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Two thin middle-crust low-velocity zones imaged in the Chuan-Dian region of southeastern Tibetan Plateau and their tectonic implications

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Science China Earth Sciences 2024年第5期67卷 1675-1686页

作者： Long LI xin WANG Guangbing hou Yuan LING Yinshuang AI Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China Innovation Academy for Earth Science Chinese Academy of SciencesBeijing 100029China

Intracrustal low-velocity zones(LVZs)indicate a mechanically weak crust and are widely observed in the southeast margin of the Tibetan Plateau.However,their spatial distributions and formation mechanisms remain controversial.To investigate their distribution and detailed morphology of the LVZs in the southeastern Tibetan Plateau,here we used teleseismic events and continuous waveform data recorded by 40 broadband seismic stations newly deployed in the Sichuan-Yunnan region from December 2018 to October 2020.A total of 12,924 high-quality P-wave receiver functions and 5–40 s fundamental Rayleigh surface wave phase velocity dispersion curves from ambient noise cross-correlation functions were obtained.The Swave velocity model at a depth interval of 0–100 km in the study area was inverted by using the trans-dimensional Markov chain Monte Carlo strategy to jointly invert the complementary data of the receiver function waveform and Rayleigh surface wave phase velocity dispersion.Our results show that there are two separate LVZs(~3.5 km/s)surrounding the rigid Daliangshan subblock at crustal depths of approximately 30–40 km,providing new constraints on the geometry of the LVZs in our study region.The two LVZs obtained in this study may represent the middle crustal flow channels,through which the material in the center of the Tibetan Plateau extrudes to its southeast margin.Blocked by the rigid Sichuan Basin and the spindle-like Daliangshan subblock,the material continues to flow southward through the mechanically weak middle crustal channels surrounding the Daliangshan subblock.In addition,the existence of thin LVZs in the middle crust plays an important role in understanding the decoupling between the upper and lower crust in the study area.It also provides new constraint on the complex tectonic deformation process of the southeastern margin of the Tibetan Plateau caused by the collision and compression of the Indian and the Eurasian plates.

关键词： Southeastern Tibetan Plateau Joint inversion Intracrustal low-velocity zone Mid-crustal channel flow

Experimental study on the size effect on the equation of state of concretes under shock loading

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Defence Technology（防务技术） 2024年第3期33卷 160-167页

作者： mei Li Jian Cui Yanchao Shi Baijian Tang xin Chen Key Laboratory of Coast Civil Structural Safety of the Ministry of Education Tianjin UniversityTianjin 300072China School of Civil Engineering Suzhou University of Science and Technology1701 Binhe RoadSuzhou 215011JiangsuChina School of Civil Engineering Tianjin UniversityTianjin 300072China

Adopting the classical theory of hydrocodes,the constitutive relations of concretes are separated into an equation of state(EoS)which describes the volumetric behavior of concrete material and a strength model which depicts the shear properties of concrete.The experiments on the EoS of concrete is always challenging due to the technical difficulties and equipment limitations,especially for the specimen size effect on the EoS.Although some researchers investigate the shock properties of concretes by fly-plate impact tests,the specimens used in their tests are usually in one size.In this paper,the fly-plate impact tests on concrete specimens with different sizes are performed to investigate the size effect on the shock properties of concrete materials.The mechanical background of the size effect on the shock properties are revealed,which is related to the lateral rarefaction effect and the deviatoric stress produced in the specimen.According to the tests results,the modified EoS considering the size effect on the shock properties of concrete are proposed,which the bulk modulus of concrete is unpredicted by up to 20% if size effects are not accounted for.

关键词： Concrete Equation of state Size effect Shock wave Fly-plate impact test

A novel Ce_(0.485)Zr_(0.485)Y_(0.03)O_(2) composite oxide with surface doping of Y and its application in Pd-only three-way catalyst

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Rare Metals 2024年第2期43卷 749-757页

作者： Zheng Zhao Wei-xin Zhao Yong-Qi Zhang mei-Sheng Cui Yong-Ke hou Dong-Ming Chen Juan-Yu Yang Zong-Yu Feng Xiao-Wei Huang National Engineering Research Center for Rare Earth Grirem Advanced Materials Co.Ltd.GRINM Group Corporation LimitedBeijing100088China Griem Hi-Tech Co.Ltd. Langfang065000China Rare Earth Functional Materials(Xiong’an)Innovation Venter Co.Ltd. Baoding071700China

The ceria-zirconia compound oxide-supported noble metal Pd(Pd@CZ)is widely used in three-way catalyst.Moreover,the surface structure of CZ plays an important role in catalytic activity of Pd.However,how to regulate the surface structure of CZ and clarify the structure–activity relationship is still a challenge.In this paper,a strategy is proposed to develop high activity Pd@CZ nanocatalysts by tuning Y doping sites in CZ.The precipitate-deposition method is developed to prepare the novel Ce_(0.485)Zr_(0.485)Y_(0.03)O_(2) composite with surface doping of Y(CZ-Y-S).In addition,the Pd@CZ-Y-S(Pd supported on CZ-Y-S)exhibits superior catalytic activity for HC,CO,and NO oxide,wherein,for CO and C_(3)H_(6) oxidation,the low-temperature activity of Pd@CZ-Y-S is still 20%higher than that of Pd@CZ-Y-B(Y bulk doping)and commercial Pd@CZ after 1000℃/4 h aging.The effect mechanism is further studied by density functional theory(DFT)calculation.Compared with Pd@CZ-Y-B,Pd@CZ-Y-S shows the lower CO oxide reaction energy barriers due to the weaker adsorption strength of O2.The Y surface doping strategy could provide valuable insights for the development of highly efficient Pd@CZ catalyst with extensive applications.

关键词： Rare earth Ceria-zirconia-supported Pd Surface doping Experiment and theory Catalytic application

Deep learning for joint channel estimation and feedback in massive MIMO systems

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Digital Communications and Networks 2024年第1期10卷 83-93页

作者： Jiajia Guo Tong Chen Shi Jin Geoffrey Ye Li xin Wang Xiaolin hou National Mobile Communications Research Laboratory Southeast UniversityNanjing210096China Department of Electrical and Electronic Engineering Imperial College LondonLondonSW72AZUK DOCOMO Beijing Communications Laboratories Co. LtdBeijingChina

The great potentials of massive Multiple-Input Multiple-Output(MIMO)in Frequency Division Duplex(FDD)mode can be fully exploited when the downlink Channel State Information(CSI)is available at base stations.However,the accurate CsI is difficult to obtain due to the large amount of feedback overhead caused by massive antennas.In this paper,we propose a deep learning based joint channel estimation and feedback framework,which comprehensively realizes the estimation,compression,and reconstruction of downlink channels in FDD massive MIMO systems.Two networks are constructed to perform estimation and feedback explicitly and implicitly.The explicit network adopts a multi-Signal-to-Noise-Ratios(SNRs)technique to obtain a single trained channel estimation subnet that works well with different SNRs and employs a deep residual network to reconstruct the channels,while the implicit network directly compresses pilots and sends them back to reduce network parameters.Quantization module is also designed to generate data-bearing bitstreams.Simulation results show that the two proposed networks exhibit excellent performance of reconstruction and are robust to different environments and quantization errors.

关键词： Channel estimation CSI feedback Deep learning Massive MIMO FDD

Effect and mechanism of nano-Ca_(10)(PO_(4))_(6)(OH)_(2)additive on compressive strength of calcium aluminate cement at high temperature

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Journal of Iron and Steel Research(International) 2022年第7期29卷 1063-1072页

作者： Qian Sun En-hui Wang xin-mei hou Zhi-jun He Tong-xiang Liang Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing 100083China School of Material and Metallurgy University of Science and Technology LiaoningAnshan 114501LiaoningChina School of Materials Science and Engineering Jiangxi University of Science and TechnologyGanzhou 341000JiangxiChina

Calcium aluminate cement(CAC)is widely used as a binder for refractory materials,and thus the improvement in compressive strength is of vital importance for CAC applied at high temperature.For this purpose,nano-Ca_(10)(PO_(4))_(6)(OH)_(2)additive with a ratio of 0.5–1.5 mass%was added with the water-cement ratio to be 0.4.X-ray diffraction and isothermal calorimetry analysis demonstrate that nano-Ca_(10)(PO_(4))_(6)(OH)_(2)additive can shorten the hydration process and promote the formation of main hydrates of CaAl2O4·10H2O(CAH10)and Ca2Al2O5·8H2O(C2AH8).In addition,scanning electron microscopy results suggest that nano-Ca_(10)(PO_(4))_(6)(OH)_(2)can protect CAH10 and C2AH8 from being destroyed during the calcination,guaranteeing that these thin lamellar crystals are intertwined to form the denser microstructure.Benefited from above effects,nano-Ca_(10)(PO_(4))_(6)(OH)_(2)can obviously improve the compressive strength of the CAC mortar samples cured for 7 d after calcination at 1100°C,while the improving effect is dependent upon its contents.Especially,compared with the one without the additive,the compressive strength of the sample with 1.0%nano-Ca_(10)(PO_(4))_(6)(OH)_(2)is increased by 14%.

关键词： Nano-Ca_(10)(PO_(4))_(6)(OH)_(2) Cement Calcination Microstructure Compressive strength

Mesenchymal stem cells for repairing glaucomatous optic nerve

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International Journal of Ophthalmology(English edition) 2024年第4期17卷 748-760页

作者： Bai-Yu Hu mei xin Ming Chen Ping Yu Liu-Zhi Zeng Eye School of Chengdu University of TCM Chengdu 610000Sichuan ProvinceChina Department of Ophthalmology Chengdu First People’s HospitalChengdu 610095Sichuan ProvinceChina

Glaucoma is a common and complex neurodegenerative disease characterized by progressive loss of retinal ganglion cells(RGCs)and axons.Currently,there is no effective method to address the cause of RGCs degeneration.However,studies on neuroprotective strategies for optic neuropathy have increased in recent years.Cell replacement and neuroprotection are major strategies for treating glaucoma and optic neuropathy.Regenerative medicine research into the repair of optic nerve damage using stem cells has Received considerable attention.Stem cells possess the potential for multidirectional differentiation abilities and are capable of producing RGCfriendly microenvironments through paracrine effects.This article reviews a thorough researches of recent advances and approaches in stem cell repair of optic nerve injury,raising the controversies and unresolved issues surrounding the future of stem cells.

关键词： stem cell glaucoma retinal ganglion cell optic nerve axon regeneration

Berberine Enhances Intestinal Mucosal Barrier Function by Promoting Vitamin D Receptor Activity

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Chinese Journal of Integrative Medicine 2024年第2期30卷 143-151页

作者： HUANG Yong-quan LIU Jia-lin CHEN Geng-xin SHEN Dan-ting ZHU Wang CHEN xin-lin LIU Feng-bin hou Qiu-ke Graduate School Guangzhou University of Chinese MedicineGuangzhou(510405)China Department of Orthopedics the Second Affiliated Hospital of Guangzhou University of Chinese MedicineGuangzhou(510006)China Department of Preventive Medicine and Health Statistics Guangzhou University of Chinese MedicineGuangzhou(510006)China Department of Gastroenterology the First Affiliated Hospital of Guangzhou University of Chinese MedicineGuangzhou(510405)China

Objective:To evaluate if berberine can act on vitamin D receptors(VDR)and thereby regulate the expression of tight junction proteins(TJPs)in irritable bowel syndrome-diarrhea-predominant(IBS-D)rats.Methods:The newborn rats were induced into IBS-D rat model via neonatal maternal separation combined with acetic acid chemical stimulation.After modeling,the model was evaluated and rats were divided into the control group and berberine treatment groups(0.85,1.7 and 3.4 mg/kg,once a day for 2 weeks).The distal colon was obtained and colonic epithelial cells(CECs)were isolated and cultured after IBS-D model evaluation.The vitamin D receptor response element(VDRE)reporter gene was determined in the CECs of IBS-D rats to analyze the effect of berberine on the VDRE promoter.VDR overexpression or silencing technology was used to analyze whether VDR plays a role in promoting intestinal barrier repair,and to determine which region of VDR plays a role in berberine-regulated intestinal TJPs.Results:The IBS-D rat model was successfully constructed and the symptoms were improved by berberine in a dose-dependent manner(P<0.05).The activity of VDRE promoter was also effectively promoted by berberine(P<0.05).Berberine increased the expression of TJPs in IBS-D CECs(P<0.05).VDR expression was significantly increased after transfection of different domains of VDR when compared to normal control and basic plasmid groups(all P<0.05).RT-qPCR and Western blot results showed that compared with the blank group,expressions of occludin and zonula occludens-1 were significantly higher in VDR containing groups(all P<0.05).Berberine plus pCMV-Myc-VDR-N group exerted the highest expression levels of occludin and zonula occludens-1(P<0.05).Conclusion:Berberine enhances intestinal mucosal barrier function of IBS-D rats by promoting VDR activity,and the main site of action is the N-terminal region of VDR.

关键词： berberine Chinese medicine irritable bowel syndrome-diarrhea-predominant vitamin D receptors intestinal mucosal barrier tight junction proteins

The action mechanism by which C1q/tumor necrosis factor-related protein-6 alleviates cerebral ischemia/reperfusion injury in diabetic mice

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Neural Regeneration Research 2024年第9期19卷 2019-2026页

作者： Bo Zhao mei Li Bingyu Li Yanan Li Qianni Shen Jiabao hou Yang Wu Lijuan Gu Wenwei Gao Department of Anesthesiology Renmin Hospital of Wuhan UniversityWuhanHubei ProvinceChina Central Laboratory Renmin Hospital of Wuhan UniversityWuhanHubei ProvinceChina Department of Critical Care Medicine Renmin Hospital of Wuhan UniversityWuhanHubei ProvinceChina

Studies have shown that C1q/tumor necrosis factor-related protein-6 (CTRP6) can alleviate renal ischemia/reperfusion injury in mice. However, its role in the brain remains poorly understood. To investigate the role of CTRP6 in cerebral ischemia/reperfusion injury associated with diabetes mellitus, a diabetes mellitus mouse model of cerebral ischemia/reperfusion injury was established by occlusion of the middle cerebral artery. To overexpress CTRP6 in the brain, an adeno-associated virus carrying CTRP6 was injected into the lateral ventricle. The result was that oxygen injury and inflammation in brain tissue were clearly attenuated, and the number of neurons was greatly reduced. In vitro experiments showed that CTRP6 knockout exacerbated oxidative damage, inflammatory reaction, and apoptosis in cerebral cortical neurons in high glucose hypoxia-simulated diabetic cerebral ischemia/reperfusion injury. CTRP6 overexpression enhanced the sirtuin-1 signaling pathway in diabetic brains after ischemia/reperfusion injury. To investigate the mechanism underlying these effects, we examined mice with depletion of brain tissue-specific sirtuin-1. CTRP6-like protection was achieved by activating the sirtuin-1 signaling pathway. Taken together, these results indicate that CTRP6 likely attenuates cerebral ischemia/reperfusion injury through activation of the sirtuin-1 signaling pathway.

关键词： brain C1q/tumor necrosis factor-related protein-6 cerebral apoptosis diabetes inflammation ischemia/reperfusion injury neuron neuroprotection oxidative damage Sirt1

A comparative study of data-driven battery capacity estimation based on partial charging curves

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Journal of Energy Chemistry 2024年第1期88卷 409-420,I0010页

作者： Chuanping Lin Jun Xu Delong Jiang Jiayang hou Ying Liang Xianggong Zhang Enhu Li Xuesong mei State Key Laboratory for Manufacturing Systems Engineering Xi’an Jiaotong UniversityXi’an 710049ShaanxiChina Shaanxi Key Laboratory of Intelligent Robots School of Mechanical EngineeringXi’an Jiaotong UniversityXi’an 710049ShaanxiChina Department of Electrical Engineering and Automation Luoyang Institute of Science and TechnologyLuoyang 471023HenanChina Wuhan Institute of Marine Electric Propulsion China State Shipbuilding Corporation LimitedWuhan 430064HubeiChina Gresgying Digital Technology Ltd. Xi’an 710086ShaanxiChina

With its generality and practicality, the combination of partial charging curves and machine learning(ML) for battery capacity estimation has attracted widespread attention. However, a clear classification,fair comparison, and performance rationalization of these methods are lacking, due to the scattered existing studies. To address these issues, we develop 20 capacity estimation methods from three perspectives:charging sequence construction, input forms, and ML models. 22,582 charging curves are generated from 44 cells with different battery chemistry and operating conditions to validate the performance. Through comprehensive and unbiased comparison, the long short-term memory(LSTM) based neural network exhibits the best accuracy and robustness. Across all 6503 tested samples, the mean absolute percentage error(MAPE) for capacity estimation using LSTM is 0.61%, with a maximum error of only 3.94%. Even with the addition of 3 m V voltage noise or the extension of sampling intervals to 60 s, the average MAPE remains below 2%. Furthermore, the charging sequences are provided with physical explanations related to battery degradation to enhance confidence in their application. Recommendations for using other competitive methods are also presented. This work provides valuable insights and guidance for estimating battery capacity based on partial charging curves.

关键词： Lithium-ion battery Partial charging curves Capacity estimation Data-driven Sampling frequency