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Effects of nitrogen supply methods on fate of nitrogen in maize under alternate partial root-zone irrigation

International Journal of Agricultural and Biological Engineering 2020年第3期13卷 129-135页

作者： Dongliang qi Tiantian Hu Xue Song Engineering Research Center of Ecology and Agriculture Use of Wetland Ministry of EducationYangtze UniversityJingzhou 434025HubeiChina Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas of Ministry of Education Northwest A&F UniversityYangling 712100ShaanxiChina

Partial root-zone irrigation(PRI)has been practiced worldwide,but little information is available on nitrogen(N)supply methods influence on fate of applied N fertilizer for crop production under PRI.A field experiment was conducted to investigate effect of N supply methods on the uptake,residual,and loss of applied N fertilizer in maize(Zea mays L.)under alternate PRI at Wuwei,northwest China in 2014.15N-labeled urea was used as N *** irrigation methods included alternate furrow irrigation(AI)and conventional furrow irrigation(CI).Two N fertilizer supply methods included conventional N supply(CN)and alternate N supply(AN),were applied in combination with each irrigation *** yield,root length density(RLD),N uptake by maize at the maturity stage,and atom%of 15N excess,residual 15N and residual NO3-N in the 0-100 cm soil layer after maize harvest were *** shown that compared to CI coupled with CN,AI coupled with AN or CN significantly increased the grain yield,harvest index,RLD,N uptake by maize,15N accumulation in grain,atom%of 15N excess in the 0-60 cm soil layer,the residual 15N and 15N uptake rates;but significantly decreased the residual NO3-N in the 0-100 cm soil layers and 15N loss ***,the synchronized rather than separation supply of N fertilizer and water enhanced the most above parameters under AI.15N uptake rate was positively correlated with RLD in the 0-40 cm soil layer,suggesting that the enhanced RLD contributed to the improved 15N uptake ***,alternate furrow irrigation coupled with conventional or alternate nitrogen supply(synchronized supply of N fertilizer and water)could help improve 15N uptake rate and reduce the 15N loss rate.

关键词： 15N-labeled technology root length density nitrogen fertilizer fate nitrogen management residual nitrogen

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A Comparative Study of the Sensitivity of F_v/F_m to Phosphorus Limitation on Four Marine Algae

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Journal of Ocean University of China 2013年第1期12卷 77-84页

作者： qi Hongju WANG Jiangtao WANG Zhaoyu Key Laboratory of Marine Chemistry Theory and Technology Ministry of Education Ocean University of China

We studied the effects of nitrogen （N） and phosphorus （P） supply on Fv/Fm （maximal quantum yield of photosystem Ⅱ） in the algae Chaetoceros debilis, Dicrateria inornata, Platymonas subcordiformis and Heterosigma akashiwo to determine the sensitivity of Fv/Fm to P-limitation of the four species. Obvious decrease of Fv/Fm value was monitored in periods of P-depletion, the decrease showing different magnitudes among algal species. A more clear decrease of Fv/Fm in Platymonas subcordiformis and Heterosigma akashiwo was observed, compared with that in Chaetoceros debilis and Dicrateria inornata. After the re-supply of P, the index Fv/Fm of the four species all recovered quickly in 24h. Cell division was maintained and chlorophyll content continued to increase until the end of the experiment in Platymonas subcordiformis and Heterosigma akashiwo, while in Chaetoceros debilis and Dicrateria inornata, the division stopped in the later period when the growth of organisms came into the stationary phase. The most obvious respond of chlorophyll content to P-additions was observed in Heterosigma akashiwo culture in 24 h. The sensitivity of Fv/Fm to nutrient limitations is different among algal species, and much should be done to improve the application of this index.

关键词： Chaetoceros debilis Dicrateria inornata Platymonas subcordiformis Heterosigma akashiwo P limitation P depletion Fv/Fm ratio

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A nested case-control study of maternal-neonatal transmission of hepatitis B virus in a Chinese population

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World Journal of Gastroenterology 2011年第31期17卷 3640-3644页

作者： Li-Zhang Chen Wen-qi Zhou Shu-Shan Zhao zhi-Yu Liu Shi-Wu Wen School of Public Health Central South UniversityChangsha 410078Hunan ProvinceChina Eight-Year Program Xiangya School of MedicineCentral South University410008 ChangshaHunan ProvinceChina Maternal and Child Health Hospital of Hunan Province Changsha 410008Hunan ProvinceChina The OMNI Research Group Department of Obstetrics and GynecologyUniversity of Ottawa501 Smyth RoadBox 241Ottawa K1H 8L6Canada Ottawa Health Research Institute Clinical Epidemiology Program Canada Department of Epidemiology and Community Medicine University of OttawaK1H 8L6Canada

AIM:To examine the determinants of maternal-neonatal transmission of hepatitis B virus(HBV) METHODS:A nested case-control study was conducted in Changsha,Hunan,People's Republic of China from January 1,2005 to September 31,2006 To avoid potential maternal blood contamination,we collected vein blood of newborns immediately after birth and before initial hepatitis B vaccination to determine the HBV infection status of the newborn For each HBsAg-positive infant,one HBsAg-negative infant born to an HBsAg-positive mother was matched by hospital at birth(same),gender(same),and date of birth(within 1 mo) A faceto-face interview was conducted to collect clinical and epidemiological data Conditional logistic regression analysis was used to estimate the independent effects of various determinants on maternal-neonatal transmission of HBV RESULTS:A total of 141 HBsAg-positive infants and 141 individually matched HBsAg-negative infants were included in the final analysis Maternal first-degree family history of HBV infection,intrahepatic cholestasis,and premature rupture of membranes were risk factors for perinatal transmission of HBV,whereas systematic treatment and HBV immunoglobulin injections for mothers with HBV infection were protective factors for maternal-neonatal transmission of HBV,after adjustment for potential confounding factors CONCLUSION:For HBsAg-positive mothers,systematic treatment,HBV immunoglobulin administration,and controlling intrahepatic cholestasis and pregnancy complications may reduce the incidence of perinatal transmission of HBV.

关键词： HBsAg-positive Hepatitis B virus Perinatal transmission:Nested case-control study

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Entanglement transfer via two arrays of coupled resonator waveguides

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Chinese Physics B 2012年第1期21卷 74-78页

作者： Zhang Ye-qi Xu Jing-Bo Zhejiang Institute of Modern Physics and Physics Department Zhejiang UniversityHangzhou 310027China

We propose a scheme for transferring entanglement through two independent arrays of coupled resonator waveguides, where a three-level atom is embedded in each resonator. We investigate the entanglement dynamics of the transferred state. The influence of initial states and applied lasers on the entanglement sudden death phenomenon is also discussed. Furthermore, we study the dynamics of pairwise quantum correlations measured by the quantum discord.

关键词： entanglement transfer resonator waveguide

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MIMO-OFDM系统中LDPC编码和自适应比特功率分配算法研究

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电子与信息学报 2008年第2期30卷 404-407页

作者：霍永青彭启琮电子科技大学通信学院成都610054

该文提出了将LDPC码与自适应比特功率分配相结合应用于MIMO-OFDM系统中的算法。文中分别对两种不同码率的LDPC码与自适应OFDM,自适应MIMO-OFDM相结合的算法进行了仿真,同时还对未编码的自适应OFDM以及MIMO-OFDM进行了仿真。仿真结果显示... 详细信息

该文提出了将LDPC码与自适应比特功率分配相结合应用于MIMO-OFDM系统中的算法。文中分别对两种不同码率的LDPC码与自适应OFDM,自适应MIMO-OFDM相结合的算法进行了仿真,同时还对未编码的自适应OFDM以及MIMO-OFDM进行了仿真。仿真结果显示,在相同的传输带宽以及相同的传输信息量(即数据"净码率")情况下,采用低码率LDPC编码的自适应OFDM系统的性能要比未编码的自适应OFDM以及自适应MIMO-OFDM系统的性能好;采用高码率LDPC编码的自适应OFDM系统的性能比未编码的自适应OFDM系统性能好,但比未编码的自适应MIMO-OFDM系统性能差。

关键词： MIMO—OFDM LDPC编码自适应分配频率选择性衰落

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部分信道状态信息对空时OFDM系统性能的影响

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电波科学学报 2005年第2期20卷 256-259页

作者：钟俊邵怀宗彭启琮电子科技大学通信信息工程学院四川成都610054

在无线通信系统中,当发射端未知信道的状态特性时,采用空时编码可得到分集增益与编码增益。然而,在一些无线通信系统中,发射端可能已知部分信道状态特性,因此空时编码与自适应调制相结合可更进一步提高通信系统的性能。部分信道状态信... 详细信息

在无线通信系统中,当发射端未知信道的状态特性时,采用空时编码可得到分集增益与编码增益。然而,在一些无线通信系统中,发射端可能已知部分信道状态特性,因此空时编码与自适应调制相结合可更进一步提高通信系统的性能。部分信道状态信息对自适应与空时编码相结合的OFDM系统性能的影响进行了讨论。仿真比较了自适应的空时OFDM与普通的空时OFDM的性能,可为时变信道的多天线OFDM系统设计提供参考。

关键词：空时编码正交频分复用发射分集自适应调制

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Controlled flight of a self-powered micro blimp driven by insect-sized flapping-wing thrusters

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Chinese Journal of Aeronautics 2024年第6期37卷 127-136页

作者： Xian YU zhiwei LIU Jiaming LENG Mingjing qi Xiaojun YAN School of Energy and Power Engineering Beihang UniversityBeijing 100191China Collaborative Innovation Center of Advanced Aero-Engine Beijing 100191China National Key Laboratory of Science and Technology on Aero-Engine Aero-thermodynamics Beihang UniversityBeijng 100191China Beijing Key Laboratory of Aero-Engine Structure and Strength Beihang UniversityBeijing 100191China

Micro aerial platforms face significant challenges in achieving long controlled endurance as most of the energy is consumed to overcome the weight of the *** this study,we present a controllable micro blimp that addresses this issue through the use of a helium-filled *** micro blimp has a long axis of 23 cm and is propelled by four insect-sized flapping-wing thrusters,each weighing 80 mg and with a wingspan of 3.5 *** distributed thrusters enable controlled motions and provide the micro blimp with an advantage in flight endurance compared to multirotors or flapping-wing micro aerial vehicles at the same size *** enhance the performance of the controlled flight,we propose a wireless control module that enables manipulation from a distance of up to 100 ***,a smartphone application is developed to send instructions to the circuit board,allowing the blimp to turn left and right,ascend and descend,and achieve a combination of these movements *** findings demonstrate that this micro blimp is one of the smallest controlled self-powered micro blimps to date.

关键词： Microairvehicle Aircraft control Self-powered micro blimp Flapping-wing thruster Wireless flight

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Construction of tissue engineered articular cartilage with the technique of centrifuge tube culture

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Chinese Journal of Biomedical Engineering(English Edition) 2001年第3期10卷 109-110页

作者： YANG zhi-ming WANG Yao XIE Hui-qi WANG Jian Department of Orthopedic Surgery the First University Hospital West China University of Medical Sciences. ChengduSichuanP. RChina 610041

INTRODUCTIONThe common construction method of tissue engineered articular cartilage is to isolate and culture chondrocytes,transplant them into the degradable scaffold materials, then to repair the defect of articular cartilage. We designed this experiment to investigate the feasibility of tissue engineered articular cartilage constructed by the technique of centrifuge tube culture without scaffold materials.

关键词： Construction of tissue engineered articular cartilage with the technique of centrifuge tube cultur

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Numerical simulation of laser ablation of molybdenum target for laser-induced breakdown spectroscopic application

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Plasma Science and Technology 2018年第8期20卷 58-64页

作者： Cailong FU qi WANG Hongbin DING School of Physics Key Laboratory of Materials Modification by LaserIon and Electron Beams（Ministry of Education）Dalian University of TechnologyDalian 116024People＇s Republic of China

Laser-induced breakdown spectroscopy has been recognized as a significant tool for element diagnostics in plasma–wall interaction. In this work, a one-dimensional numerical model is developed to simulate the laser ablation processes of a molybdenum（Mo） target in vacuum conditions. The thermal process of the interaction between the ns-pulse laser with wavelength of 1064 nm and the Mo target is described by the heat conduction equation. The plasma plume generation and expansion are described by Euler equations, in which the conservation of mass density, momentum and energy are included. Saha equations are used to describe the local thermal equilibrium of electrons, Mo atoms,Mo~＋ and Mo^（2＋） Plasma shielding and emission are all considered in this model. The mainly numerical results are divided into three parts, as listed ***, the rule of the plasma shielding effect varying with laser intensity is demonstrated quantitatively and fitted with the Nelder function. Secondly, the key parameters of plasma plume,such as the number density of species, the propagation velocity and the temperature, are all calculated in this model. The results indicate that the propagation velocity of the plume center increased with time in a general trend, however, one valley value appeared at about 20 ns due to the pressure gradient near the target surface leading to negative plasma velocity. Thirdly, the persistent lines of a Mo atom in the wavelength range from 300 nm to 600 nm are selected and the spectrum is calculated. Moreover, the temporal evolutions of Mo＇s spectral lines at wavelength of 550.6494 nm,553.3031 nm and 557.0444 nm are given and the results are compared with experimental data in this work.

关键词： LIBS ablation process molybdenum target numerical simulation

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Sorption Kinetics and Capacity of Composite Materials Made up of Polymeric Fabric and Expanded Perlite for Oil in Water

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Journal of Donghua University(English Edition) 2012年第3期29卷 233-239页

作者：祁佩时林娜刘云芝赵俊杰 State Key Laboratory of Urban Water Resource and Environment Harbin Institute of Technology

The oil sorption capacity of composite materials made up of different polymeric fabrics (namely acrylic fabric (AF), polypropylene nonwoven (PP), and silk stocking (SS) as composite out-packing materials) and expanded perlite (EP) was evaluated for oil removal from the water. The effects of sorbent dosage, desorption time, oil amount in the water, and contact time on composite materials sorption were investigated. The results showed that the optimum quantity of EP was between 0.5 g and 1.0 g for 25 cm2 polymeric fabrics bags. Oil removal efficiency for 6 L/m2 of oil amount in the water was 52%-72%, 44%-63%, and 37%-48% for AF, PP, and SS composite materials, respectively. Oil/water selectivity analysis of different composite materials showed that AF composite material had a very high degree of hydrophobicity and oil sorption capacity of approximately 10.17 g/g. Both oil sorption kinetics and equilibrium studies were carried out, and the equilibrium process of composite materials was described well by the Langmuir isotherm, and the oil sorption kinetics of composite materials showed good correlation coefficients for the pseudo-second order kinetic model. Intra-particle diffusion studies showed that oil sorption mechanism was controlled by the three processes, involving in external liquid membrane diffusion, surface sorption, and intra-particle diffusion.

关键词： composite material expanded perlite(EP) oil spill polymeric fabric sorption

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