测定方法，其最大吸收波长λｍａｘ＝５７４ｎｍ，摩尔吸光系数ε５７４＝４．８×１０４。此方法简便、快速、选择性好，灵敏度高，测定结果可靠。     

紫叶李叶片色素含量及叶绿素荧光动力学参数对SO2胁迫的响应

以盆栽紫叶李的2年生嫁接苗为试材,采用人工静态熏气装置分析了不同浓度SO2(0～22.8 mg·m-3)胁迫条件下(16d)紫叶李叶片光合色素含量及荧光动力学参数的变化情况.研究结果显示:在SO2浓度为5.7Mg·m-3的胁迫下,叶绿素a(Chla)、叶绿素b(Chlb)、Chla/Chlb、总叶绿素和类胡萝卜素(Car)含量均比对照增加,在其它浓度处理下均减小,且与对照间差异显著(11.4mg-3m胁迫下叶绿素a和类胡萝卜素除外).在SO2浓度小于11.4mg·m-3时,紫叶李叶片花青苷和类黄酮含量随着胁迫强度的增强而增加(与对照间差异显著,P<0.01);而在SO2浓度大于11.4rag·m-3时则随着胁迫强度的增强而降低(与对照间差异显著,P<0.01).荧光动力学参数中,PSⅡ原初光能转化效率Fv/Fm随着胁迫强度的增强呈现先增加后降低的变化趋势,PSlI潜在活性Fv/F.、光化学淬灭效率qP随着胁迫强度的增强而减小,而荧光非光化学淬灭效率gN 却随着胁迫强度的增强而增加.研究结果表明,紫叶李苗木在低浓度SO2 (小于11.4mg·m-3)胁迫下通过自身较强的保护系统使机体免受伤害;而在高浓度SO2(大于11.4rag·m-3)胁迫下通过增加qN耗散过剩的光能和提高qbPSⅡ消耗多余能量来保护光合器官免受损伤,但叶片的光合色素含量和其它荧光参数均受到不同程度的影响,紫叶李叶片受到伤害与PsⅡ反应中心失活有关.     

广西海域优先关注问题甄别及对策探讨

《广西北部湾经济区发展规划》已获得国务院批准实施,广西沿海地区进入了快速发展时期。在经济快速发展过程中,海洋环境污染、海洋生态损害、海洋灾害、海洋物理条件改变、海洋环境管理等方面的问题都会存在。针对不同环境问题对食品安全、人群健康、海洋资源、生态系统健康、其他经济和社会价值（如文化价值）等方面的影响,通过采用表格法和权重法,甄别广西海洋优先关注问题,确定各类环境问题优先关注次序,针对这些问题,提出相应的对策。