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Critical rainfall intensity for safe evacuation from underground spaces with flood prevention measures

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第9期11卷 668-676页

作者： wei-yun SHAO Department of Civil Engineering Zhejiang University Hangzhou 310058 China

Underground space in urban areas has been expanding rapidly during recent decades, and so has the incidence of fatal accidents and extensive damage to facilities resulting from underground flooding. To evaluate the safe evacuation potential of individual underground spaces in flood-prone urban areas, the hydraulic effects of flood prevention measures, e.g., stacked flashboards or sandbags and elevated steps, were incorporated in a proposed formula for estimating the depth of inundation of an underground floor. A mathematical expression of the critical rainfall intensity for safe evacuation from underground space was established and then evaluated for two types of underground spaces, an underground shopping mall and a building basement. The results show that the critical rainfall intensity for any individual underground space can be determined easily using the proposed analytical or graphical solution. However, traditional underground flood prevention measures cannot improve safety if people refuse to evacuate immediately once water intrudes into the underground space.

关键词： Underground space Safe evacuation potential Flood prevention measures Critical rainfall intensity

Carboxymethyl-β-cyclodextrin for Chiral Separation of Amino Acids Derivatized with Fluorescene-5-isothiocyanate by Capillary Electrophoresis and Laser-induced Fluorescence Detection

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Chinese Chemical Letters 2004年第1期15卷 112-114页

作者： Yu yun CHEN wei WANG wei Ping yang Zhu Jun ZHANG CollegeofChemistryandMaterialsScience ShaanxiNormalUniversityXi＇an710061

A method using carboxymethyl-b-cyclodextrin (CM-b-CD) as selector for chiral separation of amino acids by capillary electrophoresis and laser-induced fluorescence detection was studied. Resolution was better than tha... 详细信息

关键词： Chiral separation amino acids capillary electrophoresis derivatization CM-b-CD.

Long-term effect of vasectomy on spermatogenesis in ,en： a morphometric study

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Asian Journal of Andrology 2013年第3期15卷 434-436页

作者： Yu Xiang Peng Luo yun Cao Zheng-wei yang Morphometric Research Laboratory North Sichuan Medical College Nanchong 637007 China Department of Surgery People's Hospital of Peng'an County Nanchong 638250 China

Spermatogenic damage may occur after vasectomy, and the damage is pressure mediated, occurring when the occluded reproductive tract is unable to accommodate additional sperm produced by the testis. This study aimed to determine the long-term effect of vasectomy on spermatogenesis in humans and clarify how the balance between sperm production in the testis and sperm storage in or removal from the tract might be maintained. During inguinal hernia repair, an open biopsy was performed to obtain testicular tissue blocks from 51 Chinese men （aged ≥ 50 years）, of whom 25 （control group） had not undergone vasectomy and 26 （vasectomized group） had undergone bilateral vasectomy 22-42 years before. Methacrylate resin-embedded testicular sections were made, and morphometric studies were performed using light microscopy. In addition, sizes of the testis and epididymis were estimated with ultrasonography. The testicular tissue blocks obtained from one control and seven vasectomized men consisted almost completely of connective tissue. In the other 43 men, significant differences were not found between the two groups in the testicular or epididymal size, qualitative histology or quantitative parameters including the mean diameter or volume fraction of the seminiferous tubules. In conclusion, sperm production and sperm storage/removal reached a static equilibrium after vasectomy, likely due to spermatogenic degeneration or less sperm production as a result of aging or due to vasectomy-induced testicular （interstitial） fibrosis. Thus, complications that might occur in association with overproduction of sperm and distension of the tract would disappear or be relieved with time.

关键词： histology humans morphometry spermatogenesis testis vasectomy

Legacies and health risks of heavy metals,polybrominated diphenyl ethers,and polychlorinated dibenzo-dioxins/furans at e-waste recycling sites in South China

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Frontiers of Environmental Science & Engineering 2023年第7期17卷 1-10页

作者： Xu Zhao wei Li wei Wang Jingjing Liu yunjiang Yu yang Li Xichao Chen yun Liu State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment South China Institute of Environmental SciencesMinistry of Environmental Protection of the People's Republic of ChinaGuangzhou 510655China

Informal electronic-waste(e-waste)recycling sites pose substantial health risks to surrounding environments and populations,yet they are not properly *** this study,the soil levels of copper,lead,cadmium,eight polybrominated diphenyl ethers(PBDEs),and 18 polychlorinated dibenzo-dioxins/furans(PCDD/Fs)were measured at two e-waste recycling sites in South China between 2014 and *** sites have been abandoned for natural *** results indicate that the mean Cd and PCDD/F levels at Site A in 2019 were higher than those recommended by current safety ***,the highest exposure among children was 1.36×10^(−2)mg/(kg·d)for Cu,followed by 5.05×10^(−3)mg/(kg·d)for Pb,9.71 ng/(kg·d)for PBDEs,and 6.82 ng TEQ/(kg·d)for PCDD/*** were at elevated risk for health problem posed by Pb and Cu exposure at both sites(hazard quotient>1)and by PCDD/Fs at Site *** risk assessment was conducted on the target organs and endpoints of heavy metals and PCDD/*** hazard index(HI)for the target organ mixed-risk of heavy metals was high(HI=1.27),as was that of PCDD/Fs(HI=1.66),which can disrupt endocrine function and pose a risk of reproductive toxicity in *** to incomplete cleaning,contaminants persist in soils over long periods and may harm nearby environments and *** study demonstrates that heavy metal,PBDE,and PCDD/F contamination have not yet been remediated,and intervention is needed to reduce pollution and associated risks in areas affected by e-waste.

关键词： E-waste Human health risk Organ risk Heavy metal toxicity PBDE PCDD/F

Determination of metoprolol in rabbit blood using capillary electrophoresis with laser-induced fluorescence detection

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Chinese Chemical Letters 2011年第3期22卷 350-353页

作者： Yu yun Chen wei Ping yang Zhu Jun Zhang College of Environmental Science and Engineering Chang'an University Xi'an 710054 China Education School of Nationalities Shaanxi Normal University Xi'an 710062 China Department of Chemistry Shaanxi Normal University Xi'an 710062 China

This work described a sensitive method for determination of metoprolol in rabbit *** method involved purification by ultrafiltration,derivatization with fluorescein isothiocyanate,determination by capillary electrophoresis（CE） coupled with laser-induced fluorescence（LIF） *** components in plasma including a variety of amino acids and proteins did not interfere with the determination of metoprolol in experimental *** assay had a wide range（2.0-500 ng/mL） of linearity and a detection limit of 0.8 ng/*** intra- and inter-day precisions were satisfactory with relative standard deviation（RSD） less than 10.0%and accuracy within 10.0%.This method was successfully applied to pharmacokinetic study of metoprolol in rabbit blood.

关键词： Capillary electrophoresis Metoprolol Laser-induced fluorescence Ultrafiltration Pharmacokinetic

Inverse Estimation of Transient Heat Flux to Slab Surface

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Journal of Iron and Steel Research International 2012年第11期19卷 13-18页

作者： CUI Miao yang Kai LIU yun-fei GAO Xiao-wei State Key Laboratory of Structural Analysis for Industrial Equipment Dalian University of TechnologyDalian 116024 Liaoning China

The transient heat flux was calculated using a model for inverse heat conduction problems based on temper- ature measurements. The unknown heat flux was taken as an optimization variable and solved by minimizing the differences between the calculated temperatures and the measured ones. Several examples were given to show the ef- fectiveness and the accuracy of the inverse algorithm in estimating the transient heat flux to a slab surface. The re sults show that the inverse approach can be applied in the steel industry or in other areas where the target of investi- gation is inaccessible to direct measurements or difficult to be directly modeled.

关键词： transient heat flux inverse estimation reheating furnace least-square method sensitivity analysis

Hydrothermal Synthesis and Crystal Structure of Complex Mn_2(phen)_2(p-MBA)_4(H_2O)

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Chinese Journal of Structural Chemistry 2008年第2期27卷 149-152页

作者： yang Ying-Qun LI Chang-Hong LI wei KUANG yun-Fei Department of Chemistry and Materials Science Hengyang Normal University Hengyang 421008 China Department of Chemical Engineering Hunan Institute of Technology Hengyang 421002 China

A novel Mn（Ⅱ） complex Mn2（phen）2（p-MBA）4（H2O） has been hydrothermally synthesized by the reaction of p-methyl benzoic acid （p-MBA） with 1,10-phenanthroline （phen）. Crystal data for this complex： monoclinic, space group C2/c, a= 2.3328（3）, b =1.5549（2）, c = 1.5557（2） nm, β = 121.726（2）°, V= 4.7997（11） nm^3, Mr = 1028.85, Dc = 1.424 g/cm^3, Z = 4, F（000） = 2128, μ（MoKa） = 0.590mm^-1, GOOF = 1.060, R = 0.0333 and wR = 0.0767. In the crystal, each Mn（Ⅱ） ion is coordinated by two nitrogen atoms from one o-phenanthroline molecule, three oxygen atoms from three p-methyl benzoic acids and one oxygen atom from one water molecule, giving a six-coordinate distorted octahedral coordination geometry. Two neighboring Mn（Ⅱ） ions are bridged by two p-methyl benzoic acid groups and one water molecule, and their end positions are respectively coordinated by one 1,10-phenanthroline and one p-methyl benzoic acid molecule, giving a binuclear cage structure, of which the Mn（Ⅱ）…Mn（Ⅱ） distance is 0.3502 nm.

关键词： Mn(Ⅱ) complex hydrothermal synthesis crystal structure

Synthesis, Crystal Structure and Electrochemical Properties of a One-dimensional Chain Coordination Polymer [Cu(phen)(2,4,6-TMBA)_2(H_2O)]_n

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Chinese Journal of Structural Chemistry 2008年第2期27卷 210-214页

作者： LI wei LI Chang-Hong yang Ying-Qun KUANG yun-Fei Department of Chemistry and Materials Science Hengyang Normal University Hengyang 421008 China Department of Chemical Engineering Hunan Institute of Technology Hengyang 421002 China

A one-dimensional chain coordination polymer [Cu（phen）（2,4,6-TMBA）2（H2O）]n has been synthesized by reacting 2,4,6-trimethyl-benzoic acid, 1,10-phenanthroline and Cu（Ⅱ） perchlorate and its structure was characterized. Crystal data for this complex： tetragonal, space group I41, a = 2.0293（3）, b = 2.0293（3）, c = 1.3758（2） nm, α =β= γ = 90°, V= 5.6657（13） nm3, Dc= 1.379 g/cm3, Z = 8, μ（MoKa） = 0.815 mm-1, Mr = 588.14, F（000） = 2456, S = 1.047, R = 0.0459 and wR = 0.1053. The crystal structure shows that two neighboring Cu（Ⅱ） ions are linked together by one bridging-chelating 2,4,6-trimethyl-benzoic group, forming a one-dimensional chain structure. Each Cu（Ⅱ） ion is coordinated with two nitrogen atoms from one 1,10-phenanthroline molecule, three oxygen atoms from three 2,4,6-trimethyl-benzoic acid molecules and one oxygen atom from one water molecule, giving a six-coordinate distorted octahedral coordination geometry. The cyclic voltammetry behavior of the complex was also investigated.

关键词： Cu(Ⅱ) coordination polymer crystal structure electrochemical property analysis

Design method of reusable reciprocal invisibility and phantom device

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Chinese Physics B 2022年第8期31卷 382-390页

作者： Cheng-Fu yang Li-Jun yun Jun-wei Li School of Information Science and Engineering Yunnan Normal UniversityKunming 650500China

Reusable reciprocal invisibility and phantom device is proposed and designed based on multi-folded transformation optics and equivalent components. In comparison with the reported reciprocal invisibility cloaks, the material parameters of the device presented here are homogeneous, and the hiding of the target object does not require any “anti-object” at all,which dramatically breaks through the limitations of the “anti-object” design in previous reciprocal cloak design. Perfectly illusion effect is also found by reasonably setting the material parameters of the restored medium of the device, which can be used to confuse detection radars while hiding target objects. Last but not least, the proposed device has an open structure,which enables the target object enclosed by the device to perform material exchange and simplex transfer of information with the outside world through open channels. In other words, the proposed device has a reusable function, enabling stealth or phantom of new target objects without changing any parameters of the device.

关键词： transformation optics reciprocal cloak illusion invisibility