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Laboratory and numerical modelling of irrigation infiltration and nitrogen leaching in homogeneous soils

Pedosphere 2024年第1期34卷 146-158页

作者： Lei WU Ruizhi LI Yan wang Zongjun GUO jiaheng LI Hang YANG Xiaoyi MA Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas Ministry of EducationNorthwest A&F UniversityYangling 712100China Blackland Research and Extension Center Texas A&M AgriLife ResearchTexas A&M UniversityTemple TX 76502USA State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Northwest A&F UniversityYangling 712100China College of Water Resources and Architectural Engineering Northwest A&F UniversityYangling 712100China

Nitrogen (N) plays a key role in crop growth and production;however,data are lacking especially regarding the interaction of biochar,grass cover,and irrigation on N leaching in saturated soil profiles.Eighteen soil columns with 20-cm diameter and 60-cm height were designed to characterize the effects of different grass cover and biochar combinations,i.e.,bare soil+0%biochar (control,CK),perennial ryegrass+0%biochar (C1),Festuca arundinacea+0%biochar (C2),perennial ryegrass+1%biochar (C3),perennial ryegrass+2%biochar (C4),perennial ryegrass+3%biochar (C5),F.arundinacea+1%biochar (C6),F.arundinacea+2% biochar (C7),and F.arundinacea+3%biochar (C8),on periodic irrigation infiltration and N leaching in homogeneous loess soils from July to December 2020.Leachates in CK were 10.2%–35.3%higher than those in C1 and C2.Both perennial ryegrass and F.arundinacea decreased the volumes of leachates and delayed the leaching process in the 1%,2%,and 3%biochar treatments,and the vertical leaching rate decreased with biochar addition.The N leaching losses were concentrated in the first few leaching tests,and both total N (TN) and nitrate (NO_(3)^(-))-N concentrations in CK and C1–C8 decreased with increasing leaching test times.Biochar addition (1%,2%,and 3%) could further reduce the leaching risk of NO_(3)^(-)-N and the NO_(3)^(-)-N loss decreased with biochar addition.However,compared to 1%biochar,2% biochar promoted the leaching of TN under both grass cover types.The N leaching losses in CK,C1,C2,C3,C4,C6,and C7 were primarily in the form of NO_(3)^(-)-N.Among these treatments,CK,C1,and C2had the highest cumulative leaching fractions NO_(3)^(-)-N (>90%),followed by those in C3,C4,C6,and C7 (>80%).The cumulative leaching fraction of NO_(3)^(-)-N decreased with increasing leaching test times and biochar addition,and 3%biochar addition (i.e.,C5 and C8) reduced it to approximately 50%.The one-dimensional advective-dispersive-reactive transport equation can be used as an effective numerical approach to simulate and predict NO_(3)^(-

关键词： leaching loss nitrate nitrogen biochar grass cover analytical modelling

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Performance Analysis of an Efficient Integration System of Coal-Fired Power Plant,Solar Thermal Energy and CO2 Capture

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Journal of Thermal Science 2024年第4期33卷 1509-1522页

作者： wang Yuhao wang Ruilin LIU Lanhua XING Chenjian GUO Yafei YANG Qingshan YING jiaheng SUN Jian LI Wenjia LIU Yuanyuan ZHAO Chuanwen School of Energy and Mechanical Engineering Nanjing Normal University China Huadian Group Co.LTD.Shanghai Branch Key Laboratory of Efficient Utilization of Low and Medium Grade Energy(Tianjin University) Ministry of Education of China Huadian Zhengzhou Mechanical Design Institute Company Limited

Coal-fired power plant is a major contributor to greenhouse gas emissions.The post-combustion capture is a promising method for CO2emission reduction but the high thermal demand is unbearable.To address this issue,solar thermal energy and CO2capture are jointly integrated into the coal-fired power plant in this study.The solar thermal energy is employed to meet the heat requirement of the CO2capture process,thereby avoiding the electricity loss caused by self-driven CO2capture.Furthermore,the heat released from the carbonation reaction of MgO adsorbent is integrated into the steam Rankine cycle.By partially substituting the extracted steam for feedwater heating,the electricity output of the power plant is further increased.According to the results from the developed model,the system could achieve a CO2capture rate of 86.5% and an electricity output enhancement of 9.8% compared to the reference system,which consists of a self-driven CO2capture coal-fired power plant and PV generation unit.The operational strategy is also optimized and the amount of CO2emission reduction on a typical day is increased by 11.06%.This work shows a way to combine fossil fuels and renewable energy for low carbon emissions and efficient power generation.

关键词： CO 2 capture parabolic trough collector solar aided coal-fired electricity generation

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Blockchain-enabled wireless communications: a new paradigm towards 6G

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National Science Review 2021年第9期8卷 167-191页

作者： jiaheng wang Xintong Ling Yuwei Le Yongming Huang Xiaohu You National Mobile Communications Research Laboratory Southeast University Purple Mountain Laboratories

With the deployment of fifth-generation(5 G) wireless networks worldwide, research on sixth-generation(6 G) wireless communications has commenced. It is expected that 6 G networks can accommodate numerous heterogeneous devices and infrastructures with enhanced efficiency and security over diverse,e.g. spectrum, computing and storage, resources. However, this goal is impeded by a number of trust-related issues that are often neglected in network designs. Blockchain, as an innovative and revolutionary technology that has arisen in the recent decade, provides a promising solution. Building on its nature of decentralization, transparency, anonymity, immutability, traceability and resiliency, blockchain can establish cooperative trust among separate network entities and facilitate, e.g. efficient resource sharing,trusted data interaction, secure access control, privacy protection, and tracing, certification and supervision functionalities for wireless networks, thus presenting a new paradigm towards 6 G. This paper is dedicated to blockchain-enabled wireless communication technologies. We first provide a brief introduction to the fundamentals of blockchain, and then we conduct a comprehensive investigation of the most recent efforts in incorporating blockchain into wireless communications from several aspects. Importantly, we further propose a unified framework of the blockchain radio access network(B-RAN) as a trustworthy and secure paradigm for 6 G networking by utilizing blockchain technologies with enhanced efficiency and security.The critical elements of B-RAN, such as consensus mechanisms, smart contract, trustworthy access,mathematical modeling, cross-network sharing, data tracking and auditing and intelligent networking, are elaborated. We also provide the prototype design of B-RAN along with the latest experimental results.

关键词： blockchain wireless communication 6G

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高原河谷县域景观生态风险评价与生态安全格局构建:以云南省大理州永平县为例

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生态学杂志 2024年第5期43卷 1509-1520页

作者：杜佳衡王影雪潘悦王锦西南林业大学园林园艺学院昆明650224

维护高原河谷县域生态安全是推进高原地区新时代经济高质量发展的关键途径,对于提升住民福祉及实现高原河谷县域可持续发展具有重要意义。本研究选取高原河谷县域云南省大理州永平县为对象,基于景观生态学原理,以景观指数法建立景观生... 详细信息

维护高原河谷县域生态安全是推进高原地区新时代经济高质量发展的关键途径,对于提升住民福祉及实现高原河谷县域可持续发展具有重要意义。本研究选取高原河谷县域云南省大理州永平县为对象,基于景观生态学原理,以景观指数法建立景观生态风险评价模型,综合运用InVEST-MSPA-Conefor分析方法确定生态源地,结合最小阻力模型和重力模型提取生态廊道,利用水文分析工具提取辐射通道并识别生态战略节点、生态断裂点,运用阻力阈值法建立保护关键区,最终构建永平县的生态安全格局。结果表明:2020年永平县景观生态风险呈现出“西北、西南、东北低”,“中南、东、西高”的空间格局;生态风险低值区植被覆盖良好,受人为活动干扰较少,生态环境质量好;高值区位于耕地、建设用地集中连片分布地带,生态环境质量较差,是进行生态建设的关键区域;研究共识别出14处生态源地、102条一般廊道、18条关键廊道、138条辐射通道、62个生态战略节点、88个生态断裂点以及6片保护关键区,这些组分共同构成永平县的生态安全格局。

关键词：景观生态风险生态安全格局高原河谷永平县

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Fast-convolution multicarrier based frequency division multiple access

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Science China(Information Sciences) 2019年第8期62卷 5-21页

作者： Yining LI Wenjin wang jiaheng wang Xiqi GAO National Mobile Communications Research Laboratory Southeast University

Fast-convolution multicarrier(FCMC), the asynchronous waveform with ultra-low sidelobe, has appeared to be a promising waveform technique for future wireless communications. In this paper, we investigate the filter bank optimization as well as receiver design including low-complexity channel estimator and equalizer for FCMC based frequency division multiple access(FDMA). Starting from the conventional multi-carrier signals, we first derive a vectorized signal model as a framework to systematically design the FCMC transceiver. For nearly perfect reconstruction(NPR) filter banks design, an optimization criterion which consists of minimizing received signal segments’ mean square error(MSE) is proposed. From the fact that Toeplitz matrices can be asymptotically diagonalized by discrete Fourier transform(DFT) matrix, the channel equalizer can be simplified to one-tap frequency domain equalizer when DFT size is large enough.The minimum mean square error(MMSE) criterion is then applied to calculate the coefficients of onetap frequency domain equalizer. In practice, due to the channel fading, the channel estimation has to be performed to obtain the channel state information(CSI) which is required by the channel equalization. To this end, we propose a combined cyclic prefix(CP) and cyclic suffix(CS) pilot structure which facilitates to estimate the frequency domain CSI directly in the receiver end. The proposed FCMC based FDMA features low-complexity receiver, adjustable users’ bandwidth and low peak-to-average power ratio. Simulation results confirm the performance of the proposed scheme.

关键词： multirate signal processing filter banks fast convolution channel estimation equalizer

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通智测试——基于动态具身物理社会交互环境的通用人工智能测试

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Engineering 2024年第3期34卷 12-22页

作者： Yujia Peng jiaheng Han Zhenliang Zhang Lifeng Fan Tengyu Liu Siyuan Qi Xue Feng Yuxi Ma Yizhou wang Song-Chun Zhu National Key Laboratory of General Artificial Intelligence Beijing Institute for General Artificial IntelligenceBeijing 100086China Institute for Artificial Intelligence Peking UniversityBeijing 100871China Beijing Key Laboratory of Behavior and Mental Health School of Psychological and Cognitive SciencesPeking UniversityBeijing 100871China School of Intelligence Science and Technology Peking UniversityBeijing 100871China School of Computer Science Peking UniversityBeijing 100871China

The release of the generative pre-trained transformer(GPT)series has brought artificial general intelligence(AGI)to the forefront of the artificial intelligence(AI)field once again.However,the questions of how to define and evaluate AGI remain unclear.This perspective article proposes that the evaluation of AGI should be rooted in dynamic embodied physical and social interactions(DEPSI).More specifically,we propose five critical characteristics to be considered as AGI benchmarks and suggest the Tong test as an AGI evaluation system.The Tong test describes a value-and ability-oriented testing system that delineates five levels of AGI milestones through a virtual environment with DEPSI,allowing for infinite task generation.We contrast the Tong test with classical AI testing systems in terms of various aspects and propose a systematic evaluation system to promote standardized,quantitative,and objective benchmarks and evaluation of AGI.

关键词： Artificial general intelligence Artificial intelligence benchmark Artificial intelligence evaluation Embodied artificial intelligence Value alignment Turing test Causality

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基于纳米复合PCM集蓄热构件的建筑太阳能供暖特性研究

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中南大学学报（自然科学版） 2024年第3期55卷 1168-1177页

作者：严婷徐国英王岚陈龙余佳恒东南大学能源与环境学院江苏南京210096

设计一种基于吸光型纳米复合相变材料(PCM)模块化集蓄热构件,将其应用于建筑太阳能采暖,以降低能耗和碳排放。开展石墨烯-石蜡复合相变材料的制备和物性测试,建立PCM集蓄热数学模型,并结合典型气候工况进行供热特性的数值模拟,研究定风... 详细信息

设计一种基于吸光型纳米复合相变材料(PCM)模块化集蓄热构件,将其应用于建筑太阳能采暖,以降低能耗和碳排放。开展石墨烯-石蜡复合相变材料的制备和物性测试,建立PCM集蓄热数学模型,并结合典型气候工况进行供热特性的数值模拟,研究定风量情况下蓄热层厚度和空气流道宽度对供暖特性的影响,分析通风速度对送风温度、日供热量以及太阳能供暖保证率的影响。研究结果表明:添加石墨烯后的纳米复合PCM相对于纯石蜡的集热效率约提升了60%;对于具有18 m^(2)采光面积的集蓄热构件,当通风速度为1.0 m/s时,太阳能集蓄热墙具有较为优异的供暖性能,此时供给室内的日供热量、日平均热效率和供暖保证率分别为112.5 MJ、67.6%和90.0%,室内能够达到20℃的设定温度的时间为13 h。

关键词：吸光型PCM 模块化集蓄热构件供暖通风速度

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区块链增强的低空智联网可信协作架构及集群构建策略

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数据采集与处理 2024年第1期39卷 71-82页

作者：乐煜炜江锐江毅恒王家恒东南大学信息科学与工程学院南京211189 网络通信与安全紫金山实验室南京211111

低空生态的繁荣不断推动智能网络服务由平面向低空三维立体方向转变,低空业务呈现出规模化、协同化和智能化等演进态势,对低空智联网跨域设备协作能力、任务处理效率、数据安全性及操作可信性等提出了较严苛要求。集群式多设备联合计算... 详细信息

低空生态的繁荣不断推动智能网络服务由平面向低空三维立体方向转变,低空业务呈现出规模化、协同化和智能化等演进态势,对低空智联网跨域设备协作能力、任务处理效率、数据安全性及操作可信性等提出了较严苛要求。集群式多设备联合计算协作可提升低空智联网中复杂化大规模任务的处理效率,然而现有模式仍存在跨域设备协作困难、安全可信性缺乏保障以及资源调度灵活性不足等问题。区块链具有数据及操作不可篡改、公开透明和集体维护等特性,尤为适合在多方参与的低空智联环境中建立高效协作信任。本文提出区块链增强的低空智联网可信协作架构,为低空多源异构智联设备提供链上跨域协作计算与状态同步渠道,并设计深度融合集群任务处理流程的多级共识协议,保障低空智联网协作集群式计算服务的安全性与可信性。针对低空智联网中协作集群链上同步状态的时效性开展分析,并据此提出一种基于排队模型的低空智联协作节点链上状态修正算法与高效集群构建策略,保障链上协作任务处理效率。仿真结果表明所提架构及方案可有效提升低空智联网中协作任务处理效率和资源利用率等性能。

关键词：区块链低空智联网共识协议排队模型信息年龄

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木葡糖酸醋杆菌运动相关基因的敲除及对细菌纤维素合成的影响

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生物工程学报 2024年第6期40卷 1856-1867页

作者：刘嘉恒王旭彭昭君辛波钟成天津科技大学食品营养与安全国家重点实验室天津300457 天津科技大学教育部工业发酵微生物重点实验室天津300457

细菌纤维素(bacterial cellulose,BC)是由细菌合成的高分子生物聚合物,具有持水性高、结晶度高、纯度高等优良特性,广泛应用于食品、医疗、化妆品和功能膜等领域。木葡糖酸醋杆菌(Komagataeibacter xylinus)是BC合成研究的模式菌株。在... 详细信息

细菌纤维素(bacterial cellulose,BC)是由细菌合成的高分子生物聚合物,具有持水性高、结晶度高、纯度高等优良特性,广泛应用于食品、医疗、化妆品和功能膜等领域。木葡糖酸醋杆菌(Komagataeibacter xylinus)是BC合成研究的模式菌株。在细菌中,运动相关基因与BC合成有关,而在木葡糖酸醋杆菌CGMCC2955中,尚不清楚运动相关基因的功能及其对BC合成的影响。本研究利用λ-Red重组系统敲除细菌运动相关基因motA、motB、mot2A,以此构建了敲除菌株K.x-ΔmotA、K.x-ΔmotB、K.x-Δmot2A及双敲菌株K.x-ΔmotAB。结果表明:敲除菌K.x-ΔmotAB的BC产量最高,达到(5.05±0.26)g/L,与野生型菌株相比,提高24%左右;同时,该菌株合成的BC的孔隙率最低,达到了54.35%,并具有更优越的力学性能,杨氏模量可达5.21 GPa。在木葡糖酸醋杆菌CGMCC 2955中敲除运动相关基因之后,并未降低BC的产量,反而促进了BC的合成,进一步加深了醋酸菌中运动性与BC关系的认知;并且敲除motA和motB基因后,降低了BC的孔隙率并提升了BC的力学性能,为BC合成及膜结构调节改造提供了参考。

关键词：木葡糖酸醋杆菌细菌纤维素运动相关基因基因敲除

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FPCC改良过湿土力学性能及微观特性研究

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人民黄河 2024年第6期46卷 152-156,162页

作者：孟宪金李嘉衡王运涛黄河水利职业技术学院河南开封475004 开封市土木工程质量检测研究中心河南开封475004 开封黄河河务局河南开封475000

为达到提高过湿土强度并合理利用工业固废的目的,利用粉煤灰、磷渣、电石渣及水泥所制备的煤灰-磷渣-电石渣-水泥胶凝材料(FPCC)对过湿土进行改良,对FPCC掺量分别为4%、6%、8%及10%的过湿土进行无侧限抗压强度试验、加州承载比(CBR)试... 详细信息

为达到提高过湿土强度并合理利用工业固废的目的,利用粉煤灰、磷渣、电石渣及水泥所制备的煤灰-磷渣-电石渣-水泥胶凝材料(FPCC)对过湿土进行改良,对FPCC掺量分别为4%、6%、8%及10%的过湿土进行无侧限抗压强度试验、加州承载比(CBR)试验、抗压回弹模量试验和电子显微镜(SEM)微观扫描,并利用Matlab软件与Image-Pro Plus(IPP)软件分析其孔隙特征及分布情况,FPCC改良过湿土的力学性能及微观特性。结果表明:FPCC用于过湿土改良效果显著,掺加6%FPCC时过湿土28 d龄期各指标均满足使用要求;28 d龄期FPCC过湿土中产生了大量水化产物,随着掺量的增大,水化产物增多;随着FPCC掺量的增大,土体内部孔隙率降低、孔隙直径减小、孔隙丰度增大及孔隙定向角有序化。FPCC改良过湿土具有良好的强度及承载能力,考虑到节约水泥用量以及更合理地利用工业固废,建议FPCC掺量为6%。

关键词：过湿土工业固废 FPCC 力学性能微观结构

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