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Impact of Carbon Chain Structures in the Backbone on the Flexibility of Modified Polyarylene Sulfide Resins: Molecular Dynamics Simulations and Mesoscopic Analysis

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chinese Journal of Polymer Science 2024年第4期42卷 544-557页

作者： chi zhang Rong Liu Jing-Yuan Liu Wen-Wei Jiang Key Laboratory of Fine Chemical Engineering and Functional Materials School of Chemical EngineeringSichuan UniversityChengdu610065China

In the domain of high-performance engineering polymers, the enhancement of mechanical flexibility in poly(phenylene sulfide) (PPS) resins has long posed a significant challenge. A novel molecular structure, designated as PP-He-IS, wherein imide rings and an aliphatic hexylene chain are covalently incorporated into the PPS backbone to enhance its flexibility, is introduced in this study. Molecular dynamics (MD) simulations are employed to systematically explore the effects of diversifying the backbone chain structures by substituting phenyl units with alkyl chains of varying lengths, referred to as PP-A-IS where “A” signifies the distinct intermediary alkyl chain configurations. Computational analyses reveal a discernable decrement in the glass transition temperature (Tg) and elastic modulus, counterbalanced by an increment in yield strength as the alkyl chain length is extended. Notably, the PP-He-IS variant is shown to exhibit superior yield strength while simultaneously maintaining reduced elastic modulus and Tg values, positioning it as an advantageous candidate for flexible PPS applications. Mesoscopic analyses further indicate that structures such as PP-He-IS, PP-Pe-IS, and PP-Bu-IS manifest remarkable flexibility, attributable to the presence of freely rotatable carbon-carbon single bonds. Experimental validation confirms that a melting temperature of 504 K which is lower than that of conventional PPS, and lower crystallinity are exhibited by PP-He-IS, thereby affording enhanced processability without compromising inherent thermal stability. Novel insights into the strategic modification of PPS for mechanical flexibility are thus furnished by this study, which also accentuates the pivotal role played by molecular dynamics simulations in spearheading high-throughput investigations in polymer material modifications.

关键词： Molecular dynamics simulations Polyarylene Sulfide Main-chain modifications Flexibility Aliphatic hexylene chain

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A near-zero quiescent power breeze wake-up anemometer based on a rolling-bearing triboelectric nanogenerator

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Microsystems & Nanoengineering 2024年第2期10卷 241-249页

作者： Xianpeng Fu Zhichao Jiang Jie Cao Zefang Dong Guoxu Liu Meiling Zhu chi zhang CAS Center for Excellence in Nanoscience Beijing Key Laboratory of Micro-nano Energy and SensorBeijing Institute of Nanoenergy and NanosystemsChinese Academy of SciencesBeijing101400China School of Nanoscience and Engineering University of Chinese Academy of SciencesBeijing100049China Center on Nanoenergy Research Guangxi Colleges and Universities Key Laboratory of Blue Energy and Systems IntegrationSchool of Physical Science&TechnologyGuangxi UniversityNanning530004China Institute of Intelligent Flexible Mechatronics Jiangsu UniversityZhenjiang212013China College of Engineering Mathematics and Physical ScienceUniversity of ExeterExeterEX44QFUK

Wind sensors have always played an irreplaceable role in environmental information monitoring and are expected to operate with lower power consumption to extend service lifetime.Here,we propose a breeze wake-up anemometer(B-WA)based on a rolling-bearing triboelectric nanogenerator(RB-TENG)with extremely low static power.The B-WA consists of two RB-TENGs,a self-waking-up module(SWM),a signal processing module(SPM),and a wireless transmission unit.The two RB-TENGs are employed for system activation and wind-speed sensing.Once the ambient wind-speed exceeds 2 m/s,the wake TENG(W-TENG)and the SWM can wake up the system within 0.96 s.At the same time,the SPM starts to calculate the signal frequency from the measured TENG(M-TENG)to monitor the wind speed with a sensitivity of 9.45 Hz/(m/s).After the wind stops,the SWM can switch off the B-WA within 0.52 s to decrease the system energy loss.In quiescent on-duty mode,the operating power of the B-WA is less than 30 nW,which can greatly extend the service lifetime of the B-WA.By integrating triboelectric devices and rolling bearings,this work has realized an ultralow quiescent power and self-waked-up wireless wind-speed monitoring system,which has foreseeable applications in remote weather monitoring,IoT nodes,and so on.

关键词： generator power service

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Manipulation of magnetocaloric and elastocaloric effects in Ni-Mn-In alloys by lattice volume and magnetic variation:Effect of Co and Fe co-doping

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Journal of Materials Science & Technology 2024年第5期172卷 156-165页

作者： Xinzeng Liang chi zhang Jing Bai Jianglong Gu Yudong zhang Claude Esling Xiang Zhao Liang Zuo School of Materials Science and Engineering Shenyang University of TechnologyShenyang 110870China Key Laboratory for Anisotropy and Texture of Materials Northeastern UniversityShenyang 110819China School of Resources and Materials Northeastern University at QinhuangdaoQinhuangdao 066004China State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004China Laboratoire d’Étude des Microstructures et de Mécanique des Matériaux LEM3 CNRSUMR 7239University of Lorraine57045 MetzFrance

The effects of Co and Fe co-doping Ni-Mn-In alloy on the phase stability,lattice parameters,mag-netic properties,and electronic structures are systematically investigated by using the first-principles calculations.Results indicate that Fe atoms replace the excess Mn2 atoms by direct and indirect coex-istence(Fe→Mn 2 and Fe→In→Mn2);Co substitutes the Ni atoms by direct substitution(Co→Ni)for the Ni-Mn-In alloy.The austenites all exhibit the ferromagnetic(FM)state for the studied composi-tions.The NM martensites are in the ferrimagnetic(FIM-1)state for the Ni_(2)Mn_(1.5)In_(0.5),Ni_(2)Mn_(1.25)In_(0.5)Fe 0.25,Ni_(1.75)Mn_(1.5)In_(0.5)Co_(0.25),and Ni_(1.75)Mn_(1.25)In_(0.5)Co_(0.25)Fe 0.25 alloys,while the other compositions are in the FM state.The phase stability of austenite and martensite decreases with increasing Co and Fe co-doping.A magnetic-structural coupling transition occurs at x<0.25 and y<0.25.The Ni_(1.91)Mn_(1.5)In_(0.5)Co_(0.08)and Ni_(1.91)Mn_(1.42)In_(0.5)Co_(0.08)Fe_(0.08)alloys exhibit an A→6M→NM transformation,accompanied by a magnetic transition.When Co and Fe are co-doped,the hybridization strength between Co and Fe is greater than that between Co/Fe and Mn.The enhancement of magnetocaloric and elastocaloric effects is favored by larger magnetization difference(△M)and lattice volume change(△V/V_(0)).Based on the calculated phase stability,magneto-structure coupling,△V/V 0 and c/a ratio,one can predict that the Ni_(2)-x Mn_(1.5)-y In_(0.5)Co x Fe y alloy with Co content 0≤x≤0.25 and Fe content 0≤y≤0.05 is predicted to have good magneto-controlled functional behavior.

关键词： Ni-Mn-In-Co-Fe Phase stability Magnetocaloric effect Elastocaloric effect

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Heterointerface engineering of rhombic Rh nanosheets confined on MXene for efficient methanol oxidation

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Journal of Energy Chemistry 2024年第6期93卷 419-428,I0011页

作者： Qi zhang Quanguo Jiang Xiang Yang chi zhang Jian zhang Lu Yang Haiyan He Guobing Ying Huajie Huang College of Materials Science and Engineering Hohai UniversityNanjing 210098JiangsuChina New Energy Technology Engineering Lab of Jiangsu Province College of ScienceNanjing University of Posts&Telecommunications(NUPT)Nanjing 210023JiangsuChina School of Materials Science and Engineering Southeast UniversityNanjing 211100JiangsuChina

Although metallic rhodium(Rh)is regarded as a promising platinum-alternative anode catalyst of direct methanol fuel cell(DMFC),the conventional"particle-to-face"contact model between Rh and matrix largely limits the overall electrocatalytic performance due to their insufficient cooperative effects.Herein,we report a controllable and robust heterointerface engineering strategy for the bottom-up fabrication of rhombic Rh nanosheets in situ confined on Ti_3C_(2)T_x MXene nanolamellas(Rh NS/MXene)via a convenient stereoassembly process.This unique design concept gives the resulting 2D/2D Rh NS/MXene heterostructure intriguing textural features,including large accessible surface areas,strong"face-toface"interfacial interactions,homogeneous Rh nanosheet distribution,ameliorative electronic structure,and high electronic conductivity.As a consequence,the as-prepared Rh NS/MXene nanoarchitectures exhibit exceptional electrocatalytic methanol oxidation properties in terms of a large electrochemically active surface area of 126.2 m~2 g_(Rh)~(-1),a high mass activity of 1056.9 mA mg_(Rh)-~1,and a long service life,which significantly outperform those of conventional particle-shaped Rh catalysts supported by carbon black,carbon nanotubes,reduced graphene oxide,and MXene matrixes as well as the commercial Pt nanoparticle/carbon black and Pd nanoparticle/carbon black catalysts with the same noble metal loading amount.Density functional theory calculations further demonstrate that the direct electronic interaction at the well-contacted 2D/2D heterointerfaces effectively enhances the adsorption energy of Rh nanosheets and induces a left shift of the d-band center,thereby making the Rh NS/MXene configuration suffer less from CO poisoning.This work highlights the importance of rational heterointerface design in the construction of advanced noble metal/MXene electrocatalysts,which may provide new avenues for developing the next-generation DMFC devices.

关键词： Rhodium nanosheet Ti_(3)C_(2)T_(x)MXene Heterointerface Electrocatalyst Fuel cell

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Determining Sets and Determining Numbers of Finite Groups

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Algebra Colloquium 2024年第1期31卷 111-128页

作者： Dengyin Wang chi zhang Haipeng Qu School of Mathematics China University of Mining and Technology XuzhouJiangsu 221116China School of Mathematics and Computer Science Shanxi Normal University LinfenShanxi 041000China

A subset D of a group G is a determining set of G if every automorphism of G is uniquely determined by its action on D,and the determining number of G,a(G),is the cardinality of a smallest determining set.A group G is called a DEG-group if α(G)equals(G),the generating number of G.Our main results are as follows.Finite groups with determining number 0 or 1 are classified;finite simple groups and finite nilpotent groups are proved to be DEG-groups;for a given finite group H,there is a DEG-group G such that H is isomorphic to a normal subgroup of G and there is an injective mapping from the set of all finite groups to the set of finite DEG-groups;for any integer k≥2,there exists a group G such that α(G)=2 and(G)≥k.

关键词： determining number automorphisms nilpotent groups

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Mechanical properties and thermal deformation behavior of low-cost titanium matrix composites prepared by a structure-optimized Y_(2)O_(3) crucible

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Journal of Iron and Steel Research(International) 2024年第3期31卷 738-751页

作者： Qian Dang Gang Huang Ye Wang chi zhang Guo-huai Liu Zhao-dong Wang The State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819LiaoningChina School of Materials Science and Chemical Engineering Harbin University of Science and TechnologyHarbin 150004HeilongjiangChina School of Materials Science and Engineering Shenyang University of TechnologyShenyang 110870LiaoningChina

A porous yttrium oxide crucible with both thermal shock resistance and erosion resistance was developed by structural optimization.The structure-optimized yttrium oxide crucible was proved to be suitable for melting highly reactive titanium alloys.Low-cost(TiB+Y2O_(3))-reinforced titanium matrix composites were prepared by vacuum induction melting using the prepared crucible.The thermal deformation behavior and microstructure evolution of(TiB+Y2O_(3))-reinforced tita-nium matrix composites were investigated at deformation temperatures of 900-1100℃with strain rates of 0.001-1 s-1.The results showed that the prepared yttrium oxide crucible had both thermal shock and erosion resistance,the low-cost titanium matrix composites could be prepared by the developed yttrium oxide crucibles which were homogeneous in composition and highly sensitive to strain rate and deformation temperature,and the peak and theological stresses decreased with increasing deformation temperature or decreasing strain rate.In addition,the average thermal deformation activation energy of the composites was calculated to be 574.6 kJ/mol by establishing the Arrhenius constitutive equation in consideration of the strain variables,and the fitting goodness between the predicted stress value and the measured value was 97.624%.The calculated analysis of the hot processing map showed that the best stable thermal deformation zone was located in the deformation temperature range of 1000-1100℃and strain rate range of 0.001-0.01 s^(-1),where the peak dissipation coefficient wasη=71%.In this zone,the deformation of the reinforcement and matrix was harmonious,the reinforcement was less likely to fracture,dynamic recrystallization occurred more fully and the alloy exhibited near steady rheological characteristics.

关键词： Yttrium oxide crucible Titanium matrix composite Thermal deformation behavior Constitutive equation Hot processing map Microstructure evolution

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Lufengpithecus inner ear provides evidence of a common locomotor repertoire ancestral to human bipedalism

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The Innovation 2024年第2期5卷 122-129页

作者： Yinan zhang Xijun Ni Qiang Li Thomas Stidham Dan Lu Feng Gao chi zhang Terry Harrison Key Laboratory of Vertebrate Evolution and Human Origins Institute of Vertebrate Paleontology and PaleoanthropologyChinese Academy of SciencesBeijing 100044China University of chinese Academy of Sciences Beijing 100049China Yunnan Institute of Cultural Relics and Archeology Kunming 650118China Center for the Study of Human Origins Department of AnthropologyNew York UniversityNew YorkNY 10003USA

Various lines of evidence have been used to infer the origin of human bipedalism,but the paucity of hominoid postcranial fossils and the diversity of inferred locomotor modes have tended to confound the reconstruction of ancestral morphotypes.Examination of the bony labyrinth morphology of the inner ear of extinct and living hominoids provides independent evidence for inferring the evolution of hominoid locomotor patterns.New computed tomography data and morphometric analyses of the Late Miocene ape Lufengpithecus indicate that it and other stem great apes possess labyrinths similar to one another and show that hominoids initially evolved from a positional repertoire that included orthogrady,below-branch forelimb suspension and progression,above-branch bipedalism,climbing,clambering,and leaping(hylobatid-like)to one that comprised above-branch quadrupedalism,below-branch forelimb suspension,vertical climbing,limited leaping,terrestrial quadrupedal running and walking,possibly with knuckle walking,and short bouts of bipedalism(chimpanzee-like).The bony labyrinth morphology of Lufengpithecus indicates that it probably conforms more closely to the last common ancestors of crown hominoids and hominids in its locomotor behavior than do other Miocene hominoids.Human bipedalism evolved from this common archetypal Lufengpithecus-like locomotor repertoire.The low evolutionary rate of semicircular canal morphology suggests that Lufengpithecus experienced a relative stasis in locomotor behavior,probably due to the uplift of the Tibetan Plateau,which created a stable environment in the Miocene of southwestern china.

关键词： china probably uplift

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Development and performance evaluation of a culture-independent nanopore amplicon-based sequencing method for accurate typing and antimicrobial resistance profiling in Neisseria gonorrhoeae

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Science china(Life Sciences) 2024年第2期67卷 421-423页

作者： chi zhang Lulu zhang Feng Wang Yaling Zeng Liying Sun Di Wang Yamei Li Liqin Wang Junping Peng NHC Key Laboratory of Systems Biology of Pathogens Institute of Pathogen BiologyChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100176China Key Laboratory of Respiratory Disease Pathogenomics Chinese Academy of Medical SciencesBeijing 100730China Shenzhen Center for Chronic Disease Control Shenzhen 518020China

Dear Editor,Bacterial antimicrobial resistance(AMR)poses a serious threat to global human health(Antimicrobial Resistance Collaborators,2022).Comprehensive profiling of AMR and accurate molecular typing are important for tracking and controlling the emergence and dissemination of antibiotic-resistant bacteria(Yahara et al.,2021).We previously developed a multiplex amplicon sequencing-based method for directly sequencing AMR-related loci in N.gonorrhoeae from clinical samples(zhang et al.,2021).

关键词： gonorrhoeae resistance

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Mesenchymal-epithelial transition factor amplification correlates with adverse pathological features and poor clinical outcome in colorectal cancer

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World Journal of Gastrointestinal Surgery 2024年第5期16卷 1395-1406页

作者： Qiu-Xiao Yu Ping-Ying Fu chi zhang Li Li Wen-Ting Huang Department of Pathology National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital&Shenzhen HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeShenzhen 518116Guangdong ProvinceChina

BACKGROUND Colorectal cancer(CRC)is the third most common cancer and the second most common cause of cancer-related mortality worldwide.Mesenchymal-epithelial transition factor(MET)gene participates in multiple tumor biology and shows clinical potential for pharmacological manipulation in tumor treatment.MET amplification has been reported in CRC,but data are very limited.Investigating pathological values of MET in CRC may provide new therapeutic and genetic screening options in future clinical practice.AIM To determine the pathological significance of MET amplification in CRC and to propose a feasible screening strategy.METHODS A number of 205 newly diagnosed CRC patients undergoing surgical resection without any preoperative therapy at Shenzhen Cancer Hospital of chinese Academy of Medical Sciences were recruited.All patients were without RAS/RAF mutation or microsatellite instability-high.MET amplification and c-MET protein expression were analyzed using fluorescence in situ hybridization(FISH)and immunohistochemistry(IHC),respectively.Correlations between MET aberration and pathological features were detected using the chi-squared test.Progression free survival(PFS)during the two-year follow-up was detected using the Kaplan-Meier method and log rank test.The results of MET FISH and IHC were com pared using one-way ANOVA.RESULTS Polysomy-induced MET amplification was observed in 14.4%of cases,and focal MET amplification was not detected.Polysomy-induced MET amplification was associated with a higher frequency of lymph node metastasis(LNM)(P<0.001)and higher tumor budding grade(P=0.02).In the survival analysis,significant difference was detected between patients with amplified-and non-amplified MET in a two-year follow-up after the first diagnosis(P=0.001).C-MET scores of 0,1+,2+,and 3+were observed in 1.4%,24.9%,54.7%,and 19.0%of tumors,respectively.C-MET overexpression correlated with higher frequency of LNM(P=0.002),but no significant difference of PFS was detected between patients with different protein lev

关键词： Colorectal cancer MET Amplification Pathological features Prognosis Fluorescence in situ hybridization

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Heterogeneous expression of stearoyl-acyl carrier protein desaturase genes SAD1 and SAD2 from Linum usitatissimum enhances seed oleic acid accumulation and seedling cold and drought tolerance in Brassica napus

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Journal of Integrative Agriculture 2024年第6期23卷 1864-1878页

作者： Jianjun Wang Yanan Shao Xin Yang chi zhang Yuan Guo Zijin Liu Mingxun Chen State Key Laboratory of Crop Stress Biology for Arid Areas/National Yangling Agricultural Biotechnology&Breeding Center/Shaanxi Key Laboratory of Crop Heterosis/College of Agronomy Northwest A&F UniversityYangling 712100China

Flax(Linum usitatissimum L.)is a versatile crop and its seeds are a major source of unsaturated fatty acids.Stearoyl-acyl carrier protein desaturase(SAD)is a dehydrogenase enzyme that plays a key role in oleic acid biosynthesis as well as responses to biotic and abiotic stresses.However,the function of SAD orthologs from L.usitatissimum has not been assessed.Here,we found that two LuSAD genes,LuSAD1 and LuSAD2,are present in the genome of L.usitatissimum cultivar‘Longya 10’.Heterogeneous expression of either LuSAD1 or LuSAD2 in Arabidopsis thaliana resulted in higher contents of total fatty acids and oleic acid in the seeds.Interestingly,ectopic expression of LuSAD2 in A.thaliana caused altered plant architecture.Similarly,the overexpression of either LuSAD1 or LuSAD2 in Brassica napus also resulted in increased contents of total fatty acids and oleic acid in the seeds.Furthermore,we demonstrated that either LuSAD1 or LuSAD2 enhances seedling resistance to cold and drought stresses by improving antioxidant enzyme activity and nonenzymatic antioxidant levels,as well as reducing membrane damage.These findings not only broaden our knowledge of the LuSAD functions in plants,but also offer promising targets for improving the quantity and quality of oil,and the abiotic stress tolerance of oil-producing crops,through molecular manipulation.

关键词： LuSAD oleic acid cold tolerance drought tolerance Linum usitatissimum Brassica napus

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