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Journal of Computational Mathematics 2024年第4期42卷 979-998页

作者： Dongyang shi Houchao zhang School of Mathematics and Statistics Zhengzhou UniversityZhengzhou 450001China

The focus of this paper is on two novel linearized Crank-Nicolson schemes with nonconforming quadrilateral finite element methods(FEMs)for the nonlinear coupled Schrodinger-Helmholtz *** L^(2) and H^(1) estimates of orders O(h^(2)+τ^(2))and O(h^(2)+τ^(2))are derived respectively without any grid-ratio condition through the following two *** is that a time-discrete system is introduced to split the error into the temporal error and the spatial error,which leads to optimal temporal error estimates of order O(τ^(2))in L^(2) and the broken H^(1)-norms,as well as the uniform boundness of numerical solutions in L^(∞) *** other is that a novel projection is utilized,which can iron out the difficulty of the existence of the consistency *** leads to derive optimal spatial error estimates of orders O(h^(2))in L^(2)-norm and O(h)in the broken H^(1)-norm under the H^(2) regularity of the solutions for the time-discrete *** last,two numerical examples are provided to confirm the theoretical ***,h is the subdivision parameter,and τ is the time step.

关键词： Schrodinger-Helmholtz equations Nonconforming FEMs Linearized Crank-Nicolson scheme Optimal error estimates

Direct Transformation of Arenols Based on C—O Activation

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Chinese Journal of Chemistry 2020年第8期38卷 855-863页

作者： Feng Liu Hao-jun Jiang Yi Zhou zhang-jie shi School of Perfume and Aroma Technology Shanghai Institute of Technology100 Haiquan RdShanghai 201418China Department of Chemistry Fudan University2005 Honghu RdShanghai 200438China

Contents *** 8562.C—O Activation via the in-situ Formed Intermediate 8562.1.C—C bond formation 8562.2.C—X bond formation 8573.C—O Activation via Dearomatization-Condensation-Rearomatization Process *** catalyzed C—O cleavage of phenols,dearomatization-condensation-rearomatization process in a gas phase ***-condensation-rearomatization process in a liquid phase *** *** C—O Activation of Phenol Salts *** C—O Activation of Phenol *** and Perspective *** Transition-metal-catalyzed cross-coupling reactions of aryl electrophiles with organic or organometallic reagents emerged as one of the most powerful tools for constructing aromatic compounds.[1]In the early days,the most popular electrophiles werearyl halides because of their high reactivity and availability.

关键词： catalyzed Phenol Transformation

Effect of Bogie Cavity End Wall Inclination on Flow Field and Aerodynamic Noise in the Bogie Region of High-Speed Trains

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Computer Modeling in Engineering & Sciences 2024年第5期139卷 2175-2195页

作者： Jiawei shi Jiye zhang State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong UniversityChengdu610031China

Combining the detached eddy simulation(DES)method and Ffowcs Williams-Hawkings(FW-H)equation,the effect of bogie cavity end wall inclination on the flow field and aerodynamic noise in the bogie region is numerically ***,the simulation is conducted based on a simplified cavity-bogie model,including five cases with different inclination angles of the front and rear walls of the *** comparing and analyzing the flow field and acoustic results of the five cases,the influence of the regularity and mechanism of the bogie cavity end wall inclination on the flow field and the aerodynamic noise of the bogie region are ***,the noise reduction strategy determined by the results of the simplified cavity-bogie model is applied to a three-car marshaling train model to verify its effectiveness when applied to the real *** results reveal that the forward inclination of the cavity front wall enlarges the influence area of shear vortex structures formed at the leading edge of the cavity and intensifies the interaction between the vortex structures and the front wheelset,frontmotor,and front gearbox,resulting in the increase of the aerodynamic noise generated by the bogie *** backward inclination of the cavity rear wall is conducive to guiding the vortex structures flow out of the cavity and weakening the interaction between the shear vortex structures and the cavity rear wall,leading to the reduction of the aerodynamic noise generated by the bogie *** the rear end wall of the foremost bogie cavity of the head car is a feasible aerodynamic noise reduction measure for high-speed trains.

关键词： Bogie cavity flow aerodynamic noise end wall inclination

Geochronological and geochemical constraints on the petrogenesis and geodynamic process of Hemler,Vlinder,and Il'ichev seamount lavas in NW Pacific

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Science China Earth Sciences 2024年第6期67卷 1856-1871页

作者： Xun WEI Yan zhang Xuefa shi Hui zhang Key Laboratory of Marine Geology and Metallogeny First Institute of OceanographyMinistry of Natural ResourcesQingdao 266061China Laboratory for Marine Geology Qingdao Marine Science and Technology CenterQingdao 266237China Shandong Key Laboratory of Deep Sea Mineral Resources Development(Preparatory) Qingdao 266061China

Oceanic intraplate volcanoes with linear age progressions are usually accepted to be derived from melting of an upwelling mantle *** seamount groups in NW Pacific,however,show complex age-distance relationships that are difficult to explain using the classic“mantle plume hypothesis”,and thus their origins are *** this study,we present ^(40)Ar-^(39)Ar age,geochemical,and Sr-Nd-Pb-Hf isotopic data of lavas from Hemler,Vlinder,and Il’ichev seamounts in NW Pacific,to elucidate their petrogenesis and geodynamic *** lavas from Hemler,Vlinder,and Il’ichev seamounts are classified as alkali basalt,basanite/nephelinite,and *** with Mg O>8 wt.%exhibit high contents of CaO,FeO^(T),and TiO_(2),similar to the composition of melts formed from reaction between carbonated eclogite-derived melts and fertile *** lavas have elevated Zr/Hf ratios(40.6-45.2)and negative Zr and Hf anomalies,indicating the presence of a carbonate component in the mantle *** are enriched in incompatible trace elements and have enriched mantle 1(EM1)-like SrNd-Pb-Hf isotopic *** isotopic compositions of Vlinder,Il’ichev basanite,and Hemler lavas in this study are similar to the Rarotonga *** occurring at the same seamount,the Il’ichev alkali basalts display more depleted SrNd-Hf isotopic compositions compared to Il’ichev *** to plate tectonic reconstruction results,the ages of Hemler(100.1 Ma),Vlinder pre-(100.2 Ma)and post-shield(87.5 Ma),and Il’ichev(56.4 Ma)lavas clearly deviate from the Macdonald,Arago,Rarotonga,and Samoa hotspot tracks,indicating that they cannot directly originate from mantle *** propose that in the mid-Cretaceous,when the Pacific plate passed over Rarotonga hotspot,melting of Rarotonga plume formed the Vlinder(main-shield stage),Pako,and Ioah *** Rarotonga(and possibly Samoa)plume materials would have been dispersed into the surrounding asthenosphere by mantle conve

关键词： Mantle plume Magellan seamount trail Carbonated mantle component Hotspot Lithosphere extension

CAW-YOLO:Cross-Layer Fusion and Weighted Receptive Field-Based YOLO for Small Object Detection in Remote Sensing

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Computer Modeling in Engineering & Sciences 2024年第6期139卷 3209-3231页

作者： Weiya shi Shaowen zhang shiqiang zhang College of Artificial Intelligence and Big Data Henan University of TechnologyZhengzhou450001China College of Information Science and Engineering Henan University of TechnologyZhengzhou450001China

In recent years,there has been extensive research on object detection methods applied to optical remote sensing images utilizing convolutional neural *** these efforts,the detection of small objects in remote sensing remains a formidable *** deep network structure will bring about the loss of object features,resulting in the loss of object features and the near elimination of some subtle features associated with small objects in deep ***,the features of small objects are susceptible to interference from background features contained within the image,leading to a decline in detection ***,the sensitivity of small objects to the bounding box perturbation further increases the detection *** this paper,we introduce a novel approach,Cross-Layer Fusion and Weighted Receptive Field-based YOLO(CAW-YOLO),specifically designed for small object detection in remote *** address feature loss in deep layers,we have devised a cross-layer attention fusion *** noise is effectively filtered through the incorporation of Bi-Level Routing Attention(BRA).To enhance the model’s capacity to perceive multi-scale objects,particularly small-scale objects,we introduce a weightedmulti-receptive field atrous spatial pyramid ***,wemitigate the sensitivity arising from bounding box perturbation by incorporating the joint Normalized Wasserstein Distance(NWD)and Efficient Intersection over Union(EIoU)*** efficacy of the proposedmodel in detecting small objects in remote sensing has been validated through experiments conducted on three publicly available *** experimental results unequivocally demonstrate the model’s pronounced advantages in small object detection for remote sensing,surpassing the performance of current mainstream models.

关键词： Small object detection attention mechanism cross-layer fusion discrete cosine transform

Toughening additive manufactured Zr-based bulk metallic glass composites by martensite phase transformation

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Journal of Materials Science & Technology 2024年第3期170卷 95-102页

作者： Pengcheng zhang Cheng zhang jie Pan Di Ouyang Lin Liu State Key Laboratory of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China

Additive manufacturing technology based on laser powder bed fusion(LPBF)offers a novel approach for fabricating bulk metallic glass(BMG)products without restriction in size and ***,the BMGs prepared by LPBF usually suffered from less plasticity and poorer fracture toughness as compared to their cast counterparts due to partial crystallization in heat-affected zones(HAZs).Since crystallization in HAZs is hard to avoid completely in LPBF BMGs,it is desirable to design a suitable alloy system,in which only ductile crystalline phase,instead of brittle intermetallics,is formed in *** unique structure could effectively increase the toughness/plasticity of the LPBF *** achieve this goal,a quaternary BMG system with a composition of Zr_(47.5)Cu_(45.5)Al_(5)Co_(2)is adopted and subjected to *** is found that nearly a single phase of B_(2)-ZrCu is precipitated in HAZs,while a fully amorphous phase is formed in molten pools(MPs).This B_(2)phase reinforced BMG composite exhibits excellent mechanical properties with enhanced plasticity and ***,it is easy to modulate the mechanical properties by altering the amount of the B_(2)phase via adjusting the laser energy ***,the best combination of strength,plasticity,and notch toughness is obtained in the BMG composite containing 27.4%B_(2)phase and 72.6%amorphous phase,which exhibits yield strength(σ_(s))of 1423 MPa,plastic strain(ε_(p))of 4.65%,and notch toughness(K_(q))of 53.9 MPa m 1/***,a notable strain-hardening is also *** improvement of plasticity/toughness and appearance of strain-hardening behavior are mainly due to the martensite phase transformation from the B_(2)phase to the Cm phase during plastic deformation(i.e.,the phase transformation-induced plasticity effect).The current work provides a guide for making advanced BMGs and BMG composites by additive manufacturing.

关键词： Laser powder bed fusion Bulk metallic glass composites Phase transformation-induced plasticity Deformation mechanism

Sporophytic control of tapetal development and pollen fertility by a mitogen-activated protein kinase cascade in rice

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Journal of Integrative Plant Biology 2024年第7期66卷 1500-1516页

作者： Jianguo Zeng Manman Duan Yiqing Wang Guangtao Li Yujing You jie shi Changhao Liu Jinyang zhang Juan Xu Shuqun zhang Jing Zhao Department of Plant Pathology Nanjing Agricultural UniversityNanjing 210095China State Key Laboratory of Plant Physiology and Biochemistry College of Life SciencesZhejiang UniversityHangzhou 310058China Division of Biochemistry University of MissouriColumbia65211MOUSA

Tapetum,the innermost layer of the anther wall,provides essential nutrients and materials for pollen *** degradation of anther tapetal cells is a prerequisite for normal pollen development in flowering *** cells facilitate male gametogenesis by providing cellular contents after highly coordinated programmed cell death(PCD).Tapetal development is regulated by a transcriptional ***,the signaling pathway(s)involved in this process are poorly *** this study,we report that a mitogen-activated protein kinase(MAPK)cascade composed of OsYDA1/OsYDA2-OsMKK4-OsMPK6 plays an important role in tapetal development and male gametophyte *** of function of this MAPK cascade leads to anther indehiscence,enlarged tapetum,and aborted pollen *** cells in osmkk4 and osmpk6 mutants exhibit an increased presence of lipid body-like structures within the cytoplasm,which is accompanied by a delayed occurrence of *** of a constitutively active version of OsMPK6(CA-OsMPK6)can rescue the pollen defects in osmkk4 mutants,confirming that OsMPK6 functions downstream of OsMKK4 in this *** crosses also demonstrated that the MAPK cascade sporophyticly regulates pollen *** study reveals a novel function of rice MAPK cascade in plant male reproductive biology.

关键词： degradation MAPK cascade pollen fertility rice tapetum

Damping capacity of Fe_(83)Ga_(17) magnetostrictive alloy under magnetic field

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Rare Metals 2024年第1期43卷 402-409页

作者： Shao-Wen Yan Xing Mu Bing-jie Liu Li-Hong Xu shi-Hai Guo Yan Qi Hong-Ping zhang Department of Functional Material Research Central Iron and Steel Research InstituteBeijing 100081China

The damping performance of Fe_(83)Ga_(17) alloys has been investigated in the static magnetic field (H). The results demonstrate that the damping peak value can be adjusted between 0.020 and 0.085 under the magnetic f... 详细信息

关键词： alloy magnetic alloys

Reduction behavior of iron ore powder by high-volatile coal in thermogravimetric-gas chromatographic and kinetic analysis

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Journal of Iron and Steel Research(International) 2024年第1期31卷 92-107页

作者： Rui-meng shi Qi-yuan Mi Bin Li Xiao shi Chong Zou Jing Guo Han-jie Guo School of Metallurgical Engineering Xi’an University of Architecture and TechnologyXi’an710055ShaanxiChina China International Engineering Consulting Corporation Beijing100048China School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing100083China

The reduction behavior of iron ore powder by high-volatile coal was investigated,and its kinetic mechanism was *** effect of volatiles in coal on the reduction reaction of iron ore was compared by utilizing a Xinjiang lignite with a high volatile content and its pyrolysis carbon produced by high-temperature pyrolysis to remove volatiles,serving as a *** mass loss and gas composition of the samples during the reduction process were detected using thermo-gravimetric analysis and gas chromatography,and the morphological changes of iron ore powder were observed through scanning electron *** kinetic parameters of the iron oxide reduction reaction were calculated by the Flynn-Ozawa-Wall method,and the kinetic mechanism of volatile participation in the iron oxide reduction reaction was determined through the Coats-Redfern *** results indicate that the coupling effect between the high-volatile coal pyrolysis and reduction reactions occurs during the second stage of the entire coupling process,which corresponds to the late stage of coal pyrolysis with a substantial release of H_(2)and *** volatiles in coal actively participated in the reduction reaction,reducing the initiation temperature of the reaction by around 200℃.The reduction of iron oxides by high-volatile coal was jointly promoted by the"hydrogen cycle"and"carbon cycle",resulting in a higher reduction extent and metallization rate at the end of the *** high-volatile coal was used as the reductant,the average activation energy for the entire process was 76.5 kJ/mol,a significant decrease compared to the employment of pyrolysis carbon without volatiles as the reductant(1167 kJ/mol).

关键词： Direct reduction High-volatile coal Volatile Kinetics Reduction mechanism

Effect of perioperative chemotherapy on resection of isolated pulmonary metastases from colorectal cancer:A single center experience

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World Journal of Gastrointestinal Oncology 2024年第8期16卷 3457-3470页

作者： Zhao Gao Xuan Jin Ying-Chao Wu shi-jie zhang shi-Kai Wu Xin Wang Department of Medical Oncology Peking University First HospitalBeijing 10000China Department of General Surgery Peking University First HospitalBeijing 10000China Department of Thoracic Surgery Peking University First HospitalBeijing 10000China

BACKGROUND Numerous studies have assessed surgical resection as a standard treatment option for patients with colorectal cancer(CRC)and resectable pulmonary metastases(PM).However,the role of perioperative chemotherapy after complete resection of isolated PM from patients with CRC patients remains *** hypothesize that perioperative chemotherapy does not provide significant survival benefits for patients undergoing resection of PM from *** To determine whether perioperative chemotherapy affects survival after radical resection of isolated PM from *** We retrospectively collected demographic,clinical,and pathologic data on patients who underwent radical surgery for isolated PM from *** survival(CSS)and disease-free survival were calculated using Kaplan-Meier ***-group differences were compared using the log-rank *** multivariate analysis,Cox regression was utilized when *** This study included 120 patients with a median age of 61.6 *** 5-year CSS rate was 78.2%,with 36.7% experiencing *** resection for isolated PM resulted in a 5-year CSS rate of 50.0% for second *** chemotherapy(P=0.079)did not enhance survival *** associated with improved survival included fewer metastatic lesions[hazard ratio(HR):2.51,P=0.045],longer disease-free intervals(HR:0.35,P=0.016),and wedge lung resections(HR:0.42,P=0.035).Multiple PM predicted higher recurrence risk(HR:2.22,P=0.022).The log-rank test showed no significant difference in CSS between single and repeated metastasectomy(P=0.92).CONCLUSION Perioperative chemotherapy shows no survival benefit post-PM resection in ***-free intervals and fewer metastatic lesions predict better *** metastasectomy is warranted for eligible patients.

关键词： Pulmonary metastasis Colorectal cancer Perioperative chemotherapy Survival Repeated pulmonary metastasectomy