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Active fraction combination from Liuwei Dihuang decoction(LW-AFC) ameliorates corticosterone-induced long-term potentiation impairment in mice in vivo 被引量:4
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作者 HUANG Yan LI Dong +3 位作者 CHENG Bin LIU Gang ZHANG Yong-xiang ZHOU Wen-xia 《中国药理学与毒理学杂志》 CAS 北大核心 2019年第6期436-437,共2页
Liuwei Dihuang decoction(LW), a classic formula in traditional Chinese medicine(TCM), has been used for nearly one thousand years for various diseases with characteristic features of kidney yin deficiency. LW consists... Liuwei Dihuang decoction(LW), a classic formula in traditional Chinese medicine(TCM), has been used for nearly one thousand years for various diseases with characteristic features of kidney yin deficiency. LW consists of 6herbs including Dihuang[prepared root of Rehmannia glutinosa(Gaertn) DC], Shanyao(rhizome of Dioscorea polystachya Turcz), Shanzhuyu(fruit of Cornus officinalis Siebold Zucc), Mudanpi(root bark of Paeonia × suffruticosa Andrews),Zexie(rhizome of Alisma plantago-aquatica L) and Fuling(scleorotia of Wolfiporia extensa(Peck) Ginns)LW-active fraction combination(LW-AFC) is extracted from LW, it is effective for the treatment of kidney yin deficiency in many animal models. There are 3 fractions in LW-AFC, a polysaccharide fraction(LWB-B), a glycoside fraction(LWD-b) and an oligosaccharide fraction(CA-30). Our previous results indicate that LW-AFC has similar pharmacological effects to LW, modulating the balance of the NIM network. LW-AFC has positive effects in many animal models of kidney deficiency or disturbance of the NIM network. LW-AFC could improve the cognitive ability in Alzheimer′s disease(AD) animal models(APP/PS1, SAMP8), where modulating immune function and balancing the NIM network may play an important role in its cognition improving effects. Our study also showed that LW-AFC had protective effects on stress-induced disturbances of the NIM network. However, the underlying mechanisms remain elusive and need further investigation. OBJECTIVE This study evaluated the effects of LW-AFC and the active fractions(polysaccharide, LWB-B;glycoside, LWD-b;oligosaccharide,CA-30) on corticosterone(Cort)-induced long-term potentiation(LTP) impairment in vivo. METHODS LTP was used to evaluate the synaptic plasticity. LW-AFC was orally administered for seven days. The active fractions were given by either chronic administration(ig, ip, 7 d) or single administration(icv, ig, ip). Cort was injected subcutaneously 1 h before the high-frequency stimulation(HFS) to induce LTP impairment. Moreover, in order to research on the possible effective pathways, an antibiotic cocktail and an immunosuppressant were also used. RESULTS Chronic administration(ig) of LW-AFC and its three active fractions could ameliorate Cort-induced LTP impairment. Single administration(icv, ig, ip) of any of the active fractions had no effect on Cort-induced LTP impairment, while chronic administration(ig, ip) of LWB-B or LWD-b showed positive effects against Cort. Interestingly, CA-30 only showed protective effects via ig administration,and there was little effect when CA-30 was administered ip In addition, when the intestinal microbiota was disrupted by application of the antibiotic cocktail, CA-30 showed little protective effects against Cort. The effects of LW-AFC were also abolished when the immune function was inhibited. In the hippocampal tissue, Cort treatment increased corticosterone and glutamate, and LW-AFC could inhibit the Cort-induced elevation of corticosterone and glutamate;there was little change in D-serine in Cort-treated animals, but LW-AFC could increase the D-serine levels. CONCLUSION LW-AFC and its three active fractions could ameliorate Cort-induced LTP impairment. Their protective effects are unlikely by a direct way, and immune modulation might be the common pathway. CA-30 could protect LTP from impairment via modulating the intestinal microbiota. Decreasing corticosterone and glutamate and increasing D-serine in the Cort-treated animals’ hippocampal tissue might be one of the mechanisms for the neural protective effects of LW-AFC. Further study is needed to understand the underlying mechanisms. 展开更多
关键词 LW-active fraction COMBINATION ACTIVE FRACTIONS CORTICOSTERONE long-term potentiation SYNAPTIC plasticity stress
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Mechanisms of active fraction combination from Liuwei Dihuang Decoction(LW-AFC) on long-term potentiation impairment in vivo
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作者 HUANG Yan LI Dong +3 位作者 CHENG Bin LIU Gang ZHANG Yong-xiang ZHOU Wen-xia 《中国药理学与毒理学杂志》 CAS 北大核心 2019年第9期665-665,共1页
OBJECTIVE Liuwei Dihuang Decoction(LW)-active fraction combination(LW-AFC,consist of 3 fractions polysaccharide,LWB-B;glycoside,LWD-b;oligosaccharide,CA-30)is extracted from LW,it is effective for the treatment of kid... OBJECTIVE Liuwei Dihuang Decoction(LW)-active fraction combination(LW-AFC,consist of 3 fractions polysaccharide,LWB-B;glycoside,LWD-b;oligosaccharide,CA-30)is extracted from LW,it is effective for the treatment of kidney yin deficiency in many animal models.This study evaluated the effects and mechanisms of LW-AFC and the active fractions on corticosterone(Cort)-induced long-term potentiation(LTP)impairment in vivo.METHODS LTP was used to evaluate the synaptic plasticity.LW-AFC was orally administered for seven days.The active fractions were given by either chronic administration(ig,ip,7 d)or single administration(icv,ig,ip).Cort was injected subcutaneously 1h before the high-frequency stimulation(HFS)to induce LTP impairment.Moreover,in order to research on the possible effective pathways,an antibiotic cocktail and an immunosuppressant were also used.RESULTS Chronic administration(ig)of LW-AFC and its three active fractions could ameliorate Cort-induced LTP impairment.Single administration(icv,ig,ip)of any of the active fractions had no effect on Cort-induced LTP impairment,while chronic administration(ig,ip)of LWB-B or LWD-b showed positive effects against Cort.Interestingly,CA-30 only showed protective effects via ig administration,and there was little effect when CA-30 was administered ip In addition,when the intestinal microbiota was disrupted by application of the antibiotic cocktail,CA-30 showed little protective effects against Cort.The effects of LW-AFC were also abolished when the immune function was inhibited.In the hippocampal tissue,Cort treatment increased Cort and glutamate,and LW-AFC could inhibit the Cort-induced elevation of Cort and glutamate;there was little change in D-serine in Cort-treated animals,but LW-AFC could increase the D-serine levels.CONCLUSION LW-AFC and its three active fractions could ameliorate Cort-induced LTP impairment.Their protective effects are unlikely by a direct way,and immune modulation might be the common pathway.CA-30 could protect LTP from impairment via modulating the intestinal microbiota.Decreasing Cort and glutamate and increasing D-serine in the Cort-treated animals'hippocampal tissue might be one of the mechanisms for the neural protective effects of LW-AFC.Further study is needed to understand the underlying mechanisms. 展开更多
关键词 LW-active fraction combination active fractions CORTICOSTERONE long-term potentiation synaptic plasticity stress
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LW-AFC and its active components ameliorate corticosterone-induced long-term potentiation impairment in mice
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作者 Yan HUANG Dong LI +1 位作者 Wen-xia ZHOU Yong-xiang ZHANG 《中国药理学与毒理学杂志》 CAS CSCD 北大核心 2017年第10期989-990,共2页
OBJECTIVE LW-AFC is extracted from the classical traditional Chinese medicinal prescription-Liuwei Dihuang Decoction.Previous studies have showed that LW-AFC could improve learning&memory ability in amny animal mo... OBJECTIVE LW-AFC is extracted from the classical traditional Chinese medicinal prescription-Liuwei Dihuang Decoction.Previous studies have showed that LW-AFC could improve learning&memory ability in amny animal models.In this study,we focused on evaluating the effect of several main active components fromLW-AFC(B-B;loganin,LOG;morroniside,MOR;paeoniflorin,PF and stachyose,STA)on LTP.METHODS In vivo recording of LTP was used in this study to evaluate the effects of LW-AFC and it′s active components on coticorsterone(Cort)induced LTP impairment.RESULTS The results showed that LW-AFC could ameliorate Cort-induced LTP impairment.The effect of LW-AFC was abolished when the immune function was inhibited.Single administration(ig,ip,icv)of any of the components had no effect on Cort-induced LTP impairment.Consecutively intragastric administration or intraperitoneal injections(chronic administration)of B-B,LOG,MOR or PF for 7 d showed protective effect on Cort-induced LTP impairment.Intragastric administration of STA for 7 d protected LTP from impairment induced by Cort,while there was little improving effect when STA was administrated via intraperitoneal injection.In addition,when the intestinal microbiota was disrupted by applying the antibiotic cocktail,STA showed little protective effect against Cort.CONCLUSION In conclusion,LW-AFC and it′s components showed positive effects against cort induced LTP impairment,it seems that all displayed protective effects via indirectly,immune modulation might be the common pathway for all components;the exact pathways are different in each component,B-B,LOG,MOR and PF could be absorbed into the bloods tream and then modulate the peripheral immune function,while STA could not be absorbed and modulates the immune function via modulating intestinal microbiota.Further studies are needed to invesgate the underlying mechanisms and the synergetic effects of all components. 展开更多
关键词 LW-AFC active components synaptic plasticity long-term potentiation intestinal microbiota
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Corticosterone induced D-serine release deficit play an important role in long-term potentiation impairment by corticosterone in perforant path-dentate gyrus pathway
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作者 HUANG Yan WANG Chen +4 位作者 YU Qi LI Dong SUN Na ZHANG Yong-xiang ZHOU Wen-xia 《中国药理学与毒理学杂志》 CAS 北大核心 2021年第10期764-764,共1页
OBJECTIVE Previous studies showed that over activation of NMDA receptors may be a crucial cause of long-term potentiation(LTP)and cognitive impairment induced by stress or corticosterone.However,other studies showed t... OBJECTIVE Previous studies showed that over activation of NMDA receptors may be a crucial cause of long-term potentiation(LTP)and cognitive impairment induced by stress or corticosterone.However,other studies showed that the function of NMDA receptors is insufficient since the NMDA receptors co-agonist D-serine could improve stress-induced cognitive impairment.The purpose of this study is to clarify whether over activation of NMDA receptors or hypofunction of NMDA receptors is involved in hippocampal impairment of LTP by corticosterone and the underlying mechanisms.METHODS Cort was injected subcutaneously 1 h before the high-frequency stimulation(HFS)to induce LTP impairment.NMDA receptor antagonists and agonists were administrated by icv.RESULTS Hippocampal LTP and object location recognition memory were impaired in corticosterone-treated mice.Corticosterone increased the glutamate level in hippocampal tissues,neither NMDA receptors antagonist nor its subtype antagonists alleviated impairment of LTP,while enhancing the function of NMDA receptors by D-serine did alleviate impairment of LTP by corticosterone,suggesting that hypofunction of NMDA receptors might be one of the main reasons for impairment of LTP by corticosterone.Further results showed that the level of D-serine and its precursor L-serine did not change.D-serine release-related protein Na+-independent alanine-serine-cysteine transporter-1(ASC-1)in the cell membrane was decreased and increasing D-serine release by the selective activator of ASC-1 antiporter activity alleviated impairment of LTP by corticosterone.CONCLUSION Taken together,this study demonstrates that hypofunction of NMDA receptors may be involved in impairment of LTP by corticosterone and reduced D-serine release may be an important reason for its hypofunction,which is an important complement to existing mechanisms of corticosterone-induced LTP and cognitive impairment. 展开更多
关键词 CORTICOSTERONE long-term potentiation N-methyl-D-aspartate receptors D-SERINE Na+-independent ala⁃nine-serine-cysteine transporter-1
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Normalized Solutions of Nonlinear Choquard Equations with Nonconstant Potential
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作者 LI Nan XU Liping 《应用数学》 北大核心 2025年第1期14-29,共16页
In this paper,we mainly focus on a type of nonlinear Choquard equations with nonconstant potential.Under appropriate hypotheses on potential function and nonlinear terms,we prove that the above Choquard equation with ... In this paper,we mainly focus on a type of nonlinear Choquard equations with nonconstant potential.Under appropriate hypotheses on potential function and nonlinear terms,we prove that the above Choquard equation with prescribed 2-norm has some normalized solutions by introducing variational methods. 展开更多
关键词 Nonlinear Choquard equation Potential function Variational method Normalized solution
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Earthquake Nowcasting方法在云南地区的应用研究
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作者 张欣乐 缪淼 +2 位作者 韩鹏 王蕤 常莹 《地球物理学报》 北大核心 2025年第8期3149-3161,共13页
在过去的10年中,基于统计模型的Nowcasting方法被引入地震危险性评估工作中,形成了一种新的评价方法:Earthquake Nowcasting.该方法计算简便,可以快速给出对应时间点的地震危险性,目前已在全世界多个地震频发地区开展应用.为了探索该方... 在过去的10年中,基于统计模型的Nowcasting方法被引入地震危险性评估工作中,形成了一种新的评价方法:Earthquake Nowcasting.该方法计算简便,可以快速给出对应时间点的地震危险性,目前已在全世界多个地震频发地区开展应用.为了探索该方法在中国地震科学实验场的适用性,本文将Earthquake Nowcasting应用于云南地区,基于高频的“小地震”数目,定义“自然周期”并构建地震复发模型,估算自上一次破坏性地震发生至今该地区的应力累积水平,实现大地震发震风险的定量评估.结果表明:(1)2021漾濞M_(S)6.4地震前,震中所在区域有较高的大地震风险;(2)云南省西北部、东北部、南部以及中部的城市和地区存在较高的破坏性地震可能性,后续地震事件与预测结果具有较好一致性;(3)震级相对较高的前震可能会影响主震的危险性评价.因此,Earthquake Nowcasting具有一定的使用价值,可为云南地区的地震危险性评价工作提供参考,但因Earthquake Nowcasting方法未考虑地震的丛集性特征,在实际使用时还必须结合前震、余震的发震规律才能给出更科学、准确的地震危险性评价. 展开更多
关键词 Earthquake Nowcasting 云南省 自然周期 Earthquake potential score
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Foam and mildness study of trehalolipid surfactant in rinse off formulations
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作者 Mei Chen Yaoyao Wu +3 位作者 Dandan Xia Xiaowei Chang Guizhen Su Chen Liu 《日用化学工业(中英文)》 北大核心 2025年第9期1153-1162,共10页
The paper investigates the foaming and mildness properties of trehalolipids surfactant in rinse-off formulations,comparing it with the traditional nonionic surfactant alkyl-polyglycolide(APG).Both single surfactant an... The paper investigates the foaming and mildness properties of trehalolipids surfactant in rinse-off formulations,comparing it with the traditional nonionic surfactant alkyl-polyglycolide(APG).Both single surfactant and their surfactant complexes are evaluated.And the results show that trehalolipids have significant advantages in reducing surface tension,improving foam performance,and enhancing mildness.For mildness evaluation,multiple methods are employed in the study,including in vitro cell toxicity,inflammatory markers,colorimetric index of mildness CIM,and in vivo method of human skin patch test.The results show that the addition of trehalolipids increases IC50 and reduces the release of inflammatory markers of the binary surfactant system.However,the incorporation of trehalolipids has some negative effects on the skin’s lipid barrier function.Skin patch test results indicate that the addition of trehalolipids improves the mildness of surfactant system,particularly in sulfate-free system.Overall,trehalolipids,as nonionic surfactants,presents great potential to replace traditional surfactants in rinse off formulations with enhanced mildness and foam performance. 展开更多
关键词 trehalolipids foam MILDNESS colorimetric index of mildness CIM zeta potential skin patch test
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Some analytic results and applications in extremal Hermitian metrics
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作者 SANG Haoxin WU Yingyi 《中国科学院大学学报(中英文)》 北大核心 2025年第5期589-599,共11页
In this paper,we introduce and prove three analytic results related to uniform convergence,properties of Newtonian potential,and convergence of sequences in Sobolev space constrained by their Laplacian.Then,utilizing ... In this paper,we introduce and prove three analytic results related to uniform convergence,properties of Newtonian potential,and convergence of sequences in Sobolev space constrained by their Laplacian.Then,utilizing our analytic results,we develop a complete proof of a crucial estimate appearing in the results of Guofang Wang and Xiaohua Zhu,which states the classification of extremal Hermitian metrics with finite energy and area on compact Riemann surfaces and finite singularities satisfying small singular angles. 展开更多
关键词 extremal Hermitian metrics conical singularities of metrics Newtonian potential
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Normalized Positive Ground State Solutions for Nonhomogeneous Kirchhoff Equations
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作者 ZHANG Xiaocang XU Liping 《应用数学》 北大核心 2025年第3期711-720,共10页
This article studies a class of nonlinear Kirchhoff equations with exponential critical growth,trapping potential,and perturbation.Under appropriate assumptions about f and h,the article obtained the existence of norm... This article studies a class of nonlinear Kirchhoff equations with exponential critical growth,trapping potential,and perturbation.Under appropriate assumptions about f and h,the article obtained the existence of normalized positive solutions for this equation via the Trudinger-Moser inequality and variational methods.Moreover,these solutions are also ground state solutions.Additionally,the article also characterized the asymptotic behavior of solutions.The results of this article expand the research of relevant literature. 展开更多
关键词 Normalized positive ground state solution Nonhomogeneous Kirchhoff equation Variational method Exponential critical growth Trapping potential
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基于潜在自然植被的塔里木河下游植被最小需水量计算
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作者 王振文 陈彪 刘云飞 《科学技术与工程》 北大核心 2025年第18期7778-7784,共7页
为解决生态维护与农业生产需水量之间的矛盾,厘定干旱区生态修复最小需水量。以塔里木河下游为典型研究区,通过潜在自然植被(potential natural vegetation,PNV)模拟的方法,得出植被生长适宜区域,并对乔木、灌木和草地的适宜生长区域和... 为解决生态维护与农业生产需水量之间的矛盾,厘定干旱区生态修复最小需水量。以塔里木河下游为典型研究区,通过潜在自然植被(potential natural vegetation,PNV)模拟的方法,得出植被生长适宜区域,并对乔木、灌木和草地的适宜生长区域和面积进行了分析,结合AET数据集的多年蒸散发结果,对塔里木河下游的最小需水量进行了计算,结果表明:塔河下游得出的PNV结果以灌木为主,林地和草地对水资源的依赖程度较高,主要分布在河道周边;研究区内的林地和草地均表现出较高的生长潜力,而距离河道较远的灌木分布区域表现出退化趋势;根据PNV模拟结果计算出的塔里木河下游生态需水量约为11279.23×10^(4)m^(3),其中灌木占比最大,而林地和草地由于面积较小,需水量占比分别为7.4%和5.36%。研究结果为干旱区流域生态修复及输水量的确定提供了新的方法,能够明确流域的生态修复范围和植被种类,并有助于区域水资源的管理和优化配置。 展开更多
关键词 生态需水量 干旱区流域 PNV(potential natural vegetation) 蒸散发
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Influence and mechanism of xanthan gum on the aggregation and flotation behavior of talc,olivine,and serpentine
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作者 YANG Xu-sheng FENG Bo +1 位作者 WANG Zi-ming JIANG Long-xia 《Journal of Central South University》 2025年第7期2463-2475,共13页
Finding appropriate flotation reagents to separate copper-nickel sulfide ores from various magnesium silicate gangue minerals has always been a challenge in the mineral processing industry.This study introduced xantha... Finding appropriate flotation reagents to separate copper-nickel sulfide ores from various magnesium silicate gangue minerals has always been a challenge in the mineral processing industry.This study introduced xanthan gum(XG)as a non-toxic and environmentally friendly depressant of talc,olivine,and serpentine.The effects and mechanisms of XG on the aggregation and flotation behavior of talc,olivine and serpentine were investigated by flotation tests,sedimentation tests,IC-FBRM particle size analysis tests,adsorption quantity tests,Fourier transform infrared spectroscopy(FTIR)tests,X-ray photoelectron spectroscopy(XPS)analysis tests and Zeta potential tests.The flotation results indicated that when the three minerals were mixed,XG caused the talc-serpentine aggregation in the solution to shift to olivine-serpentine aggregation,with the remaining XG adsorbing on talc to depress its flotation.In addition,combining XPS and zeta potential tests,the-OH(hydroxyl)groups in XG molecules preferentially adsorbed on Mg sites on the surface of olivine through chemical bonding.The surface potential of olivine significantly shifted to a more negative value,with the negative charge on the olivine surface far exceeding that on the talc surface.This resulted in an increased aggregation effect between positively charged serpentine and negatively charged olivine due to enhanced electrostatic forces. 展开更多
关键词 flotation reagents copper-nickel suifide magnesium silicate gangue minerals xanthan gum AGGREGATION MECHANISMS potential
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Time-efficient cooperative attack strategy considering collision avoidance for missile swarm
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作者 HU Yixin XU Yun DANG Zhaohui 《Journal of Systems Engineering and Electronics》 2025年第5期1306-1316,共11页
In the realm of missile defense systems,the self-sufficient maneuver capacity of missile swarms is pivotal for their survival.Through the analysis of the missile dynamics model,a time-efficient cooperative attack stra... In the realm of missile defense systems,the self-sufficient maneuver capacity of missile swarms is pivotal for their survival.Through the analysis of the missile dynamics model,a time-efficient cooperative attack strategy for missile swarm is proposed.Based on the distribution of the attackers and defenders,the collision avoidance against the defenders is considered during the attack process.By analyzing the geometric relationship between the relative velocity vector and relative position vector of the attackers and defenders,the collision avoidance constrains of attacking swarm are redefined.The key point is on adjusting the relative velocity vectors to fall outside the collision cone.This work facilitates high-precision attack toward the target while keeping safe missing distance between other attackers during collision avoidance process.By leveraging an innovative repulsion artificial function,a time-efficient cooperative attack strategy for missile swarm is obtained.Through rigorous simulation,the effectiveness of this cooperative attack strategy is substantiated.Furthermore,by employing Monte Carlo simulation,the success rate of the cooperative attack strategy is assessesed and the optimal configuration for the missile swarm is deduced. 展开更多
关键词 missile swarm cooperative attack strategy collision avoidance constraint artificial potential function
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Stress corrosion cracking behavior of TIG welded Al-Mg-Mn-Sc-Zr alloy
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作者 TANG Zhong-qin JIANG Feng +2 位作者 LONG Meng-jun YE Peng-cheng WU Ming-jin 《Journal of Central South University》 2025年第9期3203-3219,共17页
Al-Mg-Mn-Sc-Zr alloys with excellent weldability have emerged as ideal candidates for aerospace applications.Currently,the investigations on the corrosion behavior of alloys under tungsten inert gas(TIG)welding condit... Al-Mg-Mn-Sc-Zr alloys with excellent weldability have emerged as ideal candidates for aerospace applications.Currently,the investigations on the corrosion behavior of alloys under tungsten inert gas(TIG)welding conditions are insufficient.Here,the stress corrosion cracking(SCC)behavior of base metal(BM)and weld zone(WZ)of TIG welded Al-Mg-Mn-Sc-Zr alloys was investigated by using pre-cracked compact tensile samples immersed in 3.5%NaCl solution.The direct current potential drop(DCPD)method was used to record the crack propagation.The microstructure and fracture morphology of different regions of TIG welded joints were studied by SEM,EBSD and TEM,and the SCC crack propagation mechanism of BM and WZ was analyzed.The results demonstrated that the critical stress intensity factor for stress corrosion cracking(K_(ⅠSCC))of BM and WZ was 7.05 MPa·m_(1/2) and 11.79 MPa·m_(1/2),respectively.Then,the crack propagation rate of BM was faster than that of WZ,and BM was more susceptible to SCC than WZ.Additionally,the fracture mode of the BM mainly exhibited transgranular fracture,while the fracture mode of the WZ mainly exhibited intergranular and transgranular mixed fracture.Moreover,SCC crack propagation was attributed to the combined effect of anodic dissolution and hydrogen embrittlement.This study will provide experimental and theoretical basis for the wide application of TIG welded Al-Mg-Mn-Sc-Zr alloys in aerospace. 展开更多
关键词 tungsten inert gas(TIG)welded Al-Mg-Mn-Sc-Zr alloy stress corrosion cracking(SCC) critical stress intensity factor(KⅠSCC) direct current potential drop(DCPD)
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Production and trade trend of oils and oilseeds in BRICS countries
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作者 ZHANG Hong 《中国油脂》 CAS CSCD 北大核心 2024年第8期1-10,共10页
In order to promote agricultural production and trade cooperation among BRICS countries,and ensure the security and stability of the oils and oilseeds industrial and supply chains in China and the world,the production... In order to promote agricultural production and trade cooperation among BRICS countries,and ensure the security and stability of the oils and oilseeds industrial and supply chains in China and the world,the production,consumption,trade trend,and cooperation potential of oils and oilseeds in BRICS countries were expounded,and relevant policy recommendations were put forward.Most of the BRICS countries are major agricultural producers,and they are also important agricultural product consumption markets in the world.In 2023/2024,the production and consumption of oilseeds in BRICS countries account for nearly half of the world's total;the production of vegetable oils exceeds a quarter of the world's total,and the consumption of vegetable oils accounts for 40%of the world's total.In 2023/2024,the import and export volume of oilseeds exceeds half of the world's total;vegetable oil imports account for 40%of the world's total,and exports account for about one tenth of the world's total.China's imports of oilseeds and oils from BRICS countries account for 68%and 29%of its global imports in 2023,respectively.BRICS countries are rich in agricultural land resources,have great potential for oils and oilseeds production,obvious complementary advantages in trade structure,and huge space for future cooperation.It is suggested that Brazil should be included in the"Belt and Road"co-construction category to promote the continuous deepening of agricultural cooperation between China and Brazil.It is suggested to explore regional agricultural trade agreements among BRICS countries,promote currency settlement and exchange among BRICS countries,and enhance the facilitation and stability of BRICS trade.It is suggested that China should increase its investment in BRICS countries and export advanced technology and management experience to benefit local agricultural development and achieve a mutually beneficial and win-win situation. 展开更多
关键词 BRICS countries oils and oilseeds production and consumption trade trend agricultural potential
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Modification of a ReaxFF potential at short range for energetic materials
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作者 Weiyi Li Tao Wang +6 位作者 Wenhua Li Jintao Wang Wanxiao Guo Zexin Jiang Yilin Fang Xiyao Yun Ning Gao 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第12期176-182,共7页
The ReaxFF can describe the properties of energetic materials(EMs)at equilibrium state,but does not work properly in simulating high-energy particle irradiation process because of its weak short-range interaction.In t... The ReaxFF can describe the properties of energetic materials(EMs)at equilibrium state,but does not work properly in simulating high-energy particle irradiation process because of its weak short-range interaction.In this paper,a modification was made for such a potential by connecting ZieglerBiersack-Littmark(ZBL)potential to ReaxFF-lg through comparing to Density Functional Theory(DFT)results to accurately describe short-range interactions.After modification,the newly fitted ReaxFF-lg/ZBL potential predicts better the equation of state for EMs In displacement cascade simulations,comparing to results from ab initio molecular dynamics(AIMD),ReaxFF-lg/ZBL presented the similar transferred energy from a primary knock-on atom to surrounding atoms,better than the original ReaxFF-lg potential.Further large-scale displacement cascade simulations indicated ReaxFF-lg/ZBL could be applied for cascade simulations with PKA energy from less than 1 keV to high energy(e.g.35 keV)cases,which is suitable for effectively simulating high-energy displacement cascades in EMs using molecular dynamics method. 展开更多
关键词 Molecular dynamics Potential modification Energetic materials Displacement cascade Density functional theory Ab initio molecular dynamics
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The biofilm characteristics and enhanced performance of a marine microbial-electrolysis-cell-based biosensor under positive anodic potential
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作者 CAO Yuanyuan ZHANG Chaoqun +2 位作者 LIU Xiang CHENG Liang YANG Yang 《土木与环境工程学报(中英文)》 CSCD 北大核心 2024年第6期221-230,共10页
Microbial fuel cells have already been used as biosensors to monitor assimilable organic carbon(AOC).However,their signal production from AOC is known to be completely suppressed by dissoved oxygen(DO).In this study,t... Microbial fuel cells have already been used as biosensors to monitor assimilable organic carbon(AOC).However,their signal production from AOC is known to be completely suppressed by dissoved oxygen(DO).In this study,two identical microbial electrolysis cell(MEC)based biosensors were inoculated with marine sediment and operated at two different anodic potentials,namely-300 mV and+250 mV relative to Ag/AgCl.The MEC biosensor operated under positive anodic potential conditions had electrochemically active microbial communities on the anode,including members of the Shewanellaceae,Pseudoalteromonadaceae,and Clostridiaceae families.However,the strictly anaerobic members of the Desulfuromonadaceae,Desulfobulbaceae and Desulfobacteraceae families were found only in the negative anodic potential MEC biosensor.The positive anodic potential MEC biosensor showed several other advantages as well,such as faster start-up,significantly higher maximum current production,fivefold improvement in the AOC detection limit,and tolerance of low dissolved oxygen,compared to those obtained from the negative anodic potential MEC biosensor.The developed positive anodic potential MEC biosensor can thus be used as a real-time and inexpensive detector of AOC concentrations in high saline and low DO seawater. 展开更多
关键词 BIOSENSOR microbial fuel cell anodic potential marine biofilm assimilable organic carbon
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Anti-off-target control method for video satellite based on potential function
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作者 FAN Caizhi WANG Mengmeng +2 位作者 SONG Chao ZHONG Zikai YANG Yueneng 《Journal of Systems Engineering and Electronics》 CSCD 2024年第6期1583-1593,共11页
Small video satellites have unique advantages of short development cycle,agile attitude maneuver,real-time video imaging.They have broad application prospects in space debris,faulty spacecraft,and other space target d... Small video satellites have unique advantages of short development cycle,agile attitude maneuver,real-time video imaging.They have broad application prospects in space debris,faulty spacecraft,and other space target detection and tracking.However,when a space target first enters the camera’s visual field,it has a relatively large angular velocity relative to the satellite,which makes it easy to deviate from the visual field and cause off-target problems.This paper proposes a novel visual tracking control method based on potential function preventing missed targets in space.Firstly,a circular area in the image plane is designed as a mandatory restricted projection area of the target and a visual tracking controller based on image error.Then,a potential function is designed to ensure continuous and stable tracking of the target after entering the visual field.Finally,the stability of the control is proved using Barbarat’s lemma.By setting the same conditions and comparing with the simulation results of the proportion-derivative(PD)control method,the results show that when there is a large relative attitude motion angular velocity between the target and the satellite,the track-ing method based on potential function can ensure that the tar-get does not deviate from the field-of-view during the tracking control process,and the projection of target is controlled to the desired position.The proposed control method is effective in eliminating tracking error and preventing off-target simultane-ously. 展开更多
关键词 small video satellite visual tracking anti-off-target attitude control potential function
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长时程突触增强现象的研究 被引量:7
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作者 韩太真 《生理科学进展》 CAS CSCD 北大核心 1990年第1期76-78,共3页
长时程增强(long-term potentiation,LTP)是神经元可塑性的反映,这一现象被认为是记忆过程中神经元生理活动的指标。伴随着海马LTP的产生,有神经元的形态学变化及蛋白质成份的改变。对LTP形成机理的研究表明,兴奋性酸性氨基酸及其NMDA... 长时程增强(long-term potentiation,LTP)是神经元可塑性的反映,这一现象被认为是记忆过程中神经元生理活动的指标。伴随着海马LTP的产生,有神经元的形态学变化及蛋白质成份的改变。对LTP形成机理的研究表明,兴奋性酸性氨基酸及其NMDA受体可能参与了海马及新皮层LTP的形成。 展开更多
关键词 长时程增强 海马结构 新皮层 NMDA 脑片 记忆过程 potentiation 记忆巩固 树突棘 幼年大鼠
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瞬时受体电位通道蛋白6在人乳腺癌细胞中的表达及其对乳腺癌细胞侵袭能力的影响 被引量:2
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作者 史海鸿 林建清 +3 位作者 郭启祥 吴鑫泉 余艺煌 陈祥荣 《吉林大学学报(医学版)》 CAS CSCD 北大核心 2014年第6期1221-1225,共5页
目的:探讨瞬时受体电位通道蛋白6(TRPC6)在人乳腺癌细胞中的表达,阐明TRPC6与乳腺癌细胞侵袭能力的关联性。方法:常规培养的不同侵袭能力乳腺癌细胞株分为MCF-7(低侵袭组)和MDA-MB-231(高侵袭组),采用Western blotting法和RT-PCR法检测... 目的:探讨瞬时受体电位通道蛋白6(TRPC6)在人乳腺癌细胞中的表达,阐明TRPC6与乳腺癌细胞侵袭能力的关联性。方法:常规培养的不同侵袭能力乳腺癌细胞株分为MCF-7(低侵袭组)和MDA-MB-231(高侵袭组),采用Western blotting法和RT-PCR法检测2组中TRPC6蛋白和mRNA的表达;将MDA-MB-231细胞分为空白对照组和SKF96365组,不同浓度SKF96365(5、25和40μmol·L-1)预处理MDA-MB-231细胞,阻滞TRPC6通道,采用Transwell实验和细胞划痕实验检测细胞侵袭能力。结果:Western blotting和RT-PCR法检测,高侵袭组MDA-MB-231细胞中TRPC6蛋白及mRNA表达水平均高于低侵袭组MCF-7细胞(P<0.05);划痕实验,5、25和40μmol·L-1SKF96365组迁移细胞数(76.24±7.54、45.33±4.50和25.12±1.57)均少于空白对照组(130.48±9.55)(P<0.05);Transwell体外侵袭实验,不同浓度SKF96365(5、25和40μmol·L-1)组迁移细胞数明显低于对照组(P<0.05)。结论:高侵袭乳腺癌细胞MDA-MB-231可通过上调TRPC6表达提高乳腺癌细胞的侵袭能力,提示TRPC6在乳腺癌转移中可能起作用。 展开更多
关键词 瞬时受体电位通道蛋白 6 乳腺肿瘤 肿瘤侵袭 transient RECEPTOR potential channel 6
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海水ORP对3C钢腐蚀行为的影响 被引量:2
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作者 丁慧 《海洋科学》 CAS CSCD 北大核心 2013年第6期73-76,共4页
研究了氧化还原电位(Oxidation Reduction Potential,ORP)对海水中碳钢腐蚀电化学特征的影响,应用动电位极化曲线法探讨了ORP与碳钢腐蚀行为之间的关系。结果表明,海水的ORP参数对碳钢腐蚀行为具有较大的影响,其中O2/OH电对的作用占主导... 研究了氧化还原电位(Oxidation Reduction Potential,ORP)对海水中碳钢腐蚀电化学特征的影响,应用动电位极化曲线法探讨了ORP与碳钢腐蚀行为之间的关系。结果表明,海水的ORP参数对碳钢腐蚀行为具有较大的影响,其中O2/OH电对的作用占主导,其他电对如Fe3+/Fe2+也有一定的影响。随着海水ORP的增大,其氧化能力越强,碳钢腐蚀电流增大,腐蚀速度加快。水质相对稳定的开放性大洋海水中,可以考虑海水氧化还原电位在碳钢腐蚀速度预测评估中的应用。 展开更多
关键词 氧化还原电位(Oxidation REDUCTION Potential ORP) 氧化还原电对 海水腐蚀
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