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MC-ICP-MS高阻放大器校正偏移对同位素测试的影响——以汞同位素为例 被引量:1
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作者 李鹏飞 郑旺 +3 位作者 孟旭男 张立欣 孙若愚 陈玖斌 《矿物岩石地球化学通报》 CAS CSCD 北大核心 2024年第1期140-150,共11页
增益(Gain)校正有助于消除MC-ICP-MS不同高阻放大器之间的阻值差异,进而提高同位素分析的精度和准确度,但有关Gain的偏移和校正频率对同位素测试的影响和作用原理还缺乏系统认识。本研究结合本实验室Neptune Plus MC-ICP-MS的Gain校正数... 增益(Gain)校正有助于消除MC-ICP-MS不同高阻放大器之间的阻值差异,进而提高同位素分析的精度和准确度,但有关Gain的偏移和校正频率对同位素测试的影响和作用原理还缺乏系统认识。本研究结合本实验室Neptune Plus MC-ICP-MS的Gain校正数据,以实际测试的汞同位素数据为例,评估了放大器Gain校正系数偏移对同位素测试的影响。结果显示,当测试标样和样品的校正系数偏移幅度一致时,汞同位素测试结果基本无变化;当偏移幅度存在明显差异且单一放大器校正系数的相对偏移幅度超过–0.070‰~0.058‰时,汞同位素的测试结果大于分析误差。Gain校正系数单日的相对变化幅度(–0.028‰~0.028‰)可保证汞同位素测试结果小于分析误差,但长期的偏移却会导致汞同位素变化远超分析误差。此外,仪器的硬件、温度和真空度等也是Gain校正系数变化的重要影响因素,因此建议定期维护仪器,并每日进行Gain校正,以保证测试结果的稳定和准确。 展开更多
关键词 多接收电感耦合等离子体质谱仪 高阻放大器 放大器校正 汞同位素
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梯级水库优化调度的改进ODDDP算法研究
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作者 方国华 郑旺 +1 位作者 吴承君 颜敏 《水电能源科学》 北大核心 2024年第9期179-184,共6页
“维数灾”问题和易陷入局部最优问题是梯级水库优化调度模型求解中的热点和难点。正交离散微分动态规划算法依据正交试验原理,解决了离散微分动态规划算法在求解水库群联合优化调度问题中的维数灾问题,但并未克服其依赖初始解质量和易... “维数灾”问题和易陷入局部最优问题是梯级水库优化调度模型求解中的热点和难点。正交离散微分动态规划算法依据正交试验原理,解决了离散微分动态规划算法在求解水库群联合优化调度问题中的维数灾问题,但并未克服其依赖初始解质量和易陷入局部最优的缺陷。对此,借鉴入侵杂草算法空间扩散机制,引入高斯随机变量,并基于三角余弦函数的周期性质,设计提出了M-IWO-ODDDP算法,从算法全局搜索能力和搜索深度两方面,提高算法全局收敛能力。采用Schaffer、Shubert两种测试函数,分析测试了M-IWOODDDP算法的收敛性和鲁棒性。并以乌江流域11级梯级水库为例开展实例应用研究,结果表明,M-IWOODDDP寻优效果显著且对初始解质量无明显依赖性,算法收敛能力强、鲁棒性好。 展开更多
关键词 水库优化调度 离散微分动态规划 正交试验 高斯分布 收敛性分析
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Review on the plastic instability of medium -Mn steels for identifying the formation mechanisms of Lüders and Portevin -Le Chatelier bands 被引量:3
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作者 Bin Hu Han Sui +3 位作者 Qinghua Wen zheng wang Alexander Gramlich Haiwen Luo 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第6期1285-1297,共13页
Plastic instability,including both the discontinuous yielding and stress serrations,has been frequently observed during the tensile deformation of medium-Mn steels(MMnS)and has been intensively studied in recent years... Plastic instability,including both the discontinuous yielding and stress serrations,has been frequently observed during the tensile deformation of medium-Mn steels(MMnS)and has been intensively studied in recent years.Unfortunately,research results are controversial,and no consensus has been achieved regarding the topic.Here,we first summarize all the possible factors that affect the yielding and flow stress serrations in MMnS,including the morphology and stability of austenite,the feature of the phase interface,and the deformation parameters.Then,we propose a universal mechanism to explain the conflicting experimental results.We conclude that the discontinuous yielding can be attributed to the lack of mobile dislocation before deformation and the rapid dislocation multiplication at the beginning of plastic deformation.Meanwhile,the results show that the stress serrations are formed due to the pinning and depinning between dislocations and interstitial atoms in austenite.Strain-induced martensitic transformation,influenced by the mechanical stability of austenite grain and deformation parameters,should not be the intrinsic cause of plastic instability.However,it can intensify or weaken the discontinuous yielding and the stress serrations by affecting the mobility and density of dislocations,as well as the interaction between the interstitial atoms and dislocations in austenite grains. 展开更多
关键词 medium manganese steel discontinuous yielding stress serrations retained austenite dislocations
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词频和语境多样性在中文词汇识别中的相对重要性:基于ERP的实验证据
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作者 宋坤莹 冯琳琳 +2 位作者 王峥 白学军 梁菲菲 《心理与行为研究》 CSSCI 北大核心 2024年第4期433-441,共9页
采用改编后的Go/No-Go词汇判断实验范式,从加工时间进程视角揭示词频、语境多样性在中文词汇识别中的相对重要性。结果发现,如果将词频、语境多样性分别纳入模型,词频效应和语境多样性效应均发生在300~800 ms,表明二者均作用于词汇识别... 采用改编后的Go/No-Go词汇判断实验范式,从加工时间进程视角揭示词频、语境多样性在中文词汇识别中的相对重要性。结果发现,如果将词频、语境多样性分别纳入模型,词频效应和语境多样性效应均发生在300~800 ms,表明二者均作用于词汇识别的晚期阶段;如果同时将词频和语境多样性纳入模型,词频效应减小,仅发生在300~400 ms,语境多样性效应则发生在300~700 ms。结果表明,语境多样性在中文词汇识别中的作用时程更长。本研究发现支持词汇识别遵循的是“可能需要”原则,而不是“简单重复”原则。 展开更多
关键词 词频 语境多样性 词汇识别 ERP
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Ultra-Robust and High-Performance Rotational Triboelectric Nanogenerator by Bearing Charge Pumping 被引量:2
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作者 Xianpeng Fu Yuhan Qin +6 位作者 Zhi Zhang Guoxu Liu Jie Cao Beibei Fan Zhaozheng wang zheng wang Chi Zhang 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2024年第2期343-349,共7页
As an emerging technology to convert environmental high-entropy energy into electrical energy,triboelectric nanogenerator(TENG)has great demands for further enhancing the service lifetime and output performance in pra... As an emerging technology to convert environmental high-entropy energy into electrical energy,triboelectric nanogenerator(TENG)has great demands for further enhancing the service lifetime and output performance in practical applications.Here,an ultra-robust and high-performance rotational triboelectric nanogenerator(R-TENG)by bearing charge pumping is proposed.The R-TENG composes of a pumping TENG(P-TENG),an output TENG(O-TENG),a voltage-multiplying circuit(VMC),and a buffer capacitor.The P-TENG is designed with freestanding mode based on a rolling ball bearing,which can also act as the rotating mechanical energy harvester.The output low charge from the P-TENG is accumulated and pumped to the non-contact O-TENG,which can simultaneously realize ultralow mechanical wear and high output performance.The matched instantaneous power of R-TENG is increased by 32 times under 300 r/min.Furthermore,the transferring charge of R-TENG can remain 95%during 15 days(6.4×10^(6)cycles)continuous operation.This work presents a realizable method to further enhance the durability of TENG,which would facilitate the practical applications of high-performance TENG in harvesting distributed ambient micro mechanical energy. 展开更多
关键词 bearing charge pumping triboelectric nanogenerators ultralow mechanical wear ultra-robust voltage-multiplying circuit
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V_(2)CF_(x)MXene衍生2D V_(2)O_(3)@介孔碳纳米片的制备及其电容脱盐特性
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作者 张泽豪 王政 李海波 《物理化学学报》 SCIE CAS CSCD 北大核心 2024年第8期18-27,共10页
采用同源金属V_(2)CF_(x)MXene作为前驱体制备了三氧化二钒@多孔碳(V_(2)O_(3)@porous carbon,V_(2)O_(3)@PC)纳米片作为电容去离子(CDI)阳极,研究其脱盐特性。实验探究了在不同在碳化温度下V_(2)O_(3)@PC的结构、结晶度、润湿性、石墨... 采用同源金属V_(2)CF_(x)MXene作为前驱体制备了三氧化二钒@多孔碳(V_(2)O_(3)@porous carbon,V_(2)O_(3)@PC)纳米片作为电容去离子(CDI)阳极,研究其脱盐特性。实验探究了在不同在碳化温度下V_(2)O_(3)@PC的结构、结晶度、润湿性、石墨化程度和电化学特性。研究表明,所制备的V_(2)O_(3)@PC呈现出典型的2D纳米片结构,高结晶度的V_(2)O_(3)纳米颗粒被高石墨化度的PC牢牢束缚。这种结构具有良好的界面润湿性和高导电性,因而可以促进电解质的渗透,加速界面电荷的转移以并促进盐离子的传输和扩散。此外,PC也能较好的抑制V_(2)O_(3)在多次循环后的体积膨胀。电化学结果表明,V的可逆电化学转化在一定程度上提高了Na^(+)的储存。当电压为1.2 V时,NaCl电导率为1000μS·cm^(−1)时,优化后的V_(2)O_(3)@PC电极具有高达2.20 mmol∙g^(−1)的脱盐容量,0.13 mmol∙g^(−1)∙min^(−1)的脱盐速率,62%的水回收率以及24.0 Wh∙m^(−3)的低能耗。 展开更多
关键词 电容去离子 三氧化二钒 金属有机框架 麦克烯 电化学
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术后淋巴结阴性肺浸润性黏液腺癌患者的预后预测模型
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作者 王正 贺靳贤 +6 位作者 沈海波 陈啸晗 林城斌 俞红艳 高家俊 何贤能 沈韦羽 《中国肺癌杂志》 CAS CSCD 北大核心 2024年第1期47-55,共9页
背景与目的肺浸润性黏液腺癌(invasive mucinous adenocarcinoma of the lung,IMA)是肺腺癌中一种少见且特殊的类型,该类肿瘤的特点往往是少有淋巴结转移,因此对于该类肿瘤的预后评估依靠现有的肿瘤原发灶-淋巴结-转移(tumor-node-metas... 背景与目的肺浸润性黏液腺癌(invasive mucinous adenocarcinoma of the lung,IMA)是肺腺癌中一种少见且特殊的类型,该类肿瘤的特点往往是少有淋巴结转移,因此对于该类肿瘤的预后评估依靠现有的肿瘤原发灶-淋巴结-转移(tumor-node-metastasis,TNM)分期存在困难。本研究的目的是构建列线图来预测术后淋巴结阴性的IMA患者的预后。方法根据纳入标准和排除标准,回顾性分析2012年7月至2017年5月宁波大学附属李惠利医院(训练队列,n=78)和宁波市第二医院(验证队列,n=66)胸外科收治的术后病理为淋巴结阴性的IMA患者的资料,分析训练队列的临床病理特征的预后价值并建立预后预测模型,并对模型性能进行评价,最后将验证队列的数据代入进行外部验证。结果单因素分析显示肺炎型、较大的肿块、包含黏液和非黏液成分的混合型、较高的总分期是5年无进展生存期(progression-free survival,PFS)及总生存期(overall survival,OS)的影响因素。多因素分析进一步表明,影像学分型、肿块大小、黏液成分是5年PFS及OS的独立预后因素。5年PFS率和OS率分别为62.82%和75.64%,亚组的生存分析显示,肺炎型和包含黏液和非黏液成分的混合型IMA患者的5年PFS及OS分别明显低于孤立型和纯黏液型IMA患者。5年PFS和OS的Harrell’s C指数分别为0.815(95%CI:0.741-0.889)和0.767(95%CI:0.669-0.865),这两个模型的校准曲线及决策曲线分析(decision curve analysis,DCA)在两个队列中显示出良好的预测性能。结论本次基于临床病理特征构建的列线图在一定程度上可以作为IMA切除术后淋巴结阴性患者的一种有效预后预测工具。 展开更多
关键词 肺肿瘤 肺浸润性黏液腺癌 淋巴结阴性 预后 预测模型
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海上风电低频输电并网技术研究现状及展望
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作者 齐磊 李志川 +4 位作者 孙兆恒 支光凝 杨季平 郑旺 陈娟 《中国海上油气》 CAS CSCD 北大核心 2024年第2期195-204,共10页
低频输电技术在中远海域的海上风电项目中具备竞争力,并有望在未来得到广泛应用。首先基于低频输电技术原理,对低频输电技术(LFAC)在海上风电应用的适应性进行了分析,表明低频输电方案在海上风电项目中不存在障碍,但仍需进一步优化低频... 低频输电技术在中远海域的海上风电项目中具备竞争力,并有望在未来得到广泛应用。首先基于低频输电技术原理,对低频输电技术(LFAC)在海上风电应用的适应性进行了分析,表明低频输电方案在海上风电项目中不存在障碍,但仍需进一步优化低频风电机组、交交变频器等关键设备。其次,通过对比分析高压交流、柔性直流与低频输电3种方案在全生命周期成本方面的差异,发现当下低频输电因其适度的初始投入成本、运行成本与废弃成本,较高故障成本与低维护成本而在离岸距离75~300 km的中远海域具有明显经济优势。然后,参照工频交直流输电可靠性评估方法,低频输电方案可靠性需按不同模块分别进行评估,通过比较低频输电方案较其他方案在可靠性评估中的差异,表明风电机组、集电系统与输电线缆的可靠性差异来源于低频运行状态或低频设备的规格差异,而海上平台可靠性差异来源于电气设备链接方式与结构差异。最后,就低频输电技术在技术性、经济性、可靠性、风险性以及环境影响方面的未来研究提出展望。本研究旨在补充低频输电技术的理论研究基础,为低频输电技术在海上风电项目中广泛铺开做好理论准备。 展开更多
关键词 海上风电 低频输电技术(LFAC) 并网技术 经济性 可靠性 研究现状 展望
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A frequency servo SoC with output power stabilization loop technology for miniaturized atomic clocks 被引量:1
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作者 Hongyang Zhang Xinlin Geng +3 位作者 Zonglin Ye Kailei wang Qian Xie zheng wang 《Journal of Semiconductors》 EI CAS CSCD 2024年第6期13-22,共10页
A frequency servo system-on-chip(FS-SoC)featuring output power stabilization technology is introduced in this study for high-precision and miniaturized cesium(Cs)atomic clocks.The proposed power stabilization loop(PSL... A frequency servo system-on-chip(FS-SoC)featuring output power stabilization technology is introduced in this study for high-precision and miniaturized cesium(Cs)atomic clocks.The proposed power stabilization loop(PSL)technique,incorporating an off-chip power detector(PD),ensures that the output power of the FS-SoC remains stable,mitigating the impact of power fluctuations on the atomic clock's stability.Additionally,a one-pulse-per-second(1PPS)is employed to syn-chronize the clock with GPS.Fabricated using 65 nm CMOS technology,the measured phase noise of the FS-SoC stands at-69.5 dBc/Hz@100 Hz offset and-83.9 dBc/Hz@1 kHz offset,accompanied by a power dissipation of 19.7 mW.The Cs atomic clock employing the proposed FS-SoC and PSL obtains an Allan deviation of 1.7×10^(-11) with 1-s averaging time. 展开更多
关键词 CMOS technology atomic clock phase-locked loop output power stabilization 1PPS
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BnaWRKY75 positively regulates the resistance against Sclerotinia sclerotiorum in ornamental Brassica napus 被引量:1
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作者 Kexin Yu Yijie Zhang +4 位作者 Xiaoyuan Fei Luyue Ma Rehman Sarwar Xiaoli Tan zheng wang 《Horticultural Plant Journal》 SCIE CAS CSCD 2024年第3期784-796,共13页
With the development of tourism at home and abroad,Rapeseed(Brassica napus)has become an important ornamental plant.However,its ornamental value at the inflorescence stage is greatly reduced by Sclerotinia sclerotioru... With the development of tourism at home and abroad,Rapeseed(Brassica napus)has become an important ornamental plant.However,its ornamental value at the inflorescence stage is greatly reduced by Sclerotinia sclerotiorum.Identification of important genes in the defense responses is critical for molecular breeding,which is an important strategy for controlling the disease.In this study,we isolated a B.napus WRKY transcription factor gene,BnaWRKY75.BnaWRKY75 was found to encode a nucleus-localized protein and exhibited relatively high expression in the stems.Arabidopsis thaliana transgenic plants expressing BnaWRKY75 showed enhanced resistance to S.sclerotiorum,and both ProBnaWRKY75:GUS and gene expression analyses showed that BnaWRKY75 was highly responsive to S.sclerotiorum infection,indicating the involvement of BnaWRKY75 in response to this infection.Furthermore,overexpression(OE)of BnaWRKY75 in B.napus significantly enhanced the resistance to S.sclerotiorum,whereas the resistance was reduced in RNAi transgenic B.napus plants.Moreover,the BnaWRKY75-OE B.napus plants exhibited constitutive activation of salicylic acid-,jasmonic acid-,and ethylene-mediated defense responses and the inhibition of both H_(2)O_(2)and O_(2)·^(-)accumulation in response to this pathogen.By contrast,BnaWRKY75-RNAi plants showed a reverse pattern,suggesting that BnaWRKY75 is involved in hormonal signaling pathways and in the control of reactive oxygen species accumulation.In conclusion,these data indicate that BnaWRKY75,a regulator of multiple defense responses,positively regulates resistance against S.sclerotiorum,which may guide the improvement of resistance in rapeseed. 展开更多
关键词 Brassica napus BnaWRKY75 Defense response Sclerotinia sclerotiorum
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基于热解技术的大气颗粒物形态汞同位素组成分析方法
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作者 苏友达 张可 +3 位作者 樊熊菲 陈玖斌 郑旺 蔡虹明 《地球与环境》 CAS CSCD 北大核心 2024年第5期621-630,共10页
汞是一种有毒重金属,其在大气中的传输、沉降和循环对生态系统和人类健康构成严重危害。大气颗粒物是汞相态转化的重要载体,在全球汞循环中起着至关重要的作用。汞同位素常被用于追踪大气汞的来源和迁移转化过程,但现有研究仅局限于大... 汞是一种有毒重金属,其在大气中的传输、沉降和循环对生态系统和人类健康构成严重危害。大气颗粒物是汞相态转化的重要载体,在全球汞循环中起着至关重要的作用。汞同位素常被用于追踪大气汞的来源和迁移转化过程,但现有研究仅局限于大气颗粒物总汞同位素,难以深入理解大气汞转化机制和生态效应。本研究旨在建立一种基于热解技术的形态汞同位素分析方法,用以分离大气颗粒物中不同汞形态并进行同位素组成检测,为深入研究颗粒态汞(PBM)在大气中的行为和源汇特性奠定基础。本研究通过自主搭建的热解装置对大气颗粒物样品进行汞形态分离,判定了天津市实际大气PBM中主要的形态为有机结合态汞(Hg-OM)、β-硫化汞(β-HgS)和α-硫化汞(α-HgS),同时测试分析了各形态汞同位素组成。结果表明,热解方法能有效区分PBM中不同汞形态并进行同位素分析,为进一步揭示大气中汞的源-汇过程和迁移转化机制开辟了新的视野。 展开更多
关键词 大气颗粒态汞 形态 热解 汞同位素
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土柱实验在土壤重金属污染研究中的应用进展与展望
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作者 李卫娜 蔡虹明 +2 位作者 袁玮 郑旺 陈玖斌 《地球与环境》 CAS CSCD 北大核心 2024年第5期652-661,共10页
近年来土壤重金属污染状况不容乐观,重金属在土壤中的吸附、迁移和转化等行为显著影响着土壤重金属污染的生态环境效应,成为学者研究热点。土柱实验能够较好地模拟污染物进入土壤中的迁移转化过程,在土壤重金属污染机制、土壤和地下水... 近年来土壤重金属污染状况不容乐观,重金属在土壤中的吸附、迁移和转化等行为显著影响着土壤重金属污染的生态环境效应,成为学者研究热点。土柱实验能够较好地模拟污染物进入土壤中的迁移转化过程,在土壤重金属污染机制、土壤和地下水环境风险评估以及土壤重金属污染的修复等方面均已得到广泛应用。但由于研究中淋滤环境、土壤性质及重金属性质等实验条件的不同,土柱实验并没有一套通用流程,需要研究者自主设计土柱结构,并制定合理的实验方案。本文回顾了近年来土柱实验在重金属污染研究方面的应用进展,总结了在设计土柱实验时供水、渗流及接收等各环节需要注意的问题,并对土柱实验在土壤重金属污染研究方面的应用前景进行了展望,为复杂条件土壤重金属污染研究提供新的研究思路和方法。 展开更多
关键词 土柱实验 土壤 重金属 综述
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Improving model performance in mapping cropland soil organic matter using time-series remote sensing data
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作者 Xianglin Zhang Jie Xue +5 位作者 Songchao Chen Zhiqing Zhuo zheng wang Xueyao Chen Yi Xiao Zhou Shi 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第8期2820-2841,共22页
Faced with increasing global soil degradation,spatially explicit data on cropland soil organic matter(SOM)provides crucial data for soil carbon pool accounting,cropland quality assessment and the formulation of effect... Faced with increasing global soil degradation,spatially explicit data on cropland soil organic matter(SOM)provides crucial data for soil carbon pool accounting,cropland quality assessment and the formulation of effective management policies.As a spatial information prediction technique,digital soil mapping(DSM)has been widely used to spatially map soil information at different scales.However,the accuracy of digital SOM maps for cropland is typically lower than for other land cover types due to the inherent difficulty in precisely quantifying human disturbance.To overcome this limitation,this study systematically assessed a framework of“information extractionfeature selection-model averaging”for improving model performance in mapping cropland SOM using 462 cropland soil samples collected in Guangzhou,China in 2021.The results showed that using the framework of dynamic information extraction,feature selection and model averaging could efficiently improve the accuracy of the final predictions(R^(2):0.48 to 0.53)without having obviously negative impacts on uncertainty.Quantifying the dynamic information of the environment was an efficient way to generate covariates that are linearly and nonlinearly related to SOM,which improved the R^(2)of random forest from 0.44 to 0.48 and the R^(2)of extreme gradient boosting from 0.37to 0.43.Forward recursive feature selection(FRFS)is recommended when there are relatively few environmental covariates(<200),whereas Boruta is recommended when there are many environmental covariates(>500).The Granger-Ramanathan model averaging approach could improve the prediction accuracy and average uncertainty.When the structures of initial prediction models are similar,increasing in the number of averaging models did not have significantly positive effects on the final predictions.Given the advantages of these selected strategies over information extraction,feature selection and model averaging have a great potential for high-accuracy soil mapping at any scales,so this approach can provide more reliable references for soil conservation policy-making. 展开更多
关键词 CROPLAND soil organic matter digital soil mapping machine learning feature selection model averaging
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Understanding the combustion behavior of electric bicycle batteries and unveiling its relationship with fire extinguishing
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作者 Zhanglong Yu Xueling Shen +6 位作者 Ran Xu zheng wang Zengming Wan Mingyang Chen Yi Cui Yanyan Fang Xiaoli Ma 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第4期609-618,共10页
In this study,a detailed analysis of the combustion behaviors of the lithium iron phosphate(LFP)and lithium manganese oxide(LMO)batteries used in electric bicycles was conducted.This research included quantitative mea... In this study,a detailed analysis of the combustion behaviors of the lithium iron phosphate(LFP)and lithium manganese oxide(LMO)batteries used in electric bicycles was conducted.This research included quantitative measurements of the combustion duration,flame height,combustion temperature,heat release rate,and total heat release.The results indicated that LMO batteries exhibited higher combustion temperatures of 600–700°C,flame heights of 70–75 cm,a significantly higher heat release rate of40.1 k W(12 Ah),and a total heat release of 1.04 MJ(12 Ah)compared to LFP batteries with the same capacity.Based on these experimental results,a normalized total heat release(NORTHR)parameter was proposed,demonstrating good universality for batteries with different capacities.Utilizing this parameter,quantitative calculations and optimization of the extinguishing agent dosage were conducted for fires involving these two types of batteries,and the method was validated by extinguishing fires for these two types of battery packs with water-based extinguishing fluids. 展开更多
关键词 Combustion behavior Electric bicycle Lithium-ion battery Fire extinguishing Normalized total heat release
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Terahertz high-sensitivity SIS mixer based on Nb–AlN–NbN hybrid superconducting tunnel junctions
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作者 刘博梁 刘冬 +8 位作者 姚明 金骏达 王争 李婧 史生才 Artem Chekushkin Michael Fominsky Lyudmila Filippenko Valery Koshelets 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第5期681-686,共6页
The terahertz band,a unique segment of the electromagnetic spectrum,is crucial for observing the cold,dark universe and plays a pivotal role in cutting-edge scientific research,including the study of cosmic environmen... The terahertz band,a unique segment of the electromagnetic spectrum,is crucial for observing the cold,dark universe and plays a pivotal role in cutting-edge scientific research,including the study of cosmic environments that support life and imaging black holes.High-sensitivity superconductor–insulator–superconductor(SIS)mixers are essential detectors for terahertz astronomical telescopes and interferometric arrays.Compared to the commonly used classical Nb/AlO_(x)/Nb superconducting tunnel junction,the Nb/AlN/NbN hybrid superconducting tunnel junction has a higher energy gap voltage and can achieve a higher critical current density.This makes it particularly promising for the development of ultra-wideband,high-sensitivity coherent detectors or mixers in various scientific research fields.In this paper,we present a superconducting SIS mixer based on Nb/AlN/NbN parallel-connected twin junctions(PCTJ),which has a bandwidth extending up to490 GHz–720 GHz.The best achieved double-sideband(DSB)noise temperature(sensitivity)is below three times the quantum noise level. 展开更多
关键词 SIS mixer TERAHERTZ gap voltage critical current density hybrid superconducting tunnel junction
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A Single-Cell Landscape of Human Liver Transplantation Reveals a Pathogenic Immune Niche Associated with Early Allograft Dysfunction
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作者 Xin Shao zheng wang +8 位作者 Kai wang Xiaoyan Lu Ping Zhang Rongfang Guo Jie Liao Penghui Yang Shusen zheng Xiao Xu Xiaohui Fan 《Engineering》 SCIE EI CAS CSCD 2024年第5期193-208,共16页
Liver transplantation(LT)is the standard therapy for individuals afflicted with end-stage liver disease.Despite notable advancements in LT technology,the incidence of early allograft dysfunction(EAD)remains a critical... Liver transplantation(LT)is the standard therapy for individuals afflicted with end-stage liver disease.Despite notable advancements in LT technology,the incidence of early allograft dysfunction(EAD)remains a critical concern,exacerbating the current organ shortage and detrimentally affecting the prognosis of recipients.Unfortunately,the perplexing hepatic heterogeneity has impeded characterization of the cellular traits and molecular events that contribute to EAD.Herein,we constructed a pioneering single-cell transcriptomic landscape of human transplanted livers derived from non-EAD and EAD patients,with 12 liver samples collected from 7 donors during the cold perfusion and portal reperfusion stages.Comparison of the 75231 cells of non-EAD and EAD patients revealed an EAD-associated immune niche comprising mucosal-associated invariant T cells,granzyme B^(+)(GZMB^(+))granzyme K^(+)(GZMK^(+))natural killer cells,and S100 calcium binding protein A12^(+)(S100A12^(+))neutrophils.Moreover,we verified this immune niche and its association with EAD occurrence in two independent cohorts.Our findings elucidate the cellular characteristics of transplanted livers and the EAD-associated pathogenic immune niche at the single-cell level,thus,offering valuable insights into EAD onset. 展开更多
关键词 Human liver transplantation Early allograft dysfunction Pathogenic immune niche Single-cell analysis Cell-cell communication
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Clinical and molecular significance of homologous recombination deficiency positive non-small cell lung cancer in Chinese population:An integrated genomic and transcriptional analysis
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作者 Yifei wang Yidan Ma +14 位作者 Lei He Jun Du Xiaoguang Li Peng Jiao Xiaonan Wu Xiaomao Xu Wei Zhou Li Yang Jing Di Changbin Zhu Liming Xu Tianlin Sun Lin Li Dongge Liu zheng wang 《Chinese Journal of Cancer Research》 SCIE CAS CSCD 2024年第3期282-297,共16页
Objective:The clinical significance of homologous recombination deficiency(HRD)in breast cancer,ovarian cancer,and prostate cancer has been established,but the value of HRD in non-small cell lung cancer(NSCLC)has not ... Objective:The clinical significance of homologous recombination deficiency(HRD)in breast cancer,ovarian cancer,and prostate cancer has been established,but the value of HRD in non-small cell lung cancer(NSCLC)has not been fully investigated.This study aimed to systematically analyze the HRD status of untreated NSCLC and its relationship with patient prognosis to further guide clinical care.Methods:A total of 355 treatment-naïve NSCLC patients were retrospectively enrolled.HRD status was assessed using the AmoyDx Genomic Scar Score(GSS),with a score of≥50 considered HRD-positive.Genomic,transcriptomic,tumor microenvironmental characteristics and prognosis between HRD-positive and HRDnegative patients were analyzed.Results:Of the patients,25.1%(89/355)were HRD-positive.Compared to HRD-negative patients,HRDpositive patients had more somatic pathogenic homologous recombination repair(HRR)mutations,higher tumor mutation burden(TMB)(P<0.001),and fewer driver gene mutations(P<0.001).Furthermore,HRD-positive NSCLC had more amplifications in PI3K pathway and cell cycle genes,MET and MYC in epidermal growth factor receptor(EGFR)/anaplastic lymphoma kinase(ALK)mutant NSCLC,and more PIK3CA and AURKA in EGFR/ALK wild-type NSCLC.HRD-positive NSCLC displayed higher tumor proliferation and immunosuppression activity.HRD-negative NSCLC showed activated signatures of major histocompatibility complex(MHC)-II,interferon(IFN)-γand effector memory CD8+T cells.HRD-positive patients had a worse prognosis and shorter progressionfree survival(PFS)to targeted therapy(first-and third-generation EGFR-TKIs)(P=0.042).Additionally,HRDpositive,EGFR/ALK wild-type patients showed a numerically lower response to platinum-free immunotherapy regimens.Conclusions:Unique genomic and transcriptional characteristics were found in HRD-positive NSCLC.Poor prognosis and poor response to EGFR-TKIs and immunotherapy were observed in HRD-positive NSCLC.This study highlights potential actionable alterations in HRD-positive NSCLC,suggesting possible combinational therapeutic strategies for these patients. 展开更多
关键词 Non-small cell lung cancer homologous recombination deficiency genetic alterations transcriptional analysis tumor microenvironment PROGNOSIS
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Mg-doped SrTaO_(2)N as a visible-light-driven H_(2)-evolution photocatalyst for accelerated Z-scheme overall water splitting
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作者 Jun Xu Ying Luo +4 位作者 Qiaoqi Guo Wenzheng Sun Shanshan Chen zheng wang Hong He 《Chinese Journal of Catalysis》 SCIE CAS CSCD 2024年第10期70-78,共9页
Perovskite SrTaO_(2)N is one of the most promising narrow-bandgap photocatalysts for Z-scheme overall water splitting.However,the formation of defect states during thermal nitridation severely hinders the separation o... Perovskite SrTaO_(2)N is one of the most promising narrow-bandgap photocatalysts for Z-scheme overall water splitting.However,the formation of defect states during thermal nitridation severely hinders the separation of charges,resulting in poor photocatalytic activity.In the present study,we successfully synthesize SrTaO_(2)N photocatalyst with low density of defect states,uniform morphology and particle size by flux-assisted one-pot nitridation combined with Mg doping.Some important parameters,such as the size of unit cell,the content of nitrogen,and microstructure,prove the successful doping of Mg.The defect-related carrier recombination has been significantly reduced by Mg doping,which effectively promotes the charge separation.Moreover,Mg doping induces a change of the band edge,which makes proton reduction have a stronger driving force.After modifying with the core/shell-structured Pt/Cr_(2)O_(3)cocatalyst,the H_(2)evolution activity of the optimized SrTaO_(2)N:Mg is 10 times that of the undoped SrTaO_(2)N,with an impressive apparent quantum yield of 1.51%at 420 nm.By coupling with Au-FeCoO_(x)modified BiVO_(4)as an O_(2)-evolution photocatalyst and[Fe(CN)_(6)]_(3)−/[Fe(CN)_(6)]_(4)−as the redox couple,a redox-based Z-scheme overall water splitting system is successfully constructed with an apparent quantum yield of 1.36%at 420 nm.This work provides an alternative way to prepare oxynitride semiconductors with reduced defects to promote the conversion of solar energy. 展开更多
关键词 Photocatalytic overall water splitting SrTaO_(2)N photocatalyst Mg doping Defect density COCATALYST
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Seed dispersal by wintering ducks in a coastal wetland of eastern China
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作者 Xin Luo Ning Li +2 位作者 Wei Tai Yao Cai zheng wang 《Avian Research》 SCIE CSCD 2024年第4期451-457,共7页
Duck species are important vectors for seed dispersal of many plants,contributing significantly to the regeneration of wetland plant communities.However,research on the temporal changes in diet and the dynamics and di... Duck species are important vectors for seed dispersal of many plants,contributing significantly to the regeneration of wetland plant communities.However,research on the temporal changes in diet and the dynamics and differences of seed dispersal among different duck species is still limited.In this study,we analyzed the diversity of duck community and the diversity of seeds in the feces of different duck species from December to February for 2022–23 and 2023–24 in the coastal wetland of Dafeng,eastern Jiangsu Province,China.A total of 13 duck species were recorded in the four habitats,of which Spot-billed Ducks(Anas zonorhyncha)and Mallards(A.platyrhynchos)were the most abundant.The diversity and abundance of ducks vary across different habitats,and tidal flat supports the greatest diversity and abundance of ducks.We collected fecal samples from Spot-billed Ducks,Gadwalls(Mareca strepera),Mallards,and Eurasian Teals(A.crecca)in the tidal flat,from which seeds belonging to 7 families,13 genera and 15 different plant species were obtained.There were significant differences in seed dispersal among the four duck species,which varied with the season.Gadwalls and Common Teals showed more significant diversity in seed dispersal,with their feces containing a greater variety of plant seeds,which is related to their broader dietary range and ecological adaptability.Furthermore,the seasonal variation in the number of seeds per feces reflected the availability of seeds in the habitat and the response of ducks to environmental changes,while variations in seed intake among different duck species may be associated with inter-annual weather condition changes.The results of this study will provide a new perspective for understanding the mechanisms of bird-mediated seed dispersal in coastal wetland and offer preliminary insights for the seed dispersal by Asian ducks. 展开更多
关键词 Coastal wetland Ducks Duck diversity Duck feces Seed dispersal
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Probiotics administration alleviates cognitive impairment and circadian rhythm disturbance induced by sleep deprivation
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作者 Peijun Tian Yunfei Hou +6 位作者 zheng wang Jiaona Jiang Xin Qian Zhihao Qu Jianxin Zhao Gang wang Wei Chen 《Food Science and Human Wellness》 SCIE CAS CSCD 2024年第4期1951-1961,共11页
Gut microbiome is indispensable for maintaining normal brain function.Specifically,gut microbiota plays a causal role in sleep deprivation(SD)-induced cognitive impairment.In this study,neurobehavioral effects of the ... Gut microbiome is indispensable for maintaining normal brain function.Specifically,gut microbiota plays a causal role in sleep deprivation(SD)-induced cognitive impairment.In this study,neurobehavioral effects of the Bifidobacterium breve strain(CCFM1025)were assessed in sleep-deprived mice.CCFM1025 improved the body weight and food and water intake of the mice.It also alleviated SD-induced cognitive behavioural abnormalities(in the novel object recognition test),but did not show beneficial effects on mood-and spatial memory-related behaviours.CCFM1025 significantly altered the gut microbial composition and genome function.Key microbial metabolites that may regulate sleep function were also identified,such as isovaleric acid andγ-aminobutyric acid in the gut and purine metabolites in the serum.Those metabolites may participate in gutbrain communication by acting on the striatal melatonin system,for example to increase melatonin levels,and by regulating the expression of circadian clock genes such as those encoding the adenosine A2A receptor and period circadian regulator 1.Collectively,administration of probiotics alleviated cognitive impairment and circadian rhythm disturbance induced by SD via modulation of gut microbiome and its metabolites.These findings may help guide the treatment of insomnia or other sleep disorders via dietary strategies. 展开更多
关键词 BIFIDOBACTERIUM SLEEP Circadian rhythm PURINE Gut microbiome
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