mlsa-iai-msu-lab/ru_sci_bench_zho_cite_reranking huggingface dataset:
奈曼旗土地利用动态及其生态系统服务功能

[目的]研究内蒙古自治区奈曼旗土地利用动态及生态系统服务功能与价值的演变情况,为该区土地的合理利用及生态治理工作提供科学依据。[方法]基于奈曼旗2000,2010与2018年土地利用数据,运用ArcGIS,Envi Classic计算土地利用动态度与土地利用转移矩阵,分析土地利用变化及生态系统服务的演变特征。[结果]①2000—2018年间奈曼旗呈“林地—水域—沙地”主导的土地类型演变特征,即林地、水域面积增加,沙地面积减少;其中林地面积净增312100 hm~2,水域面积净增500 hm~2,沙地面积净减142100 hm~2。②时间上,生态系统服务价值变化呈“一减一增”的趋势,其服务价值由2000年的3050.7万元减至2010年的至1991.58万元再增至2018年的4728.55万元。③空间上,生态系统服务高值区、中值区与低值区分别位于南部、中部和北部,形成了“高—中—低”的区域分布格局。④生态系统服务功能上,气候调节的变化最为明显,其对应的服务价值由2000年的801.64万元增至2018年的1349.85万元。[结论]2000—2018年间,研究区土地利用变化明显,其覆被结构明显优化,生态系统服务功能与服务价值也均提高。
基于土地利用变化的河北省坝上地区景观生态风险评价

[目的]对河北省坝上地区近40a来的土地利用动态变化和生态风险进行分析评价并对未来趋势作出预测,为该地区生态建设和治理、可持续发展提供科学依据。[方法]基于坝上地区1980—2018年5期土地利用数据以及通过土地转移矩阵、空间相关性分析等方法揭示和预测该区1980—2026年的土地利用变化特征并评估该区生态风险水平。[结果]①整个研究期间,坝上地区土地利用类型以耕地为主,所占比例近50%,其中,1980—2018年,耕地、林地扩张面积均超过300 km~2,草地减少近616.60 km~2,水域面积缩减36.04%,其中耕地、林地、草地之间的互相流转程度较为剧烈,空间变化上表现为各地类的重心在2000—2010年明显迁移。②1980—2026年,坝上地区6个时期内生态风险值全局空间自相关Moran's I指数均在0.500左右,其空间分布表现出较高的趋同集聚性。③近40a来,坝上生态风险水平升至为高风险级,其区域增加了123.22 km~2,较高风险区域分布在城镇地区,据CA-Markov模型预测,未来坝上地区中等及中等以上风险区域持续扩张,丰宁县和围场县将分别出现小规模高风险区和较高风险区。[结论] ①近40a来坝上地区草地退化严重,水域面积显著减少,原因系安固里淖干涸所致。②该区生态风险水平与土地格局分布具有较强相关性,且在未来会继续升高。
1990-2015年乌苏里江流域土地覆被变化

[目的]分析1990—2015年乌苏里江流域内中国和俄罗斯两国区域土地覆被变化特征和差异,为该流域内人地关系研究和土地资源管理提供科学参考。[方法]以Landsat TM/OLI遥感影像为数据源,采用基于面向对象的遥感分类方法,提取乌苏里江流域1990年和2015年的土地覆被信息,分析乌苏里江流域土地覆被变化的主要特征。[结果]1990—2015年的26a间,乌苏里江流域内农田、湿地面积变化较为明显。农田呈扩张趋势,面积增加6089.69km~2,增长率18.4%。其中,5416.7km~2农田由湿地转化而来,农田扩张主要发生在中国境内区域。湿地、林地面积分别减少了5683.51和844.09km~2,减少率分别为56.4%和3.51%。俄罗斯境内土地覆被变化作用强度较弱,各土地覆被类型间变化率均不超过2%。[结论]气候、地形、农业宏观政策和农业生产方式等是推动乌苏里江流域土地覆被变化的影响因素;其中,农业生产方式的转变和规模的扩大是该流域土地覆被变化的最主要驱动力。
京津冀生态涵养区旅游地社会-经济-生态系统脆弱性特征及其影响因素

[目的]对京津冀生态涵养区旅游地社会—经济—生态系统脆弱性特征及其影响因素进行分析,为该区旅游地降低脆弱性,实现可持续发展提供科学参考。[方法]基于社会、经济、生态子系统构建京津冀生态涵养区旅游地脆弱性综合评价体系。同时,引入线性加权法、自然断点法、障碍度模型对2017年京津冀生态涵养区23个县域单元旅游地脆弱性特征及影响因素进行分析。[结果]研究区综合脆弱性指数均值为0.271 0,呈现轻度脆弱状态;各研究单元的社会脆弱性、经济脆弱性、生态脆弱性指数分布具有明显的空间差异,且较为集中;单位面积粮食产量、城乡收入差距比、产业结构多样化指数、人均可支配收入、乡村从业人员是阻碍涵养区旅游地脆弱性降低的主要因素。[结论]目前,研究区整体可持续发展能力较好,通过对其脆弱性影响因素的有效识别,提出紧抓发展机遇,缩小城乡差距,优化产业结构,强化区域联动等对策。
川北地形过渡带地形因子对土地利用与景观格局变化的影响

[目的]基于地形特征分析不同用地类型时空分布变化,不仅能解释土地利用时空变化规律,并能更进一步为优化土地利用结果,生态环境保护奠定基础。[方法]基于四川省北部江油市2003,2010,2018年3期遥感影像,运用土地利用转移矩阵法,分析不同用地类型之间的转化情况;接着利用地形位指数法、分布指数法,分析地形因子影响下不同用地类型分布指数变化特征;之后利用移动窗口法,探究景观格局中斑块密度与Shannon多样性指数时空变化规律;最后结合双变量空间相关性分析,分析地形因子与景观指数间的空间相关性特征。[结果]①在2003—2010年期间,水田面积减少最多(减少面积2 238.98 hm~2),建设用地面积增加最多(面积增加3 360.36 hm~2);在2010—2018年期间,水田面积减少1 175.84 hm~2,建设用地面积增加1 614.78 hm~2;2003—2010年期间江油市土地利用的变化量整体高于2010—2018年。②北部山区主要由旱地转移为林草地,南部平原地区主要为水田转移为建设用地,中部丘陵区域旱地和水田相互转化强烈。③随时间变化,旱地和未利用地优势等级向中地形位等级靠拢;低地形位等级上建设用地、水田和水域优势度逐渐降低,并具有优势等级向较高地形位等级扩展趋势。④山区河流沿岸以及山地平原交汇处斑块密度与Shannon多样性指数较高,且呈线性分布;随时间变化,丘陵区域斑块密度增加,主城区附近Shannon多样性指数呈下降趋势。⑤高—高聚集区主要表现为向山地丘陵交汇处聚集;城区附近景观指数因受其他因素影响较多,导致该区域景观指数与地形位指数呈现出不显著相关性。[结论]在地形过渡带区域,不同地貌对于各类用地变化的影响在时空上存在差异性,其地形因子与景观指数的空间相关性差异明显。
减小轻载下Vienna整流过零畸变的优化设计方法

Vienna变换器凭借高效率、高功率密度、高可靠性的优点,在工业领域得到了广泛的应用。在此分析了电感或采样延时产生过零点电流尖刺及传统七段空间矢量脉宽调制(SVPWM)在过零点断续出现过零点电流平台的原因。提出一种在过零点利用五段式SVPWM替代传统七段式SVPWM的方法,来改善过零畸变。考虑到五段式SVPWM会引入更高的电流纹波,对过零点五段式SVPWM补偿范围进行优化。最后,通过Simulink搭建了Vienna整流模型,并研制一台5 kW的原理样机,验证了过零点采用五段式SVPWM后能改善电流过零波形,轻载下效果更为显著。
双Buck逆变器的有限集模型预测控制

以航空静止变流器为对象,对基于有限集模型预测控制(FCS-MPC)的单相双Buck逆变器进行研究,消除了电感电流纹波导致的过零畸变问题,并具有效率高、鲁棒性强等优点。首先建立双Buck逆变器的数学模型,分析FCS-MPC的原理。其次分析双极性正弦脉宽调制(SPWM)下,半周期控制所导致的过零畸变的原因,证明FCS-MPC可以有效减小甚至消除过零畸变。接着分析了模型参数误差的影响,得出FCS-MPC应用在双Buck逆变器上具有鲁棒性强、响应速度快等优点。最后通过仿真和实验进行了验证。
黄麻土工布覆盖对花岗岩红壤表土坡面侵蚀特性的影响

[目的]探究黄麻土工布覆盖条件下花岗岩红壤表土坡面侵蚀特性,为花岗岩红壤区坡面土壤侵蚀防治提供科学依据。[方法]通过室内模拟降雨试验,在2个坡度(5°和15°坡度)、3种密度(无覆盖,6cm×6cm及3 cm×3 cm网格)的黄麻土工布覆盖条件下,研究极端降雨条件下(90 mm/h)花岗岩红壤表土的坡面侵蚀特性,并观测径流系数、土壤侵蚀速率、泥沙颗粒变化规律及富集率等指标。[结果]坡面径流随降雨历时增加而增加,土壤侵蚀速率则相反,表明侵蚀过程是一个分离受限的过程。和对照组相比,黄麻土工布覆盖在不同试验条件下都具有明显的减流减沙作用。另外,由侵蚀泥沙的粒径分选规律可知,坡面土壤中的黏粒和粉粒大小的颗粒倾向于被优先选择性搬运,其结果致使坡面石英粗颗粒富集,在缓坡(5°)与高密度黄麻土工布覆盖条件下(3 cm×3 cm网格)尤为突出。坡面石英粗颗粒随降雨历时增加不断富集进一步增加了原位坡面的侵蚀抗性,产生了土壤侵蚀速率随降雨历时不断降低的现象。[结论]高密度黄麻土工布的覆盖能够有效地减流减沙,增加原位坡面抗蚀性,是一种有效的水土保持措施,在今后的土壤侵蚀防治和劣地恢复工作中应该被重视。
基于自适应滤波器的改进SMO矢量控制策略

针对双馈感应风力发电机的矢量控制,利用滑模观测器(SMO)对电机参数的不确定性具有较强鲁棒性的特点,提出一种基于改进SMO的矢量控制策略。该方法使用连续饱和函数,以Sigmoid函数代替Signum函数,以减少反电动势估计中的抖振;同时用自适应陷波滤波器代替传统SMO中的低通滤波器,自适应地补偿估计电动势中的谐波,消除相应的位置估计误差。通过2 MW双馈风力发电仿真系统与11 kW实验平台进行验证,结果表明:所提方法不仅能有效抑制系统抖振与谐波,而且能提高转子位置与转速动态跟踪精度,保证观测器鲁棒性。
新疆维吾尔自治区1981-2018年降雨侵蚀力的空间变化特征

[目的]分析1981—2018年新疆维吾尔自治区降雨侵蚀力空间变化特征,为该区土壤水力侵蚀理论研究和开展水土保持相关实践工作提供科学参考。[方法]以1981—2018年新疆38个气象站的逐日降雨资料为基础,采用半月降雨侵蚀力算法模型计算降雨侵蚀力因子R,进而反映降雨对土壤侵蚀的内在作用,并采用倾向率和Kriging插值方法分析新疆降雨侵蚀力的空间变化特征。[结果]①新疆多年平均降雨侵蚀力和降雨量空间格局相似,呈西高东低,中部高南北低的格局。近40a新疆年降雨侵蚀力总体上处于波动增加趋势,其平均增速为15.6〔MJ·mm/(hm~2·h·a)〕/10a,但因区域不同而有差异,其倾向率天山北部多呈正值,南部多为负值或持平,且北部高于南部。②降雨侵蚀力最大倾向率多出现在夏季(6—8月),但不同区域四季分配格局不同,北部大部分区域春、夏季较高,南部大部分区域夏、秋季较高,多年平均降雨侵蚀力年内分配呈集中在“春夏”格局,但不同区域集中程度不同,其年内集中程度均为降雨侵蚀力高于降雨量,说明能够产生土壤侵蚀的大降雨事件多出现在5—8月。[结论]气候和海拔高度是影响降雨侵蚀力格局的关键要素,在气候变化背景下,春夏季的大降水事件对新疆天山山区土壤水力侵蚀不容忽视。
基于IACA-SVR的电池SOH预测研究

针对锂电池老化机理复杂、电池健康状态(SOH)估算不准确问题,提出了一种新型电池SOH估计方法。首先,建立基于改进蚁群算法优化支持向量回归(IACA-SVR)的电池SOH预测模型,以电池放电过程平均电压和平均温度为输入变量,模拟电池老化。其次,利用样本数据训练SVR,并用IACA来优化SVR的参数。在数据集上的实验结果表明,经过优化的SVR预测结果与遗传算法SVR(GA-SVR)预测结果相比更为精确,稳定性更好,从而验证了IACA-SVR预测模型的可行性,能为电动汽车锂电池的安全使用提供准确电池数据。
一种改进的PMSM转子位置估计方法

准确的位置估计对电机无位置传感器控制尤为重要,传统高频注入法存在忽略反电动势项、交叉耦合项和电流检测偏差等问题。为了提高位置估计精度,针对上述问题在位置估计中的影响进行了理论分析,提出了一种参数自适应滤波及位置估计补偿的改进高频注入永磁同步电机(PMSM)控制策略,可消除估计位置中的二次谐波,补偿估计误差。仿真与实验结果表明,与传统方法相比,所提控制方法可显著减小位置估计误差,具有良好的控制效果。
基于LLC谐振变换器的电力电子变压器研究

介绍一种基于LLC谐振变换器的电力电子牵引变压器(PETT)功率单元系统的设计以及应用,该系统具备软开关技术、高频模块化设计及功率双向流动等优势。以高压功率模块、中频变压器等为载体进行了单元系统在牵引和制动工况下的满载试验及负载突变试验验证,通过相关试验波形和数据证明了该LLC谐振变换电路在工程应用中的有效性和可靠性。
可变电感应用的CLL谐振变换器

在此提出了一种利用磁控制的可变电感来实现定频控制下输出电压控制和调节的方法。分析了利用磁控制下的工作于定频控制下的CLL谐振变换器的原理和特性。一个可变的谐振电感有利于扩展增益范围,同时提高整体效率,并且解决了传统谐振变换器变频模式所带来的电磁干扰(EMI)问题。此处提出了一台以输入为70~90 V,输出为12 V/4 A为原型的原理样机,以验证所提可变电感方案的有效性和优点。
永磁同步电机复矢量电流调节器解耦性能分析

针对内置式永磁同步电机(IPMSM)d,g轴电流存在动态耦合的问题,在此基于有效磁链概念得到了IPMSM的复矢量数学模型,设计了相应的复矢量电流调节器,实现了d,q轴电流的动态解耦。相比于状态反馈解耦控制,复矢量解耦控制具有更好的动态解耦效果,并且在一定程度上提高了电流环控制系统的参数鲁棒性。仿真和实验结果验证了所提方法的有效性和可行性。
中国聚氯乙烯树脂与助剂动态物质流分析

中国已成为全球最大的聚氯乙烯(PVC)塑料生产国和消费国,并面临着PVC塑料广泛使用所带来的各种环境风险。 该文构建了用于定量测算PVC树脂及其助剂流量和存量的动态物质流模型,以展现PVC树脂及其助剂在8类制品、6大应用领域和4类废弃物管理方法之间的复杂流动路径与存量分布。 结果表明,1978-2017年PVC树脂和助剂的累计产量为2.54亿t。 城镇化的推进使得硬制品逐渐占据PVC塑料制品主流,但软制品仍是PVC助剂的主要流向;建筑材料占据了PVC树脂总存量的65.8%、PVC助剂总存量的41.9%,是未来潜在的最大废弃源;尽管存在潜在环境与健康风险的助剂在助剂总流入量中的占比已从62.2%下降至41.5%,但仍有0.15亿t有毒助剂以存量的形式留存在社会与环境中,并将在其使用过程中通过迁移和扩散对人类和环境造成持续性负面影响。 虽然由于数据可得性的限制使得该文结果存在一定的偏差,但不确定性分析表明该文的计算结果可信度较高。 未来必须加强对废PVC塑料的废物管理,通过技术进步和政策引导提高环保助剂的使用比例。
基于二阶广义积分的锁相环在三相VSG中的应用

锁相环(PLL)和虚拟同步发电机(VSG)技术是并网逆变器与电网保持同步的两种方法。针对传统锁相环在同步发电机系统中频率跟踪性能差、抗直流干扰能力低的问题,应用基于二阶广义积分(SOGI)的锁相环结构,建立三相VSG系统模型,将SOGI-PLL与VSG技术结合,搭建基于SOGI-PLL的三相VSG系统模型并进行仿真。仿真结果表明: SOGI-PLL可以通过锁相得到精确的电网相位信息,改善并网电流电压质量,降低谐波污染,能够有效提高三相VSG系统的稳定性。通过ModelingTech电力电子仿真实验系统验证所提出结构的准确性。
考虑障碍物避让的水下滑翔机局部路径规划方法

针对水下滑翔机“V”形轨迹的周期性运动特点,提出一种适用于水下滑翔机在三维路径中避让障碍物的粒子群优化(PSO)算法。根据水下滑翔机的运动特征,给出水下工作环境的三维空间建模方法。结合水下滑翔机能耗问题,选择用规划路径的长度、障碍物的危险度和路径平滑度来制定适应度函数。提出一种惯性权重的非线性动态调整策略,提高了算法的全局搜寻能力。将优化后的算法与基本粒子群算法比较,结果表明:优化后的算法可以生成质量更高的路径,并且可以在更少的迭代次数下收敛到全局最优,有效地提高了粒子群算法应用在水下滑翔机路径规划的算法速度和能耗效率。
中医康复临床实践指南·心肺康复

心肺功能康复是现代康复医学的重要组成内容,心肺功能是人体生理功能的根基,心肺功能的高低直接影响着患者的生活质量和康复进程。循证医学显示,心肺康复是通过全面、规范的评定,采取药物、运动、营养、教育、心理等综合医疗干预手段进行心肺康复治疗,能有效提高患者循环系统和呼吸系统功能,改善患者生活质量,促进其回归家庭和社会生活。制定心肺中医康复临床实践指南的主要目的是规范临床心肺功能障碍评估及康复治疗方法,以提高康复疗效。本指南从范围、术语和定义、心肺系疾病的中医四诊(心系、肺系辨证分型)、心肺功能评估、心肺功能训练等方面对心肺康复流程进行梳理。其中心肺功能评估主要包括以下几个方面:病史、体格检查、辅助检查(心脏超声、心电图、动态心电图、心脏导管检查、肺容量测定、肺通气功能测试、气体代谢测试)、呼吸困难程度分级、功能性肺残疾分级、心功能分级、运动耐力的评估(6 min步行试验、心肺运动试验)、体适能评估(肌力、徒手柔韧性、平衡能力评估);心肺功能训练主要包括:肺通气与肺容量改善训练、气道廓清技术、呼吸肌训练、运动训练、针刺疗法、推拿疗法、太极罐疗法、耳穴疗法、中医导引术等。本指南可为各级各类康复机构、中医医院或综合医院的康复从业人员进行心肺康复治疗提供指导,具有较好的临床适用性及有效性。
新型冠状病毒肺炎出院患者中西医结合康复指导

新型冠状病毒肺炎(新冠肺炎)疫情防控工作取得阶段性成果。大量新冠肺炎患者康复出院,通过临床观察发现,很多出院患者面临着呼吸功能、躯体功能、心理功能、日常生活能力及社会参与能力障碍等相关方面的问题。针对上述问题,本研究通过临床应用、筛选,初步拟定了一套中西医结合康复指导方案。在对患者进行康复治疗前,需对患者进行一个全面的康复评估,包括呼吸功能、心肺功能、躯体功能、心理功能及日常生活活动能力等。从中医康复角度制定中医康复技术方案,主要包括患者的自我推拿、功法导引锻炼、中药内服、艾灸、足浴熏洗、药膳调理等,同时也结合心肺康复治疗中常用的呼吸功能训练、气道廓清技术、躯体功能锻炼等技术及方法。此外,针对大量出院患者长时间的隔离治疗所产生的心理问题,本研究使用患者易于接受的传统音乐疗法和移情易性疗法。该指导方案融合中西医常用的康复技术,简单易学,患者接受程度较高,患者出院后可在专业人员的指导下根据具体问题选择合适的康复方法,加速康复进程,早日回归社会。
Radiation dimming and decreasing water clarity fuel underwater darkening in lakes

Long-term decreases in the incident total radiation and water clarity might substantially affect the underwater light environment in aquatic ecosystems. However, the underlying mechanism and relative contributions of radiation dimming and decreasing water clarity to the underwater light environment on a national or global scale remains largely unknown. Here, we present a comprehensive dataset of unprecedented scale in China's lakes to address the combined effects of radiation dimming and decreasing water clarity on underwater darkening. Long-term total radiation and sunshine duration showed 5.8% and 7.9% decreases, respectively, after 2000 compared to 1961–1970, resulting in net radiation dimming. An in situ Secchi disk depth (SDD) dataset in 170 lakes showed that the mean SDD significantly decreased from 1.80 ± 2.19 m before 1995 to 1.28 ± 1.82 m after 2005. SDD remote sensing estimations for 641 lakes with areas ≥10 km~2 showed that SDD markedly decreased from 1.26 ± 0.62 m during 1985–1990 to 1.14 ± 0.66 m during 2005–2010. Radiation dimming and decreasing water clarity jointly caused an approximately 10% decrease in the average available photosynthetically active radiation (PAR) in the euphotic layer. Our results revealed a more important role of decreasing water clarity in underwater darkening than radiation dimming. A meta-analysis of long-term SDD observation data from 61 various waters further elucidated a global extensive underwater darkening. Underwater darkening implies a decrease in water quality for potable water supplies, recession in macrophytes and benthic algae, and decreases in benthic primary production, fishery production, and biodiversity.
Nature-inspired CaCO_3 loading TiO_2 composites for efficient and durable photocatalytic mineralization of gaseous toluene

The accumulation of intermediates or final products on TiO_2 during photocatalytic volatile organic compounds (VOCs) degradation is typically neglected, despite the fact that it could result in the block of active sites and the deactivation of photocatalysts. Inspired from the natural formation of stalactite (CaCO_3 + H_2O + CO_2 ↔ Ca(HCO_3)2), we fabricated CaCO_3 loading TiO_2 composites (CCT21) to realize the spontaneously transfer of accumulated final products (CO_2 and H_2O). Efficient and durable performance for gaseous toluene removal has been demonstrated and the cost of photocatalyst is greatly reduced by the comparison of specific activity. The introduction of CaCO_3 induces the interaction between TiO_2 and CaCO_3 to stimulate abundant activated electrons for the improvement on the adsorption and activation of reactants and the transformation of photogenerated carriers, and most importantly, facilitates the transfer of final products to release active sites and thus suppress the deactivation of TiO_2. Furthermore, we develop a facile method to immobilize CCT21 powder on flexible support, which greatly reduces the loss of photocatalysts and correspondingly enables the practical application of TiO_2-based products. Therefore, this work presents a novel nature-inspired strategy to address the challenge of deactivation, and advances the development of photocatalytic technology for environmental remediation.
Trimethyltriazine-derived olefin-linked covalent organic framework with ultralong nanofibers

Two-dimensional (2D) olefin-linked covalent organic frameworks (COFs) with excellent p-electron communication and high stability are emerging as promising crystalline polymeric materials. However, because of the limited species of COFs, their characteristics, processability and potential applications have not been completely understood and explored. In this work, we prepared two novel olefin-linked 2D COFs through Knoevenagel condensation of 2,4,6-trimethyl-1,3,5-triazine with tritopic triazine-cored aldehydes. The resulting COFs exhibit highly crystalline honeycomb-like structures stacked from hexagonallatticed polymeric layers and display well-defined nanofibrillar morphologies with the uniform diameters of ca. 80 nm and ultra-lengths up to several micrometers. Such COF nanofibers can be readily composited with carbon nanotubes into high-quality continuous thin films, which are further compacted by a typical hot-pressing process to enhance their densities and mechanical strength without changing their fibrous microstructures. Such film-fabricated interdigital microelectrodes and the ionogel electrolyte are assembled into planar micro-supercapacitors (MSCs), which exhibit an outstanding areal capacitance of 44.3 mF cm~(-2), large operating voltage window of 2.5 V, high volumetric energy density of 38.5 mWh cm~(-3) as well as excellent cycling stability.
A selective control of volatile and non-volatile superconductivity in an insulating copper oxide via ionic liquid gating

Manipulating the superconducting states of high transition temperature (high-Tc) cuprate superconductors in an efficient and reliable way is of great importance for their applications in next-generation electronics. Here, employing ionic liquid gating, a selective control of volatile and non-volatile superconductivity is achieved in pristine insulating Pr2CuO4±d (PCO) films, based on two distinct mechanisms. Firstly, with positive electric fields, the film can be reversibly switched between superconducting and non-superconducting states, attributed to the carrier doping effect. Secondly, the film becomes more resistive by applying negative bias voltage up to -4 V, but strikingly, a non-volatile superconductivity is achieved once the gate voltage is removed. Such phenomenon represents a distinctive route of manipulating superconductivity in PCO, resulting from the doping healing of oxygen vacancies in copper-oxygen planes as unravelled by high-resolution scanning transmission electron microscope and in situ X-ray diffraction experiments. The effective manipulation of volatile/non-volatile superconductivity in the same parent cuprate brings more functionalities to superconducting electronics, as well as supplies flexible samples for investigating the nature of quantum phase transitions in high-Tc superconductors.
Over 15.5% efficiency organic solar cells with triple sidechain engineered ITIC

Bulk-heterojunction (BHJ) organic solar cells (OSCs) showcase great advantages in device fabrication via low-cost and convenient solution-processing techniques for diverse applications (e.g., flexible and semitransparent devices). Over the past few years, great research efforts have been made for photovoltaic material development and device optimization, pushing rapidly improved power conversion efficiencies (PCEs) for OSCs. The main driving force lies in the innovation of non-fullerene acceptors (NFAs), especially fused-ring electron acceptors (FREAs) featuring acceptor- donor-acceptor (A-D-A) architecture. Classic FREAs are ITIC, INPIC-4F, COi8DFIC and Y6. Nowadays, 15% efficiency for binary OSCs seems to be a key hurdle for newly designed acceptors. FREAs contributing high performance (PCE > 15%) are still limited, most of which belong to the ‘‘Y” family (e.g. Y6, Y11 and BTP-4Cl). In contrast, the OSCs based on classic ITIC series acceptors gradually lag behind in performance. However, the ITIC series FREAs boast their distinct strength in: (i) facile and mature syntheses; (ii) versatile structure modification; (iii) systematic researches on the structure-property relationship. Thus, in order to develop higher performance NFAs, molecular engineering on ITIC is in great demanding.
Electrically tunable topological transport of moire polaritons

Moire interlayer exciton in transition metal dichalcogenide heterobilayer features a permanent electric dipole that enables the electrostatic control of its flow, and optical dipole that is spatially varying in the moire landscape. We show the hybridization of moire interlayer exciton with photons in a planar 2D cavity leads to two types of moire polaritons that exhibit distinct forms of topological transport phenomena including the spin/valley Hall and polarization Hall effects, which feature remarkable electrical tunability through the control of exciton-cavity detuning by the interlayer bias.
Global assessment of the impact of irrigation on land surface temperature

A comprehensive and quantitative understanding of the climatic feedbacks of irrigation is of paramount importance for current and future food security. The impact of irrigation on climate, especially temperature, has been assessed by various Earth system models, which have demonstrated that, despite a slight decrease in surface albedo, the net biophysical effect of irrigation is to cool surface temperature through the increase in evapotranspiration (ET). Modeling results are effective in presenting mechanistic understandings of the effects of irrigation on climate, but show high uncertainties in the sign, magnitude, and spatial distribution of the predicted effects, due to their heavy dependence on the model's structure and parameterization. Observations from in-situ measurements (e.g., weather stations and field experiments) can provide local reliable evidence to verify the model results. However, the previous observational studies have been mostly restricted to local regions, because of the insufficient coverage of in-situ measurements, and it is still unclear as to what extent this observed local evidence can be extrapolated to larger areas. High-quality and spatially continuous land surface temperature (LST) observations from satellites such as the Moderate Resolution Imaging Spectroradiometer (MODIS) have provided a new perspective for understanding the impact of irrigation on temperature. In this study, based on MODIS LST data and other satellitederived observations (Text S1 and Fig. S1 online), we provide a global-scale quantitative assessment of the impact of irrigation on LST, and explore the possible controlling factors (i.e., albedo and ET) underlying its spatiotemporal variations.
Engineering the electronic and strained interface for high activity of PdM_(core)@Pt_(monolayer) electrocatalysts for oxygen reduction reaction

Alloyed nanoparticles with core-shell structures provide a favorable model to modulate interfacial interaction and surface structures at the atomic level, which is important for designing electrocatalysts with high activity and durability. Herein, core-shell structured Pd3M@Pt/C nanoparticles with binary PdM alloy cores (M = Fe, Ni, and Co) and a monolayer Pt shell were successfully synthesized with diverse interfaces. Among these, Pd_3Fe@Pt/C exhibited the best oxygen reduction reaction catalytic performance, roughly 5.4 times more than that of the commercial Pt/C catalyst used as reference. The significantly enhanced activity is attributed to the combined effects of strain engineering, interfacial electron transfer, and improved Pt utilization. Density functional theory simulations and extended X-ray absorption fine structure analysis revealed that engineering the alloy core with moderate lattice mismatch and alloy composition (Pd3Fe) optimizes the surface oxygen adsorption energy, thereby rendering excellent electrocatalytic activity. Future researches may use this study as a guide on the construction of highly effective core-shell electrocatalysts for various energy conversions and other applications.
Plum pudding model inspired KVPO_4F@3DC as high-voltage and hyperstable cathode for potassium ion batteries

The investigation on the cathode material of potassium ion batteries (PIBs), one of the most promising alternatives to lithium ion batteries, is of great significance. Potassium vanadium fluorophosphate (KVPO_4F) with a high working voltage is an appealing cathode candidate for PIBs, while the poor cycling performance and low electronic conductivity dramatically hinder the application. Herein, a plum pudding model inspired three-dimensional amorphous carbon network modified KVPO_4F composite (KVPO_4F@3DC) is successfully designed in this study to tackle these problems. In the composite, KVPO_4F particles are homogeneously wrapped by a layer of amorphous carbon and bridged by crosslinked large area carbon sheets. As the cathode for PIBs, the KVPO_4F@3DC composite exhibits a high average operating voltage about 4.10 V with a super-high discharge capacity of 102.96 mAh g~(-1) at 20 mA g~(-1). An excellent long cycle stability with a capacity retention of 85.4% over 550 cycles at 500 mA g~(-1) is achieved. In addition, it maintains 83.6% of its initial capacity at 50 mA g~(-1) after 100 cycles at 55 ℃. The design of KVPO_4F@3DC with plum pudding structure provides facilitative electron conductive network and stable electrode/electrode interface for electrode, successfully innovating an ultra-stable and high-performance cathode material for potassium ion batteries.
Graph attention convolutional neural network model for chemical poisoning of honey bees' prediction

The impact of pesticides on insect pollinators has caused worldwide concern. Both global bee decline and stopping the use of pesticides may have serious consequences for food security. Automated and accurate prediction of chemical poisoning of honey bees is a challenging task owing to a lack of understanding of chemical toxicity and introspection. Deep learning (DL) shows potential utility for general and highly variable tasks across fields. Here, we developed a new DL model of deep graph attention convolutional neural networks (GACNN) with the combination of undirected graph (UG) and attention convolutional neural networks (ACNN) to accurately classify chemical poisoning of honey bees. We used a training dataset of 720 pesticides and an external validation dataset of 90 pesticides, which is one order of magnitude larger than the previous datasets. We tested its performance in two ways: poisonous versus nonpoisonous and GACNN versus other frequently-used machine learning models. The first case represents the accuracy in identifying bee poisonous chemicals. The second represents performance advantages. The GACNN achieved ~6% higher performance for predicting toxic samples and more stable with ~7% Matthews Correlation Coefficient (MCC) higher compared to all tested models, demonstrating GACNN is capable of accurately classifying chemicals and has considerable potential in practical applications. In addition, we also summarized and evaluated the mechanisms underlying the response of honey bees to chemical exposure based on the mapping of molecular similarity. Moreover, our cloud platform (http://beetox.cn) of this model provides low-cost universal access to information, which could vitally enhance environmental risk assessment.
Single-layer CrI_3 grown by molecular beam epitaxy

Single- and few-layer chromium triiodide (CrI_3), which has been intensively investigated as a promising platform for two-dimensional magnetism, is usually prepared by the mechanical exfoliation. Here, we report direct growth of single-layer CrI_3 using molecular beam epitaxy in ultrahigh vacuum. Scanning tunneling microscopy (STM), together with density functional theory (DFT) calculation, revealed that the iodine trimers, each of which consists of three I atoms surrounding a three-fold Cr honeycomb center, are the basic units of the topmost I layer. Different superstructures of single-layer CrI_3 with periodicity around 2–4 nm were obtained on Au(1 1 1), while only the 1 × 1 structure was observed on the graphite substrate. At an elevated temperature of 423 K, single-layer CrI_3 began to decompose and transformed into single-layer chromium diiodide. Our bias-dependent STM images suggest that the unoccupied and occupied states are spatial-separately distributed, consistent with the results of our DFT calculation. We also discussed the role of charge distribution in the super-exchange interactions among Cr atoms in single-layer CrI_3.