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Acta Mechanica Solida Sinica 2022年第2期35卷 228-238页

作者： shahzad Fateh Ali Jitang Fan Jianqing Feng Xiangquan Wei State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China Aerospace System Engineering shanghai Shanghai 201109China

A strain-rate-sensitive polyurethane elastomer is numerically investigated to reveal improved impact characteristics and analyze the concerned rate dependencies and dynamic energy dissipation features.A physical constitutive model in view of amorphous molecular struc-ture of the elastomer is proposed by relating the macro-mechanical behaviors to micro-structural changes through molecular transitions and flow *** distinct relaxation processes are considered because of entangled molecular net works,with each possessing a unique activation *** calibration with experimental data,finite element simulations based on the model are *** to the loading rate,the structural entropy of molecular chain entanglements,rate-dependent yielding,plateau flow and densification are well predicted by the *** investigations are extended further regarding the material recoverability and accordingly,strain energy absorptions are illustrated.A power law function is proposed for designing the energy absorption relation to the applied loading ***,the inherent mechanisms causing the dynamic energy absorptions are analyzed with notable clarifications of post-experimental observations obtained via scanning elec Iron microscopy.

关键词： Elastomer Constitutive model Energy absorption Ratedependent Scanning electron microscopy

Investigation of functional,physical,mechanical and thermal properties of TiO2 embedded polyester hybrid composites:A design of experiment(DoE)study

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Progress in Natural Science:Materials International 2018年第3期28卷 266-274页

作者： muhammad Azeem Munawar Dirk Wolfram Schubert shahzad Maqsood khan muhammad Atiq Ur Rehman Nafisa Gulld Atif Islam Aneela Sabir muhammad Shafiq Bilal Haider Mudassar Azam Saba Urooge khan Monika M.Voigt Institute of Polymer Materials Friedrich-Alexander-University Department of Polymer Engineering and Technology University of the Punjab Bavarian Polymer Institute Institute of Biomaterials Friedrich-Alexander-University Institute of Chemical Engineering and Technology University of the Punjab

This paper presents a study on the Design of Experiments(Do E) approach to optimize the fabrication parameters of titania(TiO2) embedded glass fiber reinforced polyester hybrid composites(HCs). HCs of unsaturated polyester resin(UPR) were fabricated using methyl ethyl ketone peroxide(MEKP) as the curing agent by hand lay-up process(HLUP) and compression molding technique(CMT). The fabrication parameters were optimized by Taguchi Do E(an orthogonal array of L25) using 3 control factors(concentration of TiO2, concentration of MEKP and curing temperature) having 5 levels each. Statistical tools were employed to identify significant factors affecting tensile strengths and its reproducibility during HLUP. It was found that the concentration of TiO2in HCs significantly influenced the tensile strength(TS) followed by MEKP concentration and curing temperature. The highest value of TS was obtained at 3 wt% TiO2, 2 wt% MEKP and 80 °C. Nevertheless, the sensitivity of TiO2concentration was basis for fabrication of polyester titania glass fiber hybrids(PTGFHs), which were further investigated for density and void fractions, linear shrinkage, flexural strength, impact strength, hardness and thermal behaviors. Moreover, cross-linking and hydrogen-bonding between polymeric chains, styrene, silica content of glass fiber and TiO2particles in PTGFHs were confirmed by Fourier transform infrared spectroscopy.

关键词： Hybrid composites Polyester Design of experiment Titania

X-Band Power Amplifier for Next Generation Networks Based on MESFET

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China Communications 2017年第4期14卷 11-19页

作者： muhammad Saad khan Hongxin Zhang Fan Zhang Sulman shahzad Rahat Ullah Sajid Ali Qasim Ali Arain Manzoor Ahmed School of Electronic Engineering Beijing University of Posts and Telecommunications (BUPT) Beijing 100876 China Beijing Key Laboratory of Work Safety Intelligent Monitoring Beijing University of Posts and Telecommunications Beijing 100876 china College of Information Science and Electrical Engineering Zhejiang University Hangzhou Zhejiang 310027china Electrical Engineering Department University College of Engineering & Technology Bahauddin Zakariya University Multan Pakistan State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications Beijing 100876 China Department of Coxnputer Science D.G. Khan Campus. University of Education Lahore Pakistan Future lnternet & Communication Lab (FIB) Department of Electronic Engineering Tsinghua University Beijing 100084 China

Advanced wireless standards of communication like 3GPP and LTE are becoming more and more efficient and with this evolution of communication systems mobile equipment is also become smaller and smaller. Power amplifier designing has become a very crucial task in this era where efficiency and size are the main concern of any designer. In this paper we have design and analyzed X-band Class E Metal-semiconductor field effect transistor(MESFET) based Power Amplifier. This device targets the devices which use OFDM technique to improve their spectral efficiency for the next generation communication systems. Microstrip lines are used to achieve small size for our design instead of lumped components. Load Pull measurements are used to get MESFET input and output impedances optimum values. For linear and non linear operation small signal mathematical model of the design is used. To reduce thermal losses FR4 substrate is used to increase PA efficiency. Our designs shows small values of input and output return loss of about-22.3d B and-23.716 d B achieving a high gain of about25.6 d B respectively, with PAE of about 30 % having stability factor greater than 1 and 21.894 d Bm of output power.

关键词： MESFET X-band power amplifier advance design system PAE LTE

Phosphorus-Mobilizing Rhizobacterial Strain Bacillus cereus GS6 Improves Symbiotic Efficiency of Soybean on an Aridisol Amended with Phosphorus-Enriched Compost

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Pedosphere 2017年第6期27卷 1049-1061页

作者： muhammad Saleem ARIF muhammad RIAZ Sher muhammad shahzad Tahira YASMEEN Shafaqat ALI muhammad Javed AKHTAR Department of Environmental Sciences and Engineering Government College University Faisalabad Department of Soil&Environmental Sciences University College of AgricultureUniversity of Sargodha Institute of Soil&Environmental Science University of Agriculture Faisalabad

Legume plants are an essential component of sustainable farming ***(P) deficiency is a significant constraint for legume production, especially in nutrient-poor soils of arid and semi-arid *** the present study, we conducted a pot experiment to evaluate the effects of a phosphorus-mobilizing plant-growth promoting rhizobacterial strain Bacillus cereus GS6, either alone or combined with phosphate-enriched compost(PEC) on the symbiotic(nodulation-N_2 fixation) performance of soybean(Glycine max(L.) Merr.) on an *** PEC was produced by composting food waste with addition of single super *** bacterial strain *** GS6 showed considerable potential for P solubilization and mobilization by releasing carboxylates in insoluble P(rock phosphate)-enriched *** of *** GS6 in combination with PEC application significantly improved nodulation and nodule N_2 fixation *** to the control(without *** GS6 and PEC), the combined application of *** GS6 with PEC resulted in significantly higher accumulation of nitrogen(N), P, and potassium(K) in grain, shoot, and *** N:P and P:K ratios in nodules were significantly altered by the application of PEC and *** GS6, which reflected the important roles of P and K in symbiotic performance of *** combined application of PEC and *** GS6 also significantly increased the soil dehydrogenase and phosphomonoesterase activities, as well as the soil available N, P, and K *** positive relationships were found between soil organic carbon(C) content, dehydrogenase and phosphomonoesterase activities, and available N, P, and K *** study suggests that inoculation of P-mobilizing rhizobacteria, such as *** GS6, in combination with PEC application might enhance legume productivity by improving nodulation and nodule N_2 fixation efficiency.

关键词： arid and semi-arid regions carboxylate N2 fixation nodulation nutrient availability nutrient-poor soils plant growth-promoting rhizobacteria (PGPR) soil enzymes

Fission studies of gold induced by (1665 MeV) π^- using a CR-39 detector

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Chinese Physics C 2012年第2期36卷 132-135页

作者： muhammad Ikram shahzad Zafar Yasin Gul Sher Physics Division PINSTECHP.O.NiloreIslamabadPakistan

The fission cross section and fission probability of 197Au, induced by （1665 MeV） π-, have been studied using CR-39 track detectors. A 4π-geometry was used to count track statistics. A beam of negative pions of 1665 MeV was produced at AGS of Brookhaven National Laboratory, USA, and allowed to fall normally on the stack. Two detectors from the stack were scanned for fission fragment tracks after etching in 6N NaOH at 70 ℃. The statistics of fission fragment tracks in both detectors were obtained. It was found that there was a marked asymmetry of registered tracks with respect to the forward and backward hemispheres. This asymmetry could be partly accounted for on the basis of momentum transfer to the struck nucleus. On the basis of counting statistics fission cross section was measured, and fission probability was determined by dividing the fission cross section with the reaction cross section. The fission cross-section and fission probability were compared with the computed values using the caseade-exciton model code CEM95.

关键词： CR-39 fission cross section CEM95

Near real-time characterisation of urban environments: a holistic approach for monitoring dengue fever risk areas

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International Journal of Digital Earth 2014年第11期7卷 916-934页

作者： muhammad shahzad Sarfraz Nitin Kumar Tripathi Asanobu Kitamoto Department of Computer Science COMSATS Institute of Information Technology(CIIT)AbbottabadPakistan Remote Sensing and GIS Asian Institute of Technology(AIT)BangkokThailand Digital Content and Media Sciences Research Division National Institute of Informatics(NII)TokyoJapan

Despite frequent use of digital devices in everyday life,cost-effective measurement of public health issues in urban areas is still *** study was,therefore,planned to extract land-use types using object-based and spatial metric approaches to explore the dengue incidence in relation to the surrounding environment in near real-time using Google and Advanced Land Observation Satellite *** characterised image showed useful classification of an urban areawith 77%accuracy and 0.68 *** analysis on public health data indicated that most of the dengue cases were found in densely populated areas surrounded by dense *** living in independent houses having sparsely vegetated surroundings were found to be less *** incidence was more prevalent in people of 5-24 years of age(67%);while in terms of occupation,mostly students,the unemployed,labourers and farmers(88%)were *** general,males were affected slightly more(10%)than *** analyses indicated that most of the dengue cases were around institutions(40%),religious places(18%)and markets(15%).Thus,usage of Digital Earth scalable tools for monitoring health issues would open new ways for maintaining a healthy and sustainable society in the years ahead.

关键词： dengue fever land-use land-cover monitoring dengue risk urban environment object-based classification

用人工神经网络混合元启发式优化技术分析不可压缩黏性流体在收敛和发散通道中的流动:一种智能方法

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Journal of Central South University 2023年第12期30卷 4149-4167页

作者： ASLAM muhammad Naeem RIAZ Arshad SHAUKAT Nadeem ALI shahzad AKRAM Safia BHATTI M.M. Department of Physics and Applied Mathematics(DPAM) Pakistan Institute of Engineering&Applied SciencesNilore 45650IslamabadPakistan Center for Mathematical Sciences(CMS) Pakistan Institute of Engineering&Applied SciencesNilore 45650IslamabadPakistan Department of Mathematics Division of Science and TechnologyUniversity of EducationLahore 54770Pakistan School of Mathematics Minhaj UniversityLahorePakistan MCS National University of Sciences and TechnologyIslamabadPakistan College of Mathematics and Systems Science Shandong University of Science and TechnologyQingdao 266590China

本文采用人工神经网络(ANN)与进化算法(特别是阿基米德优化算法(AOA)和水循环算法(WCA)相结合的方法)对非线性磁流体动力学(MHD)的Jeffery-Hamel问题,特别是收敛和发散通道中的拉伸/收缩问题进行了数值研究。这种组合技术被称为ANN-AOA-... 详细信息

本文采用人工神经网络(ANN)与进化算法(特别是阿基米德优化算法(AOA)和水循环算法(WCA)相结合的方法)对非线性磁流体动力学(MHD)的Jeffery-Hamel问题,特别是收敛和发散通道中的拉伸/收缩问题进行了数值研究。这种组合技术被称为ANN-AOA-WCA。将基于复杂非线性磁流体动力学Jeffery-Hamel问题的偏微分方程转化为速度和温度的非线性常微分方程系统,我们建立了基于人工神经网络的适应度函数来求解非线性微分问题。随后,采用了一种新的AOA和WCA结合方法(AOAWCA)来优化基于神经网络的适应度函数,并确定了神经网络的最优权值和偏差。为了证明提出混合方法的有效性和多功能性,探索了一系列雷诺数、通道角和可拉伸边界值的MHD模型,从而开发了两种不同的情况。ANN-AOA-WCA的数值结果与参考解(NDSOLVE)非常接近,NDSOLVE与ANNAOA-WCA的绝对误差约为3.35×10^(−8),对可拉伸收敛和发散通道的理解特别关键。此外,为了验证ANN-AOA-WCA技术,我们对150多个独立运行进行了统计分析,以获得适应度值。

关键词：人工神经网络阿基米德优化水循环算法拉伸/收缩表面收敛或发散通道

Changes in Nutrient-Homeostasis and Reserves Metabolism During Rice Seed Priming:Consequences for Seedling Emergence and Growth

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Agricultural Sciences in China 2010年第2期9卷 191-198页

作者： muhammad Farooq shahzad M A Basra Abdul Wahid Nazir Ahmad Department of Agronomy University of AgricultureFaisalabad Department of Crop Physiology University of AgricultureFaisalabad Department of Botany University of AgricultureFaisalabad

In this study influence of different seed priming treatments on the nutrient-homeostasis and reserve metabolism during seedling emergence and growth of rice were determined. Seed priming treatments included pre-germination, hydropriming for 48 h, osmohardening with KCl and CaCl2, ascorbate priming and hardening. All treatments shortened the emergence time and enhanced the energy and index of seedling emergence. Seedlings from primed seeds had greater length, number of roots and fresh and dry mass than control. Among the treatments, CaCl2, ascorbate and KCl proved better in enhancing emergence and seedling growth. Seed priming changed the pattern of N and Ca^2＋ homeostasis both of the seeds and seedlings, which were associated to enhancing s-amylase activity and reducing sugars content. Positive correlations of seedling attributes with nutrient content suggested that as a result of seed priming, most of N and Ca^2＋ were partitioned to embryo, which enhanced seedling emergence and subsequent growth of rice seedlings.

关键词： rice α-amylase activity nutrient homeostasis seedling emergence seedling vigor

Influence of Seed Priming on Performance and Water Productivity of Direct Seeded Rice in Alternating Wetting and Drying

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Rice science 2015年第4期22卷 189-196页

作者： Hafeez Ur REHMAN muhammad KAMRAN shahzad Maqsood Ahmed BASRA Irfan AFZAL muhammad FAROOQ Department of Agronomy University of AgricultureFaisalabad Institute of Agriculture University of Western Australia College of Food and Agricultural Sciences King Saud University

Direct seeded rice is promising alternative to traditional transplanting, but requires appropriate crop and water management to maintain yield performance and achieve high water productivity. Present study evaluated the effect of seed priming and irrigation on crop establishment, tillering, agronomic traits, paddy yield, grain quality and water productivity of direct seeded rice in alternate wetting and drying （DSR-AWD） in comparison with direct seeded rice at field capacity （DSR- FC）. Seed priming treatments were osmo-priming with KCI （2.2%）, CaCI2 （2.2%） and moringa leaf extracts （MLE, 3.3%） including hydro-priming as control. Among the treatments, seed osmo-primed with MLE emerged earlier and had higher final emergence, followed by osmo-priming with CaCI2. Tillering emergence rate and number of tillers per plant were the highest for seed priming with CaCI2 in DSR- AWD. Total productive and non-productive tillers, panicle length, biological and grain yields, harvest index were highest for seed priming with MLE or CaCI2 in DSR-AWD. Similarly, grain quality, estimated in terms of normal grains, abortive and chalky grains, was also the highest in DSR-AWD with MLE osmo-priming. Benefit cost ratio and water productivity was also the highest in DSR-AWD for seed priming with MLE. In conclusion, seed priming with MLE or CaCI2 can be successfully employed to improve the direct seeded rice performance when practiced with alternate wetting and drying irrigation.

关键词： crop establishment grain filling rate seed priming water productivity yield direct seededrice alternating wetting and drying grain quality

Cascade-exciton model analysis of mass dependence of pion-induced fission

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Chinese Physics C 2014年第7期38卷 92-96页

作者： muhammad Ikram shahzad Zafar Yasin Warda Iram Shahida Jabeen Physics Division PINSTECH P.O. Nilore Islamabad Pakistan Physics Department Islamia University Bahawalpur Pakistan Physics Department AJ&K University Muzaffarbad Pakistan

The cascade-exciton model has been used to observe the dependence of pion induced fission cross sections on the mass of the target. The analysis has been performed at energies 80 MeV, 100 MeV and 150 MeV for both the positive and negative pions. It has been shown that a single value of the ratio af/an can satisfactorily reproduce the experimental findings when compared with the available experimental data in the literature. The general trend of the fission cross sections with mass （fissility parameter） is seen to be low and slowly changing for the lighter nuclei, and it will steeply rise for the heavy nuclei.

关键词： cascade-exciton model pion-induced fission cross sections