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Journal of Computational Mathematics 2001年第5期19卷 449-458页

作者： Wan, z.-S. Sun, z.-z. Institute of Applied Physics and CM P.O. Box 8009 Beijing 100088 China

In paper (J. Comput. Appl. Math., 76 (1996), 137-146), a difference scheme for a class of nonlocal parabolic equations with natural boundary conditions was derived by the method of reduction of order and the unique solvability and second order convergence in L2-norm are proved. In this paper, we prove that the scheme is second order convergent in L∞ norm and then obtain fourth order accuracy approximation in L∞ norm by extrapolation method. At last, one numerical example is presented.

关键词： Approximation theory Boundary conditions Convergence of numerical methods Extrapolation

CHANGES OF GLOMERULAR FIXED ANIONIC CHARGE SITES IN ADRIAMYCIN NEPHROSIS IN RATS

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中华医学杂志(英文版) 1991年第2期104卷 128-131+176-177页

作者： z Wang z G Wang z Liu Department of Pediatrics Second Teaching Hospital West China University of Medical Sciences Chengdu.

A single intravenous injection of adriamycin (5 mg/kg) into rats induced nephrotic syndrome. In the various stages of the model, alterations of glomerular fixed anionic charge sites stained with colloidal iron were analyzed quantitatively by image analyzer, which is reported here for the first time. The results showed that there was a significant decrease in glomerular fixed anionic charge sites at 3 hours after administration of adriamycin as compared with the control animals (P<0.01). Marked loss of the anionic charge sites preceded the onset of proteinuria and steadily increased along with the progress of the disease. The results suggest that the loss of glomerular fixed anionic charge sites may play an important role in the development of proteinuria in nephrotic syndrome.

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Exergy analysis of R1234ze（z） as high temperature heat pump working fluid with multi-stage compression

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Frontiers in Energy 2017年第4期11卷 493-502页

作者： Bin HU Di WU L.W. WANG R.z. WANG Institute of Refrigeration and Cryogenics Shanghai Jiao Tong University Shanghai 200240 China

In this paper, the simulation approach and exergy analysis of multi-stage compression high tempera- ture heat pump （HTHP） systems with R1234ze（z） working fluid are conducted. Both the single-stage and multi-stage compression cycles are analyzed to compare the system performance with 120℃ pressurized hot water supply based upon waste heat recovery. The exergy destruction ratios of each component for different stage compression systems are compared. The results show that the exergy loss ratios of the compressor are bigger than that of the evaporator and the condenser for the single-stage compres- sion system. The multi-stage compression system has better energy and exergy etticiencies with the increase of compression stage number. Compared with the single- stage compression system, the coefficient of performance （COP） improvements of the two-stage and three-stage compression system are 9.1% and 14.6%, respectively. When the waste heat source temperature is 60℃, the exergy efficiencies increase about 6.9% and 11.8% for the two-stage and three-stage compression system respec- tively.

关键词： multi-stage compression high temperatureheat pump heat recovery exergy destruction,R1234ze(z) working fluid

RAFTING PREDICTION CRITERION FOR NICKEL-BASE SINGLE CRYSTALS UNDER MULTIAXIAL STRESSES AND CRYSTALLOGRAPHIC ORIENTATION DEPENDENCE OF CREEP BEHAVIOR

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Acta Metallurgica Sinica(English Letters) 1999年第2期12卷 149-154页

作者： Yue, z.F. Lu, z.z. Northwestern Polytechnical Univ Xi'an China

Based on the relief of interfacial energy density by dislocation generation at the gamma - gamma ' interfaces, a rafting prediction criterion has been developed for nickel-base single crystals under multiaxial stresses. The diagrams of rafting have been presented, and confirmed by experimental results. The rafting process have been analyzed quantitatively by the relief of interfacial energy. The criterion has been applied to study the creep behavior. The example of creep life analysis shows that the criterion can be correlated greatly to the crystallographic orientation dependence of creep behavior. (Author abstract) 11 Refs.

关键词： Creep Crystallography Dislocations (crystals) Interfaces (materials) Interfacial energy Single crystals Superalloys

Epidemiological Aspects of Maternal Deaths Observed on Arrival over a Decade at the Fousseyni Daou Hospital in Kayes

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Open Journal of Obstetrics and Gynecology 2025年第1期15卷 108-117页

作者： Mahamadou Diassana Ballan Macalou Sitapha Dembele Robert Diarra Alima Sidibe Lassina Goita Samou Diarra Seydou z. Dao Mamadou Haidara Famakan Kane Fantamady Camara Soumaila Traore Department of Gynecology and Obstetrics of the Fousseyni Daou Hospital in Kayes Kayes Mali National Center for Scientific and Technological Research of Bamako Bamako Mali Kayes Reference Health Center Kayes Mali Anesthesia and Intensive Care Department of the Fousseyni Daou Hospital in Kayes Kayes Mali Management of Fousseyni DAOU Hospital Kayes Mali Reference Health Center of the Commune II Kayes Mali Kalabancoro Reference Health Center Bamako Mali Bla Reference Health Center Bla Mali Kayes Regional Health Directorate Kayes Mali Gynecology and Obstetrics Department of Sikasso Hospital Sikasso Mali

Introduction: The objective of this work was to study maternal deaths noted on arrival in the Gynecology and Obstetrics Department at Fousseyni Daou Hospital in Kayes over a period of 10 years. Materials and Methods: This was a cross-sectional, descriptive study with data collection over a period of 10 years;The data collection was retrospective over nine years from January 1, 2013 to December 31, 2021 and prospective over one year from January 1, 2022 to December 31, 2022. This study focused on all patients whose death was noted on arrival during pregnancy, labor or in the postpartum period in the Gynecology-Obstetrics Department of Fousseyni Daou Hospital. Confidentiality and anonymity were respected. The processing and analysis of statistical data were carried out using SPSS 20.0 software. Results: During the study period, we recorded 93 cases of death noted on arrival out of a total of 606 maternal deaths, i.e., a frequency of 15.34%. The average age was 27 years with the extremes of 20 years and 34 years. They came mainly from rural areas at 74%, were married at 82%, uneducated at 51.6%, housewives at 87.1%. The profession of the spouses is worker at 37.6%. In our sample, evacuated patients were the most represented with 75.3%. Postpartum hemorrhage was the most frequent reason for admission with 22.6%. The deceased patients had no medical history at 86%. In our series, 59.5% of the deceased patients had not had antenatal consultations (CPN). Patients who died on arrival and who had given birth at home were the most represented with 54.8%. Deaths from immediate postpartum hemorrhage complicated by shock were the most frequent with 25.8% followed by severe anemia 8.6%. Deaths were mainly due to direct obstetric causes at 76.3%. In these deaths observed on arrival, the 2nd delay was identified at 48.4%. Conclusion: Maternal deaths observed on arrival remain frequent in the Kayes region. The main causes are immediate postpartum hemorrhage and anemia, which are alm

关键词： Death Observed on Arrival Maternal Mortality Kayes Hospital

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钛酸盐纳米线的制备及其湿敏传感特性

材料科学与工艺 2025年第1期33卷 49-55页

作者：邢坤 z Ryan Tian 王海增淄博市建设项目环境评审服务中心山东淄博255003 Department of Chemistry and Biochemistry University of ArkansasFayettevilleArkansas72701USA 海洋化学理论与工程技术教育部重点实验室(中国海洋大学化学化工学院) 山东青岛266100

为开发一种制备工艺简单且湿敏传感特性优良的材料,本文以二氧化钛P25和NaOH为原料通过水热法制备合成了Na_(2)Ti_(3)O_(7)、Sr_(0.6)Ba_(0.4)TiO_(3)、SrTiO_(3)和BaTiO_(3)纳米线,使用SEM、EDX、XRD设备对材料进行表征,并研究其湿敏... 详细信息

为开发一种制备工艺简单且湿敏传感特性优良的材料,本文以二氧化钛P25和NaOH为原料通过水热法制备合成了Na_(2)Ti_(3)O_(7)、Sr_(0.6)Ba_(0.4)TiO_(3)、SrTiO_(3)和BaTiO_(3)纳米线,使用SEM、EDX、XRD设备对材料进行表征,并研究其湿敏传感特性。结果表明,4种纳米线均具有较大的长径比,但又明显不同,Na_(2)Ti_(3)O_(7)和SrTiO_(3)、BaTiO_(3)、Sr_(0.6)Ba_(0.4)TiO_(3)直径分别约为10、10~200、50~200 nm,长度范围为10至上百微米。以4种纳米线为基础设计的湿敏传感器随频率增大,阻抗值明显减小,变化超过4个数量级;相对湿度(RH)从11%到95%,4种纳米线湿敏传感器的响应恢复时间分别为4、10 s,8、2 s,5、2 s,5、1 s;在重复3次过程中,均无明显基线漂移,响应值相差极小,且重复响应后阻抗值仍能恢复到初值。与其他制备方法相比,该水热制备法简单温和,全为无机原料,无需添加有机前驱体或模板、调节pH值或在高温下反应。4种纳米线湿敏传感器在室温下即可对湿度进行检测,具有灵敏度高、响应恢复速度快、重复性好、稳定性高的特点,在湿敏传感特性上展现出良好的应用潜力。

关键词：纳米线 Na2Ti3O7 Sr0.6Ba0.4TiO3 SrTiO3 BaTiO3 湿敏传感器

Stress analysis near the tips of a transverse crack in an elastic semi-strip

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Applied Mathematics and Mechanics(English Edition) 2017年第7期38卷 935-956页

作者： z. zHURAVLOVA Institute of Mathematics Economics and Mechanics Odessa I. I. Mechnikov National University Odessa 65082 Ukraine

The plane elastic problem for a semi-strip with a transverse crack is inves- tigated. The initial problem is reduced to a one-dimensional continuous problem by use of an integral transformation method with a generalized scheme. The one-dimensional problem is first formulated as a vector boundary problem, and then reduced to a system of three singular integral equations （SIEs）. The system is solved by use of an orthogonal polynomial method and a special generalized method. The contribution of this work is the consideration of kernel fixed singularities in solving the system. The crack length and its location relative to the semi-strip＇s lateral sides are investigated to simplify the problem＇s statement. This simplification reduces the initial problem to a system of two SIEs.

关键词： semi-strip transverse crack Green's function integral transformation,fixed singularity singular integral equation (SIE)

EFFECT OF VINYL ACETATE CONTENT ON THE MECHANICAL PROPERTIES AND MORPHOLOGICAL STRUCTURES OF POLYPROPYLENE

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Chinese Journal of Polymer Science 2006年第1期24卷 29-34页

作者： Mustafa ksüz Technical Education Faculty Marmara University 34722 GztepeIstanbulTurkey

The effect of vinyl acetate （VA） content in ethylene vinyl acetate （EVA） copolyrner on the mechanical properties of polypropylene was investigated. Three different EVA copolymers with concentrations of 3 wt%, 6 wt%, 9 wt%, 12 wt% and 15 wt%, were blended to polypropylene. The mechanical properties such as yield and tensile strengths, elastic modulus, Izod impact strength, hardness and melt flow index of the blends were investigated. Relationship between type of vinyl acetate and concentrations, mechanical, MFI and morphological properties were explored.

关键词： Compound Mechanical properties Morphology.

Influence of Silica Fume on Corrosion Behaviour of Reinforced Steel in Different Media

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Journal of Materials Science & Technology 2002年第1期18卷 83-88页

作者： z.A.El-Hadi I.z.Selim 等 DepartmentofChemistry UniversityCollegeforGirlsAinShamsUniversityEgypt PhysicalChemistryDepartment NationalResearchCenterCairoEgypt

Electrochemical and corrosion behaviour of reinforced steel embedded in cement pastes incorporating different amounts of silica fume as a partial replacement of cement has been studied in chloride and sulphate solutions by using different electrochemical techniques. The results indicate that, while steel passivity degree is low in the control samples' upon soaking in the corrosive media, it has been high in samples incorporating silica fume and increased with increasing silica fume content. The improvement effect of silica fume may be attributed to the pore solution structure of the cement paste, which limits the mobility of aggressive ions near the surface of the steel. The mechanism of steel corrosion due to chloride and sulphate attack and passivation effect of silica fume are discussed.

关键词： Corrosion Reinforced steel Cement pastes Silica fume Aggressive ions

Interactions of molten salts with cathode products in the FFC Cambridge Process

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International Journal of Minerals,Metallurgy and Materials 2020年第12期27卷 1572-1587页

作者： George z.Chen Department of Chemical and Environmental Engineering Faculty of EngineeringUniversity of NottinghamNottingham NG72RDUK Department of Chemical and Environmental Engineering Faculty of Science and EngineeringUniversity of Nottingham Ningbo ChinaNingbo 315100China

Molten salts play multiple important roles in the electrolysis of solid metal compounds,particularly oxides and sulfides,for the extraction of metals or *** of these roles are positive in assisting the extraction of metals,such as dissolving the oxide or sulfide anions,and transporting them to the anode for discharging,and offering the high temperature to lower the kinetic barrier to break the metal-oxygen or metal-sulfur ***,molten salts also have unfavorable effects,including electronic conductivity and significant capability of dissolving oxygen and carbon dioxide *** addition,although molten salts are relatively simple in terms of composition,physical properties,and decomposition reactions at inert electrodes,in comparison with aqueous electrolytes,the high temperatures of molten salts may promote unwanted electrode-electrolyte *** article reviews briefly and selectively the research and development of the F ray-F arthing-Chen(FFC)Cambridge Process in the past two decades,focusing on observations,understanding,and solutions of various interactions between molten salts and cathodes at different reduction states,including perovskitization,non-wetting of molten salts on pure metals,carbon contamination of products,formation of oxychlorides and calcium intermetallic compounds,and oxygen transfer from the air to the cathode product mediated by oxide anions in the molten salt.

关键词： FFC Cambridge Process molten salts electrolysis extraction oxides sulfides metals alloys reaction mechanisms