检索结果-南通市图书馆

Genuine entanglement under squeezed generalized amplitude damping channels with memory

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第2期33卷 158-163页

作者： Mazhar ali Department of Electrical Engineering Faculty of EngineeringIslamic University MadinahMadinah 107Saudi Arabia

We study genuine entanglement among three qubits undergoing a noisy process that includes dissipation, squeezing,and decoherence. We obtain a general solution and analyze the asymptotic quantum states. We find that most of these asymptotic states can be genuinely entangled depending upon the parameters of the channel, memory parameter, and the parameters of the initial states. We study Greenberger–Horne–Zeilinger(GHZ) states and W states, mixed with white noise,and determine the conditions for them to be genuinely entangled at infinity. We find that for these mixtures, it is possible to start with a bi-separable state(with a specific mixture of white noise) and end with genuine entangled states. However, the memory parameter μ must be very high. We find that in contrast to the two-qubit case, none of the three-qubit asymptotic states for n → ∞ are genuinely entangled.

关键词： genuine entanglement squeezed thermal baths multipartite states

Effects of different friction stir welding conditions on the microstructure and mechanical properties of copper plates

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2016年第7期23卷 799-809页

作者： ali Alavi Nia ali Shirazi Department of Mechanical Engineering Bu-Ali Sina University

Friction stir welding is a new and innovative welding method used to fuse materials. In this welding method, the heat generated by friction and plastic flow causes significant changes in the microstructure of the material, which leads to local changes in the mechanical properties of the weld. In this study, the effects of various welding parameters such as the rotational and traverse speeds of the tool on the microstructural and mechanical properties of copper plates were investigated; additionally, Charpy tests were performed on copper plates for the first time. Also, the effect of the number of welding passes on the aforementioned properties has not been investigated in previous studies. The results indicated that better welds with superior properties are produced when less heat is transferred to the workpiece during the welding process. It was also found that although the properties of the stir zone improved with an increasing number of weld passes, the properties of its weakest zone, the heat-affected zone, deteriorated.

关键词： copper friction stir welding mechanical properties microstructure

Sero-Prevalence of Peste des Petits Ruminants Virus Antibodies in Sudanese Sheep and Goats before and after Vaccination

在线全文

学校读者我要写书评

暂无评论

Journal of Biosciences and Medicines 2025年第1期13卷 21-40页

作者： Omer Algezoli Selma Kamal Yazeed Raouf Alamin Mozdalifa Hiba ali Mohamed Aljameel Salih Sir Elkhatim Sulieman Ahmed Ibtesam Fadul Elsied Tageldin Nour Mohamed Abdalla Viral Vaccine Production Department Central Veterinary Research Laboratory Khartoum Sudan College of Veterinary Medicine Sudan University of Science and Technology Khartoum-North Sudan Epidemiology Department Central Veterinary Research Laboratory Khartoum Sudan Foot and Mouth Disease Department Central Veterinary Research Laboratory Khartoum Sudan Virology Department Central Veterinary Research Laboratory Khartoum Sudan Nyala Veterinary Research Laboratory Nyala Sudan Damazine Veterinary Research Laboratory Damazine Sudan Al Obeid Veterinary Research Laboratory Al Obeid Sudan

Peste des petits ruminants virus (PPRV) antibodies were studied in Sudanese sheep and goats (n = 855) before and after vaccination with a locally produced Nigeria 75/1 vaccine using a commercial competitive ELISA (cELISA) kit. Animals were kept healthy under field conditions, in four states: Blue Nile (n = 250), North Kordofan (n = 189), South Darfur (n = 225) and the Northern State (n = 191). Before vaccination, the overall sero-prevalence of PPRV antibodies was 54.6% (53.2% - 56%, 95% CI);high (64.8% - 76.4%, 95% CI) in Blue Nile State, medium (50.5% - 61.9%, 95% CI) in North Kordofan State and South Darfur State and low (28.6% - 35.2% 95%, CI) in Northern State. In high-risk areas (high sero-prevalence), Blue Nile (70.4%) and North Kordofan (57.7%), middle age groups (7 - 12 and 13 - 18 months) were identified as high-risk age. Middle age groups showed lower sero-prevalence than preceding (3 - 6 months) and subsequent (>18 months) age groups while the risk of exposure increased with age. Current and previous findings suggested a transmission pathway of PPRV involving the South Eastern border (Blue Nile) and neighbouring Central Sudan to North Kordofan. One month after vaccination 88.4% (343/388) of sero-negative animals were sero-converted suggesting the efficacy of the locally produced Nigeria 75/1 vaccine. Even if only individuals in the high-risk age group (7 - 18 months) were vaccinated, the overall population immunity (OPI) in high-risk areas (the Blue Nile and North Kordofan) would have surpassed the threshold of 70%, which is indicated for blocking PPRV transmission. However, lower vaccination coverage is expected in wider vaccination programmes. These findings primarily justified the targeting of PPR control in Sudan through the vaccination of high-risk age groups in high-risk areas.

关键词： Peste des Petits Ruminants (PPR) Vaccination Efficacy Seroprevalence Herd Immunity High-Risk Area

Effects of Fe_2O_3 Nanoparticles on Water Permeability and Strength Assessments of High Strength Self-Compacting Concrete

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2012年第1期28卷 73-82页

作者： ali Khoshakhlagh ali Nazari Gholamreza Khalaj Department of Materials Engineering Science and Research BranchIslamic Azad University Department of Materials Engineering Saveh BranchIslamic Azad University

In this work, compressive, flexural and split tensile strength together with coefficient of water absorption of high performance self-compacting concrete containing different amount of Fe2Os nanoparticles have been investigated. The strength and the water permeability of the specimens have been improved by adding Fe2Os nanoparticles in the cement paste up to 4.0 wt%. Fe203 nanoparticle as a foreign nucleation site could accelerate C-S-H gel formation as a result of increased crystalline Ca（OH）2 amount especially at the early age of hydration and hence increase the strength of the specimens. In addition, Fe203 nanoparticles are able to act as nanofillers and recover the pore structure of the specimens by decreasing harmful pores to improve the water permeability. Several empirical relations have been presented to predict the flexural and the split tensile strength of the specimens by means of the corresponding compressive strength at a certain age of curing. Accelerated peak appearance in conduction calorimetry tests, more weight loss in thermogravimetric analysis and more rapid appearance of peaks related to hydrated products in X-ray diffraction results indicate that Fe203 nanoparticles up to 4 wt% could improve the mechanical and the physical properties of the specimens.

关键词： Water permeability Fe203 nanoparticles Compressive strength Split tensilestrength Flexural strength

Comparative Analysis of Dietary Fat Intake among Female University Students in Riyadh: A Cross-Sectional Assessment of Health Sciences versus Non-Health Sciences Disciplines

在线全文

学校读者我要写书评

暂无评论

Food and Nutrition Sciences 2025年第1期16卷 74-94页

作者： Tarfa Albrahim Ahmad T. Almnaizel Nouf Alroqaiba Alhanouf Mohammed Alhawwas Hala ali Domari Lujain Khalid Almasri Wafa Khalid Alotaibi Huda Khalifah Almutairi Rasha Alshaalan Department of Health Sciences and Clinical Nutrition College of Health and Rehabilitation Sciences Princess Nourah Bint Abdulrahman University Riyadh Saudi Arabia Johns Hopkins Aramco Healthcare Dhahran Saudi Arabia

Background: In the global burden of non-communicable diseases, the top slot among them all is occupied by various cardiovascular diseases (CVD), which also claim primacy in mortality rates. Generally speaking, the pathophysiological pathway frequently involves either (or a combination of) elevated serum cholesterol levels, predominantly attributed to dietary patterns characterized by extremely high levels of saturated and trans-fat consumption. Day-to-day nutritional epidemiology among university students suggests that they represent a crucial demographic for the study of preventive interventions. Objective: This in-depth study and investigation were specifically aimed to quantitatively assess and compare prevailing patterns of dietary fat consumption between female students enrolled in health sciences and non-health sciences programs at major universities in Riyadh, Saudi Arabia. Methodology: This cross-sectional study was comprised of 434 Saudi female university students (age range: 18 - 25 years), utilizing a validated Block Dietary Fat Screener accompanied by anthropometric measurements and comprehensive demographic data collection. The sampling methodology consisted of a snowball technique that was spread across three major academic institutions in Riyadh. Results: Statistical analysis revealed a significant association between academic specialization and patterns of dietary fat consumption (p = 0.012). Paradoxically, students of health science exhibited a higher prevalence of very high fat intake (41.9%) compared with their non-health sciences counterparts (27.6%). Surprisingly, anthropometric stratification revealed that it was the underweight students who demonstrated very high levels of fat consumption. A notable socioeconomic gradient was observed, with students from households earning 15,000 - 20,000 SR monthly showing the highest prevalence of very high-fat consumption (47.1%), although this association did not achieve statistical significance (p = 0.104

关键词： Cardiovascular Disease Risk Factors Dietary Fat Consumption Patterns Female University Students Health Sciences Education Nutritional Epidemiology Saudi Arabia

A VERSATILE AND REGIOSELECTIVE SYNTHESIS OF VICINAL AZIDOALCOHOLS USING CROSS-LINKED POLY(4-VINYLPYRIDINE) SUPPORTED AZIDE ION UNDER SOLVENT-FREE CONDITIONS

维普期刊数据库评论

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 Journal of Polymer Science 2013年第12期31卷 1660-1669页

作者： Mohammad ali Karimi Zarchi ali Tarabsaz Department of Chemistry College of ScienceYazd University

A new polymeric reagent, cross-linked poly（4-vinylpyridine） supported azide ion, [P4-VP]N3, was introduced as polymeric reagents for efficient and regioselective conversion of epoxides to azidohydrins in the presence of cross-linked poly（4-vinylpyridine） supported sulfuric acid, [P4-VP]H2SO4, as a solid proton source and as catalyst under solvent-free conditions. The advantages of this polymeric reagent over some of those reported in the literature are easy work-up procedure and regeneration of the reagent.

关键词： Ring opening of epoxide fl-Azidoalcohols Poly(4-vinytpyridine) Solvent-free conditions Regioselectivity.

Effect of mineral additives and permeability reducing admixtures having different action mechanisms on mechanical and durability performance of cementitious systems

在线全文

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2021年第5期15卷 1277-1291页

作者： ali NEMATZADEH Burcu AYTEKIN ali MARDANL-AGHABAGLOU Department of Civil Engineering Bursa Uludag UniversityNilufer-Bursa 16059Turkey

In this paper,the effect of usage of the permeability reducing admixture(PRA)having different action mechanisms on hardened state properties of cementitious systems containing mineral additives is *** this aim,three commercial PRAs were used during *** effective parameters in the first and third PRAs were air-entraining and high-rate air-entraining,*** second one contained the insoluble calcium carbonate residue and had a small amount of the air-entraining *** mixes with binary and ternary cementitious systems were prepared by partially replacing cement with fly ash and *** hardened state properties of mortar mixtures such as compressive strength,ultrasonic pulse velocity,water absorption,drying shrinkage and freeze-thaw resistance were *** ternary cement-based mixture having both fly ash and metakaolin was selected as the most successful mineral-additive bearing mix in regard to hardened state *** this sense,PRA-B,with both insoluble residues and a small amount of air-entraining properties,showed the best performance among the mixtures containing *** combined use of mineral additive and PRA had a more positive effect on the properties of the mixes.

关键词： cementitious system mineral additive permeability reducing admixture mechanical properties durability performance

Design and Optimization of 3D Radial Slot Grain Configuration

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2010年第4期23卷 409-414页

作者： ali Kamran School of Astronautics Beijing University of Aeronautics and Astronautics

Upper stage solid rocket motors （SRMS） for launch vehicles require a highly efficient propulsion system. Grain design proves to be vital in terms of minimizing inert mass by adopting a high volumetric efficiency with minimum possible sliver. In this arti- cle, a methodology has been presented for designing three-dimensional （3D） grain configuration of radial slot for upper stage solid rocket motors. The design process involves parametric modeling of the geometry in computer aided design （CAD） software through dynamic variables that define the complex configuration. Grain bum back is achieved by making new surfaces at each web increment and calculating geometrical properties at each step. Geometrical calculations are based on volume and change-in-volume calculations. Equilibrium pressure method is used to calculate the internal ballistics. Genetic algorithm （GA） has been used as the optimizer because of its robustness and efficient capacity to explore the design space for global optimum solution and eliminate the requirement of an initial guess. Average thrust maximization under design constraints is the objective function.

关键词： solid rocket motors 3D grains radial slot configuration internal ballistics computer aided design heuristic optimization genetic algorithm

Decrease of back recombination rate in CdS quantum dots sensitized solar cells using reduced graphene oxide

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2015年第4期24卷 372-377页

作者： ali Badawi Department of Physics Faculty of Science Taif University

The photovoltaic performance of CdS quantum dots sensitized solar cells （QDSSCs） using the 0.2 wt% of reduced graphene oxide and TiO2 nanoparticles （RGO＋TiO2 nanocomposite） photoanode is investigated. CdS QDs are adsorbed onto RGO＋TiO2 nanocomposite films by the successive ionic layer adsorption and reaction （SILAR） technique for several cycles. The current density-voltage （J-V） characteristic curves of the assembled QDSSCs are measured at AM1.5 simulated sunlight. The optimal photovoltaic performance for CdS QDSSC was achieved for six SILAR cycles. Solar cells based on the RGO＋TiO2 nanocomposite photoanode achieve a 33% increase in conversion efficiency （η） compared with those based on plain TiO2 nanoparticle （NP） photoanodes. The electron back recombination rates decrease significantly for CdS QDSSCs based on RGO＋TiO2 nanocomposite photoanodes. The lifetime constant （τ） for CdS QDSSC based on the RGO＋TiO2 nanocomposite photoanode is at least one order of magnitude larger than that based on the bare TiO2NPs photoanode.

关键词： reduced graphene oxide nanocomposite photoanode back recombination rate quantum dots sensitized solar cell