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Insect Science 2021年第6期28卷 1512-1529页

作者： Farhan Ahmad Gui-Ying Yang Shi-You Liang Qi-Huan Zhou hassan ahmed gaal Jian-Chu Mo Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insect Pests Institute of Insect SciencesCollege of Agricultural and BiotechnologyZhejiang UniversityHangzhouChina Entomology Section Central Cotton Research InstituteSakrandShaheed BenazirabadSindhPakistan Department of Entomology Faculty of Veterinary and Animal HusbandrySomali National UniversityMogadishuSomalia

Fungus-growing termites are among the most successful herbivorous animals and improve crop productivity and soil fertility.A range of symbiotic organisms can be found inside their ***,interactions of termites with these symbionts are poorly *** review provides detailed information on the role of multipartite symbioses(between termitophiles,termites,fungi,and bacteria)in fungus-growing termites for lignocellulose *** specific functions of each component in the symbiotic system are also *** on previous studies,we argue that the enzymatic contribution from the host,fungus,and bacteria greatly facilitates the decomposition of complex polysaccharide plant *** host-termitophile interaction protects the termite nest from natural enemies and maintains the stability of the microenvironment inside the colony.

关键词： bacteria enzyme activity lignocellulose degradation Macrotermitinae symbiosis Termitomyces

Nanosecond pulse and dual-wavelength Q-switched 1.5 μm fiber laser using MAX phase Cr2TiAlC2 saturable absorber

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Optoelectronics Letters 2025年第1期21卷 7-12页

作者： ahmed Shakir AL-HITI Hiba hassan Department of Electrical Engineering Faculty of Engineering University of Anbar Department of Laser and Optoelectronics Engineering University of Technology-Iraq

We demonstrated a new type of MAX phase material, chromium titanium aluminum carbide（Cr2TiAlC2） polymer film, to generate a passively Q-switched erbium-doped fiber laser（EDFL）. The film thickness was measured to be around 45 μm, which was fabricated using the embedding method with polyvinyl alcohol（PVA） polymer as hoster. The saturable absorber（SA） film demonstrates a dual-wavelength passively Q-switched EDFL which operates at 1 531 nm and 1 560.19 nm, respectively. The Q-switching pulse duration could be varied from 2.46 μs to 770 ns, while the repetition rate varied from 92.76 kHz to 106.6 kHz with an increasing input pumping range from 154 mW to 300 mW. The maximum output power and pulse energy of 15.05 mW and 141.18 nJ were obtained at the maximum input power of 300 mW, respectively.

关键词： Saturable absorbers

Dry face milling of titanium alloys

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Journal of University of Science and Technology Beijing 2004年第6期11卷 545-548页

作者： ahmed hassan Manufacturing and Automation Department

In machining titanium alloys, cutting tools generally wear out very rapidlybecause of the high cutting temperature resulted from the low thermal conductivity and density ofthe work material. In order to increase the tool life, it is necessary to suppress the cutting heatas much as possible by applying an abundant amount of coolant, but this will entail serioustechno-environmental and biological problems. To study the performance and avoid these limitations,a PVD-coated insert was used to the dry face mill of (alpha + beta) titanium alloys. As a result itwas found that the inserts exhibit an excellent cutting performance at low cutting speeds and feedrates, and there is no significant difference in the dominant insert failure mode between the wetand dry cutting in discontinuous cutting.

关键词： carbide tool face milling titanium alloy

DISTRIBUTED WATER BALANCE WITH RIVER DYNAMIC-DIFFUSIVE FLOW ROUTING MODEL

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Journal of Hydrodynamics 2009年第4期21卷 564-572页

作者： hassan ahmed NORIO Tanaka NOBUYUKI Tamai Graduate School of Science and Engineering Saitama University Graduate School Kanazawa Gakuin University

This article focuses on the application of coupling both river dynamic and river diffusive modeling techniques that can be used with distributed water balance model. In an upstream watershed, both overland and river diffusive flows are routed by diffusive wave approximation of the free surface flow equations. In river downstream reaches, the river dynamic flow is routed by one-dimensional dynamic wave equations （full dynamic St. Venant equations with lateral flow）. The developed model is applied in a part of Arakawa River basin, Kanto area, Japan. The geographic data of river cross sections could be accurately represented by an 11-point cross-section approximation. The effects of both the grid size and lateral flow on the simulated results of the river dynamic flow model were studied. The grid size should be greater than the average width of the river cross-sections. The lateral flow from small drainage systems has significant effects on the simulated results using the river dynamic flow model. The simulated results show good and acceptable agreements with the observed flow discharges and water depths. Both the river discharge and water depth at any location of river network of compound channels with one/two complex floodplains could be correctly estimated.

关键词： diffusive model dynamic model natural compound channels floodplains

Relative performance of novel blast wave mitigation system to conventional system based on mitigation percent criteria

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Defence Technology（防务技术） 2021年第3期17卷 912-922页

作者： Moustafa Esa Mostafa S.Amin ahmed hassan Eng.Mechanics Dept. Military Technical CollegeKobry ElkobbahCairoEgypt Civil Eng.Dept. Military Technical CollegeKobry ElkobbahCairoEgypt

Recent researches focused on developing robust blast load mitigation systems due to the threats of terrorist *** of the main embraced strategies is the structural systems that use mitigation *** are developed from a combination of structural elements and described herein as conventional *** the promising techniques is that redirect the waves propagation through hollow *** blast wave propagation through tubes provides an efficient system since it combines many blast wave phenomena,such as reflection,diffraction,and *** this research,a novel blast load mitigation system,employed as a protection fence,is developed using a technique similar to the technique of the bent tube in manipulating the *** relative performance of the novel system to the conventional system is evaluated based on mitigation percent *** of both systems are calculated through numerical *** proposed novel system proved to satisfy high performance in mitigating the generated blast waves from charges weight up to 500 kg TNT at relatively small standoff distances(5 m and 8 m).It mitigates at least 94%of the blast waves,which means that only 6%of that blast impulse is considered as the applied load on the targeted structure.

关键词： Blast mitigation Blast barriers Protection system Mitigation percent Protection evaluation

Magnetoresistive properties of Ni-doped La_(0.7)Sr_(0.3)MnO_3 manganites

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Rare Metals 2016年第7期35卷 551-558页

作者： ahmed Mohamed ahmed Abd El-Moez ahmed Mohamed Medhat Abdelrady Abdellateef hassan ahmed Abd El-Ghanny Physics Department Faculty of ScienceSohag University

Lao.7Sr0.3Mnl_xNixO3 （x = 0, 0.025, 0.050 and 0.075） ceramics were prepared by the conventional solid-state reaction method. The partial substitution of Mn by Ni2＋ leads to a decrease in cell volume as well as a structural transition from the rhombohedral to the orthorhombic structure. Ni2＋ doping increases the electrical resistivity, decreases the semiconductor-metal transition temperature （Tms） and relatively enhances the room temperature magnetoresistance （MR）, especially in x = 0.025 and around Tins. With respect to conduction mechanism, the small polaron hopping （SPH） and the variable range hopping （VRH） models were used to ex- amine conduction in the semiconducting region.

关键词： Manganites X-ray diffraction Structure Electrical resistivity Magnetoresistance

Application of 3D Static Modelling in Reservoir Characterization:A Case Study from the Qishn Formation in Sharyoof Oil Field,Masila Basin,Yemen

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Acta Geologica Sinica(English Edition) 2022年第1期96卷 348-368页

作者： Emad A.ABDULLAH ahmed ABDELMAKSOUD Musab A.hassan Department of Mineral Developing and Oil&Gas Engineering Academy of EngineeringPeople’s Friendship University of Russia(RUDN University)Moscow 117198Russia Department of Earth Sciences Khalifa UniversityAbu Dhabi 127788United Arab Emirates Department of Geology Faculty of ScienceAssiut UniversityAssiut 71516Egypt

Three-dimensional(3 D)static modelling techniques are applied to the characterization of the Qishn Formation(Fm.)in the Sharyoof oil field locating within the Masila basin,southeastern *** present study was initiated by the seismic structural interpretation,followed by building a 3 D structural framework,in addition to analysing well log data and from these,3 D facies and petrophysical models are *** the Sharyoof oil field,the Qishn *** depth values within the range of 400-780 m below sea level,with a general increase towards the SSE.A set of high dip angle normal faults with a general ENE-WSW trend dissect the *** strata are also folded as a main anticline with an axis that is parallel to the fault trend,formed as a result of basement *** to the facies models,the Qishn *** 43.83% limestone,21.53% shale,21.26% sandstone,13.21% siltstone and 0.17% *** Qishn Carbonates Member has low porosity values making it a potential seal for the underlying reservoirs whereas the Upper Qishn Clastics SI A and C have good reservoir quality and SIB has fair reservoir *** Upper Qishn Clastics S2 and S3 also have fair reservoir quality,while the Lower Qishn Clastics zone has good reservoir *** water saturation decreases towards the west and east and increases towards north and *** total original oil in-place(OOIP)of the Upper Qishn clastics is 106 million STB within the SI A,SIC and S2 *** of development wells is recommended in the eastern study area,where good trapping configuration is exhibited in addition to the presence of a potential seal(Upper Qishn Carbonates Member)and reservoir(Qishn Clastics Member)with high porosity and low water saturation.

关键词： upstream exploration petroleum basins seismic interpretation structural modelling well log analysis facies modelling petrophysical modelling Sayun-Masila basin

CATIONIC RING-OPENING POLYMERIZATION OF TETRAHYDROFURAN WITH KEGGIN-TYPE HETEROPOLYCOMPOUNDS AS SOLID ACID CATALYSTS

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Chinese Journal of Polymer Science 2010年第3期28卷 305-310页

作者： ahmed Aouissi Salim Salem Al-Deyab hassan Al-Shehri Chemistry Department College of ScienceKing Saud UniversityRiyadhKSA

Three Keggin-type heteropolyanions, namely H3PMo12O40-13H2O, （NH4）3PMo12O40·4H2O and H3PW12O40·13H2O were prepared and tested in the ring-opening polymerization reaction of tetrahydrofuran. The effects of the counter-cation （H＋, NH4＋） and the peripheral atoms （Mo, W） on the polymerization were investigated. It has been found that when the protons of H3PMo12O40·13H2O were replaced by the ammonium cations the polymerization rate decreased dramatically. Whereas, when the peripheral atoms （Mo） were replaced by their homologous （W）, the polymerization rate increased twofold. As for the viscosity average molecular weight （My） of polymer products, it was found that the high molecular weight （7930） was obtained by using H3PW12O40·13H2O. The molecular weight （My） obtained by H3PMo12O40·13H2O and （NH4）H3PMo12O40·13H2O was 6470 and 6810, respectively.

关键词： Tetrahydrofuran Heteropoly compounds Ring opening polymerization Cyclic ether Solid acid

Optimization of Cutting Parameters for Face Milling Titanium Alloy Using MQL

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Journal of Donghua University(English Edition) 2005年第2期22卷 9-12页

作者： ahmed hassan 姚振强 Department of Manufacturing and Automation Shanghai Jiaotong University Shanghai 200030

When using MQL as a cooling technique, many parameters have to be adjusted. The Taguchi method was used in this study to investigate the cutting characteristics of face milling of titanium alloys using PVD-coated inserts. To find the optimal volume removed and surface roughness, an orthogonal array, the signal-to-noise (S/N) ratio and the analysis of variance (ANOVA) were employed. The optimum cutting parameters was obtained. Throughout this study, it was found that the feed rate is the most influencing cutting parameter in the face milling of titanium alloys.

关键词： Taguchi method milling titanium alloy MQL

Experimental and numerical investigation of the abrasive waterjet machining of aluminum-7075-T6 for aerospace applications

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Advances in Manufacturing 2021年第2期9卷 286-303页

作者： Joseck Nyaboro Mahmoud ahmed hassan El-Hofy Mohamed El-Hofy Department of Industrial and Manufacturing Engineering Egypt-Japan University of Science and Technology(E-JUST)Alexandria 21934Egypt Department of Energy Resources Engineering Egypt-Japan University of Science and Technology(E-JUST)Alexandria 21934Egypt Advanced Manufacturing Research Centre(AMRC)with Boeing The University of SheffieldRotherham S605TZUK

The machining of hard-to-cut materials with a high degree of precision and high surface quality is one of the most critical considerations when fabricating various state-of-the-art engineered *** this investigation,a comprehensive three-dimensional model was developed and numerically simulated to predict kerf profiles and material removal rates while drilling the aluminum-7075-T6 aerospace *** profile and material removal prediction involved three stages:jet dynamic flow modeling,abrasive particle tracking,and erosion rate *** investigations were conducted to validate the developed *** results indicate that the jet dynamic characteristics and flow of abrasive particles alter the kerf profiles,where the top kerf diameter increases with increasing jet pressure and standoff *** kerf depth and hole aspect ratio increase with jet pressure,but decrease with standoff distance and machining *** profiles were characterized by progressive edge rounding and parabolic *** can be minimized by utilizing high jet pressure and small standoff *** material removal rate increases with increasing jet pressure,abrasive particle size,and exposure time,but decreases with increasing standoff distance.

关键词： Non-traditional machining Abrasive waterjet machining Computational fluid dynamics(CFD) Erosion modeling Kerf characteristics