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Sustainable Nutrient Management in Chinese Agriculture: Challenges and Perspective

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Pedosphere 2006年第2期16卷 253-263页

作者： GAO Chao SUN Bo zhang tao-lin Department of Geography Nanjing University Nanjing 210093 （China）. Institute of Soil Science Chinese Academy of Sciences Nanjing 2100（78 （China）

China has to raise agricultural productivity in its limited and shrinking farmland to guarantee food security for its huge and ever-growing population. Sustainable soil nutrient management is of paramount importance to the world's most populous country. Critical challenges the country is facing in sustaining soil fertility and in alleviating the hazardous impact of intensive fertilizer use are discussed in this paper. It is emphatically pointed out that national strategies as well as area-specific action plans with respect to scientific nutrient management are urgently needed to balance productivity and sustainability in the future. Relevant proposals for addressing those challenges are also presented.

关键词： China food security nutrient management soil fertility water quality

Distribution of Magnetic Flux Density in Soft-Contact EMCC Rectangular Mold

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Journal of Iron and Steel Research International 2006年第5期13卷 14-17,24页

作者： zhang lin-tao WANG En-gang DENG An-yuan HE Ji-cheng Key Laboratory of National Education Ministry for Electromagnetic Processing of Materials Northeastern University Shenyang 110004 Liaoning China

The distribution of the magnetic flux density in a soft-contact electromagnetic continuous casting （EMCC） rectangular mold was investigated. The experimental results show that with an increase in electric power, the magnetic flux density increases. The position where the maximum magnetic flux density appears will shift up when the coil moves to the top of the mold. At the same time, the maximum magnetic flux density will increase and the effective acting range of electromagnetic pressure will widen. As a result, in practice, the coil should be placed near the top part of the mold. The meniscus should be controlled near the top part of the coil, as this not only remarkably improves the billet surface quality but also saves energy. With the same electric power input, the higher the frequency, the lower the magnetic flux density.

关键词： electromagnetic soft contact mold magnetic flux density continuous casting

Changes in Organic Carbon and Nutrient Contents of Highly Productive Paddy Soils in Yujiang County of Jiangxi Province,China and Their Environmental Application

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Agricultural Sciences in China 2006年第7期5卷 522-529页

作者： LI Zhong-pei zhang tao-lin CHEN Bi-yun Institute of Soil Science the Chinese Academy of Sciences Nanjing 210008 P.R. China

Paddy field is an important land use in subtropical China. Development of high soil fertility and productivity is the management goal of paddy field, Fertilization and management practices have not only influenced the status of organic matter and nutrients in the soil but also affected the environmental quality. This article investigates the contents of organic carbon and the nutrients, and the change over the last 20 years in highly productive paddy soils and their environmental application. Field soils were sampled and the analytical results were compared with the corresponding values in the Second Soil Survey in Yujiang County of Jiangxi Province, China. The results showed that surface soils at a depth of 0-10 cm in highly productive paddy fields in Yujiang County of Jiangxi Province had contents of organic carbon （20.2 ±3.88） g kg^-1, total nitrogen （2.09±0.55） g kg^-1, and available phosphorus （42.7 ±32.7） mg kg^-1, respectively, which were all at very rich levels. Over the last 20 years, the organic carbon pool of the highly productive paddy soils reached a steady state. Total N and available P significantly increased, whereas available K changed a little. The amount and percentage of P immobilization in the surface soil （0-10 cm） of highly productive paddy fields were （142.7 ~ 41.1） mg kg-~ and （36.2~ 10.4）% of added P, and CEC （7.93 ~ 1.32） cmol kg-~. These two parameters were not higher than the mean values of paddy soils and upland red soils in the areas. Results also showed that fertilizer P in highly productive paddy soils had a high mobility and was prone to move toward a water body, which is the main source of nutrients causing eutrophication. Because of a weak K-fixing capacity, the available K content was not high in highly productive paddy soils. This suggests that attention should be paid to the K balance and the increase of soil K pool.

关键词： Yujiang County highly productive paddy soils organic C nutrients environmental application

Discrepancy in Response of Rice Yield and Soil Fertility to Long-Term Chemical Fertilization and Organic Amendments in Paddy Soils Cultivated from Infertile Upland in Subtropical China

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Agricultural Sciences in China 2011年第2期10卷 259-266页

作者： LIU Ming LI Zhong-pei zhang tao-lin JIANG Chun-yu CHE Yu-ping State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of SciencesNanjing 210008P.R.China Graduate University Chinese Academy of SciencesBeijing 100049P.R.China

From 1990,over 17 years field experiment was carried out in paddy field cultivated from infertile upland to evaluate the response of rice productivity,soil organic carbon（SOC）,and total N to long-term NPK fertilization or NPK combined with organic *** field trials included NPK（N,P,K fertilizer）,NPKRS（NPK combined with rice straw）,NPK2RS（NPK combined with double amount of rice straw）,NPKPM（NPK combined with pig manure） and NPKGM（NPK combined with green manure） and the cropping system was rice-rice（Oryza sativa L.） *** rice yield,straw biomass,and harvesting index increased steadily with cultivation time in all *** annual rice yield from 1991 to 2006 was ranged from 7 795 to 8 572 kg ha-1 among *** yields in treatments with organic amendments were usually higher than that in treatment with *** of SOC and total N also increased gradually in the cultivation years and reached the level of 7.82 to 9.45 and 0.85 to 1.03 g kg-1,respectively,in *** fertilities in treatments with chemical fertilization combined with organic amendments were relatively appropriate than those in treatment with *** was obvious discrepancy between cumulative characters of rice yield and soil organic fertility in newly formed paddy *** with relatively high rate of crop productivity improvement,cumulative rates of SOC and total N were much lower in our *** and total N contents were still less than half of those in local highly productive paddy soils after 17 years cultivation in subtropical *** work helps to better understand the development of infertile paddy soils and to estimate the potential of yield improvement in this region.

关键词： paddy field rice yield SOC total N long-term field experiment

Deformation and Locomotion of Untethered Small-Scale Magnetic Soft Robotic Turtle with Programmable Magnetization

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Journal of Bionic Engineering 2024年第2期21卷 754-763页

作者： lin Xu Liu Yang tao Li Xingbang zhang Jianning Ding School of Mechanical Engineering Jiangsu UniversityZhenjiang212013China The Key Laboratory of Bionic Engineering(Ministry of Education) Jilin UniversityChangchun130012China Shanghai Tianchun Technology Co. LtdShanghai201802China School of Mechanical Engineering Yangzhou UniversityYangzhou225009China

Inspired by the way sea turtles rely on the Earth’s magnetic field for navigation and locomotion,a novel magnetic soft robotic turtle with programmable magnetization has been developed and investigated to achieve biomimetic locomotion patterns such as straight-line swimming and turning *** soft robotic turtle(12.50 mm in length and 0.24 g in weight)is integrated with an Ecoflex-based torso and four magnetically programmed acrylic elastomer VHB-based limbs containing samarium-iron–nitrogen particles,and was able to carry a load more than twice its own *** to the limb locomotion characteristics of sea turtles,the magnetic torque causes the four limbs to mimic sinusoidal bending deformation under the influence of an external magnetic field,so that the turtle swims continuously ***,when the bending deformation magnitudes of its left and right limbs differ,the soft robotic turtle switches from straight-line to turning swimming at 6.334 rad/***,the tracking swimming activities of the soft robotic turtle along specific planned paths,such as square-shaped,S-shaped,and double U-shaped maze,is anticipated to be utilized for special detection and targeted drug delivery,among other applications owing to its superior remote directional control ability.

关键词： Magnetic soft robotic turtle Programmable magnetization Untethered soft robotics Bending deformation

Closed-form solution to the dynamic programming for a heavy-duty parallel hybrid vehicle energy management

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Journal of Control and Decision 2024年第1期11卷 107-116页

作者： tao zhang Zhongjun Yu Huangda lin National Key Laboratory for Vessel Integrated Power System Technology Naval University of EngineeringWuhanPeople’s Republic of China

Dynamic programming(DP)is frequently used to obtain the optimal solution to the hybrid electric vehicle(HEV)energy *** trade-off between the accuracy and the computational effort is the biggest problem for the DP *** closed-form solution to the DP is proposed to solve this ***,the affine linear model of the engine fuel rate is obtained based on engine test *** piecewise linear approximation of the motor power demand is obtained considering the different energy flows in the charging and discharging stages of the ***,the second-order Taylor expansion for the cost matrix at each time and state grid point is introduced to get the closed-form solution of the optimal torque *** results show that this method can greatly reduce the computing burden by 93%while ensuring near-optimal fuel economy compared with the conventional DP method.

关键词： Dynamic programming energy management closed-form solutions fuel economy hybrid electric vehicles

Simulation and reconstruction of particle trajectories in the CEPC drift chamber

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Nuclear Science and Techniques 2024年第8期35卷 9-22页

作者： Meng‑Yao Liu Wei‑Dong Li Xing‑tao Huang Yao zhang tao lin Ye Yuan Institute of Frontier and Interdisciplinary Science Shandong UniversityQingdao 266237China Institute of High Energy Physics Beijing 100049China University of Chinese Academy of Sciences Beijing 100049China

The circular electron-positron collider(CEPC)is designed to precisely measure the properties of the Higgs boson,study electroweak interactions at the Z-boson peak,and search for new physics beyond the Standard *** a component of the 4th conceptual CEPC detector,the drift chamber facilitates the measurement of charged *** study implemented a Geant4-based simulation and track reconstruction for the drift *** the simulation,detector construction and response were implemented and added to the CEPC simulation *** development of track reconstruction involves track finding using the combinatorial Kalman filter method and track fitting using the tool of *** the simulated data,the tracking performance was *** results showed that both the reconstruction resolution and tracking efficiency satisfied the requirements of the CEPC experiment.

关键词： CEPC Drift chamber Detector simulation Track reconstruction

A New Silicon-Based Ferroelectric Sandwich Structure

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Chinese Physics Letters 2001年第1期18卷 132-133页

作者： REN Tian-ling zhang lin-tao LIU Li-Tian LI Zhi-Jian Institute of Microelectronics Tsinghua UniversityBeijing 100084

A new silicon-based PbTiO_(3)/Pb(Zr_(0.53)Ti_(0.47))O_(3)/PbTiO_(3) sandwich structure is fabricated by a sol-gel *** with other fabrication processes without PbTiO_(3) buffer layers,the annealing temperature is greatly reduced by as much as 100℃.Capacitance-voltage,polarization-electric field and dielectric-frequency properties of this sandwich structure are *** Pb(Zr_(x)Ti_(1-x))O_(3) films are proved to have good dielectric and ferroelectric properties.

关键词： properties. sandwich method.

Effect of End Shape on Flow and Heat Transfer Characteristics of Two Parallel Plates

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Journal of Thermal Science 2024年第3期33卷 815-832页

作者： zhang Guang HONG Tianxiao WANG Dongrui XIN Jialin tao Junyu lin Zhe Key Laboratory of Fluid Transmission Technology of Zhejiang Province Zhejiang Sci-Tech UniversityHangzhou310018China

Flow around a pair of flat plates is a basic hydrodynamics *** this paper,the flow and heat transfer characteristics of two parallel plates with different edge shapes are numerically *** different inclined angles,the influence of chamfered and rounded structures with different sizes at the end-edge on unsteady flow and heat transfer characteristics of two parallel plates are *** is found that the instability and unsteadiness of flow decrease with the increase of end-edge size,and the non-uniformity of wake velocity of both rounded and chamfered plates decreases *** non-uniformity of wake temperature increases firstly and then decreases at a small inclined angle,and the amplitude becomes the largest when S_(rou)(S_(cha))=3,while it basically keeps monotonically increasing at a large inclined ***,the global heat transfer performance of the flat plate is obviously affected by the end-edge modification,especially the chamfered *** the increase of chamfered size,the global Nusselt number basically shows the decreasing *** study provides a theoretical basis for the application of plate-shape structure in engineering fields.

关键词： two parallel plates end shape flow characteristic heat transfer numerical simulation