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Biosorption of copper ions from dilute aqueous solutions on base treated rubber (Hevea brasiliensis) leaves powder: kinetics, isotherm, and biosorption mechanisms

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Journal of Environmental Sciences 2008年第10期20卷 1168-1176页

作者： W.S.wan Ngah m.A.K.m.Hanafiah School of Chemical Sciences Universiti Sains malaysia Penang 11800 malaysia.

The effciency of sodium hydroxide treated rubber (Hevea brasiliensis) leaves powder (NHBL) for removing copper ions from aqueous solutions has been investigated. The e?ects of physicochemical parameters on biosorption capacities such as stirring speed, pH, biosorbent dose, initial concentrations of copper, and ionic strength were studied. The biosorption capacities of NHBL increased with increase in pH, stirring speed and copper concentration but decreased with increase in biosorbent dose and ionic strength. The isotherm study indicated that NHBL fitted well with Langmuir model compared to Freundlich and Dubinin-Radushkevich models. The maximum biosorption capacity determined from Langmuir isotherm was 14.97 mg/g at 27°C. The kinetic study revealed that pseudo- second order model fitted well the kinetic data, while Boyd kinetic model indicated that film diffusion was the main rate determining step in biosorption process. Based on surface area analysis, NHBL has low surface area and categorized as macroporous. Fourier transform infrared (FT-IR) analyses revealed that hydroxyl, carboxyl, and amino are the main functional groups involved in the binding of copper ions. Complexation was one of the main mechanisms for the removal of copper ions as indicated by FT-IR spectra. Ion exchange was another possible mechanism since the ratio of adsorbed cations (Cu2+ and H+) to the released cations (Na+, Ca2+, and mg2+) from NHBL was almost unity. Copper ions bound on NHBL were able to be desorbed at > 99% using 0.05 mol/L HCl, 0.01 mol/L HNO3, and 0.01 mol/L EDTA solutions.

关键词： copper treated rubber leaves powder kinetics isotherm ion exchange desorption

长三角典型城郊流域溶解性有机质的分子特征:以浙江樟溪为例

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湖泊科学 2024年第2期36卷 477-486页

作者：李文儒陈财万洁婷唐剑锋中国科学院城市环境研究所城市环境与健康重点实验室厦门361021 中国科学院大学北京101408 福建农林大学生命科学学院福州350002 上海应用技术大学生态技术与工程学院上海201418 厦门市城市环境智慧管理重点实验室厦门361021

溶解性有机质(DOm)在流域水环境中广泛存在,参与各种生物地球化学循环过程。快速的城镇化过程和人类活动显著改变了流域水体DOm含量和特性,从分子层面上解析DOm在流域尺度上的时空分异特征对流域水质管控具有重要的理论和应用价值。以... 详细信息

溶解性有机质(DOm)在流域水环境中广泛存在,参与各种生物地球化学循环过程。快速的城镇化过程和人类活动显著改变了流域水体DOm含量和特性,从分子层面上解析DOm在流域尺度上的时空分异特征对流域水质管控具有重要的理论和应用价值。以长三角地区樟溪流域为研究对象,依据土地利用和人类活动强度布设采样点,于2022年7月采集水样。结果表明,樟溪流域水体溶解性有机物主要的分子式元素组成为CHO、CHON、CHOS,其中木质素/富羧酸脂环分子类有机物相对占比最高。在子流域空间分布上,人类活动强的子流域CHON、CHONS类型化合物含量更高。选取采样点距城镇距离、距源头距离以及土地利用类型所占采样点缓冲区的比例来表征人类活动的影响。结果表明,流域内DOm杂原子受人类活动强度影响,距源头的距离与水体DOm分子中氮原子的强度加权平均值(N wa)和CHON化合物百分呈显著正相关,与碳、氢原子和荷质比的强度加权平均值(C wa、H wa、m/z wa)呈显著负相关。CHON分子的相对丰度与林地面积比例呈显著负相关,与农业用地比例呈显著正相关。比较具有典型土地利用类型的水体DOm:典型农田、城镇土地利用类型DOm含有更多独特的CHON分子式,农田DOm在木质素/富羧酸脂环分子区域出现CHON分子式的富集,城镇DOm在脂肪类和木质素/富羧酸脂环分子区域均出现了CHON分子式富集。研究表明在城郊流域中,人类活动显著改变了水体DOm的分子特征,增加了分子多样性,促进了特定分子式的富集。

关键词：地表水城郊流域溶解性有机物傅里叶变换离子回旋共振质谱樟溪流域

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基于含避障角人工势场法的机器人路径规划

农业机械学报 2024年第1期55卷 409-418页

作者：万俊孙薇葛敏王克鸿章晓勇南京理工大学材料科学与工程学院南京210094 江苏理工学院汽车与交通工程学院常州213001

针对基于距离的人工势场法(Artificial potential field, APF)存在的局部极小值问题,提出了一种含避障角的人工势场法的避障路径规划方法。在平面环境中,采用斜率判定路径规划过程中的位置关系,通过机器人当前点到障碍物的距离与障碍物... 详细信息

针对基于距离的人工势场法(Artificial potential field, APF)存在的局部极小值问题,提出了一种含避障角的人工势场法的避障路径规划方法。在平面环境中,采用斜率判定路径规划过程中的位置关系,通过机器人当前点到障碍物的距离与障碍物的影响半径二者之差得出人工势场法中的排斥力,并对排斥力的偏转角进行调整;另外,在空间环境中利用圆弧插补理论将机器人平面避障问题转换为空间避障问题;基于机器人构型配置对改进人工势场法进一步完善以满足实际避障要求。仿真和实验研究结果表明,含避障角的人工势场法,在单个或多个障碍物环境中进行避障路径规划时解决了局部极小值的问题,同时实现了6自由度机器人末端在避障时的轨迹曲线平滑无振荡,验证了所提出避障路径规划方法的可行性。

关键词： 6自由度机器人人工势场法避障角避障偏转角度圆弧插补

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User scheduling and power allocation for downlink multi-cell multi-carrier NOmA systems

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Digital Communications and Networks 2023年第1期9卷 252-263页

作者： Abuzar B.m.Adam Xiaoyu wan Zhengqiang wang School of Communications and Information Engineering Chongqing University of Posts and TelecommunicationsChongqing400065China

In Non-Orthogonal multiple Access(NOmA),the best way to fully exploit the benefits of the system is the efficient resource *** the NOmA power domain,the allocation of power and spectrum require solving the mixed-integer nonlinear programming NP-hard *** this paper,we investigate user scheduling and power allocation in multi-Cell multi-Carrier NOmA(mCmC-NOmA)*** achieve that,we consider Weighted Sum Rate maximization(WSRm)and Weighted Sum Energy Efficiency maximization(WSEEm)***,we tackle the problem of user scheduling for fixed power using Fractional Programming(FP),the Lagrange dual method,and the decomposition ***,we consider Successive Pseudo-Convex Approximation(SPCA)to deal with the WSRm ***,for the WSEEm problem,SPCA is utilized to convert the problem into separable scalar problems,which can be parallelly ***,the Dinkelbach algorithm and constraints relaxation are used to characterize the closed-form solution for power *** simulations have been implemented to show the efficiency of the proposed framework and its superiority over other existing schemes.

关键词： Weighted sum rate Weighted energy efficiency Non-orthogonal multiple access Successive pseudo-convex approximation Fractional programming

针对周期偏移声信标的广义二阶时延差水声定位模型

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声学学报 2024年第1期49卷 28-37页

作者：刘淼杨卓万光明孙思博付进哈尔滨工程大学水声技术全国重点实验室哈尔滨150001 工业和信息化部海洋信息获取与安全工信部重点实验室(哈尔滨工程大学) 哈尔滨150001 哈尔滨工程大学水声工程学院哈尔滨150001 中国舰船研究设计中心武汉430064 北京锐智集数电子有限公司北京100195

针对具有周期偏移的声信标定位问题,提出了一种广义二阶时延差水声定位模型。将传统二阶时延差拓展至不需要等周期间隔选取定位节点的广义情况,从而进一步提高定位精度;同时,引入松弛算法实现定位节点的最优化,并引入密度聚类算法以提... 详细信息

针对具有周期偏移的声信标定位问题,提出了一种广义二阶时延差水声定位模型。将传统二阶时延差拓展至不需要等周期间隔选取定位节点的广义情况,从而进一步提高定位精度;同时,引入松弛算法实现定位节点的最优化,并引入密度聚类算法以提高输入时延野值的鲁棒性。仿真及湖试数据处理结果表明,该模型相对于传统时延差模型或二阶时延差模型具有更高的定位精度。所提模型实现了针对周期漂移声信标的高精度定位,典型使用场景下的定位精度可达到3 m。

关键词：水声定位声信标长基线定位定位模型

Improved Test Case Selection Algorithm to Reduce Time in Regression Testing

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Computers, materials & Continua 2022年第7期72卷 635-650页

作者： Israr Ghani wan m.N.wan-Kadir Adila Firdaus Arbain Noraini Ibrahim School of Computing Faculty of EngineeringUniversiti Teknologi Malaysia(UTM)Johor Bahru81310Malaysia

Regression testing(RT)is an essential but an expensive activity in software *** confirms that new faults/errors will not have occurred in the modified *** efficiency can be improved through an effective technique of selected only modified test cases that appropriate to the modifications within the given time ***,several test case selection approaches have been introduced,but either these techniques were not sufficient according to the requirements of software tester experts or they are ineffective and cannot be used for available test suite specifications and *** address these limitations,we recommend an improved and efficient test case selection(TCS)algorithm for *** proposed technique decreases the execution time and redundancy of the duplicate test cases(TC)and detects onlymodified changes that appropriate to themodifications in test *** reduce execution time for TCS,evaluation results of our proposed approach are established on fault detection,redundancy and already executed test *** indicate that proposed technique decreases the inclusive testing time of TCS to execute modified test cases by,on average related to a method of Hybrid Whale Algorithm(HWOA),which is a progressive TCS approach in regression testing for a single product.

关键词： Test case selection regression testing change detection TCS algorithm test suite minimization

miR-15a-5p靶向PD-L1对食管癌进展、预后与肿瘤免疫反应的影响

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世界华人消化杂志 2024年第9期32卷 678-685页

作者：林亭呈张婉君浙江省台州医院药剂科浙江省台州市318050

背景微核糖核酸(microRNA,miR)-15a-5p与细胞程序性死亡蛋白配体1(programmed death-ligand 1,PD-L1)在多种肿瘤进展、治疗与预后中发挥重要作用,但其在食管癌中的作用尚不完全清楚.目的研究miR-15a-5p与PD-L1表达对食管癌进展与预后的... 详细信息

背景微核糖核酸(microRNA,miR)-15a-5p与细胞程序性死亡蛋白配体1(programmed death-ligand 1,PD-L1)在多种肿瘤进展、治疗与预后中发挥重要作用,但其在食管癌中的作用尚不完全清楚.目的研究miR-15a-5p与PD-L1表达对食管癌进展与预后的影响,并分析二者的靶向关系以及二者调控食管癌细胞生物学行为的机制.方法用癌症基因组图谱数据库、基因表达综合数据库和RNA相互作用组百科全书泛癌分析数据库分析食管癌中miR-15a-5p和PD-L1基因的表达,通过Kaplan-meier生存分析研究miR-15a-5p和PD-L1的表达与食管癌无病生存期以及总生存期的关系.信息学和荧光活性实验检测miR-15a-5p与PD-L1的靶向关系.体外培养食管癌细胞,转染miR-15a-5p mimics或miR-NC后,分别用Western blot、流式细胞术、免疫荧光实验检测PD-L1表达.将转染miR-15a-5p mimics或miR-NC的食管癌细胞与CD8+T细胞共培养,流式细胞术检测干扰素-γ(interferon-γ,INF-γ)阳性CD8+T细胞比例,ELISA检测共培养体系中上清液中INF-γ和白细胞介素(interleukin,IL)-2含量.结果miR-15a-5p在食管癌组织中表达水平较癌旁非癌变组织降低(PmiR-15a-5p表达水平的中位数为分界线,随T分期和肿瘤大小增加和淋巴结转移,miR-15a-5p低表达率增加(PmiR-15a-5p低表达的食管癌患者,miR-15a-5p高表达显示出较长的无病生存期和总生存期(PmiR-15a-5p高表达同时PD-L1低表达的无病生存期和总生存期更长(PmiR-15a-5p高表达的食管癌患者中PD-L1 mRNA多呈低表达.PD-L1为miR-15a-5p的靶基因.过表达miR-15a-5p抑制食管癌细胞中总PD-L1及膜PD-L1表达(PmiR-15a-5p可促进共培养体系中CD8+T细胞的激活(即:共培养体系中INF-γ阳性CD8+T细胞比例以及共培养体系中上清液中INF-γ和IL-2含量增加).结论miR-15a-5p可通过靶向PD-L1增强食管癌细胞的肿瘤免疫反应,且miR-15a-5p/PD-L1可作为食管癌诊断及预后生物标记物.

关键词： miR-15a-5p 食管癌 PD-L1 预后肿瘤免疫反应

Oscillating-grid turbulence at large strokes: Revisiting the equation of Hopfinger and Toly

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Journal of Hydrodynamics 2016年第3期28卷 473-481页

作者： wan hanna melini wan mohtar Department of Civil and Structural Engineering Faculty Engineering and Built Environment Universiti Kebangsaan Malaysia Bandar BaruBangi 43600 Selangor Malaysia

A quasi-isotropic, quasi-homogeneous turbulence generated by an oscillating-grid, spatially decays according to power law of u ∝ Z-nm , where u is the root mean square （rms） horizontal velocity, Z is the vertical distance from the grid and nu = 1. However, the findings of Nokes and Yi indicate that as the stroke of oscillation increases, the power law n u= 1 and does not follow the established decay law equation of Hopfinger. This paper investigates the characteristics of the turbulence that are generated using larger strokes S/m = 1.6 and 2 and compares with that obtained using a S/m = 0.8, which is the stroke used when the equation was developed. measurements of the grid-generated turbulence in a water tank were taken using particle image velocimetry （PIV）. The results showed that the homogeneity occurred at distance beyond 2.5 mesh spacings away from the grid midplane, independent of the stroke and the frequency of oscillation. Within this region, the turbulent kinetic energy distribution was quasi-homogeneous, and the secondary mean flow is negligible. The statistical characteristics of the measured turbulence confirmed that although nu decreases as stroke increases, the grid-turbulence generated at S/m = 1.6 and 2 obeys the universal decay law.

关键词： oscillating-grid turbulence large strokes decay power law

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大数据时代个人数据民事权利配置与保护问题

中阿科技论坛（中英文） 2024年第8期 157-161页

作者：万学敏青海民族大学青海西宁810007

数据主体的个人数据民事权利意在保障其对数据的自主决策权,以避免因非法收集与利用而致使其人格权益以及财产权益遭受损害。此种权利属于有别于传统物权、知识产权等的全新民事权利类型,其作用在于协调个人隐私权保护和数据利用之间的... 详细信息

数据主体的个人数据民事权利意在保障其对数据的自主决策权,以避免因非法收集与利用而致使其人格权益以及财产权益遭受损害。此种权利属于有别于传统物权、知识产权等的全新民事权利类型,其作用在于协调个人隐私权保护和数据利用之间的关系。文章立足个人数据的流通及保护需求,针对不同主体设定不同权属和保护规则。鉴于个人数据同时具备人格权益和财产权益的双重特性,认为可引入直接识别标准予以区分,普通个人数据的财产权益由数据业者与数据主体共有,而敏感个人数据的人格权益仅归数据主体所有;针对不同主体之间的权益冲突,认为可通过权利配置实现数据保护利用的有效平衡。

关键词：数据权属数据民事权利数据流通与利用