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The role of metal oxides on oxidant decay and disinfection byproduct formation in drinking waters: Relevance to distribution systems

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Journal of Environmental Sciences 2021年第12期33卷 140-149页

作者： chao Liu Key Laboratory of Drinking Water Science and Technology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China

Maintaining a residual disinfectant/oxidant(e.g., chlorine and chlorine dioxide), is a generally used strategy to control microbial contaminants and bacterial regrowth in distribution systems. Secondarily oxidant, such as hypobromous acid(HOBr), can be formed during chlorination of bromide-containing waters. The decay of oxidants and formation of disinfection byproducts(DBPs) due to the interaction between oxidants and selected metal oxides were studied. Selected metal oxides generally enhanced the decay of these halogencontaining oxidants via three pathways:(1) catalytic disproportionation to yield an oxidized form of halogen(i.e., halate) and reduced form(halide for chlorine and bromine or chlorite for chlorine dioxide),(2) oxygen formation, and(3) oxidation of a metal in a reduced form(e.g., cuprous oxide) to a higher oxidation state. Cupric oxide(Cu O) and nickel oxide(Ni O)showed significantly strong abilities for the first pathway, and oxygen formation was a side reaction. Cuprous oxide can react with oxidants via the third pathway, while goethite was not involved in these reactions. The ability of Cu O on catalytic disproportionation of HOBr remained stable up to four cycles. In chlorination process, bromate formation tends to be important(exceeding 10 μg/L) when initial bromide concentration is above 400 μg/L in the presence of dissolved organic matter. Increasing initial bromide concentrations increased the formation of DBPs and calculated cytotoxicity, and the maximum was observed at p H8.6 during chlorination process. Therefore, the possible disinfectant loss and DBP formation should be carefully considered in drinking water distribution systems.

关键词： Cupric oxide Disproportionation Bromine Bromate Chlorine dioxide Chlorate

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改进TD3算法的机械臂三维路径规划方法

电光与控制 2025年第1期32卷 100-105页

作者：马天李超杨嘉怡西安科技大学计算机科学与技术学院西安710000

在军事航空领域中,复杂任务对机械臂路径规划提出了挑战。针对双延迟深度确定性策略梯度(TD3)算法学习效率低、样本利用率低的问题,提出了一种改进的TD3算法(Recurrent-TD3算法)。首先,将LSTM结合到策略网络与价值网络中,捕获航空控制... 详细信息

在军事航空领域中,复杂任务对机械臂路径规划提出了挑战。针对双延迟深度确定性策略梯度(TD3)算法学习效率低、样本利用率低的问题,提出了一种改进的TD3算法(Recurrent-TD3算法)。首先,将LSTM结合到策略网络与价值网络中,捕获航空控制任务中的时间序列信息,增强对时间序列变化的响应能力,使其能够在决策时考虑历史动作和状态,提高网络的表达能力;然后,将事后经验回放(HER)技术集成到TD3算法中,以解决任务中稀疏奖励难以学习的问题,通过将未达到目标的经验转化为达到新目标的经验,从而更有效地利用样本;最后,设计了一种基于包围盒的碰撞检测流程,以提高机械臂在军用航空任务中的安全性。实验表明,该算法相比于其他算法能够更快地找到一条无碰撞的路径,且平均路径长度最短。

关键词：机械臂路径规则 TD3 长短期记忆网络事后经验回放技术

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急性阑尾炎手术患儿住院期间切口感染的发生率及相关因素的分析

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罕少疾病杂志 2025年第1期32卷 124-126页

作者：晁帅晁阳曹冬晓河南省漯河市召陵区中医院急诊科河南漯河462000 河南省漯河市召陵区中医院妇产科河南漯河462000

目的分析急性阑尾炎(AA)手术患儿住院期间切口感染(SSI)发生率及相关因素分析。方法回顾性分析法选择2022年7月至2023年7月68例AA手术患儿的临床资料,依据住院期间是否发生SSI进行分组,将评估出SSiIi者划分为发生组,未评估出感染者则划... 详细信息

目的分析急性阑尾炎(AA)手术患儿住院期间切口感染(SSI)发生率及相关因素分析。方法回顾性分析法选择2022年7月至2023年7月68例AA手术患儿的临床资料,依据住院期间是否发生SSI进行分组,将评估出SSiIi者划分为发生组,未评估出感染者则划分为未发生组,收集2组患儿疾病相关.特征、一般资料,分析AA手术患儿住.院期间发生SSI相关因素,通过Logstc回归分析有差异项目。结果68例AA手术患儿中19例发生SSI,发生率为2794%,未发生SS.I共有49例,占比7206%;2组年龄、体征指数(BMI)、性别、基础疾病、切口类型、切口方法、切口保.护、术前CRPi水i平比较发生无统计学意义(P>005),发生组使用预防性抗菌药物、留置腹腔引流管、手术时间、阑尾穿孔和未发生组存在显著差异(P<005);采取Logstc回归方程计算上述有差异的项目,发现使用预防性抗菌药物、留置腹腔引流管、手术时间、阑尾穿孔是AA患儿发生SSI的危险因素。结论AA手术患儿住院期间发生SSI的因素存在多种,如使用预防性抗菌药物、留置腹腔引流管、手术时间、阑尾穿孔,临床需高度引起重视,最大程度降低SSI发生风险。

关键词：急性阑尾炎住院期间切口感染留置腹腔引流管阑尾穿孔

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Pristine atmospheric condition over the Third Pole:An insight from levoglucosan records

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Geoscience Frontiers 2021年第2期12卷 851-856页

作者： chao Xu chao You Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China Key Laboratory of Tibetan Environment Changes and Land Surface Processes Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China College of Environment and Ecology Chongqing UniversityChongqing 400044China

Expanding urbanization and agricultural intensification across neighboring South Asia and East Asia have substantially threatened atmospheric condition over the Third Pole(TP)during the past few *** the atmospheric condition over the TP is still as clean as a representative of the regional background draws great *** this work,great differences in levoglucosan concentration within/above the atmospheric boundary layer height are *** results support the hypothesis that atmospheric pollutants in the mid-troposphere over the TP are mainly affected by long-range transport,although there are some local biomass burning emissions in residential *** addition,levoglucosan concentration in the midtroposphere over the TP is at the same magnitude as marine and polar regions,but about 2–3 magnitudes lower than neighboring densely-populated Asian *** insights of levoglucosan records,this work therefore proves that the high-altitude TP still has largely pristine atmospheric conditions,and is one of the cleanest remote regions on the Earth.

关键词： Pristine atmospheric condition Levoglucosan Third Pole Glacier Mid-troposphere

Women scientists in China: current status and aspirations

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National Science Review 2021年第10期8卷 159-163页

作者： chao Gu the Department of History of Science Technology and Medicine Peking University

Throughout history, gender inequality has persisted in most parts of the world. Since the founding of the People’s Republic of China(PRC) in 1949, substantial progress has been made towards gender equality in China. Today, a large number of Chinese women scientists are making significant contributions to advance science.

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Environmental significance of levoglucosan records in a central Tibetan ice core

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Science Bulletin 2019年第2期64卷 122-127页

作者： chao You Tandong Yao chao Xu Key Laboratory of Tibetan Environment Changes and Land Surface Processes Institute of Tibetan Plateau Research Chinese Academy of Sciences Center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of Sciences

The environmental significance of levoglucosan(LEV) records in Tibetan glacier ice layers on sub-annual to annual scales, in particular their suitability as a specific biomarker for indicating past fire changes, is poorly understood at present. In this work, a continuous LEV record was reconstructed in a central Tibetan ice core for the period 1990–2012. The LEV record was classified into two categories based on its LEV concentrations: background levels and extreme events. Annually-resolved LEV records and background levels in the ice core were strongly correlated with satellite observations of fire occurrence frequency over the northern Indian peninsula between 2003 and 2012, especially for strong fire events during the pre-monsoon season(March–May). In addition, peaks in LEV concentrations may represent extreme fire events in regions around the Tibetan Plateau. LEV records in the ice core reflect a longterm increasing trend in fire background and also an increase in fire extreme events, across the Tibetan Plateau and its surroundings. We therefore conclude that LEV records in Tibetan ice cores can be used as a powerful tool for calibrating and reconstructing past fire changes over subtropical Asia.

关键词： Fire variation Levoglucosan Ice core Tibetan Plateau Subtropical Asia

Mode shape description of an aero-engine casing structure using Zernike moment descriptors

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航空动力学报 2011年第4期26卷 760-770页

作者： LIU Ying-chao ZANG chao-ping College of Energy and Power Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

Vibration mode shape description of an aero-engine casing structure using Zernike moment descriptor(ZMD) was introduced in this *** mode shapes of the aero-engine casing structure can be decomposed as a linear combination of a series of Zernike polynomials,with the feature of each Zernike polynomial reflecting a part of characteristic of mode shapes,based on Zernike moment ***,the reconstruction of mode shapes with ZMD was explored and its ability to filtering the noise contaminated in the mode shapes was *** of the aero-engine casing structure indicated the advantage of this method to depict the mode shapes of a symmetric *** demonstrate that the Zernike moment description of the mode shapes can effectively describe the double modes in the symmetric structure and also has the ability to remove or significantly reduce the influence of noise in the mode *** feature shows great practical value for further research on the correlation,model updating and model validation of the symmetric structure's finite element model.

关键词： Zernike mode shape modal assurance criterion(MAC) reconstruction noise filtering

Flutter and gust response analysis of a wing model including geometric nonlinearities based on a modified structural ROM

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Chinese Journal of Aeronautics 2020年第1期33卷 48-63页

作者： chao AN chao YANG Changchuan XIE Lan YANG School of Aeronautic Science and Engineering Beihang UniversityBeijing 100083China

In this paper,a framework is established for nonlinear flutter and gust response analyses based on an efficient Reduced Order Model(ROM).The proposed method can be used to solve the aeroelastic response problems of wings containing geometric nonlinearities.A structural modeling approach presented herein describes the stiffness nonlinearities with a modal *** orthogonal spanwise modes describe the foreshortening effects of the *** linearization of the ROM under nonlinear equilibrium states is applied to a nonlinear flutter analysis,and the fully nonlinear ROM coupled with the non-planar Unsteady Vortex Lattice Method(UVLM)is applied to gust response ***,extended Precise Integration Method(PIM)ensures accuracy of the dynamic equation *** demonstrate applicability and accuracy of the method presented,a wind tunnel test is conducted and good agreements between theoretical and test results of nonlinear flutter speed and gust response deflection are *** method described in this paper is suitable for predicting the nonlinear flutter speed and calculating the gust responses of a large-aspect-ratio wing in time ***,the results derived highlight the effects of geometric nonlinearities obviously.

关键词： Aeroelasticity Flutter Geometric nonlinearity Reduced order models Response analysis Structural model

Conceptual design and flight test of two wingtipdocked multi-body aircraft

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Chinese Journal of Aeronautics 2022年第12期35卷 144-155页

作者： Yang MENG chao AN Changchuan XIE chao YANG School of Aeronautic Science and Engineering Beihang UniversityBeijing 100083China

To overcome the drawbacks such as large wing deformations,poor performance encountering gusts,limits in taking off and landing,inconvenience of transportation of High-Altitude Long-Endurance(HALE)Unmanned Aerial Vehicles(UAVs),a new conceptual aircraft called wingtip-docked Multi-Body Aircraft(MBA)has attracted lots of *** to investigate the feasibility of this concept,two UAV models were designed,manufactured and connected by a wingtip-docking mechanism,which only allows the relative roll motion between the two *** trim solution of the two connected aircraft is firstly obtained by solving the developed nonlinear flight dynamic equations,followed by the stability analysis based on the linearized *** results show that the connected aircraft is inherently unstable and cannot fly without a reasonable flight control system.A set of Proportional-Integral-Derivative(PID)control laws was then developed and implemented in the two experimental *** success of the flight tests show that the flight control can effectively eliminate the unstable motion and the wingtip-docked MBA is controllable and feasible。

关键词： Flight test Multi-body aircraft New conceptual aircraft PID control Wingtip-docking mechanism