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| 1 | Early changes to the extracellular space in the hippocampus under simulated microgravity conditions显示文摘The smooth transportation of substances through the brain extracellular space(ECS)is crucial to maintaining brain function;however,the way this occurs under simulated microgravity remains unclear.In this study,tracer-based magnetic resonance imaging(MRI)and DECS-mapping techniques were used to image the drainage of brain interstitial fluid(ISF)from the ECS of the hippocampus in a tail-suspended hindlimb-unloading rat model at day 3(HU-3)and 7(HU-7).The results indicated that drainage of the ISF was accelerated in the HU-3 group but slowed markedly in the HU-7 group.The tortuosity of the ECS decreased in the HU-3 group but increased in the HU-7 group,while the volume fraction of the ECS increased in both groups.The diffusion rate within the ECS increased in the HU-3 group and decreased in the HU-7 group.The alterations to ISF drainage and diffusion in the ECS were recoverable in the HU-3 group,but neither parameter was restored in the HU-7 group.Our findings suggest that early changes to the hippocampal ECS and ISF drainage under simulated microgravity can be detected by tracer-based MRI,providing a new perspective for studying microgravity-induced nano-scale structure abnormities and developing neuroprotective approaches involving the brain ECS. | Yajuan Gao Hongbin Han Jichen Du Qingyuan He Yanxing Jia Junhao Yan Hui Dai Bin Cui Jing Yang Xunbin Wei Liu Yang Rui Wang Ren Long Qiushi Ren Xing Yang Jiabin Lu | 2022 | Science China(Life Sciences)2022，65，3： | 2 |
| 2 | A review of in situ transmission electron microscopy study on the switching mechanism and packaging reliability in non-volatile memory显示文摘Non-volatile memory(NVM)devices with non-volatility and low power consumption properties are important in the data storage field.The switching mechanism and packaging reliability issues in NVMs are of great research interest.The switching process in NVM devices accompanied by the evolution of microstructure and composition is fast and subtle.Transmission electron microscopy(TEM)with high spatial resolution and versatile external fields is widely used in analyzing the evolution of morphology,structures and chemical compositions at atomic scale.The various external stimuli,such as thermal,electrical,mechanical,optical and magnetic fields,provide a platform to probe and engineer NVM devices inside TEM in real-time.Such advanced technologies make it possible for an in situ and interactive manipulation of NVM devices without sacrificing the resolution.This technology facilitates the exploration of the intrinsic structure-switching mechanism of NVMs and the reliability issues in the memory package.In this review,the evolution of the functional layers in NVM devices characterized by the advanced in situ TEM technology is introduced,with intermetallic compounds forming and degradation process investigated.The principles and challenges of TEM technology on NVM device study are also discussed. | Xin Yang Chen Luo Xiyue Tian Fang Liang Yin Xia Xinqian Chen Chaolun Wang Steve Xin Liang Xing Wu Junhao Chu | 2021 | Journal of Semiconductors2021，42，1： | 1 |
| 3 | Atomically-precise Janus polyoxometalate catalyst with tunable water splitting activity显示文摘The development of bifunctional catalysts for solar-driven hydrogen and oxygen evolution has been regarded as a challenging but interesting research topic.As promising multi-electron-transfer catalysts,previously reported polyoxometalate(POM)-based catalysts often contain only a single type of transition metal substitution for driving either hydrogen production or oxygen evolution.Herein,a viable two-step parental substitution approach has been developed to synthesize two structurally-new mixed-transition-metal-substituted polyoxometalates(mixed TMSPs),K_(6)Na_(4)[Mn_(2)Ni_(2)(H_(2)O)2(PW_(9)O_(34))2]·21H_(2)O({Mn_(2)Ni_(2)})and K10[Mn_(2)Co_(2)(H_(2)O)2(PW_(9)O_(34))2]·35H_(2)O({Mn_(2)Co_(2)}),using Na_(12)[Mn_(2)Na_(2)(PW_(9)O_(34))2]·36H_(2)O({Mn_(2)Na_(2)})as the precursor.Characterization results confirmed the nearly quantitative substitution of Na+with Ni_(2)+and Co_(2+)ions.X-ray absorption fine structure(XAFS)spectroscopy revealed that the Mn atoms are preferentially located in the internal positions of the central belt while Ni and Co atoms preferentially reside in the external,solvent-accessible positions.Benefiting from the second substitution of catalytically active transition metals,the resulting{Mn_(2)Ni_(2)}and{Mn_(2)Co_(2)}can be utilized as Janus catalysts towards H_(2) evolution and O_(2) evolution under visible light irradiation with greatly-enhanced activity compared to that of parental{Mn_(2)Na_(2)}.The introduction of mixed transition metals into POM structures not only enriches the POMs family,but also provides an effective strategy to control electronic structures and catalytic properties of POM-based catalysts at the atomic level. | Zhimin Wang Xing Xin Zheng Li Mo Zhang Jiangwei Zhang Yeqin Feng Junhao Zhang Hongjin Lv Guo-Yu Yang | 2023 | Science China Chemistry2023，66，6： | 0 |
| 4 | Production of aromatic hydrocarbons by co-cracking of bio-oil and ethanol over Ga_(2)O_(3)/HZSM-5 catalysts显示文摘The catalytic cracking of bio-oil is important to produce aromatic hydrocarbons,which can partially replace gasoline or diesel to greatly reduce carbon emissions from transportation.To further promote the formation of aromatic hydrocarbons,this work studied the effects of the preparation method and the acid strength of Ga_(2)O_(3)/HZSM-5 on catalytic cracking of the bio-oil distilled fraction systematically.The preparation method of Ga_(2)O_(3)/HZSM-5 had an important effect on its catalytic activity:the Ga_(2)O_(3)/HZSM-5 prepared by physical mixing showed the low dispersion of active phases and poor pore structure,resulting in its insufficient activity and severe coke deposition;the Ga_(2)O_(3)/HZSM-5 prepared by precipitation exhibited the higher activity,while many polycyclic aromatic hydrocarbons unfavorable for the subsequent utilization were in the oil phase;the Ga_(2)O_(3)/HZSM-5 prepared by impregnation showed the highest activity and 35.5%(mass)selectivity of the oil phase,including 80.3%monocyclic aromatic hydrocarbons and 12.0%polycyclic aromatic hydrocarbons.The Brønsted acidity of Ga_(2)O_(3)/HZSM-5 decreased with Si/Al ratio,leading to the decline in reactant conversion,oil phase selectivity and quality.Meanwhile,the polymerization between monocyclic aromatic hydrocarbons and oxygenates was promoted to produce many polycyclic aromatic hydrocarbons and even coke,causing catalyst deactivation. | Xing Zhang Jingfeng Wu Junhao Chen Liang Lu Lingjun Zhu Shurong Wang | 2022 | Chinese Journal of Chemical Engineering2022，35，6： | 0 |
| 5 | Review in situ transmission electron microscope with machine learning显示文摘Advanced electronic materials are the fundamental building blocks of integrated circuits(ICs).The microscale properties of electronic materials(e.g.,crystal structures,defects,and chemical properties)can have a considerable impact on the performance of ICs.Comprehensive characterization and analysis of the material in real time with high-spatial resolution are indispensable.In situ transmission electron microscope(TEM)with atomic resolution and external field can be applied as a physical simulation platform to study the evolution of electronic material in working conditions.The high-speed camera of the in situ TEM generates a high frame rate video,resulting in a large dataset that is beyond the data processing ability of researchers using the traditional method.To overcome this challenge,many works on automated TEM analysis by using machine-learning algorithm have been proposed.In this review,we introduce the technical evolution of TEM data acquisition,including analysis,and we summarize the application of machine learning to TEM data analysis in the aspects of morphology,defect,structure,and spectra.Some of the challenges of automated TEM analysis are given in the conclusion. | Zhiheng Cheng Chaolun Wang Xing Wu Junhao Chu | 2022 | Journal of Semiconductors2022，43，8： | 0 |
| 6 | Multi-ratio optical thermometry and energy storage characteristics of Yb^(3+)/Er^(3+)/Tm^(3+)doped BaNb_(2)O_(6)transparent glass-ceramics显示文摘In order to meet the needs of new materials gradually developing towards miniaturization,integration,and light weight,multifunctional BaNb_(2)O_(6):Yb^(3+)/Er^(3+)/Tm^(3+)transparent glass-ceramics were success-fully prepared by melt quenching and controllable crystallization.Its structure,luminescence,and en-ergy transmission were studied.Using the opposite temperature dependence of the Tm^(3+)emission band and the corresponding large energy level gap,a maximum relative sensitivity of 2.3%K^(-1)based on thermal coupling levels(TCLs)is obtained in a wide temperature range(298-673 K).The multi-ratio optical thermometry based on TCLs and non-TCLs is successfully realized by using the different emission bands of double emission centers,which makes it possible for self-reference optical temperature measurement modes.In addition,the transparent glass-ceramic exhibits excellent electrical properties under 700 kV cm^(-1)electric field:high discharge energy density(W_(d)=0.99 J cm^(-3)),huge instantaneous power density(225.3 MW cm^(-3)),and ultra-fast discharge rate(T_(0.9)≤15.8 ns).The prepared glass-ceramic is expected to be a new type of lead-free multifunctional photoelectric material for temperature sensors and transparent electronic devices. | Junhao Xing Feng Luo Yaoyi Qin Xiaolu Chen Yingying Liang Zhixin Gao Fei Shang Huarui Xu Guohua Chen | 2023 | Journal of Materials Science & Technology2023，，7： | 0 |
| 7 | 2-8 Direct Mass Measurements of Short-Lived A=2Z+3 Nuclides at CSRe显示文摘Nuclear mass is one of the fundamental quantity of atomic nucleus.The total binding energy of a nucleus derived from the related mass values reflects all the interactions among the constituting nucleons.Masses of short-lived A=2Z+3 nuclei of 112Sn projectile fragments have been measured at the experimental cooler storage ring CSRe,employing the Isochronous mass spectrometry(IMS).The experiment was conducted at the Heavy Ion Research Facility in Lanzhou at the beginning of 2016.The primary beam of 112Sn35+was accumulated in the synchrotron CSRm and accelerated to 467.91 MeV/u.Secondary beam were produced by impinging the high intensity 112Sn35+beam onto a 10 mm beryllium target which was located at the entrance of the radioactive beam line RIBLL2.The projectile fragments of 112Sn emerged from the target were then transmitted,separated in flight through RIBLL2 and finally injected into CSRe. | Liu Junhao Xing Yuanming Yan Xinliang Xu Xing Chen Ruijiu Zeng Qi Zhang Peng Shuai Peng Li Hongfu Zhang Yuhu Wang Meng Yuan Youjin Fu Chaoyi Sun Mingze Chen Xiangchen Bao Tong Lam Yihua | 2016 | IMP & HIRFL Annual Report2016，，1： | 0 |
| 8 | Dual Effects of Interfacial Interaction and Geometric Constraints on Structural Formation of Poly(butylene terephthalate)Nanorods显示文摘When the size of the material is smaller than the size of the molecular chain,new nanostructures can be formed by crystallizing polymers in nanoporous alumina.However,the effect of pore wall and geometric constraints on polymer nanostructures remains unclear.In this study,we demonstrate three new restricted nanostructures{upright-,flat-and tilting-ring}in polybutylene terephthalate(PBT)nanorods prepared from nanoporous alumina.The dual effects of geometrical constraints and interfacial interactions on the formation of PBT nanostructures were investigated for the first time by using X-ray diffraction and Cerius^(2) modeling packages.Under weak constraints,the interaction between pore wall and the PBT rings is dominant and the ring plane tends to be parallel to the pore wall and radiate outward to grow the upright-ring crystals.Surprisingly,in strong 2D confinement,a structural formation reversal occurs and geometrical constraints overpower the effect of pore wall.Rings tend to pile up vertically or obliquely along the long axis of the rod,so the flat-and tilting-ring crystals are predominate in the constrained system.In principle,our study of the nanostructure formation based on the geometrical constraints and the pore wall interfacial effects could provide a new route to manipulate the chain assembly at the nanoscale,further improving the performance of polymer nanomaterial. | Kaichao Wang Ziwei Lai Jiaman Huang Haiying Li Ziying Liang Junhao Liang Xing Ouyang Xiaoguang Li Yan Cao | 2022 | Chinese Journal of Polymer Science2022，40，6： | 0 |
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