吉林省前郭灌区表层土壤有机氯农药残留水平及生态风险评估

本研究以东北四大灌区之一的前郭灌区农田土壤为研究对象,选用GC/ECD对该地区表层农田土壤中有机氯农药（Organochlorine pesticides,OCPs）中滴滴涕类（DDTs）和六六六类（HCHs）进行分析,并探讨其组成特征和来源.结果表明,前郭灌区表层土壤受OCPs污染较为严重,γ-HCH、p,p＇-DDT和o,p＇-DDT为本区域OCPs的主要残留物.土壤HCHs的污染历史较长,HCHs残留以α-HCH和γ-HCH为主;大部分采样点P,P＇-DDT/（P,P＇-DDD＋P,P＇-DDE）大于1,表明前郭灌区土壤中的DDTs仍有新源输入.生态风险评估结果表明,HCHs对土壤生物的生态风险较低,而DDTs对于土壤中的鸟类消费者具有一定的生态风险.     

一种全息光栅曝光系统结构

采用双透镜组的结构引入补偿镜,使工作波长和装调波长共像面。采用有限元分析方法对机械系统的设计结果进行模态分析,结果表明,该曝光系统具有较高的波前质量和系统稳定性。     

前凉与两晋关系及国祚问题探析

前凉为十六国之一,疆域极盛时涵盖今甘肃、新疆及内蒙古、青海各一部分。前凉政权孕育于张轨时期,脱胎于西晋地方政府---凉州。前凉张氏政权对晋中央王朝的微妙关系,以西晋亡国前后而大相径庭。西晋存国之时,张氏政权极力拥护中央政权。西晋灭亡后,又鉴于领边复杂的民族关系,左右逢源其间,对东晋采取若即若离的策略。纵观前后之异,盖出于凉州本位性和自身利益性的考虑。     

Significant isostatic imbalance near the seismic gap between the M8.0 Wenchuan and M7.0 Lushan earthquakes

A gravity network with 302 observation points has been established in the western Sichuan Foreland Basin （SFB） to explore Bouguer gravity anomalies （BGAs）. Our observational results reveal that the BGAs are negative as a whole, with a maximum value of -220 mGal （10^-5m s^-2） at the northwest region of the study area. The real Moho depths beneath the SFB revealed by BGA data change smoothly from 39.5 km in the southeast to 43.7 km in the northwest of the monitoring region. However, the isostatic ones deduced from Airy isostatic model and topographical data vary approximately 39.5-42.0 km. The maximum differences of 2.7 km between the real and isostatic Moho depths are found near the seismic gap between the M8.0 Wenchuan and M7.0 Lushan earthquakes, where the crust is in the greatest isostatic imbalance of the monitoring region. Analysis of the isostatic state indicates that the deep dynamic environment near the seismic gap between these two earthquakes indicates an M ≥ 7.0 earthquake in the future. This study indicates that we can use isostasy as a potential approach to study the dynamic process of crustal material movement and to analyze regional potential seismic risks.     

A potential ethnic difference in the association between 5-HTTLPR polymorphisms and the brain default mode network

The serotonin-transporter-linked polymorphic region （5-HTTLPR） is associated with mood disorders. This association is thought to be due to amygdala hyper- responsiveness to negative emotional stimuli as a result of reduced frontal cortical control. In Caucasians, the short form is associated with this effect, but in Han Chinese we recently found that the long form is involved. Serotonin receptors have rich expression in default mode network （DMN） regions and the recent studies have found an association between the short form of the 5-HTTLPR and DMN functional connectivity （FC） in Caucasians. The present study has investigated whether there may also be an ethnic difference in this influence of 5-HTTLPR on the DMN. We recruited 233 young Han Chinese subjects and calculated the resting-state default-network FC. Our study found that the L carriers had decreased FC in the bilateral medial prefrontal cortex, right parahippocampal gyrus, left middle temporal gyrus, and increased FC in left precuneus （Pcu） compared to SS. The PCC-Pcu FC in L carriers was significantly negatively correlated with the depression scores. Our findings, therefore, suggest that there is also a difference between Caucasian and Han Chinese subjects in the association between the different forms of the 5-HTTLPR and DMN functional connectivity.     

溴离子对NDMA前体物Chlortoluron的

研究了不同pH下,投加不同浓度的外加溴离子时,NDMA前体物—Chlortoluron的氯化动力学降解情况.实验结果表明,在pH分别为6,7,10,Chlortoluron浓度为9.4μmol·L-1,Cl2浓度为188.0μmol·L-1的条件下,控制投加不同浓度的溴离子时,Chlortoluron的降解仍然符合拟一级动力学模型.当pH分别为6,7时,Chlortoluron的降解速率随着外加溴离子浓度的增加而增大,外加溴离子浓度相同时,偏酸性的环境使Chlortoluron的降解速率更快,这可能与反应体系中HOBr的生成有关.当pH为10时,溴离子浓度的变化对Chlortoluron的降解速率没有显著影响,可能是ClO-与Br-基本不发生反应,从而没有生成HOBr.根据对反应体系的动力学分析,求解了在本实验条件下,不同pH时拟一级反应动力学常数kobs与[Br2]/[Cl2]的线性关系,进而通过求解常微分方程组计算了HOBr与Chlortoluron的反应速率常数(k5=(1.95±0.44)×105).这也从动力学的角度解释了外加溴离子时Chlortoluron氯化速率显著增大的原因.     

塔中北斜坡碳酸盐岩裂缝分布特征叠前叠后综合预测方法

针对塔中北斜坡碳酸盐岩内多期应力作用下形成的裂缝,研究了采用叠前P波方位AVO反演和叠后相干属性相结合的裂缝分布特征预测方法。结果显示,塔中北斜坡碳酸盐岩内发育单组裂缝和多组裂缝,叠后相干属性预测的裂缝多与断裂控制的裂缝分布一致,这些裂缝多发育在断裂破碎带中,由于断裂附近为两个方向的应力释放区,北东向和北西向裂缝都易发育,易形成多组裂缝;叠前P波方位AVO反演预测的裂缝多分布在隆起、背斜顶部,由于隆起、背斜等构造带主要受北东向挤压应力作用,易形成单个方向的裂缝(单组裂缝)。结果表明,叠后预测能够表述裂缝与断裂之间的关系,而叠前预测则能够补充表述断裂之间的裂缝分布,两者结合的预测方法能够更准确地揭示裂缝分布特征,且与塔中北斜坡的地质规律相符合。     

协同设计中的任务调度算法及实现

 在协同设计子任务间形成的任务前趋图的基础上,面向协同设计的实际需求,采用了两个任务调度算法：改进的AGA（Adaptive Genetic Algorithm, 自适应遗传算法）及GASA（Genetic Simulated Annealing Algorithm,遗传-模拟退火算法)。分别给出了算法的详细实现,分析并比较了算法与其它任务调度算法的效能。最后,针对较大规模的任务实例对这两个算法进行了横向比较,分析了它们的时间效率和适用场合。     

阿尔茨海默病与血管性痴呆患者血浆β-微管蛋白和APP的变化

目的: 对阿尔茨海默病(Alzheimers disease, AD)与血管性痴呆(vascular dementia, VD)血浆β-微管蛋白与淀粉样蛋白前体(APP)进行定量分析,分析这些指标的变化是否可以为临床诊断阿尔茨海默病提供生物学方面的帮助.方法:用蛋白免疫印迹法(Western-blot)测定11例AD、11例VD和8个正常老年人血浆β-微管蛋白和APP的水平.结果:(1)血浆APP含量AD患者(84.36±41.34)的高于VD患者(56.34±18.68)和正常人(43.25±27.67), P<0.05;(2)血浆中β-微管蛋白含量AD患者(105.91±41.25)高于VD患者(64.36±28.27)和正常人(52.25±11.11), P<0.05;(3)VD患者和正常人之间APP和β-微管蛋白比较无明显差异(P>0.05).(4)Pearson相关分析显示:血浆中APP和β-微管蛋白含量可能存在一定的相关性,相关系数为0.451(P<0.05).结论:AD患者血浆APP和β-微管蛋白含量明显高于正常人和VD患者,对AD患者血浆APP和β-微管蛋白含量的测定对AD的诊断可能具有一定的意义.     

武术健身在社区体育运动中发展前景之研究

本文运用文献资料法、访问调查法和逻辑分析法,探讨武术健身在社区体育中开展的优势、武术健身在社区体育中发展的对策以及武术健身在社区体育中发展的前号等,旨在为武术健身在社区体育中的广泛开展提供参考。