检索结果-南通市图书馆

The competitive and synergistic effect between adsorption enthalpy and capacity in D_(2)/H_(2)separation of M_(2)(m-dobdc)frameworks

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2021年第11期32卷 3562-3565页

作者： Fan Wu Liqiong Li Yanxi Tan El-sayed M.El-sayed Daqiang Yuan State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China University of the Chinese Academy of Sciences Beijing 100049China College of Chemistry Fuzhou UniversityFuzhou 350108China Chemical Refining Laboratory Refining DepartmentEgyptian Petroleum Research InstituteNasr CityCairo 11727Egypt

Hydrogen isotope separation is a challenging task due to their similar ***,based on the chemical affinity quantum sieve(CAQS)effect,the D_(2)/H_(2)separation performance of M_(2)(m-dobdc)(M=Co,Ni,Mg,Mn;m-dobdc^(4-)=4,6-dioxido-1,3-benzenedicarboxylate),a series of honeycomb-shaped MOFs with high stability and abundant open metal sites,are studied by gases sorption and breakthrough experiments,in which two critical factors,gas uptake and adsorption enthalpy,are taken into *** these MOFs,Co_(2)(m-dobdc)exhibits the longest D_(2)retention time of 180 min/g(H_(2)/D_(2)/Ne:1/1/98)at 77 K because of its second-highest adsorption enthalpy(10.7 kJ/mol for H_(2)and 11.8 kJ/mol for D_(2))and the best sorption capacity(5.22 mmol/g for H_(2)and 5.49 mmol/g for D_(2))under low pressure of 1 kPa and 77 K,which make it a promising material for industrial hydrogen isotope ***,the results indicate that H_(2)and D_(2)capacities under low pressure(about 1 kPa)dominate the final D_(2)/H_(2)separation property of MOFs.

关键词： Breakthrough experiment Open metal sites Hydrogen isotope separation Sorption and separation Chemical affinity quantum sieve

Tie-line Power Flow Control Method for Gridconnected Microgrids with SMES Based on Optimization and Fuzzy Logic

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Journal of Modern Power Systems and Clean Energy 2020年第5期8卷 941-950页

作者： sayed M.Said abdelfatah Ali Bálint Hartmann Department of Electrical Engineering Aswan University81542 AswanEgypt Department of Electric Power Engineering Budapest University of Technology and Economics1111 BudapestHungary Department of Electrical Engineering South Valley University83523 QenaEgypt

In an active distribution grid,renewable energy sources(RESs)such as photovoltaic(PV)and energy storage systems(e.g.,superconducting magnetic energy storage(SMES))can be combined with consumers to compose a microgrid(MG).The high penetration of PV causes high fluctuations of tie-line power flow and highly affects power system *** can lead to several technical problems such as voltage fluctuations and excessive power *** this paper,a fuzzy logic control based SMES method(FSM)and an optimized fuzzy logic control based SMES method(OFSM)are proposed for minimizing the tie-line power ***,the fluctuations and transmission power losses are *** FSM,SMES is used with a robust fuzzy logic controller(FLC)for controlling the tie-line power *** optimization model is employed in OFSM to simultaneously optimize the input parameters of the FLC and the reactive power of the voltage source converter(VSC)of *** objective function of minimizing the tieline power flow is incorporated into the optimization *** swarm optimization(PSO)algorithm is utilized to solve the optimization problem while the constraints of the utility power grid,VSC,and SMES are *** simulation results demonstrate the effectiveness and robustness of the proposed methods.

关键词： Utility power grid microgrid photovoltaic(PV) superconducting magnetic energy storage(SMES) tie-line power fuzzy logic control(FLC)

Simulation of Fracture Process of Lightweight Aggregate Concrete Based on Digital Image Processing Technology

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第6期79卷 4169-4195页

作者： Safwan Al-sayed Xi Wang Yijiang Peng Key Laboratory of Urban Security and Disaster Engineering Ministry of EducationBeijing University of TechnologyBeijing100124China

The mechanical properties and failure mechanism of lightweight aggregate concrete(LWAC)is a hot topic in the engineering field,and the relationship between its microstructure and macroscopic mechanical properties is also a frontier research topic in the academic *** this study,the image processing technology is used to establish a micro-structure model of lightweight aggregate *** the information extraction and processing of the section image of actual light aggregate concrete specimens,the mesostructural model of light aggregate concrete with real aggregate characteristics is *** numerical simulation of uniaxial tensile test,uniaxial compression test and three-point bending test of lightweight aggregate concrete are carried out using a new finite element method-the base force element method ***,the image processing technology is used to produce beam specimens,uniaxial compression specimens and uniaxial tensile specimens of light aggregate concrete,which can better simulate the aggregate shape and random distribution of real light aggregate ***,the three-point bending test is numerically ***,the uniaxial compression specimen generated by image processing technology is numerically ***,the uniaxial tensile specimen generated by image processing technology is numerically *** mechanical behavior and damage mode of the specimen during loading were *** results of numerical simulation are compared and analyzed with those of relevant *** feasibility and correctness of the micromodel established in this study for analyzing the micromechanics of lightweight aggregate concrete materials are *** processing technology has a broad application prospect in the field of concrete mesoscopic damage analysis.

关键词： Digital image processing lightweight aggregate concrete mesoscopic model numerical simulation fracture analysis bending beams

The Role of Bcl-2, CD10 and CD34 Expression in Differentiation between Basal Cell Carcinoma and Trichoepithelioma

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Pathology 2014年第3期4卷 116-124页

作者： sayed abdel Raheem Rabee Alsahaer Alsayed Tealeb Emad Rushdy Pathology Department Faculty of Medicine Al-Azhar University Cairo Egypt

Background: Basal cell carcinoma (BCC) and trichoepithelioma (TE) have some similarities clinically and histologically. The aim of this work is to evaluate the role of Bcl-2, CD10 and CD34 in differentiation between BCC and TE. Methods: The immunohistochemical expression of Bcl-2, CD10 and CD34 was evaluated in 20 BCCs and 12 TEs in a retrospective study. The localization of these markers in tumor and stromal cells was determined and comparison between BCC and TE was done. Immunohistochemistry for Bcl-2, CD10 and CD34 was performed on sections obtained from formalin-fixed, paraffin-embedded blocks. Bcl-2, CD10 and CD34 immunoreactivity in the stromal and/or tumor cells was determined as follows: negative (0);1+ (10% - 50% positive cells);and 2+ (>50% positive cells). Results: In BCC (20 cases), the expression of Bcl-2 in stromal cells showed (0) immunoreactivity in 8 cases (40%), (1+) immunoreactivity in 7 cases (35%), and (2+) immunoreactivity in 5 cases (25%). Tumoral cells showed diffuse positivity in 20 out of 20 cases (100%), (1+) immunoreactivity in 5 cases (25%) and (2+) immunoreactivity in 15 cases (75%). On the other hand, the expression of Bcl2 in TE, 4 cases showed positive stromal cells out of 12 (33.33%), (1+) immunoreactivity in 2 cases (16.6%) and (2+) immunoreactivity in 2 cases (16.6%), and 8 cases showed no immunoreactivity. Tumoral cells showed positivity in 12 out of 12 cases (100%), (1+) immunoreactivity in 5 cases (41.6%), (2+) immunoreactivity in 7 cases (58.3%). In BCC cases, the expression of CD10 was noted in stromal cells in 8 out of 20 cases (40%), 5 cases showed positivity in stromal and basaloid cells and 3 cases showed positivity in stromal cells only, and 12 cases showed no immunoreactivity (60%). Tumor cells showed positivity in 11 cases out of 20 (55%), (1+) immunoreactivity in 6 cases (30%), (2+) in 5 cases (25%), and 9 cases showed no immunoreactivity (45%). On the other hand, the expression of CD10 in TE 7 cases showed positive s

关键词： Basal Cell Carcinoma Trichoepithelioma Bcl-2 CD10 CD34

The Aghajari (Upper Fars) Formation in the Folded Zagros Zone, Iran: Insights to Identify Facies, Architectural Elements, Fluvial Systems, Petrography and Provenance

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2013年第4期87卷 1019-1031页

作者： Mohammad SAHRAEYAN Mohammad BAHRAMI sayed Hassan HEJAZI Department of Geology Islamic Azad University Khorasgan (Esfahan) Branch Department of Geology Islamic Azad University Fars Science and Research Branch

The Aghajari Formation, called also the Upper Fars, develops throughout the Folded Zagros Zone and its thickness in the type section in southwest of Iran is 2966 meters. To analyze the sedimentary basin of this Formation, lithofacies, architectural elements and petrofacies of the related deposits in a section in southeast of Sarvestan in Fars Province of Iran with a thickness of 2221.45 meters were examined. Microscopically studying thin sections, the petrography and the occurrence of the deposits were determined. In this section, 16 lithofacies, 10 architectural elements and 2 sandstone petrofacies were identified. The lithofacies were divided into two major and minor groups, in which the major lithofacies consist of coarse-grained （Gh, Gp, Gt and Gm）, medium-grained （Sh, Sp, St, Sl, Sm, Sr and Ss and fine-grained ones （Fm, Fl and Fsm）, and the minor lithofacies were evaporative and mixed silisiclastic-carbonate. The identified architectural elements are CH, SB, GB, LA, DA, CR, CS, LV, LS, CH （FF） and FF. By combining evidences from facies analysis and architectural elements together, the Aghajari Formation was divided into three parts in which the related sedimentation environments, from top to bottom, are gravel, gravel-sand and fine-grained meandering river respectively. There have also been playas and shoreface in the lower part. Based on petrography, the sandstones of this formation were classified into two groups： litharenite and sublitharenite. The origin of these deposits （sandstones） was appointed to the recycled orogeny and the source of quartz is low and medium to high metamorphic rank. Using the field evidences, the paleocurrent direction was achieved indicating the direction of the paleocurrent from northwest to southeast at the time of deposition. It is hoped that these data can be used in the interpretation of the basin and reconstruction of the paleogeography in the local and regional scales.

关键词： Aghajari Formation lithofacies architectural elements folded Zagros zone Iran,provenance

Fabrication and characterization copper/diamond composites for heat sink application using powder metallurgy

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Natural Science 2011年第11期3卷 936-947页

作者： Zeinab abdel Hamid sayed F. Moustafa Fatma A. Morsy Nevien abdel Atty khalifa Fatma abdel Mouez 不详

Copper composites reinforced with diamond particles were fabricated by the powder metallurgical technique. Copper matrix and diamond powders were mixed mechanically, cold com- pacted at 100 bar then sintered at 900?C. The prepared powders and sintered copper/diamond composites were investigated using X-ray diffraction (XRD) and scanning electron microscope equipped with an energy dispersive X-ray analysis (SEM/EDS). The effect of diamond contents in the Cu/diamond composite on the different properties of the composite was studied. On fracture surfaces of the Cu/uncoated diamond composites, it was found that there is a very weak bonding between diamonds and pure copper matrix. In order to improve the bonding strength between copper and the reinforcement, diamond particles were electroless coated with NiWB alloy. The results show that coated diamond particles distribute uniformly in copper composite and the interface between diamond particles and Cu matrix is clear and well bonded due to the formation of a thin layer from WB2, Ni3B, and BC2 between Cu and diamond interfaces. The properties of the composites materials using coated powder, such as hardness, transverse rupture strength, thermal conductivity, and coefficient of thermal expansion (CTE) were exhibit greater values than that of the composites using uncoated diamond powder. Additionally, the results reveals that the maximum diamond incorporation was attained at 20 Vf%. Actually, Cu/20 Vf% coated diamond com- posite yields a high thermal conductivity of 430 W/mK along with a low coefficient of thermal expansion (CTE) 6 × 10–6/K.

关键词： Powder Metallurgy Ceramic-Matrix Composites (CMCs) Ceramics Coating Electroless

Fabrication and Characterization of Tungsten Heavy Alloys Using Chemical Reduction and Mechanical Alloying Methods

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Applied Sciences 2013年第1期3卷 15-27页

作者： Zeinab abdel Hamid sayed Farag Moustafa Walid Mohamed Daoush Fatema abdel Mouez Mona Hassan Corrosion Control and Surface Protection Department Central Metallurgical R&D Institute Helwan Cairo Egypt Powder Technology Department Central Metallurgical R&D Institute Helwan Cairo Egypt

A novel reduction technique has been developed to synthesize nano-sized tungsten heavy alloys powders and compared with the same powders processed by mechanical alloying technique. In the first method, nano-sized tungsten heavy alloys powders have been obtained by reduction of precursors obtained by spray drying of several appropriate aqueous solutions, which were made from salts containing tungsten, cobalt, and nickel. By adjusting the stoichiometry of the component of the solutions, it is possible to obtain the desired chemical composition of the tungsten heavy alloys powders. In the second method, highly pure elemental powders of tungsten heavy alloys have been mechanically alloyed in a tumbler ball mill for different milling time. The investigated tungsten heavy alloy powders with the composition (95%W-3.5%Ni-1.5%Fe), (93%W-4.5%Ni-1.0%Fe-1.5%Co), and (90%W-6%Ni-4%Cu) have been prepared using both methods. The prepared powders have been compacted at 70 bar (200 MPa) and sintered in vacuum furnace at 1400℃. Vacuum sintering was carried out to achieve full densification of the produced tungsten heavy alloys. The investigated materials were going to be evaluated the physical and mechanical properties of the sintered parts such as density;electrical conductivity, hardness, and transverse rupture strength. The results reveal that, the grain size of alloys fabricated by chemical reduction technique (53.1 - 63.8 nm) is smaller than that fabricated by mechanical alloying technique (56.4 - 71.4 nm).

关键词： Tungsten Heavy Alloys Mechanical Alloying Chemical Reduction Powder Metallurgy Hardness Transverse Rupture Strength Conductivity

Synthesis and Spectral Identification of Novel Stable Triazene: As Raw Material for the Synthesis Biocompatible Surfactants-Pyrazole-Isoxazole-Dihydropyrimidine-Tetrahydropyridine Derivatives

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Organic Chemistry 2016年第1期6卷 44-54页

作者： Mohamed Ahmed Mahmoud abdel Reheim Ahmed Mahmoud El-sayed Tolba Department of Chemistry Faculty of Science Suez Canal University Arish Egypt

The chemical reactivity of novel stable triazene 3 toward some nucleophilic and electrophilic reagents was investigated. Traizene 3 was used as a key precursor for the synthesis of some novel important heterocyclic compounds such as Pyrazole, Isoxazole, Dihydropyrimidine, Tetrahydro-pyridine derivatives with expected antimicrobial activity. The synthesized compounds were obtained in good yields. The structures of the newly synthesized compounds were confirmed by elemental analysis, IR, 1H-NMR and Ms spectral data.

关键词： Biocompatible Surfactants Pyrazole Isoxazole Dihydropyrimidine Tetrahydropyridine Derivatives Spectral Characteristics

The Role of CK20, p53 and p63 in Differentiation of Some Urothelial Lesions of Urinary Bladder, Immunohistochemical Study

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Pathology 2014年第4期4卷 181-193页

作者： sayed abdel Raheem abdel Naby Saied Rabee Al Shaer Osama Mustafa Ali Hassan Ali Departments of Pathology and Anatomy Faculty of Medicine Al Azhar University Cairo Egypt

Background: Differentiation of urothelial hyperplasia, dysplasia and carcinoma in situ (CIS) may pose diagnostic difficulties. We aim to evaluate the role of CK20, p53 and p63 in differentiation of such lesions. Methods: we evaluate these markers in 213 cases of bladder lesions (14 hyperplasia, 7 dysplasia, 5 CIS, 25 noninvasive and 162 invasive urothelial carcinoma) in a retrospective study on sections from formalin-fixed, paraffin-embedded blocks. Cytoplasmic staining considered for CK20 and nuclear staining for p53 and p63. Results: CK20 was expressed in 14 out of 14 hyperplasia (4 strong, 7 moderate, 3 weak), in 7 out of 7 dysplasia (4 strong , 3 moderate), in 5 out of 5 CIS, in 19 out of 25 noninvasive carcinoma;strong in 11 (7 low grade, 4 high grade), moderate in 7 (5 low grade, 2 high grade), and weak in 1 case of low grade, in 136 out of 162 invasive carcinoma;strong in 46 (22 grade II, 24 grade III), moderate in 71 (2 grade I, 58 grade II, 11 grade III), and weak in 19 (2 grade I, 15 grade II, 2 grade III), no expression in 2 cases of grade IV. p53 was expressed in 7 out of 14 hyperplasia (weak in all cases), in 7 out of 7 dysplasia (5 strong, 2 moderate), in 5 out of 5 CIS (strong in all cases), in 20 out of 25 noninvasive carcinoma (8 strong, 9 moderate, 3 weak), in 135 out of 162 invasive carcinoma (34 strong, 73 moderate, 28 weak). p63 was expressed in 14 out of 14 hyperplasia, in 7 out of 7 dysplasia, in 4 out of 5 CIS, in 25 out of 25 noninvasive carcinoma, and in 134 out of 162 invasive carcinoma (28 strong, 63 moderate, 43 weak). CK20 was insignificant in noninvasive and significant in invasive carcinoma, while p53 and p63 were significant in noninvasive and invasive carcinoma. Conclusion: CK20, p53 and p63 are useful in differentiation of different bladder lesions.

关键词： Urothelial Lesions CK20 p53 p63