检索结果-南通市图书馆

聚脲甲醛缓释肥减量深施对小麦和玉米产量及氮肥吸收率的影响

在线全文

学校读者我要写书评

暂无评论

中国土壤与肥料 2024年第3期 96-103页

作者：吕金岭尤克何斌寇长林李太魁河南省农业科学院植物营养与资源环境研究所河南郑州450002 农业农村部原阳农业环境与耕地保育科学观测实验站河南新乡453500 河南省农业生态环境重点实验室河南郑州450002 河南省生态环境监测中心河南郑州450000 西平县土壤肥料技术服务站河南西平463900

为了探究聚脲甲醛缓释肥(PF)减量深耕对小麦和玉米作物产量、氮肥利用效率以及矿质养分迁移的影响,设置对照(CK)、尿素+旋耕(OPTX)、尿素+深耕(OPTS)、PF+旋耕(PFX)和PF+深耕(PFS)5个处理,在豫南砂姜黑土小麦、玉米农田开展大区试验。... 详细信息

为了探究聚脲甲醛缓释肥(PF)减量深耕对小麦和玉米作物产量、氮肥利用效率以及矿质养分迁移的影响,设置对照(CK)、尿素+旋耕(OPTX)、尿素+深耕(OPTS)、PF+旋耕(PFX)和PF+深耕(PFS)5个处理,在豫南砂姜黑土小麦、玉米农田开展大区试验。结果表明,对比传统尿素(OPT)处理,PF处理小麦、玉米产量显著高于OPT处理,尤其PFS处理较OPTX处理小麦和玉米季产量分别高12%和6.4%,较OPTS处理分别高3.4%和1.8%;与产量不同,PFS处理仅显示玉米季氮肥利用率(NUE)高于OPTX和OPTS处理,而小麦季NUE甚至低于OPTS处理,这可能与PF在小麦季深耕条件下养分释放速度慢有关。对比两种耕作方式,发现PFS处理小麦季产量与PFX处理产量无显著差别,而玉米季产量显著高于PFX处理;与产量不同,PFS处理小麦季NUE显著低于PFX处理,而玉米季无显著差别,这可能与玉米季更适宜的气象条件和小麦季PF养分的后续释放有关。对比土壤铵态氮(NH_(4)^(+)-N)、硝态氮(NO_(3)^(-)-N)残留量和总氮浓度,发现作物收获后,PFS处理0~30和30~60 cm土层NH_(4)^(+)-N残留量与PFX处理无显著差异,NO_(3)^(-)-N残留量显著低于PFX处理,而总氮含量略高于PFX处理,这可能与PF处理在小麦季深耕条件下氮素未释放完全有关。总而言之,依据作物的产量和氮肥利用效率,聚脲甲醛缓释肥在深耕条件下显示出更高的产量效益和增产潜势,尤其玉米季作物吸氮量、产量和NUE有了显著提升,值得被推荐。

关键词：聚脲甲醛缓释肥小麦玉米轮作深耕与旋耕砂姜黑土氮肥利用率

维普期刊数据库博看期刊

Analytical Study of Nonlinear Dust Acoustic Waves in Two-Dimensional Dust Plasma with Dust Charge Variation

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2005年第2X期44卷 247-251页

作者： lin chang ZHANG Xiu-Lian College of Physics and Electronic Engineering Northwest Normal University Lanzhou 730070 China

The nonlinear dust acoustic waves in two-dimensional dust plasma with dust charge variation is analytically investigated by using the formally variable separation approach. New analytical solutions for the governing equation of this system have been obtained for dust acoustic waves in a dust plasma for the first time. We derive exact analytical expressions for the general case of the nonlinear dust acoustic waves in two-dimensional dust plasma with dust charge variation.

关键词： nonlinear dust acoustic waves plasma formally variable separation approach exact analytical solution

Stability of Viscous Shock Wave for One⁃Dimensional Compressible Navier⁃Stokes System

在线全文

学校读者我要写书评

暂无评论

Journal of Harbin Institute of Technology(New Series) 2022年第4期29卷 49-57页

作者： lin chang School of Mathematical Sciences Beihang UniversityBeijing 100191China

In this article, the nonlinear stability of viscous shock wave for 1-D compressible Navier-Stokes system is studied. By the standard local existence method, it is found that the solution exists on a finite time interval [0,T](T<∞). However, this method is not available for global existence since the solution may blow up as time t tends to infinity. Thus a priori estimate needs to be established, which can reduce the upper bound of the solution on the time interval [0,T]. Moreover, the bound of the solution at time t=T is made equal to the bound at the initial time. By the same method, it is known the solution exists on [T,2T],[2T,3T],….Thus the global existence of the solution is obtained. During the process of obtaining a priori estimate by the standard method, some additional conditions are proposed. To weaken those conditions, two suitable weighted functions were chosen, a double side weighted energy method was used, and a priori estimate was obtained under some weaker conditions. Thus when the adiabatic exponent γ satisfies 1<γ<1.5, the solution not only exists globally but also tends to a viscous shock wave as time goes to infinity.

关键词： initial value problem viscous shock asymptotic stability

Effect of annealing temperature on the microstructure and mechanical properties of an as-rolled Mg-9wt.%Li-3wt.%Al-1wt.%Zn alloy sheet

在线全文

学校读者我要写书评

暂无评论

Frontiers of Materials Science 2014年第3期8卷 271-280页

作者： Meng-chang lin Shang-Qiu lin Jun-Yen UAN Department of Materials Science and Engineering Chung Hsing University 250 kuo-kuang Rd. Taichung 40277 Taiwan China Green Energy and Environment Research Laboratories Industrial Technology Research Institute 195 Sec. 4 Chung-Hsing Road Hsin-Chu 31040 Taiwan China

This study investigated the effect of annealing temperature on the mechanical properties of an as-rolled Mg-9.26wt.%Li-3,03wt,%Al-1,10wt.%Zn （LAZ931） alloy sheet. The dual-phase （a ＋ 13） LAZ931 alloy plate of 3 mm in thickness were roiled （67% reduction） and then annealed at temperatures at 100℃-350℃. The alloy＇s ductility showed a sharp concave downward tendency as a function of annealing temperature, The elongation of the LAZ931 alloy sheet increased with annealing temperature up to 150℃, followed by a sharp decrease of the alloy＇s ductility as the annealing temperature higher than 150℃. The specimen exhibited an extremely low elongation （only -0,5%） at annealing temperature around 300℃. Formation of brittle AILi particles on boundary resulted in Li depletion zone near by grain boundary, transforming the Li depletion zone into a （hcp） layer. The combined effects including brittle AILi particles on boundary and the hcp α layer on boundary resulted in the brittlement of the high-temperature-annealing sample.

关键词： Mg-Li alloy annealing AILi embrittlement

A power-aware code-compression design for RISC/VLIW architecture

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science C(Computers and Electronics) 2011年第8期12卷 629-637页

作者： Che-Wei lin chang Hong lin Wei Jhih WANG Department of Electronic Engineering National Taiwan University of Science and Technology Taiwan 106 Taipei

We studied the architecture of embedded computing systems from the viewpoint of power consumption in memory systems and used a selective-code-compression (SCC) approach to realize our *** on the LZW (Lempel-Ziv-Welch) compression algorithm,we propose a novel cost effective compression and decompression *** goal of our study was to develop a new SCC approach with an extended decision policy based on the prediction of power *** decompression method had to be easily implemented in hardware and to collaborate with the embedded *** hardware implementation of our decompression engine uses the TSMC 0.18μm-2p6m model and its cell-based *** calculate power consumption more accurately,we used a static analysis method to estimate the power overhead of the decompression *** also used variable sized branch blocks and considered several features of very long instruction word (VLIW) processors for our compression,including the instruction level parallelism (ILP) technique and the scheduling of *** code-compression methods are not limited to VLIW machines,and can be applied to other kinds of reduced instruction set computer (RISC) architecture.

关键词： LZW compression Cell-based libraries Instruction level parallelism (ILP) VLIW processors

Two Theorems on the Commutativity of Arbitrary Rings

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2001年第1期17卷 133-140页

作者： chang lin FU Xin Song YANG Department of Mathematics Harbin Univrsity of Science and Technology

We prove a theorem on the commutativity of the PI ring and use it to generalize a famous theorem of Herstein.

关键词： PI rings Commutativity Strong property F_k

在线全文

学校读者我要写书评

暂无评论

升降工装切割作业振动故障特性分析

机械设计与制造 2024年第1期395卷 191-194,199页

作者：谢昌霖王湘江王永乐南华大学机械工程学院湖南衡阳421000 中核四0四有限公司甘肃嘉峪关735100

切割设备在大进给,大切深的作业工况下易出现切割片断裂飞崩的情况,会降低切割效率并且造成人员危险。通过提取作业时的振动加速度信号从时域和频域两个方面进行分析,利用小波包变换的方法对振动信号进行逐层分解,得到了不同进给速度下... 详细信息

切割设备在大进给,大切深的作业工况下易出现切割片断裂飞崩的情况,会降低切割效率并且造成人员危险。通过提取作业时的振动加速度信号从时域和频域两个方面进行分析,利用小波包变换的方法对振动信号进行逐层分解,得到了不同进给速度下升降工装切割作业的振动特性。建立切割片横向振动方程研究振动的产生机理并分析切割故障时信号特征的产生原因及影响,最后提出合适的减振策略。研究方法对延长切割片使用寿命及减少切割作业故障产生的频率具有重要意义。

关键词：断裂切割作业振动特性横向振动方程减振

TRANSPOSITION INHIBITION OF Tn5 IN Rhizobium leguminosarum

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 1991年第4期34卷 429-437页

作者： WANG chang-lin Institute of Plant Physiology Academia SinicaShanghai 200032PRC

A recombinant transposon Tn5-GmSp,produced by replacing the central BglⅡfragmentwith a BamHⅠone of R1033,was utilized to detect Tn5 transposition inhibition in Rhizo-bium *** types of suicide plasmids(pXS102 and pCW3/pCW30)were con-structed for Tn5-GmSp *** frequency of transposition in both constructs wasgreatly reduced in the Rhizobium strains where a resident Tn5 was already ***102 was transferred into a Tn5-containing Rhizobium strain,the transconjugants retainedthe deleted forms of pXS102,indicating that the failure of transposition was due to the lossof the unstable prophage Mu *** the case of pCW3/pCW30,vectors were not ob-served in the transconjugants although most of them retained the antibiotic resistant *** result suggested the integration of Tn5-GmSp into the rhizobial host genome through recombination.

关键词： R.leguminosarum recombinant Tn5-CmSp transposition inhibition Tn5 in situ replacement

Carbothermal reduction characteristics of oxidized Mn ore through conventional heating and microwave heating

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2021年第2期28卷 221-230页

作者： Yang He Jian Liu Jian-hua Liu Chun-lin Chen chang-lin Zhuang Institute of Engineering Technology University of Science and Technology BeijingBeijing 100083China Commonwealth Scientific and Industrial Research Organisation Melbourne 3168Australia Dongbei Special Steel Group Co. Ltd.Dalian 116105China College of Materials and Metallurgy Guizhou UniversityGuiyang 550025China

For the purpose of exploring a potential process to produce FeMn,the effects of microwave heating on the carbothermal reduction characteristics of oxidized Mn ore was *** microwave heating curve of the mixture of oxidized Mn ore and coke was analyzed in association with the characterization of dielectric *** comparative experiments were conducted on the carbothermal reductions through conventional and microwave heatings at temperatures ranging from 973 to 1373 *** thermogravimetric analysis showed that carbothermal reactions under microwave heating proceeded to a greater extent and at a faster pace compared with those under conventional *** metal phases were observed in the microstructures only under microwave *** carbothermal reduction process under microwave heating was *** electric and magnetic susceptibility differences were introduced into the thermodynamics analysis for the formation of metal *** developed thermodynamics considered that microwave heating could make the reduction of MnO to Mn more accessible and increase the reduction extent.

关键词： carbothermal reduction manganese ore manganese oxides microwave heating thermodynamics electromagnetic fields