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Tailoring microstructure evolution and mechanical properties of a high-performance alloy steel through controlled thermal cycles of a direct laser depositing process

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China Foundry 2021年第5期18卷 463-473页

作者： shi-yun Dong Xuan zhao shi-xing Yan Yao-hui Lü Xiao-ting Liu Yu-xin Liu Peng He Bin-shi Xu National Key Laboratory for Remanufacturing Army Academy of Armored ForcesBeijing 100072China State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China

Direct laser deposition(DLD),as a popular metal additive manufacturing process,shows advantages of technical flexibility and high efficiency to gain a high-performance alloy steel ***,during the processing of DLD,the deposited steel layer is affected by the subsequent layer *** DLD block shows different microstructure and mechanical properties at the bottom,middle and top of the deposited *** date,there are few research works about the effects of inter-layer interval time and laser power on the microstructure evolution and mechanical properties of the deposited *** this study,the idle time and laser power layer by layer during DLD of 12CrNi2 steel were controlled to cause the deposited layers to maintain a high cooling rate,while the bottom deposited layer was subjected to a weak tempering *** show that a high proportion of martensite is produced,which improves the strength of the deposited *** the laser scanning strategy of laser power 2,500 W,scanning velocity 5 mm·s^(-1),powder feeding rate 11 g·min^(-1),overlap rate 50%,and a laser power difference of 50 W and a 2 min interval,the tensile strength of the deposited layer of 12CrNi2 steel is in the range of 873-1,022 MPa,and the elongation is in the range of 16.2%-18.9%.This study provides a method to reduce the tempering effect of the subsequent deposition layers on the bottom layers,which can increase the proportion of martensite in the low-alloy high-strength steel,so as to improve the yield strength of the alloy steel.

关键词： alloy steel direct laser deposition thermal cycles microstructure evolution mechanical properties

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Combining controlled-release urea and normal urea with appropriate nitrogen application rate to reduce wheat stem lodging risk and increase grain yield and yield stability

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Journal of Integrative Agriculture 2023年第10期22卷 3006-3021页

作者： ZHANG Guang-xin zhao De-hao FAN Heng-zhi LIU shi-ju LIAO yun-cheng HAN Juan College of Agriculture Shanxi Agricultural UniversityTaigu 030801P.R.China State Key Laboratory of Sustainable Dryland Agriculture Shanxi Agricultural UniversityTaiyuan 030031P.R.China College of Agronomy Northwest A&F UniversityYangling 712100P.R.China

A mixture of controlled-release urea and normal urea(CRUNU)is an efficient nitrogen(N)fertilizer type,but little is known about its effects on stem lodging resistance,grain yield,and yield stability of *** this study,a 4-year field experiment(from 2017 to 2021)was conducted to analyze the effects of N fertilizer types(CRUNU and normal urea(NU))and application rates(low level(L),135 kg ha^(–1);medium level(M),180 kg ha^(–1);high level(H),225 kg ha^(–1))on population lodging resistance,basal internode strength,lignin content and synthetase activity,stem lodging resistance,grain yield,and yield stability of *** results showed that the two N fertilizer types had the highest lodging rate under high N application rates,and the M-CRUNU treatment showed the lowest lodging *** with NU,CRUNU improved the wheat population lodging resistance under the three N application rates,mainly related to improving wheat population characteristics and breaking the strength of the second basal *** analysis showed that the breaking strength of the second basal internode was related to the physical characteristics,chemical components,and micro-structure of the *** with NU,CRUNU significantly increased wheat grain yield by 4.47,14.62,and 3.12%under low,medium,and high N application rates,*** addition,CRUNU showed no significant difference in grain yield under medium and high N application rates,but it presented the highest yield stability under the medium N application *** summary,CRUNU,combined with the medium N application rate,is an efficient agronomic management strategy for wheat production.

关键词： controlled-release urea lodging grain yield yield stability wheat

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Effects of Monoclonal Antibody Against Porcine 40-kDa Adipocyte-Specific Membrane Protein on Endocrine Secretion in Pigs

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Agricultural Sciences in China 2009年第8期8卷 1004-1009页

作者： LIU Ling-yun HU Hong-mei zhao Su-mei ZHANG Xi DUAN Gang GAO shi-zheng Kunming Normal School Kunming 650201 P.R.China Institute of Animal Science and Veterinary Medicine Shandong Academy of Agricultural Sciences Jinan 250100 P.R.China yunnan Key' Laboratory of Animal Nutrition attd Feed Yunnan Agricultural University Kunming 650201 P..R. China

The present study was to investigate the effect of monoclonal antibody against porcine 40-kDa adipocyte-specific membrane protein on endocrine secretion in pigs, in order to provide the evidence for application of this antibody to reduce excessive fat deposition in pig production. 40 Landrace×Saba pigs were randomly divided into 8 groups： 2 control groups were given saline with 10 mL, respectively, and the 6 treatment groups were given monoclonal antibody against porcine 40-kDa adipocyte-specific membrane protein with 0.1, 0.5, and 1.0 mg ·kg^-1 body weight at 15 or 60 kg body weight, respectively, all treatments were performed by intraperitoneal injection. The results showed that this monoclonal antibody could significantly reduce serum insulin level and increase levels of serum growth hormone （GH）, insulin-like growth factor-1（IGF-1）, triiodothyronine （T3）, and tetraiodothyronine （T4） either at 15 or 60 kg body weight injection. However, more marked effect was observed at 15 kg body weight treatment. Moreover, the dose-dependent effect of this monoclonal antibody on endocrine secretion was also observed. This result revealed that this monoclonal antibody increased secretion of hormones regulating fat lysis and reduced secretion of hormones regulating fat synthesis, suggests the reduction of porcine excessive fat deposition by this monoclonal antibody was carried out through affecting hormones regulating fat metabolism.

关键词： adipocyte membrane protein monoclonal antibody endocrine pig

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Model Potential Calculations of Oscillator Strength Spectra of Rydberg Li Atoms in External Fields

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Communications in Theoretical Physics 2009年第8期52卷 333-338页

作者： MENG Hui-Yan shi Ting-yun School of Applied Science of Taiyuan University of Science and Technology Taiyuan 030024 China State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics and Mathematics Chinese Academy of Sciences Wuhan 430071 China

By combining the B-spline basis set with model potential (B-spline + MP),we present oscillator strengthspectra of Rydberg Li atoms in external *** photoabsorption spectra are *** the narrow energyranges considered in this paper,the structure of the spectra can be independent of the initial state chosen for a *** results are in good agreement with previous high-precision experimental data and theoretical calculations,where the R-matrix approach together with multichannel quantum defect theory (R-matrix+MQDT) was *** issuggested that the present methods can be applied to deal with the oscillator strength spectra of Rydberg atoms incrossed electric and magnetic fields.

关键词： B-spline spectra

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The Steinberg Lie Algebra st2（S）

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Algebra Colloquium 2016年第1期23卷 129-136页

作者： Yongjie Wang Yiqian shi yun Gao Wu Wen-Tsun Key Laboratory of Mathematics School of Mathematical Sciences University of Science and Technology of China Hefei 230026 China Department of Mathematics and Statistics York University Toronto Ontario M3J1P3 Canada

Let S be a nonassociative k-algebra. By using the Lie triple system, we study the subspace I2（S） of the Steinberg Lie algebra st2（S） and give a necessary and sufficient condition for I2（S） = 0.

关键词： Steinberg Lie algebra Steinberg unitary Lie algebra Lie triple system

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Tetrahydroxy stilbene glucoside improved the behavioral disorders of APP695V717l transgenic mice by inhibiting the expression of Beclin-1 and LC3-Ⅱ

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Journal of Traditional Chinese Medicine 2015年第3期35卷 295-300页

作者： Luo Hongbo Li yun Guo Jiankui Liu Zunjing Zhang Zhiqiang Wang Yong Liu zhao shi Xiangqun Department of Neurology Lanzhou General HospitalLanzhou Military Area Command Department of Neurology China-Japan Friendship Hospital

OBJECTIVE:To observe the effect of tetrahydroxy stilbene glucoside(TSG) on the behavior of APP695V717 I transgenic mouse models and the expression of autophagy-associated proteins Beclin-1and LC3-Ⅱ.METHODS:Forty 3-month-old APP695V717 I transgenic mice were randomized equally into either a TSG group(n = 20) or a model group(n = 20).A normal control group consisted of C57BL/6J mice of the same age and background(n = 20).The TSG group received TSG intragastric administration for1 *** was measured using the Morris water maze and the Y-maze *** in protein expression and mRNA of autophagy-associated Beclin-1 and LC3-Ⅱ in mice hippocampus were detected by western blot and Reverse Transcription-Polymerase Chain Reaction(RT-PCR) ***:The number of electric-stimulus escapes significantly increased and the Morris water maze test showed prolonged escape latency,greater swimming distance,less time taken to cross the exact former platform location in the model group,and increased mRNA and protein expressions of Beclin-1 and LC3-Ⅱ compared with the control group(P < 0.05).The TSG group showed a decrease in the number of electric-stimulus escapes,shorter escape latency and swimming distance,greater time taken to cross the exact former platform location,and decreased mRNA and protein expressions of Beclin-1 and LC3-Ⅱ compared with the model group(P< 0.05).CONCLUSION:These results indicate that tetrahydroxy stilbene glucoside can decrease expressions of Beclin-1 and LC3-Ⅱ in the autophagy *** can attenuate injury to endoplasmic reticulum functions caused by Ab neurotoxicity,improving learning,memorizing,and spatial orientation behavior in mice.

关键词： Mice,tansgenic Becn1 protein LC3 protein Tetrahydroxy stilbene glucoside Behavior

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A Rapid and Simple Method for Quantitative Aziridination from Aminobrominated Derivatives of Olefins under Solvent-free and Mild Conditions

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Chinese Journal of Chemistry 2012年第2期30卷 391-399页

作者： Wei,Junfa Chen,Zhanguo Gao,Yanni Zhang,Peng Wang,Chuanning zhao,Pengfei Wang,yun shi,Xianying School of Chemistry and Chemical Engineering Key Laboratory for Macromolecular Scienee of Shaanxi ProvinceShaanxi Normal UniversityXi'anShaanxi 710062China State Key Laboratory of Applied Organic Chemistry Lanzhou UniversityLanzhouGansu730000China

The urea-catalyzed aziridination of 1,2-vicinal haloamines derived from aminohalogenation of olefins has been developed. This rapid and simple method was carried out by simply grinding the solid mixture of the substrate, K2CO3 and catalytic amount of urea at room temperature in air. The reaction provides a protocol for quantitative preparation of aziridines in a large scope of aminohalogenated derivatives of olefins including α,β-unsaturated ketones, α,β-unsaturated esters and simple olefins. The possible mechanism involving an H-bond promoting deprotonation has been suggested for this reaction.

关键词： rapid quantitative aziridination aminobromination derivative solvent-free olefins

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Kir2.1 Channel Regulation of Glycinergic Transmission Selectively Contributes to Dynamic Mechanical Allodynia in a Mouse Model of Spared Nerve Injury

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Neuroscience Bulletin 2019年第2期35卷 301-314页

作者： Yiqian shi Yangyang Chen yun Wang Department of Neurology Institutes of Brain Science and State Key Laboratory of Medical NeurobiologyFudan University

Neuropathic pain is a chronic debilitating symptom characterized by spontaneous pain and mechanical allodynia. It occurs in distinct forms, including brushevoked dynamic and filament-evoked punctate mechanical allodynia. Potassium channel 2.1(Kir2.1), which exhibits strong inward rectification, is and regulates the activity of lamina I projection neurons. However, the relationship between Kir2.1 channels and mechanical allodynia is still unclear. In this study, we first found that pretreatment with ML133, a selective Kir2.1 inhibitor, by intrathecal administration, preferentially inhibited dynamic, but not punctate, allodynia in mice with spared nerve injury(SNI).Intrathecal injection of low doses of strychnine, a glycine receptor inhibitor, selectively induced dynamic, but not punctate allodynia, not only in na¨?ve but also in ML133-pretreated mice. In contrast, bicuculline, a GABAAreceptor antagonist, induced only punctate, but not dynamic,allodynia. These results indicated the involvement of glycinergic transmission in the development of dynamic allodynia. We further found that SNI significantly suppressed the frequency, but not the amplitude, of the glycinergic spontaneous inhibitory postsynaptic currents(gly-sIPSCs) in neurons on the lamina II-III border of the spinal dorsal horn, and pretreatment with ML133 prevented the SNI-induced gly-sIPSC reduction. Furthermore, 5 days after SNI, ML133, either by intrathecal administration oracute bath perfusion, and strychnine sensitively reversed the SNI-induced dynamic, but not punctate, allodynia and the gly-sIPSC reduction in lamina IIi neurons, *** conclusion, our results suggest that blockade of Kir2.1 channels in the spinal dorsal horn selectively inhibits dynamic, but not punctate, mechanical allodynia by enhancing glycinergic inhibitory transmission.

关键词： Dynamic allodynia ML133 Kir2.1 channel Glycinergic transmission Spared nerve injury

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The total flow control equations and the characteristics of unsteady gradually varied flow in open channels

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Journal of Hydrodynamics 2019年第1期31卷 177-185页

作者： shi-he Liu Qian-yi zhao Qiu-shi Luo State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan 430072China Yellow River Engineering Consulting Co. LtdZhengzhou 450003China

Most unsteady channel flows in nature and practical engineering appear as gradually varied ones,and in the free surface,the deformation conforms to the long wave ***-dimensional total flow models were usually used to for the numerical simulation of long-term and long-distance reaches to describe the water movements,however,the models lack a clear relationship between the three-dimensional flow field and the total flow ***,few studies of the variations of the roughness coefficient against the time in unsteady flows were *** following results are obtained through the theoretical analysis and the numerical simulations in this paper.(1) One-dimensional total flow control equations of the unsteady gradually varied flow in open channels are obtained directly from the mathematical model of the viscous fluid motion,and can both reflect the influence of the turbulence and provide an explicit expression of the energy slope *** equations establish a direct connection between the descriptions of the three-dimensional flow fields and the one-dimensional total flows.(2) Synchronous prototype observation data and planar two-dimensional numerical simulation results are used to extract the one-dimensional total flow information and discuss the total flow characteristics.(3)The orders of magnitude for terms in the total flow motion equation are compared,and the variation of the roughness coefficient against the time is analyzed.

关键词： Open channel unsteady flow total flow characteristics control equations

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SIMULATION OF LOW-CONCENTRATION SEDIMENT-LADEN FLOW BASED ON TWO-PHASE FLOW THEORY

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Journal of Hydrodynamics 2007年第5期19卷 653-660页

作者： LIU shi-he zhao shi-lai LUO Qiu-shi School of Water Resource and Hydropower Wuhan University Wuhan 430072 China

Low concentration sediment-laden flow is usually involved in water conservancy, environmental protection, navigation and so on. In this article, a mathematical model for low-concentration sediment-laden flow was suggested based on the two-phase flow theory, and a solving scheme for the mathematical model in curvilinear grids was worked out. The observed data in the Zhang River in China was used for the ver/fication of the model, and the calculated results of the water level, velocity and river bed deformation are in agreement with the observed ones.

关键词： two-phase flow sediment-laden flow,numerical simulation

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