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Aggregation-induced suppression of quantum tunneling by manipulating intermolecular arrangements of magnetic dipoles

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Aggregate 2024年第2期5卷 229-238页

作者： Wei Deng Shan-Nan Du ze-Yu Ruan Xiao-Jun Zhao Yan-cong Chen Jun-Liang Liu Ming-Liang Tong Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education IGCMESchool of ChemistrySun Yat-Sen UniversityGuangzhouP.R.China

The relaxation time under zero field reflects the memory retention capabilities of single-molecule magnets(SMMs)when used as storage *** magnetic dipole interaction is ubiquitous in aggregates of magnetic molecules and can greatly influence relaxation ***,such interaction is often considered harmful and challenging to manipulate in molecular solids,especially for high-performance lanthanide single-ion magnets(SIMs).By an elaborately designed combination of ion pairing and hydrogen bonding,we have synthesized two pseudo-D5h SIMs with supramolecular arrangements of magnetic dipoles in staggered and side-by-side patterns,the latter of which exhibits a 104-fold slower zero-field relaxation time at 2 ***,the side-by-side complex exhibits a significantly accelerated magnetic relaxation upon diamagnetic dilution,contrary to the general trend observed in the staggered *** strongly reveals the presence of aggregation-induced suppression of quantum tunneling in a side-by-side arrangement,which has not been observed in mononuclear *** leveraging ion-pairing aggregation and converting to a side-by-side pattern,this study successfully demonstrates an approach to transform a harmful intermolecular dipole interaction into a beneficial one,achieving aτQTM of 980 s ranking among the best-performance SMMs.

关键词： magnetic dipoles arrangements magnetization dynamics single-ion magnets supramolecular aggregates

Light-induced stepped thermal relaxation in a Hofmann-type metal-organic framework

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Science China Chemistry 2024年第6期67卷 1983-1989页

作者： Wen Cui Wei-Wei Wu ze-Yu Ruan Yan-cong Chen guang-Jun ze.g guan-Xi Chen Si-guo Wu Zhao-Ping Ni Ming-Liang Tong Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education School of ChemistryInstitute of Green Chemistry and Molecular EngineeringGuangdong Basic Research Center of Excellence for Functional Molecular EngineeringSun Yat-sen UniversityGuangzhou510275China

Spin-crossover(SCO)materials with light-induced multistability have potential applications in multi-addressable opto-magnetic memory devices and multiple ***,we reported a three-dimensional Hofmann-type metal-organic framework(MOF)[Fe(bpy){Pt(CN)_(4)}]·coumarin(1·coumarin,bpy=4,4′-bipyridine),which exhibits an incomplete and hysteretic SCO *** importantly,the light-induced stepped thermal relaxation(LISTR)with obvious magnetic plateau for a hidden intermediate spin state is firstly *** hidden spin state is also observed for the first time in the thermal relaxation after light-assisted spin state annealing(LASSA).Meanwhile,an extremely rare bi-directional light-induced excited spin-state trapping(LIESST)with the highest reverse-LIESST temperature is ***,five spin states can be captured in 1·coumarin and the tristability can be modulated below 102 K through the excitation-relaxation ***,the light-and temperatureinduced multistability provides a new strategy for developing multistable materials.

关键词： light magnetic multistability iron metal-organic framework spin-crossover

Flexible and multifunctional triboelectric nanogenerator based on liquid metal/polyvinyl alcohol hydrogel for energy harvesting and self-powered wearable human-machine interaction

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Rare Metals 2024年第3期43卷 1186-1196页

作者： Hou-Wang Zhou cong Zhao ze-Yu Zhao Jun-Chen Jiang Hui-Le Jin Shun Wang Shuang Pan Min-Yi Xu Yi-Huang Chen Hai-Ming Jin Department of Orthopaedics The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical UniversityWenzhou325027China College of Chemistry and Materials Engineering Wenzhou UniversityWenzhou325035China Dalian Key Laboratory of Marine Micro/Nano Energy and Self-Powered Systems Marine Engineering CollegeDalian Maritime UniversityDalian116026China

Hydrogel-based triboelectric nanoge nerator(TENg)has a promising applied prospect in wearable electronic ***,its low performance,poor stability,insufficient recyclability and inferior self-healing seriously hinder its ***,we report a robust route to a liquid metal(LM)/polyvinyl alcohol(PVA)hydrogel-based TENg(LP-TENg).Owing to the intrinsically liquid feature of conductive LM within the flexible PVA hydrogel,the as-prepared LP-TENg exhibited comprehensiye advantages of adaptability,biocompatibility,outstanding electrical performance,superior stability,recyclability and diverse applications,which were unattainable by traditional ***,the LP-TENg delivered appealing open circuit voltage of 250 V,short circuit current of 4μA and transferred charge of 120 nC with high stability,outperforming most advanced TENg *** LP-TENg was successfully employed for versatile applications with multifunctionality,including human motion detection,handwriting recognition,energy collection,message transmission and human-machine *** work presents significant prospects for crafting advanced materials and devices in the fields of wearable electronics,flexible skin and smart robots.

关键词： Liquid metal Hydrogel Wearable TENg Multifunctionality Human-machine interaction

Plasma electrolytic liquefaction of sawdust

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Chinese Physics B 2019年第4期28卷 425-432页

作者： cong-cong Jiang Shi-Yun Liu Zhe Feng Zhi Fang Xian-Hui Zhang Dan-Hua Mei Deng-Ke Xi Bing-Yu Luan Xing-Quan Wang Si-ze Yang Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance Institute of Electromagnetics and Acoustics Department of Electronic ScienceCollege of Electronic Science and Technology Xiamen University College of Electrical Engineering and Control Science Nanjing Technology University School of Physics and Electronic InformationInstitute of Low Temperature Plasma Technologygannan Normal University Department of Electronics College of Information Engineering Zhengzhou University

As a renewable carbon resource, biomass can be converted into polyols, aromatic hydrocarbons, alkanes, and other products by traditional catalytic liquefaction method, which has been widely used in production and life. The efficient development and utilization of biomass energy will play a very positive role in solving the problems of energy and ecological environment. A way of combining the plasma electrolysis with traditional catalytic liquefaction realizes the efficient liquefaction of sawdust, which provides a new liquefaction way for traditional biomass conversion. In this experiment, the effects of solution composition, catalyst content and power supply on solution resistance and liquefaction rate are *** is found that solution composition and catalyst content have a great influence on solution resistance. The results show that the liquefaction rate is highest and the resistance is smallest when the solution resistance is 500 ?. The liquefaction rate is greatly affected by the solution temperature, and the solution temperature is determined by the output power between the two electrodes. The output power includes the heating power of the electric field and the discharge power of the *** measure the electric potential field distribution in the solution and the plasma power. It is found that the output power between the two poles increases nonlinearly(from 0 to 270 W) with time. In two minutes, the electric field heating power increases from 0 to 105 W and then decreases to 70 W, while the plasma power increases from 0 to 200 W. It is well known that in the first 70 seconds of the experiment the electric field heating is dominant, and then the plasma heating turns into a main thermal source. In this paper, plasma electrolysis and traditional catalytic liquefaction are combined to achieve the efficient liquefaction of sawdust, which provides a new way for biomass liquefaction.

关键词： biomass liquefaction plasma electrolytic

Effects of heteroatoms on 1,2-rearrangements of 3-membered ring carbenes

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Chinese Journal of Chemistry 1990年第4期8卷 319-324页

作者： WANg, Bing-ze LIU, Jin-Ting LI, Xiao-Fang DENg, cong-Hao College of Chemistry, Shandong University, Jinan 250100 College of Chemistry Shandong University Jinan 250100

1,2-rearrangements of carbenes :CCH_2X(X=CH_2, NH and O) are studied by using ab initio gradient method. Heteroatoms N and O stabilize the carbene and decrease its reactivity, mainly by changing frontier molecular orbitals, but retain the way of the reaction. The reaction starts from the attack of the migrating hydrogen on the carbene p AO and ends with the entrance of the hydrogen into the carbene σ orbital. Reactivities are in the order of X=CH_2>NH>O. The reaction is exothermic or endothermic according to whether the product is a 4n+2 or 4n π electron molecule.

关键词： Effects of heteroatoms on 1,2-rearrangements of 3-membered ring carbenes ring

Enhancing single-molecule magnet behavior of linear Co~Ⅱ-Dy~Ⅲ-Co~Ⅱ complex by introducing bulky diamagnetic moiety

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Science China Chemistry 2018年第11期61卷 1399-1404页

作者： guo-Zhang Huang ze-Yu Ruan Jie-Yu Zheng Jie-Yi Wu Yan-cong Chen Quan-Wen Li Muhammad Nadeem Akhtar Jun-Liang Liu Ming-Liang Tong Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education School of Chemistry Sun Yat-Sen University

Single-molecule magnets （SMMs） are regarded as promising candidates for ultrahigh-density storage, quantum information processing and molecular spintronics. It is a crucial challenge for chemists to modulate magnetic dynamics of SMMs. Here, we successfully synthesized two 3d-4f polynuclear compounds [Co2Dy（TTTTCl）2（MeOH）]NO3.3MeOH （1） and [Co2Dy（TTTTCl）2 （MeOH）][Co（HTTTTCl）]（NO3）z-2.5MeOH＇2H20 （2）, where H3TTTTCl=2,2＇,2＂-（（（nitrilotris（ethane-2,1-diyl）） tris（azanediyl）） tris（methylene））tris-（4-chlorophenol）. On applying the approach by co-crystallization of bulky diamagnetic moiety, the effective energy barrier enhances from 401 K （1） to 536 K （2）, which are both among the highest d-f heterometallic SMMs.

关键词： 3d-4f single-molecule magnets co-crystallization magnetic dynamics

Neurological outcomes of untreated brainstem cavernous malformations in a prospective observational cohort and literature review

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Stroke & Vascular Neurology 2021年第4期6卷 501-510,I0001,I0002页

作者： Da Li Jing-Jie Zheng Jian-cong Weng Pan-Pan Liu ze-Yu Wu Li-Wei Zhang Jun-Ting Zhang Liang Wang Zhen Wu Neurosurgery Beijing Tiantan HospitalCapital Medical UniversityBeijingChina Obstetrics and gynecology Beijing Chaoyang HospitalCapital Medical UniversityBeijingChina

Background Haemorrhages of brainstem cavernous malformations(CMs)can lead to neurological deficits,the natural history of which is *** study aimed to evaluate the neurological outcomes of untreated brainstem CMs and to identify the adverse factors associated with worsened *** From 2009 to 2015,698 patients(321 women)with brainstem CMs were entered into the prospective cohort after excluding patients lost to follow-up(n=43).All patients were registered,clinical data were collected and scheduled follow-up was *** After a median follow-up of 60.9 months,prospective haemorrhages occurred in 167 patients(23.9%).The mean modified Rankin Scale scores at enrolment and at censoring time were 1.6 and *** status was improved,unchanged and worsened in 334(47.9%),293(42.0%)and 71(10.2%)patients,respectively;233(33.4%)recovered to normal *** crossing the axial midpoint(relative risk(RR)2.325,p=0.003)and developmental venous anomaly(DVA)(RR 1.776,p=0.036)were independently significantly related to worsened *** percentage of worsened outcomes was 5.3%(18 of 337)in low-risk patients(neither DVA nor crossing the axial point)and increased to 26.0%(13 of 50)in high-risk patients(with both DVA and crossing the axial point).The percentage of worsened outcomes significantly increased as the number of prospective haemorrhages increased(from 1.5%(8 of 531,if 0 prospective ictus)to 37.5%(48 of 128,if 1 ictus)and 38.5%(15 of 39,if>1 ictus)).Conclusions The neurological outcomes of untreated brainstem CMs were improved/unchanged in majority of patients(89.8%)with a fatality rate of 1.7%in our cohort,which seemed to be *** features significantly predicted worsened *** results provide evidence for clinical consultation and individualised *** referral bias of our cohort was underlined.

关键词： prospective brainstem unchanged

Development and high-gradient test of a two-half accelerator structure

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Nuclear Science and Techniques 2021年第6期32卷 54-62页

作者： Mao-Mao Peng Jia-Ru Shi Hao Zha Xian-Cai Lin ze-Ning Liu Yu-Liang Jiang Jian gao Liu-Yuan Zhou Fo-Cheng Liu Xiang-cong Meng Huai-Bi Chen Department of Engineering Physics Tsinghua UniversityBeijing 100084China Key Laboratory of Particle and Radiation Imaging Tsinghua UniversityMinistry of EducationBeijing 100084China

This paper reports on the design,fabrication,RF measurement,and high-power test of a prototype accelerator—such as 11.424 gHz with 12 cells—and a traveling wave of two *** was found that the unloaded gradient reached 103 MV/m during the high-power test and the measured breakdown rate,after 3.17×10^(7) pulses,was 1.62×10^(-4)/pulse/m at 94 MV/m and a 90 ns pulse *** thus concluded that the high-gradient two-half linear accelerator is cost-effective,especially in high-frequency RF linear ***,we suggest that silverbased alloy brazing can further reduce costs.

关键词： Two-half structure Silver-based alloy brazing Low cost High gradient

Expression and functional characterization of odorant-binding protein genes in the endoparasitic wasp Cotesia vestalis

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Insect Science 2021年第5期28卷 1354-1368页

作者： Yue-Nan Zhou Shuang Xie Jia-Ni Chen ze-Hua Wang Pei Yang Si-cong Zhou Lan PangZ Fei Li Min Shi Jian-Hua Huang Xue-Xin Chen nstitute of Insect Sciences College of Agriculture and BiotechnologyZhejiang UniversityHangzhou310058China Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insect Pests Zhejiang UniversityHangzhou310058China Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province Zhejiang UniversityHangzhou310058China State Key Lab of Rice Biology Zhejiang UniversityHangzhou310058China

Odorant-binding proteins(OBPs)are crucial in insect's olfactory perception,which participate in the initial step of odorant molecules transporting from the external environment to olfactory receptor *** better understand the roles for OBPs in olfactory perception in Cotesia vestalis,a solitary larval endoparasitoid of diamondback moth,Plutella xylostella,we have comprehensively screened the genome of ***,and obtained 20 CvesOBPs,including 18 classic OBPs and two minus-C ***-pattern analysis indicates that the motifs of *** OBPs are highly conserved in *** results of tissue expression analysis show that five OBPs(CvesOBP1/11/12/14/16)are highly expressed in male antennae,whereas six other OBP genes(CvesOBP7/8/13/17/18/19)are significantly transcriptionally enriched in female *** results of RNA interference experiments for three most highly expressed OBP genes(CvesOBP17/18/19)in female antennae demonstrate that they are likely involved in parasitic processes of female wasps,as the wasps take a longer time to target the hosts when they are knoc ked down.

关键词： Cotesia vestalis expression odorant-binding proteins parasitic bchavior phylogenetic analyses RNA interference