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Transformation of Carbon and Nitrogen by Earthworms in the Decomposition Processes of Broad-leaved Litters

Chinese Geographical Science 2007年第2期17卷 166-172页

作者： dong Weihua yin Xiuqin College of Urban and Environmental Science Northeast Normal University Changchun 130024 China

Earthworms are the important constituents in the decayed food web and the main ecological conditioners in the process of decomposition and nutrient mineralization. The transformation of organic carbon (C) and total nitrogen (N) in the broad-leaved litters ingested by earthworms was researched by means of a laboratory experiment. Experimental samples were collected from broad-leaved Korea Pine mixed forest in Liangshui National Natural Reserve (47°10′50″N, 128°53′20″E) in the northeastern Xiao Hinggan Mountains of Northeast China. The contents of organic C and total N in earthworms, leaf litters and earthworm faeces were analyzed. Results show that the organic C content was in the fol- lowing order: leaf litters>faeces>earthworms, while total N content was contrary to that of the organic C. The organic C contents in the different leaf litters were in the following order: Tilia amurensis>Betula costata>Acer mono, whereas the total N contents in the different leaf litters were: Betula costata>Tilia amurensis>Acer mono. The contents of organic C and total N in the faeces from the different leaf litters were almost consistent with the contents of the leaf litters. After the leaf litters were ingested by earthworms, the organic C, which was transformed to increase earthworms' weights, ac- counted for 3.90%-13.31% of the total ingestion by earthworms, while that in the earthworm faeces accounted for 6.14%-13.70%. The transformed organic C through the other metabolism (e.g., respiration) of earthworms accounted for 75.04%-89.92%. The ingested organic C by earthworms was mostly used for metabolic activities. The N ingested by earthworms was less than organic C. It is estimated that 37.08% of total N was transformed to increase the earthworm's weight, 19.97% into earthworm faeces and 47.86% for the consumption of the earthworm's activities. The earthworms not only increased the content of organic C and total N in the soil, but also decreased the values of C/N in the soil and

关键词： broad-leaved litters organic carbon total nitrogen earthworm C transformation N transformation

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Combined Bearing Capacity of Spudcans on a Double Layer Deposit of Strong-Over-Weak Clays

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Journal of Ocean University of China 2019年第1期18卷 133-143页

作者： yin Qilin dong Sheng College of Engineering Ocean University of China

An extreme sea storm process can lead to a jack-up rig under the combined loading condition of vertical load(V), horizontal load(H), and moment(M) to have stability problems. This paper presents the analysis of combined bearing capacities of a circular spudcan on layered clays with a strong layer overlying a comparatively weaker layer. Numerical models combined with displacement-based load tests, swipe tests, and constant ratio displacement probe tests are adopted to calculate the uniaxial bearing capacities, failure envelopes in combined V-H, V-M planes, and failure envelopes in a combined V-H-M load space, respectively. A parametric study on the effects of vertical load level V, the layer strength ratio s_(u,t)/s_(u,b), and the hard layer thickness t_1 on the bearing capacities is then performed. Results show that the vertical load level is a key factor that influences the values of H and M and the size of the H-M failure envelope. The existence of the underlying weak clay decreases the bearing capacities in all directions, and the vertical capacity Vult is affected more than the horizontal(H_(ult)) and moment(M_(ult)) capacities based on a single uniform deposit. The influence of the underlying weak clay on H-M failure envelope is mainly shown where H and M are coupled in the same direction. In contrast, little difference is observed when H and M are coupled in opposite directions.

关键词： combined bearing capacity circular spudcan layered clays vertical load level strength ratio hard layer thickness

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Recent progress in reactivity study and synthetic application of N-heterocyclic phosphorus hydrides

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National Science Review 2021年第4期8卷 181-194页

作者： Jingjing Zhang Jin-dong Yang Jin-pei Cheng Center of Basic Molecular Science Department of Chemistry Tsinghua University State Key Laboratory of Elemento-Organic Chemistry College of Chemistry Nankai University

N-heterocyclic phosphines(NHPs) have recently emerged as a new group of promising catalysts for metal-free reductions, owing to their unique hydridic reactivity. The excellent hydricity of NHPs, which rivals or even exceeds those of many metal-based hydrides, is the result of hyperconjugative interactions between the lone-pair electrons on N atoms and the adjacent σ*(P–H) orbital. Compared with the conventional protic reactivity of phosphines, this umpolung P–H reactivity leads to hydridic selectivity in NHP-mediated reductions. This reactivity has therefore found many applications in the catalytic reduction of polar unsaturated bonds and in the hydroboration of pyridines. This review summarizes recent progress in studies of the reactivity and synthetic applications of these phosphorus-based hydrides, with the aim of providing practical information to enable exploitation of their synthetically useful chemistry.

关键词： N-heterocyclic phosphine diazaphospholene hydride transfer metal-free reduction σ-bond metathesis

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Vertical-horizontal coupling nonlinear vibration characteristics of rolling mill under mixed lubrication

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Journal of Iron and Steel Research International 2021年第5期28卷 574-585页

作者： dong-xiao Hou Liang Xu pei-ming Shi School of Control Engineering Northeastern University at QinhuangdaoQinhuangdao 066004HebeiChina School of Electrical Engineering Yanshan UniversityQinhuangdao 066004HebeiChina

Considering the dynamic influence of the roll vibration on the lubricant film thickness in the rolling deformation area,nonlinear dynamic rolling forces related to film thickness in the vertical and horizontal directions were obtained based on the Karman balance *** on these dynamic rolling forces and the mechanical vibration of the rolling mill,a vertical-horizontal coupling nonlinear vibration dynamic model was *** amplitude-frequency equation of the main resonance was derived by using the multiple-scale *** last,the parameters of the 1780 rolling mill were used for numerical simulation,and the time-domain response curves of the system’s vibration displacement and lubricating film thickness under the steady and unsteady conditions were *** influences of parameters such as interface contact ratio,nonlinear parameters and external disturbances on the primary resonance frequency characteristics were obtained,which provided a theoretical reference for the suppression of rolling mill vibration.

关键词： Vertical-horizontal coupling Nonlinear vibration Mixed lubrication Dynamic rolling force Main resonance Amplitude-frequency characteristic

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Time-Varying Channel Estimation Based on Air-Ground Channel Modelling and Modulated Learning Networks

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Chinese Journal of Electronics 2022年第3期31卷 430-441页

作者： LIU Chunhui WANG Meilin dong Zanliang WANG pei Institute of Unmanned System Beihang University School of Electronic and Information Engineering Beihang University

To improve the time-varying channel estimation accuracy of orthogonal frequency division multiplexing air-ground datalink in complex environment, this paper proposes a time-varying air-ground channel estimation algorithm based on the modulated learning networks,termed as MB-Chan Est-TV. The algorithm integrates the modulated convolutional neural networks(MCNN) with the bidirectional long short term memory(Bi-LSTM),where the MCNN subnetworks accomplish channel interpolation in frequency domain and compress the network model while the Bi-LSTM subnetworks achieve channel prediction in time domain. Considering the unique characteristics of airframe shadowing for unmanned aircraft systems, we propose to combine the classical 2-ray channel model with the tapped delay line model and present a more realistic channel impulse response samples generation approach, whose code and dataset have been made publicly available. We demonstrate the effectiveness of our proposed approach on the generated dataset, where experimental results indicate that the MB-Chan Est-TV model outperforms existing state-of-the-art methods with a lower estimation error and better bit error ratio performance under different signal to noise ratio *** also analyze the effect of roll angle of the aircraft and the duration percentage of the airframe shadow on the channel estimation.

关键词： OFDM modulation channel prediction realistic channel impulse response samples generation approach modulated learning networks Bi-LSTM subnetworks telecommunication computing air-ground datalink wireless channels 2-ray channel model convolutional neural nets interpolation time-varying channels MB-ChanEst-TV model air-ground channel modelling frequency domain error statistics recurrent neural nets channel estimation modulated convolutional neural networks bidirectional long short term memory learning (artificial intelligence) time-varying air-ground channel estimation algorithm network model channel interpolation MCNN tapped delay line model lower estimation error time-varying channel estimation accuracy

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Early-diverging Titanosauriform(Dinosauria,Sauropoda)Teeth from the Lower Cretaceous Yixian Formation of Southeastern Inner Mongolia,Northeast China

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Acta Geologica Sinica(English Edition) 2024年第2期98卷 303-310页

作者： ZHANG Honggang yin Yalei pei Rui ZHOU Changfu College of Earth Science and Engineering Shandong University of Science and TechnologyQingdaoShandong 266570China College of Paleontology Shenyang Normal UniversityShenyang 110034China Key Laboratory of Evolution of Past Life in NE Asia Ministry of Natural ResourcesShenyang 110034China Key Laboratory of Evolutionary Systematics of Vertebrates Institute of Vertebrate Paleontology and PaleoanthropologyChinese Academy of SciencesBeijing 100044China CAS Center for Excellence in Life and Paleoenvironment Beijing 100044China

Three eusauropod teeth(SDUST-V1064,PMOL-AD00176,PMOL-ADt0005)are reported from the Lower Cretaceous Yixian Formation of Ningcheng,southeastern Inner Mongolia,*** of them(SDUST-V1064,PMOL-AD00176)are assigned to early-diverging titanosauriforms in having slightly mesiodistal expansion at the base of the tooth crown,a slenderness index value>2.0 and<4.0,and D-shaped cross ***,SDUST-V1064 and PMOL-AD00176 are referred as an Euhelopus-like titanosauriform on the basis of having a sub-circular boss on the lingual surface and an asymmetrical crown-root margin which slants apically,*** scan data of SDUST-V1064 reveals new dental information of early-diverging titanosauriforms,for example,the enamel on the labial side thicker than that on the lingual side,an enamel/dentine ratio of 0.26 and a boss present on the lingual side of the dentine of the crown.

关键词： teeth Titanosauriformes Lower Cretaceous Yixian Formation Ningcheng

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Design,fabrication and kinematics of a bio-inspired robotic bat wing

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Science China(Technological Sciences) 2016年第12期59卷 1921-1930页

作者： yin dong Fu ZHANG Zhi Sheng School of Mechanical Engineering Southeast University

The current work is oriented toward the development of a novel biologically inspired bat aerial robot with morphing wings. Based on the flight characteristics data of natural bats(Eptesicus fuscus), a novel four degrees of freedom robotic bat wing was developed to emulate the movements of bat wing. The design, fabrication, programing and wind tunnel experiments of the robot bat wing are described in this paper. Based on this robotic wing, the influence of flap amplitude, wind speed, flight frequency, downstroke ratio and stroke plane angle as well as the contributions of flap, elbow, sweep and wrist motions on the aerodynamic force and mechanical power were studied and analyzed. Results of wind tunnel experiments validated that higher lift would bring greater power consumption, and the flap motion would generate the most force and need more energy expenditure compared with other motions of bat. The experimental results suggest that the flap and fold motions are indispensable to make a robotic bat wing that has a better flight performance. This study provides some implications and a better understanding for the future robotic bat.

关键词： bio-inspiration wing robotic bat flight kinematics wrist motion

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Quasi-concave optimization of secrecy redundancy rate in HARQ-CC system

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Science China(Information Sciences) 2020年第2期63卷 160-173页

作者： Yue WU Shishu yin Jian ZHOU pei YANG Hongwen YANG School of Management Science and Engineering Anhui University of Finance and Economics School of Information and Communication Engineering Beijing University of Posts and Telecommunications

In a hybrid automatic repeat request with chase combining(HARQ-CC) system, we analyze physical layer secure performance and determine the secrecy redundancy rate by proposed quasi-concave optimization methods with effective secrecy throughput(EST) criteria. First, key performance metrics,including connection outage probability(COP), secrecy outage probability(SOP), EST, and delay, are discussed. Then, under the constraint of COP, we optimize the secrecy redundancy rate to maximize the EST,which is a quasi-concave function, by both the bisection and fixed-point methods. Furthermore, under the simultaneous constraints of COP and SOP, the bisection and Lagrangian multiplier methods are applied to optimize the secrecy redundancy rate. From the comparison of the numerical and simulated results, it is concluded that EST demonstrates practical secure performance of HARQ-CC, and the proposed optimization methods adjust the secrecy redundancy rate for improved security.

关键词： physical layer security(PLS) hybrid automatic repeat request(HARQ) chase combining(CC) effective secrecy throughput(EST) quasi-concave optimization

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Optimization of Distributed Integrated Multi-energy System Considering Industrial Process Based on Energy Hub

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Journal of Modern Power Systems and Clean Energy 2020年第5期8卷 863-873页

作者： Yizhi Zhang Xiaojun Wang Jinghan He yin Xu Wei pei IEEE School of Electrical Engineering Beijing Jiaotong UniversityBeijing 100044China Institute of Electrical Engineering Chinese Academy of SciencesBeijing 100190China

As a typical scenario of distributed integrated multi-energy system(DIMS),industrial park contains complex production constraints and strong associations between industrial productions and energy *** industrial production process(IPP)consists of controllable subtasks and strict timing *** IPP as a control variable of optimal scheduling,it is an available approach that models the IPP as material flow into an extension energy hub(EH)to achieve the optimization of industrial *** this paper,considering the coupling between the production process and energy demands,a model of IPP is proposed by dividing the process into different adjustable steps,including continuous subtask,discrete subtask,and storage ***,a transport model of material flow is used to describe the IPP in an industrial park *** on the concept of EH,a universal extension EH model is proposed considering the coupling among electricity,heat,cooling,and ***,an optimal scheduling method for industrial park DIMS is proposed to improve the energy efficiency and operation ***,a case study of a typical battery factory is shown to illustrate the proposed *** simulation results demonstrate that such a method reduces the operation cost and accurately reflects the operation state of the industrial factory.

关键词： Distributed integrated multi-energy system(DIMS) industrial production process(IPP) energy hub(EH) optimal operation battery production

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Investigation of the Short-Time Photodissociation Dynamics of Furfural in S2 State by Resonance Raman and Quantum Chemistry Calculations

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Computers, Materials & Continua 2018年第4期55卷 189-200页

作者： Kemei pei Yueben dong Lei Chen Department of Chemistry Zhejiang Science Techology UniversityHangzhou 310018China

Raman(resonance Raman,FT-Raman),IR and UV-visible spectroscopy and quantum chemistry calculations were used to investigate the photodissociation dynamics of furfural in S2 *** resonance Raman(RR)spectra indicate that the photorelaxation dynamics for the S0→S2 excited state is predominantly along nine motions:C=O stretchν5(1667 cm-1),ring C=C antisymmetric stretchν6(1570 cm-1),ring C=C symmetric stretchν7(1472 cm-1),C2-O6-C5 symmetric stretch/C1-H8 rock in planeν8(1389 cm-1),C3-C4 stretch/C1-H8 rock in planeν9(1370 cm-1),C5-O6 stretch in planeν12(1154 cm-1),ring breathν13(1077 cm-1),C3-C4 stretchν14(1020 cm-1),C3-C2-O6 symmetric stretchν16(928 cm-1).Stable structures of S0,S1,S2,T1 and T2 states with Cs point group were optimized at CASSCF method in Franck-Condon region there are S2/S1 conical intersection was found by state average method and RR spectra.

关键词： Furfural resonance Raman quantum chemistry calculation excited state structural dynamics

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