闽江某河段河蚬组织中多环芳烃和有机氯农药的蓄积特征

用GC／MS和GC-μECD测定了闽江某河段河蚬体内多环芳烃（PAHs）和有机氯农药（OCPs）的含量，并分析了河蚬各器官组织中的蓄积特征．结果表明：河蚬体内鳃、肌肉以及内脏团中检测到的PAHs的总量分别为1322．03，397．24，951．04ng／g干重，河蚬易累积低分子量的PAHs，主要是3环PAHS，鳃、肌肉和内脏团中检测到的3环芳烃的比率分别为62．23％，47．04％和36．96％；河蚬对OCPs的蓄积种类主要是DDT类和HCH类农药，OCPs在河蚬鳃、肌肉以及内脏团中的总含量相差不大，分别为19．73，25．46，23．06ng／g干重，河蚬肌肉和内脏团中OCPs的含量与整体中OCPs的含量相关性较好（R^2=0．98和R^2=0．98），肌肉中含量与整体有机氯的含量相关系数为R^2=0．19．     

氮磷钾配施对土壤氮素累积及烤烟产量品质的影响

通过大田试验研究了不同氮磷钾配施对NH4^＋-N和NO2^- —N在植烟土壤中累积及烤烟产量品质的影响．结果表明：在烤烟团棵期，合理的氮磷钾配施能较大幅度提高0～20cm土层NH4^＋ -N和NO3^- —N的含量，对NH4^＋ -N和NO3^- —N含量的影响随着土层的加深而减弱．不同氮磷钾配施对烤烟产量和品质有较大的影响，重庆市植烟区氮磷钾适宜的比例为1：1．6：2．5，即施用N肥105．45kg／hm^2，P肥168．72kg／hm^2，K肥263．63kg／hm^2烟叶产量最高．     

基于标幺值法的三相PWM整流电源

采用DSP2407控制器、基于标幺值法及电流解耦控制完成了三相两电平PWM整流电源的研制。对基于开关模式的单闭环定频控制和双闭环解耦控制的控制效果进行了分析对比。为了保证整流器系统的稳定,有精确恒定的直流输出电压及良好的网侧电流波形和单位功率因数,提出采用比例调节器代替积分调节器,简化了双闭环解耦电流控制器的设计。实验和仿真结果表明,该控制方案正确、可行,系统性能稳定,闭环参数调整及DSP软件编程简单易行。     

微型流动注射化学发光仪测定蔬菜中残留的有机磷农药

目的利用便携式流动注射化学发光仪和紫外降解装置,检测蔬菜中残留的有机磷农药。方法过硫酸钾在紫外光的催化下能将有机磷降解为无机磷,无机磷在酸性条件下可以和钒酸盐、钼酸盐反应生成具有氧化性的磷钼钒杂多酸,可直接氧化鲁米诺产生强而稳定的化学发光信号;根据发光强度与磷的浓度在一定范围内呈线性关系,从而实现有机磷农药的定量测定。结果测定磷的检出限为1.0×10-10g/mL,线性范围为1.0×10-9~3.0×10-6g/mL,对浓度为2.0×10-7g/mL的磷平行测定11次,相对标准偏差为2.1%;当青菜中有机磷农药的添加浓度为1.00 mg/kg和2.00 mg/kg时,方法回收率在89.5%~113.5%之间。结论此方法简便快捷、准确可靠,实现了检测仪器的自动化和微型化,为市售蔬菜中有机磷农药残留的现场检测奠定了基础。     

陕西省可持续发展预警分析

目的计算陕西省近10年来经济、社会、人口、资源、环境及总系统可持续发展预警值,参照警界划分标准得出各年各系统的预警评价,并预测今后的发展趋势,为宏观调控和决策提供科学依据,促进生态环境与经济社会的可持续协调发展。方法采用层次分析法,建立可持续预警指标体系及预警模型,确定警界划分标准以及相应的警情信号系统,从定量的角度度量陕西省可持续发展状态。结果陕西省总体发展状况逐年提高,但发展水平低,尚处于初级阶段,系统比较脆弱,自我调节能力不强,环境、资源子系统的脆弱性对总系统影响逐渐凸显,必须对发生预警的年份做出反应,否则将威胁系统的运行。结论总系统可持续发展取决于环境、经济、社会各子系统交叉作用的结果,是以人为中心的发展。     

Co ⅩⅦ离子Rydberg态能级的最弱受约束电子势模型理论计算

利用最弱受约束电子势模型的理论，通过对最弱受约束电子的识别，将Martin关于单价原子量子亏损公式推广到多价原子(离子)系统，从而计算了Co ⅩⅦ离子的2p6np2Po1/2,3/2(n=3～20)和2p6nd2D3/2, 5/2(n=3～20)系列Rydberg态的能级，理论计算值与实验值吻合较好，两者的相对误差不超过4.64×10-3%，达到了很高的精度.     

Right prefrontal laterality of Chinese boys during a Chinese high conflict Stroop task measured by multi-channel near-infrared spectroscopy imaging

Some studies have shown that native Chinese speakers have different laterality in matched Stroop tasks from native English speakers. Recently, many imaging data, which show left laterality of English-matched Stroop interference, have been reported. And a few functional imaging studies have been conducted to investigate the phenomenon of the Chinese version of Stroop task. In this study, functional activity in the lateral prefrontal cortex of a group of normal Chinese boys with functional near-infrared imaging during a Stroop color-word task was measured to show different Stroop interferences in the prefrontal cortex. The results show obvious fluctuation of the cerebral blood volume in the right prefrontal cortex in all boys, which agrees with the finding of previous studies, that is, Chinese native boys have right laterality in their brain when the Chinese version of Stroop color-word task is applied.     

Numerical simulation of Meiyu front and the diagnosis of moist vorticity vector

Moist vorticity vector is introduced to study the development and evolution of mesoscale convective vortex (MCV) in the Meiyu front precipitation with the Advanced Regional Predication System (ARPS). In this study, the heavy rainfall is simulated to investigate the genesis, development and dissipation of middle scale convective vortex, which occurred from 0000 UTC 3 July to 1200 UTC 5 July over the Jianghuai River valley. Moist vorticity vector (MVV) has zonal, radial and vertical components in its 3D spatial distribution. The simulation shows that the vertical component of moist vorticity vector well demonstrates the spatial distribution characteristics of middle scale convective vortex, especially in the process of Meiyu front precipitation. Diagnosis upon zonal, radial averaged and mass-integrated quantities of MVV shows that its vertical component and the surface precipitating ratio are in phase with a correlation coefficient of 0.68, indicating that the vertical component of MVV is closely associated with the Meiyu front precipitation. In addition, the tendency of the vertical component of MVV is mainly determined by the interaction between the vorticity and the zonal and radial gradient of condensational or depositional heating.     

煤矿软岩巷道顶底板剪切变形破坏机理

通过石嘴山一矿38区 600 m轨道巷表面收敛监测及变形破坏的研究,总结出了变形破坏特征。以矿山压力假说为前提,对巷道围岩典型破坏特征作出理论推断,建立巷道顶底板的力学模型,并应用关键层理论、块体理论、弹性力学对巷道变形破坏进行理论分析与求解,得出了巷道顶底板发生剪切破坏判定条件,并用FLAC3D数值模拟验证其正确性,为深部巷道支护提供了新的理论依据。     

Right prefrontal laterality of Chinese boys during a Chinese high conflict Stroop task measured by multi-channel near-infrared spectroscopy imaging

Some studies have shown that native Chinese speakers have different laterality in matched Stroop tasks from native English speakers.Recently,many imaging data,which show left laterality of English-matched Stroop interference,have been reported.And a few functional imaging studies have been conducted to investigate the phenomenon of the Chinese version of Stroop task.In this study,functional activity in the lateral prefrontal cortex of a group of normal Chinese boys with functional near-infrared imaging during a Stroop color-word task was measured to show different Stroop interferences in the prefrontal cortex.The results show obvious fluctuation of the cerebral blood volume in the right prefrontal cortex in all boys,which agrees with the finding of previous studies,that is,Chinese native boys have right laterality in their brain when the Chinese version of Stroop color-word task is applied.