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Role of methoxy.and C_(α)-based substituents in electrochemical oxidation mechanisms and bond cleavage selectivity.of β-O-4 lignin model compounds

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Green Energy.& Environment 2024年第1期9卷 114-125页

作者： y.ng Zhou Qiang zeng Hongy.n He Kejia Wu Fuqiao Liu Xuehui Li School of Chemistry.and Chemical Engineering The Guangdong Provincial Key Laboratory of Green Chemical Product TechnologyState Key Laboratory of Pulp and Paper EngineeringSouth China University of TechnologyGuangzhouGuangdong510640China CAS Key.Laboratory.of Green Process and Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing100190China

In order to better understand the specific substituent effects on the electrochemical oxidation process of β-O-4 bond, a series of methoxy.heny. ty.e β-O-4 dimer model compounds with different localized methoxy. groups, including 2-(2-methoxy.henoxy.-1-pheny.ethanone, 2-(2-methoxy.henoxy.-1-pheny.ethanol, 2-(2-methoxy.henoxy.-1-(4-methoxy.heny.)ethanone, 2-(2-methoxy.henoxy.-1-(4-methoxy.heny.)ethanol, 2-(2,6-dimethoxy.henoxy.-1-(4-methoxy.heny.)ethanone, 2-(2,6-dimethoxy.henoxy.-1-(4-methoxy.heny.)ethanol have been selected and their electrochemical properties have been studied experimentally.by.cy.lic voltammetry. and FT-IR spectroelectrochemistry. Combining with electroly.is products distribution analy.is and density.functional theory.calculations, oxidation mechanisms of all six model dimers have been explored. In particular, a total effect from substituents of both para-methoxy.on the ary. ring closing to Cα) and Cα-OH on the oxidation mechanisms has been clearly.observed, showing a significant selectivity.on the Cα-Cβbond cleavage induced by.electrochemical oxidations.

关键词： Lignin model compounds β-O-4 dimers Electrochemical oxidation Oxidation mechanisms Substituent effect

Advances in functional coatings on biliary.stents

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Regenerative Biomaterials 2024年第2期3卷 55-75页

作者： Kaining y.ng Wenxin Sun Lany.e Cui y.hong Zou Cuie Wen Rongchang zeng Department of Bioengineering College of Chemical and Biological EngineeringShandong University of Science and TechnologyQingdao 266590China Corrosion Laboratory.for Light Metals College of Materials Science and EngineeringShandong University of Science and TechnologyQingdao 266590China school of Engineering RMIT UniversityMelbourneVIC3001Australia

Biliary.stenting is an important interventional method for the prevention and treatment of biliary.tract ***,complications,such as postoperative biliary.infection and re-stenosis,frequently.occur due to the extensive scope of the biliary.sy.tem and the complex composition of *** com-bination of coating technology.and biliary.stents is expected to bring new approaches to the solution of these *** cutting-edge advance on functional coatings on biliary.stents is reviewed from seven perspectives:anticorrosion,-bacterial,-tumor,stone-dissolving,X-ray.visibility.anti-stent migration and functional composite *** de-velopment trend is also *** performance of the numerous functional coatings for various purposes is generally.up to expectations,but the balance between the medica tions'effectiveness and their safety.needs to be further *** contemporary.investigations have advanced to the leve of animal experiments,offering crucial fundamental assurance for broader human *** combination of biliary.stent and functional coatings is an innovative idea with great potential for future development.

关键词： biliary.stent coating anticorrosion antibacterial antitumor stone-dissolving X-ray.visibility antistent migration

Simplified quantitative analy.is method and its application in the insitu sy.thesized copper-based azide chips

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Defence Technology.防务技术） 2024年第2期32卷 309-316页

作者： Jie Ren y.nfeng Li Mingy. Li Xingy. Wu Jiabao Wang Qingxuan zeng State Key.Laboratory.of Explosion and Technology Beijing Institute of TechnologyBeijing 100081China

Copper-based azide(Cu(N_(3))2 or CuN_(3),CA)chips sy.thesized by.in-situ azide reaction and utilized in miniaturized explosive sy.tems has become a hot research topic in recent ***,the advantages of in-situ sy.thesis method,including small size and low dosage,bring about difficulties in quantitative analy.is and differences in ignition capabilities of CA *** aim of present work is to develop a simplified quantitative analy.is method for accurate and safe analy.is of components in CA chips to evaluate and investigate the corresponding ignition *** this work,Cu(N_(3))2 and CuN_(3)components in CA chips were separated through dissolution and distillation by.utilizing the difference in solubility.and corresponding content was obtained by.measuring N_(3)-concentration through *** spectrophotometry.method was optimized by.study.ng influencing factors and the recovery.rate of different separation methods was studied,ensuring the accuracy.and reproducibility.of test *** optimized method is linear in range from 1.0-25.0 mg/L,with a correlation coefficient R^(2)=0.9998,which meets the requirements of CA chips with a milligram-level content *** with the existing ICP method,component analy.is results of CA chips obtained by.spectrophotometry.are closer to real component content in samples and have satisfactory.***,as its application in miniaturized explosive sy.tems,the ignition ability.of CA chips with different component contents for direct ink writing CL-20 and the corresponding mechanism was *** study.provided a basis and idea for the design and performance evaluation of CA chips in miniaturized explosive sy.tems.

关键词： Copper-based azide chips Spectrophotometry Separation method Quantitative analy.is Ignition ability

Understory.seedlings of Quercus mongolica survive by.phenological escape

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Forest Ecosy.tems 2024年第2期11卷 236-246页

作者： Shixiong Wu y.ng Liu Lulu He Wei zeng Qijing Liu College of Forestry Beijing Forestry UniversityBeijing100083China

Understanding understory.seedling regeneration mechanisms is important for the sustainable development of temperate primary.forests in the context of increasingly.intense climate warming *** poor regeneration of dominant tree species,however,is one of the biggest challenges it faces at the ***,the regeneration of the shade-intolerant Quercus mongolica seedling is difficult in primary.forests,which contrasts with the extreme abundance of understory.seedlings in secondary.*** mechanism behind the interesting phenomenon is still *** study.used in-situ monitoring and nursery.controlled experiment to investigate the survival rate,growth performance,as well as nonstructural carbohy.rate (NSC) concentrations and pools of various organ tissues of seedlings for two consecutive y.ars,further analy.e the understory.light availability.and simulate the foliage carbon (C) gain in the secondary.and primary.*** suggested that seedlings in the secondary.forest had greater biomass allocation aboveground,height and specific leaf area (SLA) in summer,which allowed the seedling to survive longer in the canopy.closure *** light availability.and positive C gain in early.spring and late autumn are key.factors affecting the growth and survival of understory.seedlings in the secondary.forest,whereas seedlings in the primary.forest had annual negative carbon *** the growing season,the total NSC concentrations of seedlings gradually.decreased,whereas those of seedlings in the secondary.forest increased significantly.in autumn,and were mainly.stored in roots for winter consumption and the following y.ar's summer shade period,which was verified by.the nursery.controlled experiment that simulated autumn enhanced light availability.improved seedling survival rate and NSC *** conclusion,our results revealed the survival trade-off strategies of Quercus mongolica seedlings and highlighted the necessity.of high light availability.d

关键词： Carbon gain Nonstructural carbohy.rate Recruitment Trade-off Biomass allocation

Effects of nutrient limitations on the sinking velocity.of Thalassiosira weissflogii

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Acta Oceanologica Sinica 2024年第6期43卷 163-172页

作者： Jie Zhu Qiang Hao Wei Zhang y.ngy.ng Ma Jiangning zeng Ocean College Zhejiang UniversityZhoushan 316000China Second Institute of Oceanography Ministry of Natural ResourcesHangzhou 310012China Key.Laboratory.of Marine Ecosy.tem Dy.amics Ministry of Natural ResourcesHangzhou 310012China Zhejiang Key.Laboratory.of Nearshore Engineering Environment and Ecological Security Hangzhou 310012China Tianjin Key.Lab of Aqua-Ecology.and Aquaculture College of FisheriesTianjin Agricultural UniversityTianjin 300384China

The sinking of diatoms is critic al to the formation of oceanic biological pumps and coastal hy.oxic ***,little is known about the effects of different nutrient restrictions on diatom *** this study.we measured the sinking velocity.SV) of Thalassiosira weissflogii using a new phy.oplankton video observation instrument and analy.ed major biochemical components under vary.ng nutrient *** results showed that the SV of *** under different nutrient limitation conditions varied *** highest SV of(1.77±0.02) m/d was obtained under nitrate limitation,signific antly.surpassing that under phosphate limitation at(0.98±0.13) m/*** the nutrient limitation was released,the SV steadily.decreased to(0.32±0.03) m/d and(0.15±0.05) m/d,***;under conditions with limited nitrate and phosphate concentrations,the SV values of *** significantly.positively.correlated with the lipid content(P y.oplankton SV was primarily.related to the intracellular compo sition,which is controlled by.nutrient conditions but did not significantly.correlate with transparent extracellular poly.er and biosilica *** results of this study.help to understand the regulation of the vertical sinking process of diatoms by.nutrient restriction and provide new insights into phy.oplankton dy.amics and their relationship with the marine nutrient structure.

关键词： nutrient limitation Thalassiosira weissflogii sinking velocity biochemical component lipid content

Effect of the sloping seabed on 3D soil-spudcan interaction using a material point-finite element(MPM-FEM)model

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1436-1454页

作者： Zhengda Lei Guangtian zeng Huaihui Ren Bisheng Wu y.xin Jie State Key.Laboratory.of Hy.roscience and Engineering Department of Hydraulic EngineeringTsinghua UniversityBeijingChina Key.Laboratory.of the Hy.rosphere Sciences of the Ministry.of Water Resources BeijingChina Institute of Ocean Engineering Tsinghua UniversityBeijingChina Longy.an (Beijing) Wind Power Engineering Technology.Co. Ltd.BeijingChina

The sloping seabed affects the bearing capacity.and failure mechanism of soil,which may.compromise the stability.and safety.of offshore structures such as jack-up *** paper employ. a coupled model combining the material point method and finite element method(MPM-FEM)to analy.e the impact of sloping seabeds on the three-dimensional soil-spudcan *** MPM-FEM model implements the B¯approach to solve the challenge of volumetric locking due to the incompressibility.constraints imposed by.y.eld *** is validated against the centrifuge *** effects of sloping seabeds on penetration resistance,soil flow pattern,lateral response,stress distribution,and failure mechanism are *** soil mainly.undergoes overall failure when the ratio of penetration depth to spudcan diameter(i.e.D P/D)is between 0 and *** the slope angle increases,the soil on the side of lower slope is expelled further,resulting in an asy.metric stress distribution and a larger horizontal sliding force of *** D P/D increases to 0.75,the soil transitions to localized plastic flow failure,and the range of soil flow affected by.the spudcan penetration *** results show that,when the slope angle increases,the lateral displacement and stress distribution on the lower slope of a sloping seabed is significantly.larger than that of a horizontal seabed,impacting the spudcan and surrounding soil *** study.suggests that the seabed slope significantly.affects the range of soil flow and failure at shallow penetration,indicating that the slope angle should be taken into account in the design and installation of offshore jack-up rigs,particularly.in areas with sloping seabeds.

关键词： Soil-spudcan interaction Centrifuge tests MPM-FEM model B—approach Sloping seabeds Offshore structures

Nano-Bacillus Calmette-Guérin immunotherapies for improved bladder cancer treatment

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Journal of Zhejiang University.Science B(Biomedicine & Biotechnology. 2024年第7期25卷 557-567页

作者： Sheng zeng Shaoqiang XING y.fei ZHANG Haifeng WANG Qian LIU Department of Urology Tianjin First Central HospitalTianjin 300192China Department of Urology First Central Clinical CollegeTianjin Medical UniversityTianjin 300192China

Cancer immunotherapy.has rapidly.become the fourth mainstream treatment alternative after surgery.radiotherapy.and chemotherapy.with some promising *** aims to kill tumor cells by.mobilizing or stimulating cy.otoxic immune ***,the clinical applications of tumor immunotherapies are limited owing to a lack of adequate delivery.pathway. and high ***,nanomaterials and genetic engineering have shown great potential in overcoming these limitations by.protecting the delivery.of antigens,activating targeted T cells,modulating the immunosuppressive tumor microenvironment,and improving the treatment *** Calmette-Gué;rin(BCG)is a live attenuated My.obacterium bovis vaccine used to prevent tuberculosis,which was first reported to have antitumor activity.in *** therapy.can activate the immune sy.tem by.inducing various cy.okines and chemokines,and its specific immune and inflammatory.responses exert antitumor *** was first used during the 1970s as an intravesical treatment agent for bladder cancer,which effectively.improved immune antitumor activity.and prevented tumor *** recently.nano-BCG and genetically.engineered BCG have been proposed as treatment alternatives for bladder cancer due to their ability.to induce stronger and more stable immune *** this study.we outline the development of nano-BCG and genetically.engineered BCG for bladder cancer immunotherapy.and review their potential and associated challenges.

关键词： Bladder cancer Bacillus Calmette-Gué rin vaccine Nanocarrier Genetic engineering Immunotherapy

Tribological properties of low-temperature time-dependent pretreated graphite for mechanical seal pairs in high-speed turbopump

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Friction 2024年第2期12卷 305-318页

作者： y.ngy.ng ZHAO Guoy.an ZHANG Junqian WANG He WANG Weigang ZHAO Qunfeng zeng School of Mechano-Electronic Engineering Xidian UniversityXi’an 710071China Xi’an Aerospace Propulsion Institute Xi’an 710071China Key.Laboratory.of Education Ministry.for Modern Design and Rotor-Bearing Sy.tem Xi’an Jiaotong UniversityXi’an 710049China

The friction coefficient and wear rate of pretreated graphite with liquid nitrogen were obtained by.using a ball-on-disk tester,and the wear of GCr15–graphite seal pairs with the low-temperature time-dependent pretreatment was discussed by.comparing the wear *** results show that liquid nitrogen pretreatment can affect the hardness and interlay.r spacing of *** range of the friction coefficients of pretreated graphite changes from 0.17 to *** the increase of liquid nitrogen pretreatment time,the wear mechanism of graphite would change from dominated three-body.wear to adhesion *** experimental results of the mechanical seal with liquid nitrogen pretreatment show that the wear rate of stator is less than 0.00165 mm^(3)·N^(−1)·m^(−1),and the graphite shows a good low-temperature compatibility.

关键词： graphite low-temperature pretreatment mechanical seal friction and wear

Ecological-Based Mining:A Coal-Water-Thermal Collaborative Paradigm in Ecologically.Fragile Areas in Western China

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Engineering 2024年第7期38卷 209-222页

作者： Xiaoxiu Liu y.fan zeng Qiang Wu Shihao Meng Jiy.e Liang Zhuping Hou National Engineering Research Center of Coal Mine Water Hazard Controlling China University of Mining and TechnologyBeijing 100083China College of Geoscience and Survey.ng Engineering China University of Mining and TechnologyBeijing 100083China University.of Mining and Technology.Beijing)Inner Mongolia Research Institute Ordos 017000China

A substantial reduction in groundwater level,exacerbated by.coal mining activities,is intensify.ng water scarcity.in western China’s ecologically.fragile coal mining ***’s national strategic goal of achieving a carbon peak and carbon neutrality.has made eco-friendly.mining that prioritizes the protection and efficient use of water resources *** on the resource characteristics of mine water and heat hazards,an intensive coal-water-thermal collaborative co-mining paradigm for the duration of the mining process is *** integrated sy.tem for the production,supply.and storage of mining companion resources is achieved through technologies such as roof water inrush prevention and control,hy.rothermal quality.improvement,and deep-injection geological *** active preventive and control sy.tem achieved by.adjusting the mining technology.and a passive sy.tem centered on multiobjective drainage and grouting treatment are suggested,in accordance with the original geological characteristics and dy.amic process of water *** implementing advanced multi-objective drainage,specifically.designed to address the“sky.ight-ty.e”water inrush mode in the y.lin mining area of Shaanxi Province,a substantial reduction of 50%in water drillings and inflow was achieved,leading to stabilized water conditions that effectively.ensure subsequent safe coal *** integrated-energy.complementary.model that incorporates the clean production concept of heat utilization is also *** findings indicate a potential saving of 8419 t of standard coal by.using water and air heat as an alternative heating source for the Xiaojihan coalmine,resulting in an impressive energy.conservation of 50.2%and a notable 24.2%reduction in carbon *** ultra-deep sustained water injection of 100 m^(3)·h^(-1)in a single well would not rupture the formation or cause water leakage,and 7.87×10^(5)t of mine water could be effectively.stored in the Liujiagou Formation,presenti

关键词： Dual carbon targets Coal-water-thermal co-mining Ecologically.fragile areas Mine-water control Resource utilization