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Alternative flexible correction forming of a blade: multipoint correction with surface measurement and deformation simulation

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Advances in Manufacturing 2023年第4期11卷 587-600页

作者： Da-wei zhang Wen-Long Gao-zhang qi zhang Xi’an Key Laboratory of Intelligent Equipment and Control School of Mechanical EngineeringXi’an Jiaotong UniversityXi’an710049People’s Republic of China

Distortion during the forging or machining processes of a blade causes problems in subsequent manufacturing. This paper proposes an alternative multipoint correction method integrated with blade measurement, determination of correcting parameters, and adjustment of the correcting die. An iterative algorithm for determining the correcting parameters is proposed. Measuring equipment combining a laser displacement sensor with multipoint flexible support is manufactured to measure the blade shape. Multipoint correcting equipment with an adaptive lower die and rapid adjustment is manufactured, and software is developed for data analysis and equipment control. The correction experiment for a rough-machined steam-turbine blade indicates that the correcting parameters can be determined after one modification based on numerical simulation, and that a rough blade that meets the allowance for finish machining can be obtained using the determined correction parameters.

关键词： Blade Surface measurement Numerical simulation Multipoint correction

Transcatheter arterial chemoembolization followed by surgical resection for hepatocellular carcinoma: a focus on its controversies and screening of patients most likely to benefit

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Chinese Medical Journal 2021年第19期134卷 2275-2286页

作者： Zhan-qi wei Yue-wei zhang School of Medicine Tsinghua UniversityHaidian DistrictBeijing 100084China Beijing Tsinghua Changgung Hospital School of Clinical MedicineTsinghua UniversityBeijing 102218China

Surgical resection(SR)is recommended as a radical procedure in the treatment of hepatocellular carcinoma(HCC).However,postoperative recurrence negatively affects the long-term efficacy of SR,and preoperative adjuvant therapy has therefore become a research hotspot.Some clinicians adopt transcatheter arterial chemoembolization(TACE)as a preoperative adjuvant therapy in patients undergoing SR to increase the resection rate,reduce tumor recurrence,and improve the prognosis.However,the findings of the most relevant studies remain controversial.Some studies have confirmed that preoperative TACE cannot improve the long-term survival rate of patients with HCC and might even negatively affect the resection rate.Which factors influence the efficacy of preoperative TACE combined with SR is a topic worthy of investigation.In this review,existing clinical studies were analyzed with a particular focus on several topics:screening of the subgroups of patients most likely to benefit from preoperative TACE,exploration of the optimal treatment regimen of preoperative TACE,and determination of the extent of tumor necrosis as the deciding prognostic factor.

关键词： Hepatocellular carcinoma Surgical resection Transcatheter arterial chemoembolization Adjuvant therapy

Stomatal dynamics are regulated by leaf hydraulic traits and guard cell anatomy in nine true mangrove species

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Plant Diversity 2024年第3期46卷 395-405页

作者： Ya-Dong qie Qi-wei Zhang Scott A.M.McAdam Kun-Fang Cao State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources College of ForestryGuangxi UniversityNanning 530004China Guangxi Key Laboratory of Forest Ecology and Conservation College of ForestryGuangxi UniversityNanning 530004China Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection Ministry of EducationGuangxi Normal UniversityGuilin 541001China Guangxi Key Laboratory of Landscape Resources Conservation and Sustainable Utilization in Lijiang River Basin Guangxi Normal UniversityGuilin 541001China Purdue Center for Plant Biology Department of Botany and Plant PathologyPurdue UniversityWest LafayetteIN 47907USA

Stomatal regulation is critical for mangroves to survive in the hyper-saline intertidal zone where water stress is severe and water availability is highly fluctuant.However,very little is known about the stomatal sensitivity to vapour pressure deficit(VPD)in mangroves,and its co-ordination with stomatal morphology and leaf hydraulic traits.We measured the stomatal response to a step increase in VPD in situ,stomatal anatomy,leaf hydraulic vulnerability and pressure-volume traits in nine true mangrove species of five families and collected the data of genome size.We aimed to answer two questions:(1)Does stomatal morphology influence stomatal dynamics in response to a high VPD in mangroves?with a consideration of possible influence of genome size on stomatal morphology;and(2)do leaf hydraulic traits influence stomatal sensitivity to VPD in mangroves?We found that the stomata of mangrove plants were highly sensitive to a step rise in VPD and the stomatal responses were directly affected by stomatal anatomy and hydraulic traits.Smaller,denser stomata was correlated with faster stomatal closure at high VPD across the species of Rhizophoraceae,and stomata size negatively and vein density positively correlated with genome size.Less negative leaf osmotic pressure at the full turgor(πo)was related to higher operating steady-state stomatal conductance(gs);and a higher leaf capacitance(Cleaf)and more embolism resistant leaf xylem were associated with slower stomatal responses to an increase in VPD.In addition,stomatal responsiveness to VPD was indirectly affected by leaf morphological traits,which were affected by site salinity and consequently leaf water status.Our results demonstrate that mangroves display a unique relationship between genome size,stomatal size and vein packing,and that stomatal responsiveness to VPD is regulated by leaf hydraulic traits and stomatal morphology.Our work provides a quantitative framework to better understand of stomatal regulation in mangroves in an environment with high salinity and dynami

关键词： Stomatal temporal kinetics Vapour-pressure deficit(VPD) Leaf water relations Leaf hydraulic vulnerability Leaf osmotic potential Genome size

Radical SAM-Dependent Demetallation of Heme

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Chinese Journal of Chemistry 2022年第9期40卷 1053-1058页

作者： Jinduo Cheng wei Ding qi zhang Department of Chemistry Fudan UniversityShanghai 200433China State Key Laboratory of Microbial Metabolism School of Life Sciences&BiotechnologyShanghai Jiao Tong UniversityShanghai 200240China

Demetallation of heme to release iron is a chemical difficult reaction and is highly rare in biochemistry,with apoferritin as the only known enzyme responsible for this process.Here we show the heme degradation enzyme Chuw catalyzes heme demetallation besides its known methyltransferase activity(which converts heme to a ring-open product anaerobilin).We show the demetallation activity of Chuw is radical SAM-dependent,and likely involves the same set of intermediates involved in the anaerobilin-producing pathway.The ChuW-catalyzed demetallation reaction does not require external reductant,and can occur on several heme analogs with different metal centers.These findings establish a brand-new chemistry in the radical SAM enzymes,highlighting the remarkable catalytic diversity of this superfamily of enzymes.

关键词： Biosynthesis Biotransformations Cofactors Enzymes Hemin

Consecutive Methylation Catalyzed by TsrM,an Atypical Class B Radical SAM Methylase

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Chinese Journal of Chemistry 2022年第14期40卷 1693-1698页

作者： Runze Wu wei Ding qi zhang Department of Chemistry Fudan UniversityShanghai 200433China State Key Laboratory of Microbial Metabolism School of Life Sciences&BiotechnologyShanghai Jiao Tong UniversityShanghai200240China

TsrM is a cobalamin-dependent radical S-adenosylmethionine(SAM)methyltransferase belonging to the Class B radical SAM methylase(RSM)family.This enzyme catalyzes the C-2 methylation of L-tryptophan to produce 2-methyltrytophan(2-MeTrp),an intermediate involved in the biosynthesis of thiostrepton A.In this work,we report characterization of an unexpected activity of TsrM,which carries out an additional methylation reaction on the product 2-MeTrp.A series of isotopic labeling studies and assays with different Trp analogs revealed that TsrM is able to transfer a methyl group from SAM to the C4 of 2-MeTrp to produce 2,4-dimethyltryptophan.These results reveal the intriguing substrate specificity of TsrM,further expanding the reaction promiscuity of the radical SAM superfamily enzymes.

关键词： Biosynthesis Biotransformations Catalytic promiscuity Enzyme Methyltransferase

Effect of morphological gene mutation and decay on energy dissipation behaviour of granular soils

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2023年第4期24卷 303-318页

作者： wei XIONG qi-min zhang Jian-feng WANG Department of Architecture and Civil Engineering City University of Hong KongHong KongChina Shenzhen Research Institute of City University of Hong Kong Shenzhen 518057China

In this paper,the X-ray micro-computed tomography(X-rayμCT),spherical harmonical-based principal component analysis(SH-PCA),and discrete element method(DEM)were incorporated to generate virtual samples with morphological gene mutation at different length scales.All samples were subjected to axial compression and constant confining stress.The effects of multiscale particle morphology on the stress-strain and energy storage/dissipation responses of granular soils were investigated.It is found that:(a)the effects of particle morphology on the initial stiffness,stress-strain,volumetric strain,and frictional energy dissipation behaviours are more pronounced for looser samples than for denser ones;(b)among different length scales,the particle morphology at the local roundness-level outperforms the one at the general form-level in dictating the macro-scale responses of granular soils;(c)the energy dissipation of a granular assemblage is a result of competition between particle morphology and initial void ratio.

关键词： X-ray micro-computed tomography(X-rayμCT) Spherical harmonic analysis(SHA) Discrete element method(DEM) Morphological gene mutation Energy dissipation

On Skew Polycyclic Codes over Z4[u]/2-2>

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Journal of Mathematical Research with Applications 2023年第2期43卷 241-252页

作者： wei qi Xiaolei zhang School of Mathematics and Statistics Shandong University of Technology

In this paper, we investigate some classes of skew polycyclic codes and polycyclic codes over R = Z4[u]/. We first obtain the generator polynomials of all(1, 2u)-polycyclic codes over R. Then, by defining some Gray maps, we show that the images of(skew)(1, 2u)-polycyclic codes over R are cyclic or quasi-cyclic with index 2 over Z4. Finally, an example of some(1, 2u)-polycyclic codes over R is given to exhibit the main results of the paper.

关键词： skew polycyclic code polycyclic code cyclic code generator polynomial Gray map

Reduced graphene oxide-embedded nerve conduits loaded with bone marrow mesenchymal stem cell-derived extracellular vesicles promote peripheral nerve regeneration

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Neural Regeneration Research 2023年第1期18卷 200-206页

作者： wei zhang Xing-Xing Fang qi-Cheng Li wei Pi Na Han Department of Orthopedics and Trauma Peking University People’s HospitalBeijingChina National Center for Trauma Medicine BeijingChina Central Laboratory Peking University People’s HospitalBeijingChina

We previously combined reduced graphene oxide(rGO)with gelatin-methacryloyl(GelMA)and polycaprolactone(PCL)to create an rGO-GelMA-PCL nerve conduit and found that the conductivity and biocompatibility were improved.However,the rGO-GelMA-PCL nerve conduits differed greatly from autologous nerve transplants in their ability to promote the regeneration of injured peripheral nerves and axonal sprouting.Extracellular vesicles derived from bone marrow mesenchymal stem cells(BMSCs)can be loaded into rGO-GelMA-PCL nerve conduits for repair of rat sciatic nerve injury because they can promote angiogenesis at the injured site.In this study,12 weeks after surgery,sciatic nerve function was measured by electrophysiology and sciatic nerve function index,and myelin sheath and axon regeneration were observed by electron microscopy,immunohistochemistry,and immunofluorescence.The regeneration of microvessel was observed by immunofluorescence.Our results showed that rGO-GelMA-PCL nerve conduits loaded with BMSC-derived extracellular vesicles were superior to rGO-GelMA-PCL conduits alone in their ability to increase the number of newly formed vessels and axonal sprouts at the injury site as well as the recovery of neurological function.These findings indicate that rGO-GelMA-PCL nerve conduits loaded with BMSC-derived extracellular vesicles can promote peripheral nerve regeneration and neurological function recovery,and provide a new direction for the curation of peripheral nerve defect in the clinic.

关键词： angiogenesis axon bone mesenchymal stem cell extracellular vesicles hybrid nanofibers myelin sheath nerve conduit neurological function peripheral nerve injury reduced graphene oxide

Design and implementation of China Hydrogen Price Index system

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Clean Energy 2023年第1期7卷 148-156页

作者： wei Liu Yanming Wan Yan zhang qi Liu China Hydrogen Alliance Research Institute Co. LtdBeijing100007China Guohua Energy Investment Co. LtdBeijing100007China

Hydrogen will be an important part of China’s energy system in the future and an important carrier for energy-using terminals to realize green and low-carbon transformation.It is important to establish a nationwide hydrogen market to promote the healthy and orderly development of the hydrogen industry chain.The core is to form a complete hydrogen price mechanism and play a decisive role in the process of resource allocation by the market.In this paper,we have developed the framework of the‘China Hydrogen Price Index’system by establishing the‘Assessment+Collection’model,which covers four types of hydrogen:hydrogen,clean hydrogen,renewable hydrogen and high-purity hydrogen.The model considers the raw materials required for hydrogen production,fixed equipment,engineering construction costs and carbon prices,and conducts sensitivity analysis on the trends and influencing factors of national and regional hydrogen prices of multiple categories since 2018.The results show that,with respect to the level of hydrogen prices,fossil-energy-rich and renewable-energy-rich areas have more advantages than other regions.The price of raw materials is the main factor of the hydrogen price change,and the utilization hours of renewable energy and hydrogen production equipment have a key influence on the price of renewable hydrogen.Next,by establishing an index update mechanism,improving the standard system and building a trading platform,we can further exert the role of price signals and continue to promote the efficient and smooth expansion of the domestic hydrogen market.

关键词： hydrogen price index market price