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Engineered spidroin-derived high-performance fibers for diverse applications

Nano Research 2024年第2期17卷 492-502页

作者： Dawen Qin Jingjing li Huanrong li Hongjie zhang kai liu National-Local Joint Engineering Laboratory for Energy Conservation in Chemical Process Integration and Resources Utilization Tianjin Key Laboratory of Chemical Process SafetySchool of Chemical Engineering and TechnologyHebei University of TechnologyTianjin 300130China State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China Engineering Research Center of Advanced Rare Earth Materials Ministry of EducationDepartment of ChemistryTsinghua UniversityBeijing 100084China University of Science and Technology of China Hefei 230026China

Spider silks are well known for their exceptional mechanical properties that are tougher than Kevlar and steel.However,the restricted production amounts from their native sources limit applications of spider silks.Over the decades,there have been significant interests in fabricating man-made silk fibers with comparable performance to natural silks,inspiring many efforts both for biosynthesizing recombinant spider silk proteins(spidroins)in amenable heterologous hosts and biomimetic spinning of artificial spider silks.These strategies provide promising routes to produce high-performance and functionally optimized fibers with diverse applications.Herein,we summarize the hosts that have been applied to produce recombinant spidroins.In addition,the fabrication and mechanical properties of recombinant spidroin fibers and their composite fibers are also introduced.Furthermore,we demonstrate the applications of recombinant spidroin-based fibers.Finally,facing the challenges in biosynthesis,scalable production,and hierarchical assembly of high-performance recombinant spidroins,we give a summary and perspective on future development.

关键词： spider silk recombinant spidroin heterologous expression fiber fabrication mechanical property

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Variation characteristics of acid rain in Zhuzhou,Central China over the period 2011-2020

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Journal of Environmental Sciences 2024年第4期138卷 496-505页

作者： Jiahao Ren liquan Zhu Xi zhang Yuqian Luo Xuecai Zhong Bowen li Yuwen Wang kai zhang State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012China Zhuzhou Environment Monitoring Center Zhuzhou 412000China Faculty of Environmental Engineering The University of Kitakyushu1–1 HibikinoWakamatsuKitakyushuFukuoka 808-0135Japan College of Natural Resources and Environment South China Agricultural UniversityGuangzhou 510642China

Zhuzhou was one of the most polluted cities in China with the serious acid rain.Due to the implementation of air pollution control measures from 2016 to 2018,the acid rain pollution in this city has reduced.In order to understand the recent situation,a comprehensive study on the acid rain was carried out from January 2011 to December 2020.The pH values during the study period varied from 3.3 to 7.5,with a volume-weighted mean value of 4.7.The predominant acidic components of the precipitation were SO_(4)^(2-)and NO_(3)^(-),accounting for 89.3% of the total anions.The ratio of non-sea-salt SO_(4)^(2-)to NO_(3)^(-)showed a decreasing trend,revealing that the pollution type of acid rain changed from sulfuric acid type to sulfuric acid and nitric acid compound type.The correlation analysis(p<0.05)showed that SO_(4)^(2-)was positively correlated with NH_(4)^(+),Ca^(2+),and Mg^(2+);hence,it predominated in precipitation as(NH_(4))_(2)SO_(4),NH_(4)HSO_(4),CaSO_(4),and MgSO_(4).Significant positive correlation of Ca^(2+)with Mg^(2+)shows that they may originated mainly from crust.Significant positive correlation between SO_(4)^(2-)and F^(-)and Cl^(-)indicate that their source may be related to the non-ferrous metal smelting industry in Zhuzhou.Further correlation analysis shows that emissions from the non-ferrous metal smelting industry in the area have a large significant on SO_(4)^(2-)and F^(-)in precipitation,while Cl^(-)may still be emitted from other anthropogenic sources.

关键词： Acid rain pH Chemical composition Neutralization factor Correlation analysis

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Evolution hydrothermal aging resistance mechanism study of zirconium and manganese doped CeO2 catalysts in soot catalytic combustion based on low Miller indices crystal surface effect

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Journal of Rare Earths 2024年第7期42卷 1272-1281页

作者： Zonglin li Pan Wang Hong Ni Chengcheng Ao lidong zhang Hefeng zhang kai li School of Automotive and Traffic Engineering Jiangsu University State Environmental Protection Key Laboratory of Vehicle Emission Control and Simulation Chinese Research Academy of Environmental Science National Synchrotron Radiation Laboratory University of Science and Technology of China

The thermogravimetric analysis（TGA） experiments were carried out to reveal the mechanism of Zr and Mn doping on catalytic activity of CeO2catalyst both fresh and after hydrothermal aging,and the lattice morphology and valence changes were characterized by means of Brunauer-Emmett-Teller（BET）method,X-ray diffraction（XRD）,X-ray photoelectron spectroscopy（XPS）,and H2-temperature programmed reduction（H2-TPR）.Density functional theory（DFT） and molecular thermodynamics calculations were applied to investigate the change in catalytic activity,crystal surface energy and crystal morphology caused by hydrothermal aging.The maximum reaction rate temperature of fresh Mn/CeO2（389℃） is similar to that of CeO2（371℃） and lower than that of Zr/CeO2（447℃）,but the catalytic performance of CeO2decreases more severely after hydrothermal aging.The catalyst crystals show different degrees of crystal surface migration after hydrothermal aging,which leads to the reduction of Ce3+/Ce4+ratio and the active sites shift.DFT calculations indicate that the doping of Zr and Mn reduces the surface energy of the low Miller indices surface and increases the oxygen vacancy formation energy,leading to better thermal stability and lower catalytic activity.The Zr and Mn doping also changes the adsorption energy and Gibbs free energy of H2O,which dominates the migration of（1 1 1） to（1 1 0） and（1 0 0） in the vapor environment.The crystal surface migration mechanism of CeO2catalysts doped with Zr and Mn induced by H2O molecules at high temperature obtained in this study can provide a valuable addition to the regeneration of CeO2catalysts in the after-treatment systems of diesel engines.

关键词： CDPF CeO2-based catalyst DFT calculations Rare earth metal oxides Soot

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Stability analysis of a liquid crystal elastomer self-oscillator under a linear temperature field

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Applied Mathematics and Mechanics(English Edition) 2024年第2期45卷 337-354页

作者： Haiyang WU Jiangfeng LOU Biao zhang Yuntong DAI kai li School of Civil Engineering Anhui Jianzhu UniversityHefei 230601China

Self-oscillating systems abound in the natural world and offer substantial potential for applications in controllers,micro-motors,medical equipments,and so on.Currently,numerical methods have been widely utilized for obtaining the characteristics of self-oscillation including amplitude and frequency.However,numerical methods are burdened by intricate computations and limited precision,hindering comprehensive investigations into self-oscillating systems.In this paper,the stability of a liquid crystal elastomer fiber self-oscillating system under a linear temperature field is studied,and analytical solutions for the amplitude and frequency are determined.Initially,we establish the governing equations of self-oscillation,elucidate two motion regimes,and reveal the underlying mechanism.Subsequently,we conduct a stability analysis and employ a multi-scale method to obtain the analytical solutions for the amplitude and frequency.The results show agreement between the multi-scale and numerical methods.This research contributes to the examination of diverse self-oscillating systems and advances the theoretical analysis of self-oscillating systems rooted in active materials.

关键词： self-oscillation stability analysis multi-scale method liquid crystal elastomer linear temperature field

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Heterobimetallic lanthanide tetrahedral cages:Synthesis,design and application for potential multimodal imaging contrast agent

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Journal of Rare Earths 2024年第2期42卷 278-285,I0002页

作者： Yongxiu li Feng Guo Siwei Wei Duofu li Jun zhang kai Xu Dongping li Department of Chemistry Nanchang UniversityNanchang330031China Key Laboratory of Functional Molecule Design and Interface Process Anhui Jianzhu UniversityHefei230601China Department of Otolaryngology Head and Neck SurgeryThe Second Affiliated Hospital of Nanchang UniversityNanchang330006China

The construction and functionalization of lanthanide-organic cages have been a research hotspot in coordination chemistry.Benefiting from the unique luminescent and magnetic properties of lanthanide ions,the potential applications of lanthanide-organic cages in biological imaging applications are promising,but only a few corresponding explorations have been reported.He rein,we introduced a series of lanthanide tetrahedral cages,(Eu_(n)Gd_(4-n)L_(4))(sol)_8(n=0,1,2,3 and 4,where L=(4,4',4"-tris(4,4,4-trifluoro-1,3-dioxobutyl)-triphenylamine,and sol=dimethyl sulfoxide and methanol),with potential applications in biological imaging.Given the good luminescent and magnetic properties of Eu^(3+) and Gd^(3+) ions,Eu_(4)L_(4) and Gd_(4)L_(4) complexes show a high luminescence quantum yield of 29% in DMSO and large longitudinal relaxivity(r_(1)) of 11.4(mmol/L)^(-1)/s at 0.5 T in water containing 1 vol% DMSO,respectively.The heterobimetallic Eu-Gd complexes achieve a dual imaging mode by combining luminescent and magnetic centers in one cage.When the Gd:Eu ratio increases from 1:3 to 3:1,the r_(1) values increases from 5.33 to 8.64(mmoI/L)^(-1)/s,higher than that of commercial contrast agent Gd-DOTA(3.23(mmol/L)^(-1)/s).Owing to their low toxicity and good cell imaging ability toward ECA 109 cells,the selfassembled Eu-Gd heterobimetallic tetrahedral cages could be potential candidates for the multimodal imaging contrast agent.

关键词： Lanthanide organic cage Luminescence Cell imaging Contrast agents Rare earths

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Microbiota treatment of functional constipation:Current status and future prospects

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World Journal of Hepatology 2024年第5期16卷 776-783页

作者： Yan li Xiao-Han zhang Zi-kai Wang Department of Gastroenterology and Hepatology The First Medical CenterChinese PLA General HospitalBeijing 100853China Medical School Nankai UniversityTianjin 300071China National Clinical Research Center for Geriatric Diseases Chinese PLA General HospitalBeijing 100853China

Functional constipation(FC)is a common disorder that is characterized by diffi-cult stool passage,infrequent bowel movement,or both.FC is highly prevalent,recurs often,accompanies severe diseases,and affects quality of life;therefore,safe and effective therapy with long-term benefits is urgently needed.Microbiota treatment has potential value for FC treatment.Microbiota treatments include modulators such as probiotics,prebiotics,synbiotics,postbiotics,and fecal micro-biota transplantation(FMT).Some probiotics and prebiotics have been adopted,and the efficacy of other microbiota modulators is being explored.FMT is con-sidered an emerging field because of its curative effects;nevertheless,substantial work must be performed before clinical implementation.

关键词： Functional constipation Gut microbiota Microbiota modulators Fecal microbiota transplantation Dysbiosis

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Double plasma molecular adsorption system for Stevens–Johnson syndrome/toxic epidermal necrolysis:A case report

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World Journal of Clinical Cases 2024年第7期12卷 1371-1377页

作者： You-Wen Tan li-Ping liu kai zhang Department of Hepatology The Third Hospital of Zhenjiang Affiliated Jiangsu UniversityZhenjiang 212003Jiangsu ProvinceChina

BACKGROUND Stevens–Johnson syndrome and toxic epidermal necrolysis(SJS/TEN)are very serious skin allergies,with an etiology related to infections and medication.Since the coronavirus disease 2019(COVID-19)pandemic,severe acute respiratory syndrome coronavirus-2 has also been considered to cause SJS/TEN.CASE SUMMARY We report the case of a woman in her thirties who took acetaminophen after contracting COVID-19.After 3 d of fever relief,she experienced high fever and presented with SJS/TEN symptoms,accompanied by intrahepatic cholestasis.Three days of corticosteroid treatment did not alleviate the skin damage;therefore,double plasma molecular adsorption system(DPMAS)therapy was initiated,with treatment intervals of 48 h.Her skin symptoms improved gradually and were resolved after seven DPMAS treatments.CONCLUSION DPMAS therapy is beneficial for abrogating SJS/TEN because plasma adsorption and perfusion techniques reduce the inflammatory mediators(e.g.,tumor necrosis factor-alpha and interleukin-10 and-12)speculated to be involved in the pathology of the skin conditions.

关键词： Stevens-Johnson Toxic epidermal necrolysis COVID-19 Double plasma molecular adsorption system SARS-CoV-2 Case report

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Efficient nitrite-to-ammonia electroreduction over Zr-Ni frustrated Lewis acid-base pairs

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Science China Chemistry 2024年第5期67卷 1707-1714页

作者： Ying zhang Zhuohang li Wenyu Du kai Chen Ke Chu School of Materials Science and Engineering Lanzhou Jiaotong UniversityLanzhou 730070China

Electrochemical NO_(2)~--to-NH_(3) conversion(NO_(2)RR) offers a green route to NH_(3) electrosynthesis, while developing efficient NO_(2)RR catalysis systems at high current densities remains a grand challenge. Herein, we report an efficient Zr-NiO catalyst with atomically dispersed Zr-dopants incorporated in NiO lattice, delivering the exceptional NO_(2)RR performance with industriallevel current density(>0.2 A cm^(-2)). In situ spectroscopic measurements and theoretical simulations reveal the construction of ZrNi frustrated Lewis acid-base pairs(FLPs) on Zr-Ni O, which can substantially increase the number of absorbed nitrite(NO_(2)~-),promote the activation and protonation of NO_(2)~- and concurrently hamper the H coverage, boosting the activity and selectivity of Zr-NiO towards the NO_(2)RR. Remarkably, Zr-NiO exhibits the exceptional performance in a flow cell with high Faradaic efficiency for NH_(3) of 94.0% and NH_(3)yield rate of 1,394.1 μmol h^(-1)cm^(-2) at an industrial-level current density of 228.2 m A cm^(-2),placing it among the best NO_(2)RR electrocatalysts for NH_(3) production.

关键词： electrochemical nitrite-to-ammonia conversion frustrated Lewis acid-base pairs(FLPs) in situ spectroscopy theoretical computations

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Wideband spectrum sensing using step-sampling based on the multipath nyquist folding receiver

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Defence Technology（防务技术） 2024年第1期31卷 523-536页

作者： kai-lun Tian kai-li Jiang Sen Cao Jian Gao Ying Xiong Bin Tang Xu-ying zhang Yan-fei li University of Electronic Science and Technology of China Chengdu611731China China Electronics Technology Group Corporation 29th Research Institute Chengdu610036China

Wideband spectrum sensing with a high-speed analog-digital converter(ADC) presents a challenge for practical systems.The Nyquist folding receiver(NYFR) is a promising scheme for achieving cost-effective real-time spectrum sensing,which is subject to the complexity of processing the modulated outputs.In this case,a multipath NYFR architecture with a step-sampling rate for the different paths is proposed.The different numbers of digital channels for each path are designed based on the Chinese remainder theorem(CRT).Then,the detectable frequency range is divided into multiple frequency grids,and the Nyquist zone(NZ) of the input can be obtained by sensing these grids.Thus,high-precision parameter estimation is performed by utilizing the NYFR characteristics.Compared with the existing methods,the scheme proposed in this paper overcomes the challenge of NZ estimation,information damage,many computations,low accuracy,and high false alarm probability.Comparative simulation experiments verify the effectiveness of the proposed architecture in this paper.

关键词： Wideband spectrum sensing Sub-Nyquist sampling Step-sampling Nyquist folding receiver(NYFR) Multisignal processing

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Exploring Trade-offs in Thermal Interface Materials:The Impact of Polymer-Filler Interfaces on Thermal Conductivity and Thixotropy

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Chinese Journal of Polymer Science 2024年第7期42卷 916-925,I0006页

作者： Bin zhang Zheng-li Dou Yong-Zheng zhang Qiang Fu kai Wu College of Polymer Science and Engineering State Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu610065China

Effective thermal transport across solid-solid interfaces which is essential in thermal interface materials(TIMs),necessitates both optimal thixotropy and high thermal conductivity.The role of filler surface modification,a fundamental aspect of TIM fabrication,in the influence of these properties is not fully understood.This study employs the use of a silane coupling agent(SCA)to modify alumina,integrating experimental approaches with molecular dynamics simulations,to elucidate the interface effects on thixotropy and thermal conductivity in polydimethylsiloxane(PDMS)-based TIMs.Our findings reveal that the variations of SCAs modify both interface binding energy and transition layer thickness.The interface binding energy restricts macromolecular segmental relaxation near the interface,hindering desirable thixotropy and bond line thickness.On the contrary,the thickness of the transition layer at the interface positively influences thermal conductivity,facilitating the transport of phonons between the polymer and filler.Consequently,selecting an optimal SCA allows a balance between traditionally conflicting goals of high thermal conductivity and minimal bond line thickness,achieving an impressively low interface thermal resistance of just 2.45-4.29 K·mm^(2)·W^(-1)at275.8 kPa.

关键词： Thermal interface material Surface modification Thermal conductivity Thixotropy Interface thermal resistance

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