Results 111 to 120 of about 717,024 (165)

蔬菜产地土壤重金属含量空间分布研究

Shuitu Baochi Xuebao, 2008
以浙江省湖州市长兴县为例,应用GIS技术研究了蔬菜产区土壤重金属污染状况及空间分布规律。结果表明:长兴县蔬菜产地平均土壤汞和镉含量明显大于本地背景值,锌平均含量也超过背景值,而砷、铬、铅、铜4种重金属的平均含量则低于或接近背景值。长兴县大部分蔬菜产区土壤重金属含量在国家无公害蔬菜基地标准以下,汞、镉超标的样点分别占总样点的10.4%和4.5%,分别有43%和58.0%的样点超过当地汞、镉背景值,土壤汞、镉含量的最大值分别达到945.85 ng/g和478.88 ng/g。蔬菜产区土壤汞 ...
姜丽娜, 王强, 郑纪慈, 顾杰炜, 吴晓荣, 于春兰   +5 more
doaj  

基于网络的自重构机器人重构路径研究

, 2009
文中针对自重构机器人的重构问题提出了一种基于网络的分析方法.自重构模块机器人"AMOEBA-I"的9种不同构形组成了一个构形网络.机器人的每种构形被看成带有权值的有向构形网络中的一个节点.一种构形向另一种构形的转换可描述为一条非负值的有向路径.将图论应用于构形变化的分析,根据构形的拓扑信息相应定义了重构路径、可重构矩阵和路径矩阵.在此基础上,将图论中的算法应用于重构路径的计数和最佳重构路径的选择.数值分析与仿真实验结果验证了该方法的可行性.同时 ...
刘金国, 马书根, 李斌, 王越超
core  

[Impact of overweight and obesity on quality of life and body image satisfaction in school-aged children and the mediating effects on academic performance]. [PDF]

Zhongguo Dang Dai Er Ke Za Zhi
Zhang ZY, Zhang L, Duan XX, Li ZY, Liu HJ, Jiao J, Zhang T, Li Y.   +7 more
europepmc   +1 more source

Distribution characteristics and influencing factors of overweight and obesity among urban and rural primary and secondary school students in Hunan Province. [PDF]

Zhong Nan Da Xue Xue Bao Yi Xue Ban
Qin L, Luo M, Li K, Zhou Y, Chen Y, Tan Y, Wang F.   +6 more
europepmc   +1 more source

[A randomized controlled trial of weight management based on mobile health techno-logy among overweight or obese pregnant women]. [PDF]

Beijing Da Xue Xue Bao Yi Xue Ban
Li P, Wang H, Gao X, Han Y, Wang H, Wang H, Mu Y.   +6 more
europepmc   +1 more source

Association between 24<b>-</b>hour movement behaviors and psychological well<b>-</b>being in overweight and obese children. [PDF]

Zhong Nan Da Xue Xue Bao Yi Xue Ban
Cai W, Liang W, Zhou L, Su N, Zhou J, Yang Y, Liu S.   +6 more
europepmc   +1 more source

[Meta analysis of the prevalence and risk factors of non-alcoholic fatty liver disease in overweight and obese children and adolescents in China]. [PDF]

Zhongguo Dang Dai Er Ke Za Zhi
Xiao Y, Pan YF, Dai Y, Sun YJ, Zhou Y, Yu YF.   +5 more
europepmc   +1 more source

多重雷击下500 kV超高压站内MOA损坏原因分析

Dianci bileiqi
金属氧化物避雷器的优异非线性、良好的陡度响应特性和大的通流容量，在电力系统过电压保护方面作用显著。近年来随着超高压电力网覆盖面扩大，电力系统运行环境愈加复杂，运行中出现了多起在多重雷击情况下500 kV超高压站内MOA损坏事故，损坏的表象大多是MOA电阻片贯穿性炸裂。为了探究多重雷击下500 kV 超高压站内MOA的损坏原因，笔者使用EMTP-RV，结合某次故障实际录波图模拟分析了多重雷侵入波下500 kV站内MOA动作负荷特性和能量积累，并依据MOA固有的温度、能量特性 ...
康超, 王致远, 张宗扬, 郭洁
doaj  

[Effects of overweight and obesity on symptoms, overall condition and quality of life in patients with fibromyalgia syndrome]. [PDF]

Beijing Da Xue Xue Bao Yi Xue Ban
Long M, Wang Y, Wu S, Li Z, Li Y, Li Y, Jiao J.   +6 more
europepmc   +1 more source

Association of whole blood copper, zinc, calcium, magnesium, and iron with non-alcoholic fatty liver disease in overweight and obese children. [PDF]

Zhong Nan Da Xue Xue Bao Yi Xue Ban
Huang Z, Luo M, Dai W, Yao Z, Ouyang S, Xu N, Zhou H, Li X, Zhong Y, Luo J.   +9 more
europepmc   +1 more source