[Progress in preparation of plant biomass-derived biochar and application in pesticide residues field]. [PDF]
Zhang X, Zhen D, Liu F, Peng Q, Wang Z.
europepmc +1 more source
为了提高杆塔接地装置的降阻效率,通过电磁分析软件CDEGS建模,研究了降阻材料敷设厚度和敷设位置对接地电阻的影响。结果表明:随着降阻材料敷设厚度的增加,一维直线型接地装置的工频接地电阻和冲击接地电阻的降低呈现出先快后慢的趋势,并且土壤电阻率越高,接地电阻降幅越明显。至于敷设位置,对于放射型接地极,土壤电阻率为100~2 000Ω·m时,对射线敷设就可以达到全部敷设的降阻效果。对于复合型接地极,仅射线敷设和仅垂直接地极敷设降阻效果相同。土壤电阻率为2 000Ω·m时,射线 ...
马超 +4 more
doaj
[Applications of functional materials-based solid phase microextraction technique in forensic science]. [PDF]
Xie WY +8 more
europepmc +1 more source
对接地工程上相关参数的取值与降阻方法存在的误区进行了分析。变电站工频接地电阻目标值应根据最大接地短路电流值确定,在接地设计中应注意避免将接地电阻目标值与计算值混淆使用。在接地工程实践中发现,当下层土壤电阻率远小于上层土壤电阻率时,可以采用深井接地法;数学模型计算结果表明,深井接地极应设置在人工地网四周并保持2倍井深的距离。外延装置的设计应在实测的前提下选择土壤电阻率较低的地区;根据外延接地装置中屏蔽的影响以及对跨步电压的要求,确定外延接地装置金属网格的参数,避免过疏或过密。
李孛, 李景禄
doaj
[Determination of four fungicides in water by magnetic solid phase extraction-ultrahigh performance liquid chromatography-tandem mass spectrometry using covalent organic framework material]. [PDF]
Wang P, Ma J, Li S, Cheng J, Zou Z.
europepmc +1 more source
介绍了非金属接地模块的组成及降阻原理,通过冲击电流试验平台,在不同土壤电阻率下分别对不同大小、不同形状、不同材料的接地体进行冲击电流试验。分析试验数据结果表明,施加不同冲击电流时,相同散流面积下圆柱形接地模块的散流效果比长方体形的散流效果好,冲击电流越大效果越明显;随着接地模块体积和散流面积的增加,降阻效果的增加呈饱和趋势;接地模块的降阻率不随土壤电阻率的改变而改变,土壤电阻率越高,接地模块的降阻效果越好;石墨型接地模块的降阻效果堪比传统金属接地体,石墨部分降阻效果非常明显,为工程应用提供参考。
吴昊 +5 more
doaj
[Determination of 22 organophosphates and their metabolites and 11 phthalate metabolites in human whole blood by ultra performance liquid chromatography-tandem mass spectrometry]. [PDF]
Shi FY, Xu HY, Li JH, Xu MY.
europepmc +1 more source
[Application of non-stationary phase separation hyphenated with inductively coupled plasma mass spectrometry in the analysis of trace metal-containing nanoparticles in the environment]. [PDF]
Jiang H +8 more
europepmc +1 more source
[Matrix solid-phase dispersion extraction of organophosphorus flame retardants in soil based on response surface methodology]. [PDF]
Wang J +6 more
europepmc +1 more source
A case of Elizabethkingia meningoseptica septicemia. [PDF]
Wu L, Ye T, Pan X, Hong L, Shi Y.
europepmc +1 more source

