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A generalization of banach's lemma and its applications to perturbations of bounded linear operators

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Applied Mathematics(A Journal of Chinese Universities) 2024年第2期39卷 363-369页

作者： WANG Zi DING jiu WANG Yu-wen School of Mathematics Sciences Harbin Normal UniversityHarbin 150025China School of Mathematics and Natural Sciences The University of Southern MississippiHattiesburg MS 39406-5043USA Academic Committee Harbin Institute of PetroleumHarbin 150027China

Let X be a banach space and let P:X→X be a bounded linear *** an algebraic inequality on the spectrum of P,we give a new sufficient condition that guarantees the existence of(I-P)^(-1) as a bounded linear operator on X,and a bound on its spectral radius is also *** generalizes the classic banach *** apply the result to the perturbation analysis of general bounded linear operators on X with commutative perturbations.

关键词： banach lemma spectral radius generalized inverse perturbation analysis

Realizing the excellent oxidation resistance of an environmental barrier coating through aluminum surface modification

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Journal of Advanced Ceramics 2024年第7期13卷 976-986页

作者： Lin Dong wen-Qi Yang Lin Chen Guan-Jun Yang Chang-jiu Li State Key Laboratory for Mechanical Behavior of Materials School of Materials Science and EngineeringXi’an Jiaotong UniversityXi’an 710049China Xi’an Aerospace Engine Company Limited in China Aerospace Science and Technology Corporation Xi’an 710065China

The lifetime of Si-based environmental barrier coatings(EBCs)is constrained by thermally grown SiO_(2)oxidelayer(SiO_(2)-TGO),which can cause premature cracking and *** address this issue,a new approach for surfacemodification using aluminum is *** oxidation performance was examined in a 50 vol%H_(2)O-50 vol%O_(2)environment at 1350℃for up to 300 *** results indicate that a dense ytterbium aluminum garnet(YbaG)layer wasformed after modification,decreasing the porosity by 80%.Due to the elimination of fast diffusion channels and the lowoxygen permeability of YbaG,aluminum modification significantly reduced the growth rate of SiO_(2)-TGO by nearly twoorders of ***,its thickness decreased by more than 70%after 300 h of exposure.A diffusioncontrolled oxidation mechanism indicates that the modified dense surface is equivalent to an initial SiO_(2)layer with a specificthickness,causing a shift in the oxidation time and increasing the oxidation *** research provides valuableinsights for designing Si-based EBC with improved lifetimes.

关键词： environmental barrier coating(EBC) oxidation modification diffusion cracking

Durable dual-state duplex Si-HfO_(2)with excellent oxidation and cracking resistance

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Journal of Advanced Ceramics 2024年第3期13卷 388-401页

作者： Lin Chen Jing-Chuan Luo wen-Qi Yang Chang-jiu Li Guan-Jun Yang State Key Laboratory for Mechanical Behavior of Materials School of Materials Science and EngineeringXi’an Jiaotong UniversityXi’an 710049China Xi’an Aerospace Engine Company Limited in CASC Xi’an 710065China

The lifetime of Si bond coatings in environmental barrier coatings is constrained by phase-transition-induced cracking of the SiO_(2)*** this study,Si-HfO_(2)dual-state duplex composite materials are proposed to address this issue by partially forming HfSiO_(4)and minimizing the SiO_(2)*** as-prepared composite exhibited a structure comprising discrete HfO_(2)“bricks”embedded in a continuous Si“mortar”,while the oxidized state transformed into discrete HfSiO_(4)“bricks”within continuous thin SiO_(2)“mortars”.The results indicate that continuous thin SiO_(2)contributes to reducing the oxidation rate to a level comparable to that of pure Si,and discrete HfSiO_(4)particles aid in relieving phase transition-induced stress and inhibiting crack propagation,thereby enhancing oxidation and cracking resistance ***,the composite with 20 mol%HfO_(2)and a mean particle size of~500 nm at 1370℃exhibited a service lifetime 10 times greater than that of pure *** research provides valuable insights for designing Si-based bond coatings with improved service lifetime.

关键词： oxidation environmental barrier coatings(EBCs) phase transition cracking bond coatings

A_(2)B_(7)-type La-Mg-Ni alloys prepared by Mg thermal diffusion for improved hydrogen storage performance

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Rare Metals 2024年第7期43卷 3260-3272页

作者： Yong-Xi Zhang Guan-jiu Wu Jing Gu Hong-Xing Kang Yuan Li Di Zhou wen-Feng Wang Lu Zhang Shu-Min Han Hebei Key Laboratory of Applied Chemistry School of Environmental and Chemical EngineeringYanshan UniversityQinhuangdao 066004China Department of Chemistry and Biochemistry San Diego State UniversitySan DiegoCA92182-1030USA State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004China

A novel approach based on thermal diffusion was used to achieve controllable Mg content in A_(2)B_(7)-type La-Mg-Ni-based *** formation mechanism of the A_(2)B_(7)-type phase as a result of the thermal diffusion process and the effect of Mg content on hydrogen storage performance were investigated.X-ray diffraction(XRD)patterns and Rietveld refinement results showed that increased Mg transformed the LaNi_(5)phase in the La_(0.74)Sm_(0.03)Y_(0.23)Ni_(4.32)Al_(0.04)precursor alloy into a superlattice *** electron microscopy(SEM)images showed that Mg was evenly distributed in the alloy *** in the superlattice significantly inhibited the phase decomposition of the superlattice structure during the hydrogen absorption/desorption *** A_(2)B_(7)-type La_(0.57)Sm_(0.02)Y_(0.18)Mg_(0.23)Ni_(3.38)Al_(0.03)alloy composed of Gd_(2)Co_(7)and Ce_(2)Ni_(7)phases was successfully *** pressure-composition isotherm profiles showed that the alloy had a hydrogen storage capacity as high as 1.73 wt%,with good cycling *** 50 cycles of hydrogen absorption/desorption,the alloy retained a hydrogen storage capacity of 1.45 wt%,with a capacity retention rate of up to 84.28%.The Mg thermal diffusion process thus provides a new approach for the controlled preparation of La-Mg-Ni-based alloys.

关键词： La-Mg-Ni-based hydrogen storage alloy A_(2)B_(7)-type superlattice alloy Mg thermal diffusion process Phase transformation Hydrogen storage property

Unexplained fetal tachycardia:A case report

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World Journal of Clinical Cases 2024年第9期12卷 1698-1703页

作者： Hui Wang Run-Zi Duan Xin-jiu bai Bing-Ting Zhang Jie Wang wen-Xia Song Department of Nutrition Changzhi Maternal and Child Health Care Hospital Affiliated to Changzhi Medical CollegeChangzhi 046000Shanxi ProvinceChina Department of Obstetrics Changzhi Maternal and Child Health Care Hospital Affiliated to Changzhi Medical CollegeChangzhi 046000Shanxi ProvinceChina Department of Gynaecology Changzhi Maternal and Child Health Care Hospital Affiliated to Changzhi Medical CollegeChangzhi 046000Shanxi ProvinceChina Department of Medical Genetic Changzhi Maternal and Child Health Care Hospital Affiliated to Changzhi Medical CollegeChangzhi 046011Shanxi ProvinceChina

baCKGROUND This study aimed to explore the possible etiology and treatment of severe fetal tachycardia in the absence of organic disease and provide a reference for clinical management of severe fetal *** SUMMARY A 29-year-old pregnant woman,with a gravidity 1 parity 0,presented with a fetal heart rate(FHR)of 243 beats per minute during a routine antenatal examination at 31+2 wk of *** termination of pregnancy at 38 wk of gestation,the FHR repeatedly showed serious abnormalities,lasting more than 30 ***,the pregnant woman and the fetus had no clinical symptoms,and repeated examination revealed no organic *** mother and the baby were regularly followed *** This was a case of severe fetal tachycardia with no organic lesions and management based on clinical experience.

关键词： Fetal heart rate disorder Fetal tachycardia Severe tachycardia Case report

Adrenocorticotropic hormone combined with magnesium sulfate therapy for infantile epileptic spasms syndrome:a real-world study

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World Journal of Pediatrics 2024年第8期20卷 834-847页

作者： wen He Qiu-Hong Wang jiu-Wei Li Yang-Yang Wang Xiao-Mei Luo Lin Wan Jing Wang Xiu-Yu Shi Wei-Hua Zhang Fang Fang Li-Ping Zou Senior Department of Pediatrics the Seventh Medical Center of Chinese PLA General HospitalDepartment of Pediatricsthe First Medical Center of Chinese PLA General HospitalBeijing 100853China Department of Neurology Beijing Children’s HospitalCapital Medical UniversityBeijingChina Center of Epilepsy Beijing Institute for Brain DisordersBeijing 100069China

background Infantile epileptic spasms syndrome(IESS)is a serious disease in infants,and it usually evolves to other epilepsy types or syndromes,especially refractory or super-refractory focal *** adrenocorticotropic hormone(ACTH)is one of the first-line and effective treatment plans for IESS,it has serious side effects and is not sufficiently *** A retrospective study of the clinical outcomes of ACTH combined with magnesium sulfate(MgSO4)therapy for IESS in two hospital centers was *** major outcome of the single and combined treatment was evaluated by changes in seizure frequency and improvements in hypsarrhythmia electroencephalography(EEG).To reduce the confounding bias between the two groups,we used SPSS for the propensity score matching(PSM)*** We initially recruited 1205 IESS patients from two Chinese hospitals and treated them with ACTH combined with MgSO4 and ACTH *** 1005 patients were enrolled in the treatment(ACTH combined with MgSO4:744,ACTH:261),and both treatment plans had a more than 55%response ***,compared to patients treated with ACTH alone,those patients treated with ACTH combined with MgSO4 had better performance in terms of the seizure frequency and hypsarrhythmia *** PSM,the two groups also showed significant differences in responder rate[70.8%(95%confidence interval,CI)=66.7%–74.8%)vs.53.8%(95%CI=47.4%–60.2%),P3 months(P<0.05).In addition,the overall incidence of adverse reactions in the ACTH combined with MgSO4 group was much lower than that in the ACTH group(31.4%vs.63.1%,P<0.001).During the treatment,only

关键词： Adrenocorticotropic hormone Clinical trial Infantile epileptic spasms syndrome Magnesium sulfate Real-world study

Strong metal-support interactions between highly dispersed Cu^(+) species and ceria via mix-MOF pyrolysis toward promoted water-gas shift reaction

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Journal of Energy Chemistry 2024年第4期91卷 475-483页

作者： Xiao-Chen Sun Xing-Chi Li Ze-Wei Xie Chen-Yue Yuan De-jiu Wang Qian Zhang Xiao-Yu Guo Hao Dong Hai-Chao Liu Ya-wen Zhang Beijing National Laboratory for Molecular Sciences(BNLMS) State Key Laboratory of Rare Earth Materials Chemistry and ApplicationsPKU-HKU Joint Laboratory in Rare Earth Materials and Bioinorganic ChemistryCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China Beijing National Laboratory for Molecular Sciences(BNLMS) College of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China Beijing National Laboratory for Molecular Sciences(BNLMS) State Key Laboratory for Structural Chemistry of Stable and Unstable SpeciesCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China

The modulation of metal-support interfacial interaction is significant but challenging in the design of high-efficiency and high-stability supported ***,we report a synthetic strategy to upgrade Cu-CeO_(2)interfacial interaction by the pyrolysis of mixed metal-organic framework(MOF)*** obtained highly dispersed Cu/CeO_(2)-MOF catalyst via this strategy was used to catalyze water-gas shift reaction(WGSR),which exhibited high activity of 40.5μmolCOgcat^(-1).s^(-1)at 300℃and high stability of about 120 *** on comprehensive studies of electronic structure,pyrolysis strategy has significant effect on enhancing metal-support interaction and then stabilizing interfacial Cu^(+)species under reaction *** Cu^(+)species and generated oxygen vacancies over Cu/CeO_(2)-MOF catalyst played a key role in CO molecule activation and H2O molecule dissociation,*** collaborated closely and then promoted WGSR catalytic performance in comparison with traditio nal supported *** study shall offer a robust approach to harvest highly dispersed catalysts with finely-tuned metal-support interactions for stabilizing the most interfacial active metal species in diverse heterogeneous catalytic reactions.

关键词： Cu-based catalyst MOF derivative Water-gas shift reaction Metal-support interaction

Spatial Morphology Evolution Characteristics Analysis of the Resident Population Distribution in Henan, China

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Journal of Geoscience and Environment Protection 2024年第3期12卷 163-180页

作者： Kaiguang Zhang Hongling Meng Mingting ba Danhuan wen School of Geography and Tourism Zhengzhou Normal University Zhengzhou China

The population spatial distribution pattern and its evolving pattern play an important role in regional allocation of social resources and production factors, formulation of regional development plans, construction of a better life society, and promotion of regional economic development. based on the resident population statistics data of Henan province from 2006 to 2021, with county as the basic study unit, the paper studies the spatial morphology characteristics and its evolution patterns of resident population distribution, by using spatial analysis methods such as population distribution center, standard deviation ellipse, and spatial auto correlation analysis. The results show that: the resident population spatial distribution shows unbalanced state, the population agglomeration areas mainly distribute in the northeast part and north part, where the resident population growth rate is significantly higher than other regions, over time, this trend is gradually becoming significant. The resident population distribution has a trend of centripetal concentration, with the degree and trend of centripetal gradually strengthening. The resident population distribution has obvious directional characteristics, but the significance is not high, the weighted resident population average center is approximately located at (4.13740˚N, 113.8935˚E), and the azimuth of the distribution axis is approximately 11.19˚. The population distribution has obvious agglomeration characteristics, with the built-up areas of Zhengzhou and Luoyang as their centers, where have a significant siphon effect on the surrounding population. The southern and southwestern regions in the province form a relatively stable belt area of Low-Low agglomeration areas.

关键词： Resident Population Spatial Distribution Spatial Morphology Temporal and Spatial Evolution Center Migration Standard Deviation Ellipse Spatial Autocorrelation

Study on the Impact of Post-Mastectomy Radiotherapy on Immediate Breast Reconstruction and Complications: A Meta-Analysis

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Journal of Clinical and Nursing Research 2024年第6期8卷 64-76页

作者： wen Li Manman Sun Lihao Zheng Yibo Jiang Nan ba Department of Radiation Oncology Fifth Affiliated Hospital of Zhengzhou UniversityZhengzhou CityHenan Province 450000China

background and objective:Immediate breast reconstruction not only reduces the number of surgeries for patients after mastectomy but also decreases psychological and physical trauma,making it increasingly ***,there is currently no consensus on the integration of post-mastectomy radiotherapy(PMRT)with reconstruction *** review evaluates the impact of PMRT on complications following immediate breast reconstruction,providing guidance for clinical treatment ***:PubMed,Web of Science,Embase,and other databases were searched for studies published in the past 15 years on outcomes of implant-based breast reconstruction in the context of radiotherapy to identify articles for *** 5.4 software was used to analyze the risks of seroma,infection,wound dehiscence,flap necrosis,implant exposure,capsule contracture,and reconstruction ***:A total of 1l relevant studies were included,comprising 6323 cases of immediate breast *** was found that breasts receiving postoperative irradiation had a significantly increased risk of complications,with statistically significant differences in seroma(P=0.004),infection(Pbased *** measures may be taken in advance with the assistance of healthcare providers if necessary.

关键词： Breast cancer Immediate breast reconstruction Radiotherapy Post-mastectomy Complications