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A novel strategy of tannery sludge disposal–converting into biochar and reusing for Cr(Ⅵ)removal from tannery wastewater

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Journal of Environmental Sciences 2024年第4期138卷 637-649页

作者： Zhiwei Li Di yu Xingdong Wang Xuejiao liu Zhen Xu Yin Wang CAS Key Laboratory of Urban Pollutant Conversion Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China University of Chinese Academy of Sciences Beijing 100049China Zhejiang Key Laboratory of Urban Environmental Processes and Pollution Control CAS Haixi Industrial Technology Innovation Center in BeilunNingbo 315830China Key Laboratory of Urban Environment and Health Ningbo Observatio

Tannery sludge with high chromium content has been identified as hazardous solid waste due to its potential toxic *** safety disposal and valorization of the tannery sludge remains a *** this study,the chromium stabilization mechanism was systematically investigated during chromium-rich tannery sludge was converted to biochar and the removal performance of the sludge biochar(SBC)for Cr(Ⅵ)from tannery wastewater was also *** results showed that increase in pyrolysis temperature was conductive to the stabilization of Cr and significant reduction of the proportion of Cr(Ⅵ)in *** was confirmed that the stabilization of chromium mainly was attributed to the embedding of chromium in the C matrix and the transformation of the chromium-containing substances from the amorphous Cr(OH)_(3)to the crystalline state,such as(FeMg)Cr_(2)O_(5).The biochar presented high adsorption capacity of Cr(Ⅵ)at low pH and the maximal theoretical adsorption capacity of SBC produced at 800°C can reach 352 mg Cr(Ⅵ)/g,the process of which can be well expressed by Langmuir adsorption isotherm and pseudo second order *** electrostatic effect and reduction reaction were dominantly responsible for the Cr(Ⅵ)adsorption by ***,this study provided a novel strategy for the harmless disposal and resource utilization for the solid waste containing chromium in leather industry.

关键词： Chromium-rich tannery sludge Pyrolysis Biochar Stabilizationmechanisms Cr(Ⅵ)adsorption

An anti-icing scaling method for wind tunnel tests of aircraft thermal ice protection system

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Chinese Journal of Aeronautics 2024年第6期37卷 1-6页

作者： yu liu Qiang WANG Xian YI Ningli CHEN Jinghao REN Weihao LI Key Laboratory of Icing and Anti/de-icing China Aerodynamics Research and Development CenterMianyang 621000China State Key Laboratory of Aerodynamics Mianyang 621000China

The efficiency of the aircraft Ice Protection Systems(IPSs)needs to be verified through icing wind tunnel ***,the scaling method for testing the IPSs has not been systematically established yet,and further research is *** the present study,a scaling method specifically designed for thermal IPSs was derived from the governing equation of thin water *** scaling parameters were adopted to address the heat and mass transfer involved in the thermal anti-icing *** method validation,icing wind tunnel tests were conducted using a jet engine nacelle model equipped with a bleed air *** non-dimensional surface temperature and runback ice closely matched for both the reference and scaled *** validation confirms that the scaling method is capable of achieving the similarity of surface temperature and the runback ice *** anti-icing scaling method can serve as an important supplement to the existing icing similarity theory.

关键词： Scaling method Ice protection system Water film Anti-icing test Icing wind tunnel

Sensitivity analysis of spacecraft in micrometeoroids and orbital debris environment based on panel method

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Defence Technology（防务技术） 2023年第1期19卷 126-142页

作者： Di-qi Hu Run-qiang Chi yu-yan liu Bao-jun Pang Hypervelocity Impact Research Center Harbin Institute of Technology150080HarbinChina

To reduce the risk of mission failure caused by the MM/OD impact of the spacecraft,it is necessary to optimize the design of the *** survivability assessment is the key technology in the optimal design of *** survivability assessment includes spacecraft impact sensitivity analysis and spacecraft component vulnerability analysis under MM/OD *** impact sensitivity refers to the probability of a spacecraft encountering an MM/OD impact while in *** refers to the probability that each component of a spacecraft may fail or malfunction when impacted by space *** this paper mainly analyzes the impact sensitivity and proposes a spacecraft sensitivity assessment method under the MM/OD environment based on a panel *** this panel method,a spacecraft geometric model is discretized into small panels,and whether they are impacted by MM/OD or not is determined through the analysis of the shielding or shadowing relationships between *** number of impacts on each panel is obtained through calculation,and accordingly the probability of each spacecraft component encountering MM/OD impact can be acquired,thus generating the impact *** paper extracts data from the NASA’s ORDEM2000,the ESA’s MASTER8 as well as the SDEEM2015(Space Debris Environmental Engineering Model developed by HIT),and uses the PCHIP(Piecewise Cubic Hermite Interpolating Polynomial)method to interpolate and fit the size-flux relationship of space *** with linear interpolation and cubic spline interpolation,the fitting results through the method are relatively more *** feasibility of this method is also demonstrated through two actual examples shown in this paper,whose results are close to those from ESABASE,although there are some minor errors mainly due to different debris data *** the cross-check by three risk assessment software-BUMPER,MDPANTO and MODAOST-under standard operating condit

关键词： Shielding algorithm Panel method Spacecraft Sensitivity

Charge structures and cloud-to-ground lightning discharges characteristics in two supercell thunderstorms

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Chinese Science Bulletin 2006年第2期51卷 198-212页

作者： ZHANG Yijun MENG qing LU Weitao Paul Krehbiel liu Xinsheng ZhOU Xiuji Chinese Academy of Meteorological Sciences Beijing 100081 China New Mexico Institute of Mining and Technology Socorro New Mexico 87801 USA Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China

The charge structures and temporal and spatial characteristics of cloud-to-ground (CG) light- ning discharges in two supercell thunderstorms have been analyzed based on the data of three-dimen- sional VHF radiation sources with high time and space resolution produced by lightning discharges. The results indicate that the charge structures in main part (convective region) of the thunderstorms were inverted tripole while a number of positive CG lightning discharges were occurring in the two thun- derstorms. The positive CG lightning discharges oc- curred in main part of the thunderstorms and origi- nated from the positive charge region located at the middle part of the thunderstorms. While a number of negative CG lightning discharges were occurring, the negative CG lightning discharges occurred in the anvil of the thunderstorm. The charge structure is inverted dipole in the region due to the slant of charge structure in main region toward anvil region. The negative charge region located at the upper part of anvil produced a lot of negative CG lightning dis- charges. No or less CG lighting was produced di- rectly by the charge region located at the lower part of the thunderstorm. The charge region in lower part of the thunderstorm plays an important role for the occurrence of CG lightning from charge region above it.

关键词：雷暴电荷结构云地闪电放电特征

PTEN knockdown with the Y444F mutant AAV2 vector promotes axonal regeneration in the adult optic nerve

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Neural Regeneration Research 2018年第1期13卷 135-144页

作者： Zheng-ru Huang Hai-ying Chen Zi-zhong Hu Ping Xie qing-huai liu Department of Ophthalmology the First Affiliated Hospital of Nanjing Medical University Nanjing Jiangsu Province China Department of Ophthalmology the Second People's Hospital of Changshu Changshu Jiangsu Province China

The lack of axonal regeneration is the major cause of vision loss after optic nerve injury in adult mammals. Activating the PI3K/AKT/mTOR signaling pathway has been shown to enhance the intrinsic growth capacity of neurons and to facilitate axonal regeneration in the central nervous system after injury. The deletion of the mTOR negative regulator phosphatase and tensin homolog （PTEN） enhances regeneration of adult corticospinal neurons and ganglion cells. In the present study, we used a tyrosine-mutated （Y444F） AAV2 vector to efficiently express a short hairpin RNA （shRNA） for silencing PTEN expression in retinal ganglion cells. We evaluated cell survival and axonal regeneration in a rat model of optic nerve axotomy. The rats received an intravitreal injection of wildtype AAV2 or Y444F mutant AAV2 （both carrying shRNA to PTEN） 4 weeks before optic nerve axotomy. Compared with the wildtype AAV2 vector, the Y444F mutant AAV2 vector enhanced retinal ganglia cell survival and stimulated axonal regeneration to a greater extent 6 weeks after axotomy. Moreover,post-axotomy injection of the Y444F AAV2 vector expressing the shRNA to PTEN rescued ～19% of retinal ganglion cells and induced axons to regenerate near to the optic chiasm. Taken together, our results demonstrate that PTEN knockdown with the Y444F AAV2 vector promotes retinal ganglion cell survival and stimulates long-distance axonal regeneration after optic nerve axotomy. Therefore, the Y444F AAV2 vector might be a promising gene therapy tool for treating optic nerve injury.

关键词： nerve regeneration optic nerve axotomy gene therapy Müller cell retinal ganglion cell AAV2 shRNA PTEN GLAST mTOR neural regeneration

Multiple advanced surgical techniques to treat acquired seminal duct obstruction

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Asian Journal of Andrology 2014年第6期16卷 912-916页

作者： Hong-Tao Jiang Qian yuan yu liu Zeng-Qin liu Zhen-yu Zhou Ke-Feng Xiao Jiang-Gen Yang Department of Urology Shenzhen People's Hospital Shenzhen 518020 China Department of Laboratory Medicine Shenzhen People's Hospital Shenzhen 518020 China

The aim of this study was to evaluate the outcomes of multiple advanced surgical treatments （i.e. microsurgery, laparoscopic surgery and endoscopic surgery）for acquired obstructive azoospermia. We analyzed the surgical outcomes of 51 patients with suspected acquired obstructive azoospermia consecutively who enrolled at our center between January 2009 and May 2013. Modified vasoepididymostomy, laparoscopically assisted vasovasostomy and transurethral incision of the ejaculatory duct with holmium laser were chosen and performed based on the different obstruction sites. The mean postoperative follow-up time was 22 months （range： 9 months to 52 months）. Semen analyses were initiated at four postoperative weeks, followed by trimonthly （months 3, 6, 9 and 12） semen analyses, until no sperm was found at 12 months or until pregnancy was achieved. Patency was defined as 〉10,000 sperm m1-1 of semen. The obstruction sites, postoperative patency and natural pregnancy rate were recorded. Of 51 patients, 47 underwent bilateral or unilateral surgical reconstruction; the other four patients were unable to be treated with surgical reconstruction because of pelvic vas or intratesticular tubules obstruction. The reconstruction rate was 92.2% （47/51）, and the patency rate and natural pregnancy rate were 89.4% （42/47） and 38.1% （16/42）, respectively. No severe complications were observed. Using multiple advanced surgical techniques, more extensive range of seminal duct obstruction was accessible and correctable; thus, a favorable patency and pregnancy rate can be achieved.

关键词： azoospermia endoscopy laparoscopy male infertility microsurgery

Chlorine drying with hygroscopic ionic liquids

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Green Energy & Environment 2021年第3期6卷 350-362页

作者： Gangqiang yu Chengna Dai Bin Wu Ning liu Biaohua Chen Ruinian Xu College of Environmental and Energy Engineering Beijing University of TechnologyBeijing100124China

The chlorine(Cl2)drying technology using ionic liquids(ILs)as absorbents was proposed for the first time and systematically investigated from the molecular level scaled up to the industrial *** hygroscopic IL[EMIM][CH3SO3]was screened as a suitable absorbent from 238 potential IL candidates consisting of 14 cations and 17 anions,by calculating the Cl2 and H2O solubility and separation selectivity of Cl2 to H2O in different ILs based on the COSMO-RS *** microscopic atomic and molecular insights into the separation mechanisms were deeply revealed by using COSMO-RS model analyses(i.e.,σ-profiles,σ-potentials,excess enthalpies,entropies,and Gibbs free energies)and quantum chemistry calculation(binding energies and weak interaction analyses).The Cl2 solubility in pure IL and H2O+IL systems were predicted by the COSMO-RS model,and the results agree with the microscopic mechanism ***,the strict equilibrium stage model employed with the COSMO-RS model parameters was built to perform the process simulation,and continuous Cl2 drying with ILs was conceptually designed and optimized at industrial *** was confirmed that[EMIM][CH3SO3]is a very promising absorbent leading to a less IL amount,a much lower energy consumption than the other IL[EMIM][BF4],which has a very bright industrialization potential used for Cl2 drying technology.

关键词： Ionic liquid Chlorine drying COSMO-RS model Quantum chemistry calculation Process design

Model for Influences of Magnetic Fields on Intracellular Calcium Oscillations

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Communications in Theoretical Physics 2009年第7期52卷 168-172页

作者： ZHANG yu-Hong ZHAN Yong ZHAO Tong-Jun CHEN Ya-Fei yuAN Chang-qing School of Sciences Hebei University of Technology Tianjin 300130 China

Based on the model of the two calcium stores developed by Goldbeter, the influence of external magnetic field on the calcium concentration has been discussed. We believe that the cell membrane is a major site of interaction for extremely-low-frequency （ELF） electromagnetic fields, and the permeability of ions can be changed with the changing electromagnetic fields. It is shown that magnetic field initiates intraeellular calcium oscillation with a threshold in flux density, and that the calcium oscillations do not occur if the density of magnetic field is below the threshold. The results of theoretical calculation are consistent with that of the experiment. The intracellular free calcium concentrations of different cells exposed to the same magnetic fields are different from each other. It is indicated that the different behaviors such as oscillation, rise and invariability of calcium concentration are associated with the sort of cells.

关键词： calcium oscillation magnetic fields calcium concentration

Validation of Bacteroidales-based microbial source tracking markers for pig fecal pollution and their application in two rivers of North China

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Frontiers of Environmental Science & Engineering 2020年第4期14卷 139-146页

作者： Youfen Xu Zong Li Ruyin liu Hongxia Liang Zhisheng yu Hongxun Zhang College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China

In China,pig feces is the predominant source of excrement produced b y animal *** use or direct discharge of pig feces can result in contamination of natural water *** source tracking(MST)technology can identify the sources of fecal pollution in environmental water,and contribute to the management of pig fecal pollution by local environmental protection ***,the accuracy of such assays can be context-dependent,and they have not been comprehensively evaluated under Chinese *** aimed to compare the performance of five previously reported nig-specific MST assays(PF,Pig-Bac 1 STBR,Pig-Bac2 SYBR,Pig-1-Bac TaqMan,and Pig-2-Bac TaqMan,which are based on Bacteroidales 16S rRNA gene markers)and apply them in two rivers of North *** collected a total of 173 fecal samples from pigs,cows,goats,chickens,humans,and horses across *** PF assay optimized in this study showed outstanding qualitative performance and achieved 100%specificity and ***,the two SYBR green qPCR assays(Pig-Bac1 SYBR and Pig-Bac2 SYBR)cross-reacted with most non-pig fecal *** contrast,both the Pig-l-Bac TaqMan and Pig-2-Bacr TaqMan assays gave 100%specificity and *** these,the Pig-2-Bac TaqMan assay showed higher *** results regarding the specificity of these pig-specific MST assays differ from those reported in Thailand,Japan,and *** the PF and Pig-2-Bac TaqMan assays,a field test comparing the levels of pig fecal pollution in rivers near a pig farm before and after comprehensive environmental pollution governance indicated that pig fecal pollution was effectively controlled at this location.

关键词： Microbial source tracking Pig fecal pollution 16S rRNA genem arkers Pig-specific Bacteroidales