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Research on the design method for uniform wear of shield cutters in sand-pebble strata

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Deep Underground Science and Engineering 2024年第2期3卷 216-230页

作者： Jinxun Zhang Bo li Guihe Wang Yusheng jiang hua jiang Minglun Yin Zhengyang Sun Beijing Urban Construction Group Co. Ltd.BeijingChina China University of Geosciences BeijingChina China University of Mining and Technology BeijingChina

During shield tunneling in highly abrasive formations such as sand–pebble strata,nonuniform wear of shield cutters is inevitable due to the different cutting *** downtimes and cutter replacements have become major obstacles to long-distance shield driving in sand–pebble *** on the cutter wear characteristics in sand–pebble strata in Beijing,a design methodology for the cutterhead and cutters was established in this study to achieve uniform wear of all cutters by the principle of frictional *** applicability of the design method was verified through three-dimensional simulations using the engineering discrete element *** results show that uniform wear of all cutters on the cutterhead could be achieved by installing different numbers of cutters on each trajectory radius and designing a curved spoke with a certain arch height according to the shield *** the uniform wear scheme,the cutter wear coefficient is greatly reduced,and the largest shield driving distance is increased by approximately 47%over the engineering *** research results indicate that the problem of nonuniform cutter wear in shield excavation could be overcome,thereby providing guiding significance for theoretical innovation and construction of long-distance shield excavation in highly abrasive strata.

关键词： cutter wear EDEM model long-distance shield driving sand-pebble stratum shield tunnel uniform wear design method

Synergistic catalysis of the N-hydroxyphthalimide on flower-like bimetallic metal-organic frameworks for boosting oxidative desulfurization

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Petroleum Science 2024年第1期21卷 674-682页

作者： Jing He Kun Zhu Wei jiang Dong-Ao Zhu lin-hua Zhu Hai-Yan huang Wen-Shuai Zhu hua-Ming li Institute for Energy Research Jiangsu UniversityZhenjiang212013JiangsuChina College of Chemistry and Chemical Engineering Hainan Normal UniversityKey Laboratory of Water Pollution Treatment and Resource Reuse of Hainan ProvinceHaikou571158HainanChina

Synergic catalytic effect between active sites and supports greatly determines the catalytic activity for the aerobic oxidative desulfurization of fuel *** this work,Ni-doped Co-based bimetallic metal-organic framework(CoNi-MOF)is fabricated to disperse N-hydroxyphthalimide(NHPI),in which the whole catalyst provides plentiful synergic catalytic effect to improve the performance of oxidative desulfurization(ODS).As a bimetallic MOF,the second metal Ni doping results in the flower-like morphology and the modification of electronic properties,which ensure the exposure of NHPI and strengthen the synergistic effect of the overall *** with the monometallic Co-MOF and naked NHPI,the NHPI@CoNi-MOF triggers the efficient activation of molecular oxygen and improves the ODS performance without an *** sulfur removal of dibenzothiophene-based model oil reaches 96.4%over the NHPI@CoNi-MOF catalyst in 8 h of ***,the catalytic product of this aerobic ODS reaction is sulfone,which is adsorbed on the catalyst surface due to the difference in *** work provides new insight and strategy for the design of a strong synergic catalytic effect between NHPI and bimetallic supports toward high-activity aerobic ODS materials.

关键词： Metal-organic frameworks Doped Bimetallic N-hydroxyphthalimide Aerobic processes Oxidative desulfurization

Efficiency and safety evaluation of Baimai ointment for alleviating hypermyotonia following cerebral infarction

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Neural Regeneration Research 2007年第10期2卷 607-610页

作者： Sheng da liu Chu ming jiang Dong hua li Cui peng Xie Jian xin Yan Department of Neurology Beijing Aerospace General HospitalBeijing 100076China

Baimai ointment has Shujin and Huoluo efficiency. It has been confirmed by basic pharmacodynamic experiments that Baimai ointment has some therapeutic effects on stroke. However, the detailed evaluations of Baimai ointment on clinically treating stroke patients for function recovery are still insufficient with little reports. OBJECTIVE： To observe the efficiency and safety of Baimai ointment on alleviating hypermyotonia following cerebral infarction DESIGN： A randomized, parallel and controlled experiment. SETTING： Department of Neurology, Beijing Aerospace General Hospital. PARTICIPANTS： A total of 120 patients with acute front-cycle cerebral infarction were selected from Department of Neurology, Beijing Aerospace General Hospital from July to December 2006 and met the diagnosis criteria modified by Forth National Seminar on Cerebrovascular Disease. The experiment had got confirmed consent from local ethic committee. All 120 patients with cerebral infarction were randomly divided into experimental group （n =80; 32 in the acute phase, 32 in the recovery phase and 16 in the sequela phase） and control group （n =40; 16 in the acute phase, 16 in the recovery phase and 8 in the sequela phase）. METHODS： Within 4 weeks after the patients were enrolled in this study, no other traditional Chinese medicines containing similar components were adopted besides routine supporting therapy. The Baimai ointment being consisted of jianghuang, Roudoukou, Gansong, Yangqishi, Gancao, She, shannai, Zanghuixiang, Zangchangpu, huajiao and dianhua was used by trial group （20 g/ampoule, Tibet lingzhiqizheng Tibetan Drug Factory; batch number： 050403）, 2-3 times per day, the ointment was moderately coated traveling parts of Baimai. MAIN OUTCOME MEASURES： The evaluation of National Institutes of Health Stroke Scale （NIHSS）, Modified Rankin Scale and Modified Ashworth Scale were performed before administration, 2 and 4 weeks after administration. RESULTS： All 120 patients with acute front-cycle

关键词： ointments acupuncture points brain infarction muscle tonus

Optimizing the sulfur-resistance and activity of perovskite oxygen carrier for chemical looping dry reforming of methane

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Journal of Energy Chemistry 2024年第9期96卷 259-271页

作者： Yuelun li Dong Tian Lei jiang Huicong Zuo liNan huang Mingyi Chen Jianchun Zuo hua Wang Kongzhai li Engineering Research Center of Metallurgical Energy Conservation and Emission Reduction Ministry of EducationKunming University of Science and TechnologyKunming 650093YunnanChina Faculty of Metallurgical and Energy Engineering Kunming University of Science and TechnologyKunming 650093YunnanChina State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization Kunming University of Science and TechnologyKunming 650093YunnanChina

Perovskite oxides has been attracted much attention as high-performance oxygen carriers for chemical looping reforming of methane,but they are easily inactivated by the presence of trace H_(2)***,we propose to modulate both the activity and resistance to sulfur poisoning by dual substitution of Mo and Ni ions with the Fe-sites of LaFeO_(3)*** is found that partial substitution of Ni for Fe substantially improves the activity of LaFeO_(3)perovskite,while Ni particles prefer to grow and react with H_(2)S during the long-term successive redox process,resulting in the deactivation of oxygen *** the presence of Mo in LaNi_(0.05)Fe_(0.95)O_(3−σ)perovskite,H_(2)S preferentially reacts with Mo to generate MoS_(2),and then the CO_(2)oxidation can regenerate Mo via removing *** addition,Mo can inhibit the accumulation and growth of Ni,which helps to improve the redox stability of oxygen *** LaNi_(0.05)Mo_(0.07)Fe_(0.88)O_(3−σ)oxygen carrier exhibits stable and excellent performance,with the CH_(4)conversion higher than 90%during the 50 redox cycles in the presence of 50 ppm H_(2)S at 800℃.This work highlights a synergistic effect in the perovskite oxides induced by dual substitution of different cations for the development of high-performance oxygen carriers with excellent sulfur tolerance.

关键词： Perovskite oxygen carriers Chemical looping reforming Sulfur-resistance Dual substitution Syngas

Spherical Polyelectrolyte Brush Nanoreactor:Preparation of Hollow TiO_(2) Nanospheres and Characterization by Small Angle X-Ray Scattering

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Chinese Journal of Polymer Science 2024年第9期42卷 1393-1400,I0009页

作者： Yu-hua Zhang Zi-Yu Zhang Xin liu En-Guang Ma jiang-Tao Guo li li Xu-Hong Guo State Key Laboratory of Chemical Engineering East China University of Science and TechnologyShanghai200237China Shandong Provincial Key Laboratory of Monocrystalline Silicon Semiconductor Materials and Technology College of Chemistry and Chemical EngineeringDezhou UniversityDezhou253023China Institute of Bast Fiber Crops&Center of Southern Economic Crops Chinese Academy of Agricultural SciencesChangsha410205China

Titanium dioxide(TiO_(2))hollow nanoparticles present significant potential for photocatalytic applications while their straightforward preparation with precise structure control is still *** work reports the approach to preparing tunable hollow TiO_(2) nanospheres by utilization of spherical polyelectrolyte brushes(SPB)as nanoreactors and *** the preparation,the evolution of the structure was characterized by small angle X-ray scattering(SAXS),and in combination with dynamic light scattering and transmission electron *** formation of TiO_(2) shell within the brush(SPB@TiO_(2))is confirmed by the significant increase of the electron density,and its internal structure has been analyzed by fitting SAXS data,which can be influenced by Titanium precursors and ammonia *** calcining SPB@TiO_(2) in a muffle furnace,hollow TiO_(2) nanospheres are produced,and their transition to the anatase crystal form is triggered,as confirmed by X-ray diffraction *** the advantages of their hollow structure,these TiO_(2) nanospheres exhibit exceptional catalytic degradation efficiency of methylene blue(MB),tetracycline(TC),and 2,4-dichlorophenoxyacetic acid(2,4-D),and also demonstrate excellent recyclability.

关键词： Spherical polyelectrolyte brush Nanoreactor Hollow titanium dioxide X-ray scattering

A Dynamic Covalent Bonding-based Nanoplatform for Intracellular Co-Delivery of Protein Drugs and Chemotherapeutics with Enhanced Anti-Cancer Effect

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Chinese Journal of Polymer Science 2024年第5期42卷 559-569,I0005页

作者： Sai-Nan liu Jia-Hui Meng li-Yun Cui hua Chen lin-Qi Shi Ru-jiang Ma Key Laboratory of Functional Polymer Materials of Ministry of Education Institute of Polymer ChemistryTianjin Key Laboratory of Functional Polymer MaterialsState Key Laboratory of Medicinal Chemical BiologyFrontiers Science Center for New Organic MatterCollege of ChemistryNankai UniversityTianjin300071China Haihe Laboratory of Sustainable Chemical Transformations Tianjin300192China

Efficient intracellular delivery of protein drugs is critical for protein *** combination of protein drugs with chemotherapeutics represents a promising strategy in enhancing anti-cancer ***,co-delivery systems for efficient delivery of these two kinds of drugs are still lacking because of their different ***,we show a well-designed delivery system based on dynamic covalent bond for efficient intracellular co-delivery of ribonuclease A(RNase A)and doxorubicin(DOX).Two polymers,PEG-b-P(Asp-co-AspDA)and PAE-b-P(Asp-co-AspPBA),and two 2-acetylphenylboronic acid(2-APBA)-functionalized drugs,2-APBA-RNase A and 2-APBA-DOX,self-assemble into mixed-shell nanoparticles(RNase A/DOX@MNPs)via dynamic phenylboronic acid(PBA)-catechol bond between PBA and dopamine(DA)*** PBA-catechol bond endows the nanoparticles with high stability and excellent stimulus-responsive drug release *** the slight acidic environment at tumor tissue,RNase A/DOX@MNPs are positively charged,promoting their *** cellular uptake into endosome,further protonation of PAE chains leads to the rupture of endosomes because of the proton sponge effect and the cleavage of PBA-catechol bond promotes the release of two *** cytoplasm,the high level of GSH removed the modification of 2-APBA on *** restored RNase A and DOX show a synergistic and enhanced antic-cancer *** system may be a promising platform for intracellular co-delivery of protein drugs and chemotherapeutics.

关键词： Drug co-delivery Combination therapy Dynamic covalent bond

Preparation of vanadium-based electrode materials and their research progress in solid-state flexible supercapacitors

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Rare Metals 2024年第2期43卷 431-454页

作者： Rui-Jie Zhu jiang liu Chao hua Hao-Yu Pan Yi-Jun Cao Meng li Zhongyuan Critical Metals Laboratory Zhengzhou UniversityZhengzhou450001China School of Chemical Engineering Zhengzhou UniversityZhengzhou450001China

Solid-state flexible supercapacitors(SCs)have many advantages of high specific capacitance,excellent flexibility,fast charging and discharging,high power density,environmental friendliness,high safety,light weight,ductility,and long cycle *** are the ideal choice for the development of flexible energy storage technology in the future,and provide a good prospect for energy storage *** present,solid-state flexible SCs are widely used for portable electronic equipment and wearable energy storage equipment,the research of them has become the focus of a growing number of *** material is the key part of SCs and always determines the electrochemical performance of *** has been a hotspot and focus of ***-based compounds are considered to be a promising electrode material for SCs because of variable valence,open structure,high theoretical capacity,and low ***,this study first gives an overview of solid-state flexible SCs,then reviews the current research status of vanadium-based electrode materials in solid-state flexible SCs,and proposes some strategies to solve some problems of vanadium-based electrode materials.

关键词： Vanadium-based materials Flexible energy storage Specific capacitance Supercapacitors(SCs)

Clinically significant changes in anal sphincter hiatal area in patients with gestational diabetes mellitus and pelvic organ prolapse

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World Journal of Diabetes 2024年第8期15卷 1726-1733页

作者： Qing-Hong Wang li-hua liu hua Ying Ming-Xu Chen Chang-jiang Zhou Hui li Department of Sonography People's Hospital Affiliated to Shandong First Medical UniversityJinan 271100Shandong ProvinceChina Department of Obstetrics and Gynecology People's Hospital Affiliated to Shandong First Medical UniversityJinan 271100Shandong ProvinceChina

BACKGROUND The prevalence of pelvic organ prolapse(POP)increases with age and ***,the prevalence of POP among women aged 20 to 39 is 9.7%,while it rises to 49%among women over 80 years ***,as the number of deliveries increases,the prevalence of POP also rises accordingly,with a rate of 12.8%for women with one delivery history,18.7%for those with two deliveries,and 24.6%for women with three or more *** causes immense suffering for pregnant *** To evaluate the relationship between the levator ani muscle’s hiatus(LH)area and POP in patients with gestational diabetes mellitus(GDM)using perineal *** The study cohort comprised 104 patients aged 29.8±3.7 years who sought medical care at our institution between January 2021 and June *** were singleton pregnancies consisting of 75 primiparas and 29 multiparas,with an average parity of 1.7±*** to the POP diagnostic criteria,the 104 subjects were divided into two groups with 52 members each:POP group(patients with GDM combined with POP)and non-POP group(patients with GDM without POP).Perineal ultrasound was used to measure differences in the anteroposterior diameter,transverse diameter,and LH *** operating characteristic curves were drawn to determine the optimal cutoff values for the LH anteroposterior diameter,transverse diameter,and area for diagnosing *** Statistically significant increase in the LH area,anteroposterior diameter,and lateral diameter were observed in the POP group compared with the non-POP group(P<0.05).Both groups exhibited markedly elevated incidence rates of macrosomia and stress urinary *** the POP group,the area under the curve(AUC)for the LH area was 0.906 with a 95%confidence interval(CI):*** optimal cutoff was 13.54cm²,demonstrating a sensitivity of 83.2%and a specificity of 64.4%.The AUC for the anteroposterior diameter reached 0.836 with a 95%CI:*** optimal cutoff was 5

关键词： Ultrasound Levator ani muscle hiatus Gestational diabetes mellitus Pelvic organ prolapse

Heat Transfer and Friction Characteristics of Printed Circuit Heat Exchangers with Different Channel Structures for S-CO_(2) Power System

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Journal of Thermal Science 2024年第3期33卷 1132-1147页

作者： jiang Tao li Mingjia Key Laboratory of Thermo-Fluid Science and Engineering of Ministry of Education School of Energy and Power EngineeringXi’an Jiaotong UniversityXi’an710049China School of Mechanical Engineering Beijing Institute of TechnologyBeijing100081China

Printed circuit heat exchanger(PCHE)has been widely used in supercritical carbon dioxide(S-CO_(2))power systems because of its high heat transfer efficiency and good ***,due to the large variety of PCHE configurations,channel selection in practical applications lacks a ***,this paper discussed the heat transfer and friction characteristics and the synergy of three fields in the channel under the guidance of the field synergy principle for four typical PCHE ***,the comprehensive performance of four channels was ***,the heat transfer and friction factor correlations for S-CO_(2)in four channels were *** findings demonstrate that the synergy of velocity and pressure fields of the straight channel PCHE is better(β≈180°),so its resistance loss is relatively *** zigzag and sinusoidal wavy channels and the airfoil fins can reduce the angle a between the temperature gradient and velocity,thus enhancing the heat *** sinusoidal wavy channel can reduce flow resistance compared to the zigzag channel due to the rounded *** streamlined airfoil structure can guide the flow and reduce backflow,thus reducing resistance *** the range of Re studied in this paper,the maximum error of the proposed heat transfer and friction factor correlations of PCHE is 7.0%,which shows good fitting *** research in this paper can provide a reference for the selection and design of PCHE with different channel configurations.

关键词： printed circuit heat exchanger supercritical carbon dioxide typical channel structure field synergy analysis