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Cerebral dopamine neurotrophic factor promotes the proliferation and differentiation of neural stem cells in hypoxic environments

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Neural Regeneration Research 2020年第11期15卷 2057-2062页

作者： Chao-Qun Lin Lu-kui chen School of Medicine Southeast UniversityNanjingJiangsu ProvinceChina Department of Neurosurgery Cancer CenterIntegrated Hospital of Traditional Chinese MedicineSouthern Medical UniversityGuangzhouGuangdong ProvinceChina

Previous research found that cerebral dopamine neurotrophic factor(CDNF)has a protective effect on brain dopaminergic neurons,and CDNF is regarded as a promising therapeutic agent for neurodegenerative ***,the effects of CDNF on the proliferation,differentiation,and apoptosis of neural stem cells(NSCs),which are very sensitive to hypoxic environments,remain *** this study,NSCs were extracted from the hippocampi of fetal rats and cultured with different concentrations of *** results showed that 200 nM CDNF was the optimal concentration for significantly increasing the viability of NSCs under non-hypoxic environmental ***,the cells were cultured with 200 nM CDNF under the hypoxic conditions of 90%N_2,5%CO_2,and 5%air for 6 *** results showed that CDNF significantly improved the viability of hypoxic NSCs and reduced apoptosis among hypoxic *** detection of markers showed that CDNF increased the differentiation of hypoxic NSCs into neurons and *** also reduced the expression level of Lin28 protein and increased the expression of Let-7 mRNA in NSCs,under hypoxic *** conclusion,we determined that CDNF was able to reverse the adverse proliferation,differentiation,and apoptosis effects that normally affect NSCs in a hypoxic ***,the Lin28/Let-7 pathway may be involved in this regulated function of *** present study was approved by the Laboratory Animal Centre of Southeast University,China(approval No.20180924006)on September 24,2018.

关键词： apoptosis astrocyte cerebral dopamine neurotrophic factor differentiation hypoxia Let-7 Lin28 neural stem cells neuron proliferation

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Notes on Canonical Forms of Integrable Vector Nonlinear Schr?dinger Systems

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Chinese Physics Letters 2017年第10期34卷 5-7页

作者： kui chen Da-Jun Zhang Department of Mathematics Shanghai University Shanghai 200444

We present canonical forms of integrable vector nonlinear Sehr6dinger systems. Mathematically, it is enough to focus on these canonical forms.

关键词： NLS Notes on Canonical Forms of Integrable Vector Nonlinear Schr?dinger Systems

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New correlations for evaluating the equivalent bare charge mass for a cased charge

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Defence Technology（防务技术） 2023年第10期28卷 251-266页

作者： Long-kui chen Sheng-hong Huang Hong-jin chen He-ming Wen CAS Key Laboratory of Mechanical Behavior and Design of Materials Department of Modern MechanicsUniversity of Science and Technology of ChinaHefei230026China

Munitions contain casings that consume explosive *** blast load(e.g.,peak overpressure and maximum impulse)intensity generated by ammunition explosion will be lower than that generated by a bare charge with equal *** evaluate the blast load of a cased charge under different conditions,the equivalent bare mass needs to be ***,the accuracy of existing correlations strongly depends on the empirical determination of relevant controlling parameters and lacks theoretical *** this paper,new correlations are proposed based on a more rigorous theoretical derivation,considering both the mechanical behaviors of the casing’s material and the change of the polytropic exponent during the expansion process of the explosion *** controlling parameters are attributed to the rupture radius ratio and the polytropic exponent of detonation products expansion to casing rupture *** reasonability is validated by both comprehensive numerical simulations with dynamic mechanical constitutive model and theoretical *** results calculated by the new correlation show better agreement with the experimental results than those calculated by previous correlations,and the results difference is explained in more consistency with the thermos-physical properties of the charge and mechanical behaviors of casing ***,the correlation of the cased-to-bare impulse ratio is also theoretically improved,providing a more accurate theoretical basis for both the equivalent bare mass and impulse evaluation for a cased charge.

关键词： Cased charge Energy conservation Equivalent bare charge Fracture strain Polytropic exponent

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Selective detection of mercury(II) and methylmercury(II) via coordinationinduced emission of a small-molecule probe

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Science China Chemistry 2016年第12期59卷 1651-1657页

作者： Yan Yang Zhiyi Yao Wei Li kui chen Lei Liu Hai-chen Wu Key Laboratory for Biomedical Effects of Nanomaterials & Nanosafety Institute of High Energy Physics Chinese Academy of Sciences College of Chemical Engineering Beijing Institute of Petro-chemical Technology

Mercury is one of the major toxic pollutants and has many adverse effects on human health. The main mercury species in the environment or in living organisms are inorganic mercuric ion （Hg2＋） and organic methylmercury （CH3Hg＋）. Detection of the two mercury ions is a particularly active topic in the molecular sensing field during the past decade. However, efficient sensors that can sensitively detect and discriminate the two species are rare. In this work, we adopt the concept of restriction of intramolecular rotations which is the basis of aggregation induced emission, and design a molecular probe with pyridyl group as the chelating unit and 1,8-naphthalimide as the fluorescent unit for the detection of both Hg2＋ and CH3Hg＋. When the probe is free in solution, it exhibits weak fluorescence because free intramolecular rotations of the 1,8-naphthalimide moieties non-radiatively annihilate its excited state. However, upon coordination with Hg2＋ or CH3Hg＋, the rotation of 1,8-naphthalimide moieties would be restricted due to the chelation between 1,8-naphthalimide and Hg2＋ or CH3Hg＋, leading to significantly enhanced fluorescent emission. The response induced by Hg2＋ is much stronger than CH3Hg＋; but for specific detection of CH3Hg＋, we introduced a T-rich DNA fragment which could completely mask Hg2＋ in solution. Furthermore, we have employed the sensor for confocal imaging of rig2＋ and CH3Hg＋in immobilized cells. We expect the probe design tactics can be generally useful for sensing many other analytes.

关键词： mercury methylmercury coordination-induced emission fluorescence enhancement selectivity

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Influence of crucible material on inclusions in 95Cr saw-wire steel deoxidized by Si–Mn

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International Journal of Minerals,Metallurgy and Materials 2020年第8期27卷 1083-1099页

作者： Yang Li Chang-yong chen Guo-qing Qin Zhou-hua Jiang Meng Sun kui chen School of Metallurgy Northeasten UniversityShenyang 110819China

To investigate the interaction mechanism between 95 Cr saw-wire steel and different refractories,we conducted laboratory experiments at 1873 *** crucible materials(SiO2,Al2 O3,MgO·Al2 O3,MgO,and MgO-CaO)were *** results indicate that SiO2,Al2 O3,and MgO·Al2 O3 are not suitable for smelting low-oxygen,low-[Al]s 95 Cr saw-wire steel,mainly because they react with the elements in the molten steel and pollute the steel *** contrast,MgO-CaO is an ideal choice to produce 95 Cr saw-wire *** offers three advantages:(ⅰ)It does not decompose by itself at the steelmaking temperature of 1873 K because it exhibits good thermal stability;(ⅱ)[C],[Si],and[Mn]in molten steel cannot react with it to increase the[O]content;and(ⅲ)it not only desulfurizes and dephosphorizes but also removes Al2 O3 inclusions from the steel *** a result,the contents of the main elements([C],[Si],[Mn],[Cr],N,T.O(total oxygen))in the steel are not affected and the content of impurity elements([Al]s,P,and S)can be perfectly controlled within the target ***,the number and size of inclusions in the steel samples decrease sharply when the MgO-CaO crucible is used.

关键词： nonmetallic inclusions 95Cr saw-wire steel crucible material MgO–CaO refractory

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Lax Triad Approach to Symmetries of Scalar Modified Kadomtsev–Petviashvili Hierarchy

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Communications in Theoretical Physics 2017年第2期67卷 131-136页

作者： Xiao Deng kui chen Da-Jun Zhang Department of Mathematics Shanghai University Shanghai 200444 China

By means of Lax triads we reconstruct isospectral and nonisospectral scalar modified Kadomtsev–Petviashvili(mKP) hierarchies. In this approach the argument y is treated as an independent variable which is independent of time parameters {t_1, t_2,...}. Consequently, the isospectral and nonisospectral scalar mKP flows can have clear zero curvature representations, which enables us to handle investigation of symmetries of the scalar isospectral mKP hierarchy as freely as for(1+1)-dimensional systems. As a result, we obtain Lie algebraic structures of the scalar mKP flows and construct symmetries for the scalar isospectral mKP hierarchy.

关键词： scalar modified Kadomtsev–Petviashvili hierarchies Lax triads symmetries Lie algebra

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Nitrogen Leaching in Vegetable Fields in the Suburbs of Shanghai

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Pedosphere 2005年第5期15卷 641-645页

作者： CAO Lin-kui chen Guo-Jun LU Yi-Tong School of Agriculture and Biology Shanghai Jiaotong University Shanghai 201101 （China）

Nitrogen (N) leaching in vegetable fields from December 2002 to May 2003 with equal dressings of total N for asequential rotation of Chinese flat cabbage (Brassica chinensis L. var. rosularis) and lettuce (Lactuca sativa L.) in asuburban major vegetable production base of Shanghai were examined using the lysimeter method to provide a scientificbasis for rational utilization of nitrogen fertilizers so as to prevent nitrogen pollution of water resources. Results showedthat leached N consisted mainly of nitrate N, which accounted for up to more than 90% of the total N loss and couldcontribute to groundwater pollution. Data also showed that by partly substituting chemical N (30%) in a basal dressingwith equivalent N of refined organic fertilizer in the Chinese flat cabbage field, 64.5% of the leached nitrate N was reduced,while in the lettuce (Lactuca sativa L.) field, substituting 1/2 of the chemical N in a basal dressing and 1/3 of the chemicalN in a top dressing with equivalent N of refined organic fertilizers reduced 46.6% of the leached nitrate N. In the two-year sequential rotation system of Chinese flat cabbage and lettuce, nitrate-N leaching in the treatment with the highestamount of chemical fertilizer was up to 46.55 kg ha-1, while treatment plots with the highest amount of organic fertilizerhad only 17.58 kg ha-1. Thus, partly substituting refined organic fertilizer for chemical nitrogen in the first two seasonshas a great advantage of reducing nitrate-N leaching.

关键词： leaching loss nitrogen organic fertilizer vegetable field

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Stability of GOY Model Under Modulation of Periodic External Force

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Communications in Theoretical Physics 2008年第2期49卷 521-524页

作者： ZHAO Ying-kui chen Shi-Gang WANG Guang-Rui Institute of Applied Physics and Computational Mathematics P.O. Box 8009（14） Beijing 100088 China

There is a phase transition between quasi-periodic state and intermittent chaos in GOY model with a critical value δ0. When we add a modulated periodic externa/force to the system, the phase transition can also be found with a critical value δe. Due to coupling between the force and the intrinsic fluctuation of the velocity on shells in GOY model, the stability of the system has been changed, which results in the variation of the critical value. For proper intensity and period of the force, δe is unequal to δ0. The critical value is a nonlinear function of amplitude of the force, and the fluctuation of the velocity can resonate with the external force for certain period Te.

关键词： chaos GOY model phase transition

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Supergravity separation of Pb and Sn from waste printed circuit boards at different temperatures

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International Journal of Minerals,Metallurgy and Materials 2018年第2期25卷 173-180页

作者： Long Meng Zhe Wang Yi-wei Zhong kui-yuan chen Zhan-cheng Guo State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing

Printed circuit boards（PCBs） contain many toxic substances as well as valuable metals, e.g., lead（Pb） and tin（Sn）. In this study, a novel technology, named supergravity, was used to separate different mass ratios of Pb and Sn from Pb–Sn alloys in PCBs. In a supergravity field, the liquid metal phase can permeate from solid particles. Hence, temperatures of 200, 280, and 400°C were chosen to separate Pb and Sn from PCBs. The results depicted that gravity coefficient only affected the recovery rates of Pb and Sn, whereas it had little effect on the mass ratios of Pb and Sn in the obtained alloys. With an increase in gravity coefficient, the recovery values of Pb and Sn in each step of the separation process increased. In the single-step separation process, the mass ratios of Pb and Sn in Pb–Sn alloys were 0.55, 0.40, and 0.64 at 200, 280, and 400°C, respectively. In the two-step separation process, the mass ratios were 0.12 and 0.55 at 280 and 400°C, respectively. Further, the mass ratio was observed to be 0.76 at 400°C in the three-step separation process. This process provides an innovative approach to the recycling mechanism of Pb and Sn from PCBs.

关键词： printed circuit boards supergravity separation recovery Pb–Sn alloy gravity coefficient

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Multiphase microstructure formation and its effect on fracture behavior of medium carbon high silicon high strength steel

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Journal of Materials Science & Technology 2021年第13期72卷 81-92页

作者： kui chen Huabing Li Zhouhua Jiang Fubin Liu Congpeng Kang Xiaodong Ma Baojun Zhao School of Metallurgy Northeastern UniversityShenyang 110819China State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819China School of Chemical Engineering The University of QueenslandBrisbane 4072Australia

This work investigated the evolution of multiphase microstructure and impact fracture behavior of medium carbon high silicon high strength steel subjected to the austempering treatment at 240,360,and400℃.The results show that martensite,bainite,and retained austenite(RA)are the main microstructural *** austempering treatments at 360 and 400℃ caused the formation of carbon-poor ferrite in the matrix,and the transformation of ultrafine bainite into coarse lath bainite and granular bainite,*** filmy RA was distributed between bainite *** polygonal martensiteaustenite islands and blocky RA formed along the grain *** average carbon concentration in the matrix decreased with the temperature increase,while the impact toughness initially increased and then dropped with *** quasi-cleavage brittle fracture dominated the impact fracture mechanism of the sample austempered at 240℃ by forming tearing surfaces and tearing *** microcracks disappeared in the RA on the prior austenite grain *** the other side,the fracture surface of the sample austempered at 360℃ exhibited ductile fracture with deep dimples and brittle fracture with cleavage river *** polygonal martensite-austenite islands or blocky RA constrained the *** austempered at 400℃,the brittle fracture was dominant,showing river patterns,and the microcracks propagated through the granular bainite without any resistance.

关键词： Medium carbon high silicon steel Austempering Martensite Bainite Retained austenite Microcracks

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