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Chain Dynamics Heterogeneity in Plasticized Poly(vinyl butyral)(PVB) as Elucidated by Solid-State NMR

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Chinese Journal of Polymer Science 2024年第1期42卷 113-124,I0010页

作者： Jing Lv Xu chen zi-Shuo Wu Ya-Hui Li Wei chen National Synchrotron Radiation Laboratory Anhui Provincial Engineering Laboratory of Advanced Functional Polymer FilmCAS Key Laboratory of Soft Matter ChemistryUniversity of Scienceand Technology of ChinaHefei 230026China

The chain dynamics heterogeneity of the poly(vinyl butyral)(PVB) plasticized by triethylene glycol bis(2.ethylhexa noate)(TEG-EH) was investigated by various solid-state NMR *** plasticized PVB shows two domains in distinct molecular dynamics differences,namely,rigid and soft domains,where the latter is the plasticizer-rich *** time domain low field NMR was first used to investigate the dynamics heterogeneity of the plasticized PVB,and the results show the decreasing activated energy of components in the soft domain of plasticized PVB(E_a=2..2.kJ/mol) as compared with that of the pristine one(E_a=2..3 kJ/mol).Detailed dynamics heterogeneity was obtained by high-field NMR with site-specific *** quadrupole-echo ~2.-NMR was adopted to elucidate the dynamics heterogeneity of the vinyl alcohol(VA) units,where only the hydroxyl group of VA is *** ~1H-^(13)C WISE NMR spectra show that there is not much difference in the mobility of the VB unit in PVB with and without plasticizer,whereas the glass transition temperature differed by approximately 53℃.This is further supported by Torchia's T_1 relaxation *** origin of such an unusual phenomenon is attributed to the critical role of the remaining VA(~2.%) in the soft domain,where the VA units locally aggregate through hydrogen ***,the existence of a mobility gradient in the VB unit has been ***,the mobility difference for VB with different stereo-geometry(meso or racemic conformation) is observed for the first *** indicates the importance of modulating the ratio of meso over racemic VB for controlling the macroscopic perfo rmance of PVB.

关键词： Poly(vinyl butyral) Dynamics heterogeneity Plasticizer Solid state NMR

Rational design and energy catalytic application of high-loading single-atom catalysts

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Rare Metals 2024年第10期43卷 4844-4866页

作者： zi-Wei Deng Yue Liu Jie Lin Wen-Xing chen Energy and Catalysis Center School of Materials Science and EngineeringBeijing Institute of Technology Ningbo Institute of Materials Technology and Engineering Chinese Academy of Science

It is well known that single-atom catalysts(SACs)have become a hot topic in the field of catalysis due to their advantages such as 100% metal atom utilization efficiency,high catalytic activity and selectivity compared with conventional catalysts and nanocatalysts. However, the isolated metal atoms on SACs have thermodynamic instability and tend to agglomerate, which limit their catalytic ***, it is of great significance to synthesize stable and high-loading single-atom catalysts(HLSACs). In this paper,we review the research progress of HLSACs from two aspects:design and application. Firstly, we comprehensively introduce the synthesis strategies of HLSACs, namely, top-down and bottom-up methods. Secondly, we overview the application status of HLSACs in three fields: electrocatalysis, thermal catalysis and photocatalysis. Finally, we summarize the development prospects and challenges of HLSACs.

关键词： Design Electrocatalysis High-loading single-atom catalysts Photocatalysis Thermal catalysis

Microstructure and mechanical properties of a cast TRIP-assisted multiphase stainless steel

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China Foundry 2024年第3期21卷 221-228页

作者： Meng-xin Wang zi-xiang Wu Jing-yu He Xiang chen School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China Key Laboratory for Advanced Materials Processing Technology Ministry of EducationBeijing 100084China

Stainless steels are used in a wide range of complex environments due to their excellent corrosion *** stainless steels can offer an excellent combination of strength,toughness and corrosion resistance due to the coexistence of different *** microstructure and mechanical properties of a novel cast multiphase stainless steel,composed of martensite,ferrite,and austenite,were investigated following appropriate heat treatment processes:solution treatment at 1,050℃ for 0.5 h followed by water quenching to room temperature,and aging treatment at 500℃ for 4 h followed by water quenching to room *** show reversed austenite is formed by diffusion of Ni element during aging process,and the enrichment of Ni atoms directly determines the mechanical stability of *** austenite with a lower Ni content undergoes a martensitic transformation during plastic *** tensile strength of the specimen exceeds 1,100 MPa and the elongation exceeds 2.%after solid solution,and further increases to 1,2.7 MPa and 2.%after aging *** enhancement is due to the TRIP effect of austenite and the precipitation of the nanoscale G-phase pinning dislocations in ferrite and martensite.

关键词： multiphase stainless steel mechanical properties TRIP effect reversed austenite G-phase

Photocaged activity-based probes for improved monitoring of protein S-sulfenylation in living cells

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Chinese Chemical Letters 2024年第2期35卷 451-454页

作者： Jiahao Zhang Haiyue Peng zi'an chen Guorui Li Jing Huang State Key Laboratory of Chemo/Biosensing and Chemometrics Hunan Provincial Key Laboratory of Animal Models and Molecular MedicineSchool of Biomedical SciencesHunan UniversityChangsha 410082China

Protein S-sulfenylation(protein sulfenic acid),as one of the most significant oxidative post-translational modifications(OxiPTMs),plays a vital role in regulating protein function.A variety of activity-based probes have been developed to profile sulfenic acid in living ***,due to the transient presence and low content of sulfenic acid in living cell,high doses of probes are needed to achieve efficient *** importantly,current probes have no temporal control over sulfenic acid *** overcome these limitations,two caged cysteine sulfenic acid probes DYn-2.ONB and DYn-2.Cou with either an o-nitrobenzyl or coumarin protecting group were developed in this *** probes can be efficiently uncaged via irradiation to produce the active C-nucleophile probe *** assay in living cells demonstrated DYn-2.ONB exhibited better labeling capacity compared with DYn-2.providing it as a powerful tool for improved monitoring of protein S-sulfenylation in living cells.

关键词： Cysteine Sulfenic acid Activity-based probe Photocage Light activation Protein S-sulfenylation

WRKY11 up-regulated dirigent expression to enhance lignin/lignans accumulation in Lilium regale Wilson during response to Fusarium wilt

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Journal of Integrative Agriculture 2024年第8期23卷 2703-2722页

作者： Jie Deng zi’e Wang Wenyun Li Xiaohua chen Diqiu Liu Faculty of Life Science and Technology Kunming University of Science and TechnologyKunming 650500China

Lilium are highly economically valuable ornamental plants that are susceptible to Fusarium wilt caused by Fusarium *** regale Wilson,a wild lily native to China,is highly resistant to *** this study,a WRKY transcription factor,WRKY11,was isolated from ***,and its function during the interaction between *** and *** was *** ectopic expression of LrWRKY11 in tobacco increased the resistance to F oxysporum,moreover,the transcriptome sequencing and UHPLC-MS/MS analysis indicated that the methyl salicylate and methyl jasmonate levels rose in LrWRKY11 transgenic tobacco,meanwhile,the expression of lignin/lignans biosynthesis-related genes including a dirigent(DiR)was *** lignin/lignans contents in LrWRKY11-transgenic tobacco also significantly increased compared with the wild-type *** addition,the resistance of *** scales in which LrWRKY11 expression was silenced by RNAi evidently decreased,and additionally,the expression of lignin/lignans biosynthesis-related genes including LrDIR1 was significantly ***,LrDIR1 and its promoter(PLrDIR1)sequence containing the W-box element were isolated from *** interaction assay indicated that LrWRKY11 specifically bound to the W-box element in PLrDIR1 and activated LrDIR1 ***,β-glucuronidase activity in the transgenic tobacco co-expressing LrWRKY11/PLrDIR1-β-glucuronidase was higher than that in transgenic tobacco expressing PLrDIR1-β-glucuronidase ***,the ectopic expression of LrDIR1 in tobacco enhanced the resistance to *** and increased the lignin/lignans *** brief,this study revealed that LrWRKY11 positively regulated *** resistance to *** through interaction with salicylic acid/jasmonic acid signaling pathways and modulating LrDIR1 expression to accumulate lignin/lignans.

关键词： Lilium regale Fusarium oxysporum WRKY transcription factor dirigent

Human influence on the duration of extreme temperature events in Asia's hotspot regions

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Advances in Climate Change Research 2024年第2期15卷 312-326页

作者： zi-Meng WANG Hong-Yun MA Wei LI Hai-Shan chen Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)/Key Laboratory of Meteorological Disaster Ministry of Education(KLME)Nanjing University of Information Science and TechnologyNanjing 210044China

Observations and models indicate that human activities exert a considerable impact on the frequency and intensity of extreme temperature events,which are associated with global ***,changes in the duration of extreme temperature events and their association with human influence have not been considered in most ***,the possible relationship between the observed changes in the warm and cold spell duration(WSDI and CSDI)in hotspot regions during 1960-2.14 and human influence was investigated based on the NCEP/NCAR reanalysis version 1 and Coupled Model Inter-comparison Project Phase 6(CMIP6)*** projection based on these attribution results was also *** optimal fingerprinting technique was used to compare observed changes in WSDI and CSDI to simulated changes averaged across eight CMIP6 *** show that anthropogenic(ANT)forcing contributed to the observed increase in WSDI in the three hotspot regions(West Asia,South Asia and Southeast Asia),with the majority of the changes being attributed to greenhouse gas ***,a generally weak ANT signal can be observed in the decreasing trend of CSDI and can be detected in South and Southeast *** influence of aerosol forcing remains undetected in either WSDI or CSDI,which differs from the results for frequency and intensity of extreme *** attribution results revealed that the constrained projection of WSDI is lower than the raw projection for 2.15-2.00 in West Asia and Southeast ***,no differences in future CSDI changes are found in Southeast Asia between the constrained and raw projections.

关键词： Extreme temperature events Duration Detection attribution Constraint projection Hotspot regions

Experimental research on the launching system of auxiliary charge with filter cartridge structure

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Defence Technology（防务技术） 2024年第1期31卷 41-48页

作者： zi-Jun chen Ze He Hong-Hao Ma Lu-Qing Wang Zhao-Wu Shen CAS Key Laboratory of Mechanical Behavior and Design of Materials Department of Modern MechanicsUniversity of Science and Technology of ChinaHefeiAnhui230027PR China State Key Laboratory of Fire Science University of Science and Technology of ChinaHefeiAnhui230026PR China

A launching system with a filter cartridge structure was proposed to improve the muzzle velocity of the *** combustion chamber of the launching system is divided into two fixed chambers,one is located in the breech chamber,and the other is arranged in the *** breech chamber charge was ignited first,and the charges in the auxiliary chambers were ignited by the high-temperature,highpressure combustible gas trailing the *** this way,the combustible gas in the auxiliary chambers could compensate for the pressure drop caused by the movement of the *** proposed device features the advantage of launching a projectile with high muzzle velocity without exceeding the maximum pressure in the *** order to obtain some internal ballistic characteristics of the launch system,some critical structure,such as the length of the filter cartridge auxiliary charge,the combustion degree of the propellant in the chamber,and the length of the barrel,are *** experimental results show that with the increased auxiliary charge length,a pressure plateau or even a secondary peak pressure can be formed,which is less than the peak *** projectile velocity increased by 2..57%,14.64%,and 7.65%when the diaphragm thickness was 0 mm,1 mm,and2.mm,*** muzzle velocity of the projectile can be increased by 13.42.by increasing the length of the *** the same charge condition,with the increase of barrel length,the energy utilization rate of propellant increases by 2..64%.

关键词： Interior ballistics Charge structures Launch system Charge design

Intelligent geochemical interpretation of mass chromatograms:Based on convolution neural network

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Petroleum Science 2024年第2期21卷 752-764页

作者： Kai-Ming Su Jun-Gang Lu Jian Yu zi-Xing Lu Shi-Jia chen Hubei Key Laboratory of Petroleum Geochemistry and Environment Wuhan430100HubeiChina College of Resources and Environment Yangtze UniversityWuhan430100HubeiChina School of Geoscience and Technology Southwest Petroleum UniversityChengdu610500SichuanChina Changqing Oilfield Company PetroChinaXi'an710021ShaanxiChina

Gas chromatography-mass spectrometry(GC-MS)is an extremely important analytical technique that is widely used in organic *** is the only approach to capture biomarker features of organic matter and provides the key evidence for oil-source correlation and thermal maturity ***,the conventional way of processing and interpreting the mass chromatogram is both timeconsuming and labor-intensive,which increases the research cost and restrains extensive applications of this *** overcome this limitation,a correlation model is developed based on the convolution neural network(CNN)to link the mass chromatogram and biomarker features of samples from the Triassic Yanchang Formation,Ordos Basin,*** this way,the mass chromatogram can be automatically *** research first performs dimensionality reduction for 15 biomarker parameters via the factor analysis and then quantifies the biomarker features using two indexes(*** and PMI)that represent the organic matter thermal maturity and parent material type,***,training,interpretation,and validation are performed multiple times using different CNN models to optimize the model structure and hyper-parameter setting,with the mass chromatogram used as the input and the obtained MI and PMI values for supervision(label).The optimized model presents high accuracy in automatically interpreting the mass chromatogram,with R2.alues typically above 0.85 and0.80 for the thermal maturity and parent material interpretation results,*** significance of this research is twofold:(i)developing an efficient technique for geochemical research;(ii)more importantly,demonstrating the potential of artificial intelligence in organic geochemistry and providing vital references for future related studies.

关键词： Organic geochemistry Biomarker Mass chromatographic analysis Automated interpretation Convolution neural network Machine learning

Engineered extracellular vesicles: A new approach for targeted therapy of tumors and overcoming drug resistance

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Cancer Communications 2024年第2期44卷 205-225页

作者： chen Ming-Kun chen {2.-Xian Cai Mao-Ping chen Hong chen Zhuang-Fei Zhao Shan-Chao Department of Urology The Third Affiliated Hospital of Southern Medical UniversityGuangzhouGuangdongP.R.China The Third Clinical College Southern Medical UniversityGuangzhouGuangdongP.R.China Luoyang Key Laboratory of Organic Functional Molecules College of Food and DrugLuoyang Normal UniversityLuoyangHenanP.R.China Department of Urology Nanfang HospitalSouthern Medical UniversityGuangzhouGuangdongP.R.China

Targeted delivery of anti-tumor drugs and overcoming drug resistance in malig-nant tumor cells remain significant clinical ***,there are only few effective methods to address these *** vesicles(EVs),actively secreted by cells,play a crucial role in intercellular information transmis-sion and cargo *** studies have demonstrated that engineered EVs can serve as drug delivery carriers and showed promising application ***,there is an urgent need for further improvements in the isolation and purification of EVs,surface modification techniques,drug assem-bly processes,and precise recognition of tumor cells for targeted drug delivery *** this review,we summarize the applications of engineered EVs in cancer treatment and overcoming drug resistance,and current challenges asso-ciated with engineered EVs are also *** review aims to provide new insights and potential directions for utilizing engineered EVs as targeted delivery systems for anti-tumor drugs and overcoming drug resistance in the near future.

关键词： drug delivery drug resistance extracellular vesicles nanoparticles