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The Extension Dimension of Subcategories and Recollements of Abelian Categories

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Acta mathematica Sinica,English Series 2024年第4期40卷 1042-1058页

作者： xin ma Ye Yang PENG Zhao Yong HUANG College of Science Henan University of EngineeringZhengzhou 451191P.R.China Department of mathematics Nanjing UniversityNanjing 210093P.R.China

We investigate the behavior of the extension dimension of subcategories of abelian categories under ***Λ',Λ,Λ"be art in algebras such that(modΛ',mod A,modΛ")is a recollement,and let D'and D"be subcategories of modΛand modΛ"*** any n,m≥0,under some conditions,we get dimΩ^(k)(D)≤dimΩ^(n)(D')+dimΩ^(m)(D")+1,where k=max{m,n}and D is the subcategory of modΛglued by D'and D";moreover,we give a sufficient condition such that the converse inequality holds *** applications,some results for Igusa-Todorov subcategories and syzygy finite sub categories are obtained.

关键词： Recollements extension dimension Igusa–Todorov subcategories syzygy finite subcategories

A new method for evaluating wedges of steel plates and strips

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Journal of Iron and Steel Research(International) 2024年第7期31卷 1719-1735页

作者： Xiao-bao ma Xiao-xin ma Tao Wang Zhong-kai Ren Yu-cheng Ren College of Mechanical and Vehicle Engineering Taiyuan University of TechnologyTaiyuan 030024ShanxiChina Ministry of Education Engineering Research Center of Advanced Metal Composite Forming Technology and Equipment Taiyuan University of TechnologyTaiyuan 030024ShanxiChina National Key Laboratory of Metal Forming Technology and Heavy Equipment Taiyuan University of TechnologyTaiyuan 030024ShanxiChina China National Heavy machinery Research Institute Co. Ltd.Xi'an 710018ShaanxiChina Faculty of Mechanical Engineering Hebei University of ArchitectureZhangjiakou 075000HebeiChina

To overcome the inaccuracy problem of the traditional wedge evaluation of steel plates and strips caused by the ran-domness of the thicknesses of two local points and improve the reliability of the wedge index,the double-centroid method for the wedge evaluation was proposed,and a model based on the centroid theory was ***,an integral model for the discrete thickness values of the cross-section profiles was *** discussion focused on the distinct characteristics of the two-point method,asymmetric method,and double-centroid method in evaluating the asymmetric distribution of *** three methods were employed to evaluate the wedge values of both the theoretical and measured cross-sections of steel plates and strips,and the accuracies of three wedge evaluation models were analyzed and *** results showed that the double-centroid method objectively reflects the degree and variation characteristics of the wedge values of the cross-sections of steel plates and strips,and this method is feasible,reliable,and outstanding.

关键词： Steel plate and strip Wedge Two-point method Double-centroid method Reliability

Left Frobenius Pairs,Cotorsion Pairs and Weak Auslander-Buchweitz Contexts in Triangulated Categories

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Algebra Colloquium 2024年第2期31卷 285-308页

作者： xin ma Tiwei Zhao Zhaoyong Huang Nanqing Ding College of Science Henan University of EngineeringZhengzhou 451191China School of mathematical Sciences Qufu Normal University QufuShandong 273165China Department of mathematics Nanjing UniversityNanjing 210093China 不详

Let T be a triangulated category with a proper classξof *** introduce the notions of left Frobenius pairs,left(n-)cotorsion pairs and left(weak)Auslander-Buchweitz contexts with respect toξin *** show how to construct left cotorsion pais from left n-cotorsion pairs,and establish a one-to-one correspondence between left Frobenius pairs and left(weak)Auslander-Buchweitz *** applications are given in the Gorenstein homological theory of triangulated categories.

关键词： left Frobenius pairs left n-cotorsion pairs left(weak)Auslander-Buchweitz contexts homological dimensions

A Nonlinear Grey Bernoulli Model with Conformable Fractional-Order Accumulation and Its Application to the Gross Regional Product in the Cheng-Yu Area

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Journal of Systems Science and Information 2024年第2期12卷 245-273页

作者： Wenqing WU xin ma Bo ZENG Yuanyuan ZHANG School of Science Civil Aviation Flight University of ChinaDeyang 618307China School of mathematics and Physics Southwest University of Science and TechnologyMianyang 621010China College of Business Planning Chongqing Technology and Business UniversityChongqing 400067China

This study considers a nonlinear grey Bernoulli forecasting model with conformable fractionalorder accumulation,abbreviated as CFNGBM(1,1,λ),to study the gross regional product in the ChengYu *** new model contains three nonlinear parameters,the power exponentγ,the conformable fractional-orderαand the background valueλ,which increase the adjustability and flexibility of the CFNGBM(1,1,λ)*** parameters are determined by the moth flame optimization algorithm,which minimizes the mean absolute prediction percentage *** CFNGBM(1,1,λ)model is applied to the gross regional product of 16 cities in the Cheng-Yu area,which are Chongqing,Chengdu,Mianyang,Leshan,Zigong,Deyang,Meishan,Luzhou,Suining,Neijiang,Nanchong,Guang’an,Yibin,Ya’an,Dazhou and *** data from 2013 to 2021,several grey models are established and results show that the new model has higher accuracy in most cases.

关键词： nonlinear grey Bernoulli model conformable fractional-order operator moth flame optimization algorithm gross regional product the Cheng-Yu area

A statistical analysis of the Kappa-type energy spectrum distribution of radiation belt electrons observed by Van Allen Probes

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Earth and Planetary Physics 2024年第2期8卷 368-374页

作者： LuHuai Jiao xin ma YuanNong Zhang TaiFeng Jin Song Fu BinBin Ni Department of Space Physics School of Electronic InformationWuhan UniversityWuhan 430072China

The energy spectrum of energetic electrons is a key factor representing the dynamic variations of Earth’s Van Allen radiation *** measurements have indicated that the commonly used maxwellian and Kappa distributions are inadequate for capturing the realistic spectral distributions of radiation belt *** we adopt the Kappa-type(KT)distribution as the fitting function and perform a statistical analysis to investigate the radiation belt electron flux spectra observed by the Van Allen *** calculating the optimal values of the key KT distribution parameters(i.e.,κandθ2)from the observed spectral shapes,we fit the radiation belt electron fluxes at different L-shells under different geomagnetic *** this manner,we obtain typical values of the KT distribution parameters,which are statistically feasible for modeling the radiation belt electron flux profiles during either geomagnetically quiet or active periods.A comparison of the KT distribution model results with those using the maxwellian or Kappa distribution reveals the advantage of the KT distribution for studying the overall properties of the radiation belt electron spectral distribution,which has important implications for deepening the current understanding of the radiation belt electron dynamics under evolving geomagnetic conditions.

关键词： radiation belt electron Kappa-type distribution fitting geomagnetic storm

Cancer organoids:A platform in basic and translational research

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Genes & Diseases 2024年第2期11卷 614-632页

作者： xin ma Qin Wang Guozheng Li Hui Li Shouping Xu Da Pang Department of Breast Surgery Harbin Medical University Cancer HospitalHarbinHeilongjiang 150081China Sino-Russian Medical Research Center Harbin Medical University Cancer HospitalHarbinHeilongjiang 150081China Heilongjiang Academy of Medical Sciences HarbinHeilongjiang 150086China Department of Pharmacology (The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China) College of Pharmacy of Harbin Medical UniversityHarbinHeilongjiang 150086China

An accumulation of previous work has established organoids as good preclinical models of human tumors,facilitating translation from basic research to clinical *** are changing the paradigm of preclinical cancer research because they can recapitulate the heterogeneity and pathophysiology of human cancers and more closely approximate the complex tissue environment and structure found in clinical tumors than in vitro cell lines and animal ***,the potential applications of cancer organoids remain to be comprehensively *** the review,we firstly describe what is currently known about cancer organoid culture and then discuss in depth the basic mechanisms,including tumorigenesis and tumor metastasis,and describe recent advances in patient-derived tumor organoids(PDOs)for drug screening and immunological ***,the present challenges faced by organoid technology in clinical practice and its prospects are *** review highlights that organoids may offer a novel therapeutic strategy for cancer research.

关键词： Drug assays Immunotherapy Mechanism research Organoids Precision medicine

The size effect and analogous boundary states in a circular non-Hermitian chain

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Communications in Theoretical Physics 2024年第2期76卷 157-165页

作者： xin-Yu ma Yi-Han Guan Qiao-Nan Li Ai-Lei He Lu Qi School of Physical Science and Technology Yangzhou UniversityYangzhou 225002China

We investigate the size effect and boundary states based on a circular non-Hermitian chain under the nonreciprocal intra-cell coupling and inter-cell coupling *** find that the circular non-Hermitian chain exhibits an even–odd effect on the unit cell corresponding to a large chain,which is different from the open non-Hermitian chain only exhibiting the same effect for a small ***,we find that the originally localized bulk states become totally extended via designing the boundary coupling strength *** extended bulk states reveal the fact of the disappearance of the non-Hermitian skin *** particular,we show that the circular non-Hermitian chain also possesses the analogous edge states under some parameter regimes,which is pretty counterintuitive since the circular chain usually cannot define a *** investigations supply the different non-Hermitian phenomena in a circular non-Hermitian chain.

关键词： boundary states non-Hermitian chain topological state

Efficacy and safety of perioperative therapy for locally resectable gastric cancer:A network meta-analysis of randomized clinical trials

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World Journal of Gastrointestinal Oncology 2024年第3期16卷 1046-1058页

作者： Zi-Yu Kuang Qian-Hui Sun Lu-Chang Cao xin-Yi ma Jia-Xi Wang Ke-xin Liu Jie Li Graduate College Beijing University of Traditional Chinese MedicineBeijing 100029China Oncology Department Guang’anmen HospitalChina Academy of Chinese Medical SciencesBeijing 100053China

BACKGROUND Gastric cancer(GC)is the fifth most commonly diagnosed malignancy worldwide,with over 1 million new cases per year,and the third leading cause of cancer-related *** To determine the optimal perioperative treatment regimen for patients with locally resectable *** A comprehensive literature search was conducted,focusing on phase II/III randomized controlled trials(RCTs)assessing perioperative chemotherapy and chemoradiotherapy in treating locally resectable *** R0 resection rate,overall survival(OS),disease-free survival(DFS),and incidence of grade 3 or higher nonsurgical severe adverse events(SAEs)associated with various perioperative regimens were analyzed.A Bayesian network meta-analysis was performed to compare treatment regimens and rank their *** Thirty RCTs involving 8346 patients were included in this *** XELOX plus neoadjuvant radiotherapy and neoadjuvant CF were found to significantly improve the R0 resection rate compared with surgery alone,and the former had the highest probability of being the most effective option in this *** plus adjuvant FLOT was associated with the highest probability of being the best regimen for improving *** to limited data,no definitive ranking could be determined for *** nonsurgical SAEs,FLO has emerged as the safest treatment *** This study provides valuable insights for clinicians when selecting perioperative treatment regimens for patients with locally resectable *** studies are required to validate these findings.

关键词： Gastric cancer Perioperative treatment Network meta-analysis Efficacy and safety

Simulation study on cuttings transport of the backreaming operation for long horizontal section wells

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Petroleum Science 2024年第2期21卷 1149-1170页

作者： Yu-Fei Chen Hui Zhang Wen-xin Wu Jun Li Yong Ouyang Zong-Yu Lu De-xin ma Yong-Chuan Wu Jun-Bo Liu Ke-Rou Liu Zhuo-xin Dong China University of Petroleum(Beijing) Beijing102249China Beijing Normal University at Zhuhai Experimental and Practical Education Innovation CenterZhuhai519087GuangdongChina Oil&Gas Technology Research Institute of PetroChina Changqing Oilfield Company Xi'an710016ShaanxiChina PetroChina xinjiang Oilfield Company Karamay834002XinjiangChina China Oilfield Services Ltd. Tianjin300459China

The backreaming operation plays a significant role in safe drilling for horizontal wellbores, while it may cause severe stuck pipe accidents. To lower the risk of the stuck pipe in backreaming operations, the mechanism of cuttings transport needs to be carefully investigated. In this research, a transient cuttings transport with multiple flow patterns model is developed to predict the evolution of cuttings transported in the annulus while backreaming. The established model can provide predictions of the distribution of cuttings bed along the wellbore considering the bulldozer effect caused by large-size drilling tools(LSDTs). The sensitivity analyses of the size of LSDTs, and backreaming operating parameters are conducted in Section 4. And a new theory is proposed to explain the mechanism of cuttings transport in the backreaming operation, in which both the bit and LSDTs have the “cleaning effect” and “plugging effect”.The results demonstrate that the cuttings bed in annuli is in a state of dynamic equilibrium, but the overall trend and the distribution pattern are obvious. First, larger diameters and longer drilling tools could lead to a higher risk of the stuck pipe. Second, we find that it is not the case that the higher flow rate is always better for hole cleaning, so three flow-rate intervals are discussed separately under the given conditions. When the “dangerous flow rate”(maller flow rate instead facilitates borehole cleaning. If the flow rate is large enough to be in the “high flow rate” interval(>35 L/s in Case 4),the higher the flow rate, the better the cleaning effect of cuttings beds. Third, an interval of tripping velocity called “dangerous velocity” is proposed, in which the cuttings bed accumulation near the LSDTs is more serious than

关键词： Backreaming Stuck pipe Hole cleaning Transient solid transport Multiple flow patterns