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77篇 您的检索式:作者名="Muhammad Naveed"
    题名 作者 年代 出处 被引量
1黄土高原半干旱偏旱区草粮轮作田土壤水分恢复效应模拟显示文摘采用实地调查和EPIC模型相结合的方法,模拟研究了黄土高原半干旱偏旱区不同草粮轮作模式的土壤水分恢复效应.结果表明:多年生苜蓿地和苜蓿翻耕后种植粮食作物农田0~10m土层土壤湿度调查值与模拟值间的相关系数均超过0.9(P<0.01),相对均方根误差在0.05~0.16,相对误差均低于10%;模拟与实测的土壤湿度剖面分布变化趋势一致.在黄土高原半干旱偏旱区,苜蓿地深层土壤干层恢复难度较大,在种植苜蓿期间应避免8~10m土层土壤湿度降到5.7%以下.苜蓿地适宜种植年限为4~6a,最长不应超过8a.苜蓿翻耕后适宜采用马铃薯→马铃薯→春小麦轮作模式进行土壤水分恢复,32~33a后可以再次种植苜蓿.王学春 李军 方新宇 孙剑 Muhammad Naveed Tahir 2011应用生态学报2011,22,1:8
2国外农业航空静电喷雾技术研究进展与借鉴显示文摘农业航空静电喷雾技术作为中国发展精准农业航空应用技术的内容之一,对农药的有效利用和减少环境污染有积极意义。农业航空静电喷雾技术在国外发展较早也相对成熟,美国已有应用于有人机的商业化产品,并在美国、巴西等国各类粮食作物、经济作物和杂草防治作业中开展了大规模田间应用。该研究首先从基础研究、田间应用和优化工作等方面梳理了国外农业航空静电喷雾技术的研究进展,分析了农业航空静电喷雾技术在增加雾滴沉积、减少飘移和具备低施药液量等方面的优势。在此基础上结合中国植保无人机快速发展的实际对研究和应用适合中国国情的农业航空静电喷雾技术进行思考,提出了农业航空静电喷雾技术的研究路线,最后从采用接触式等非感应式充电方式、开发农业航空静电喷雾的测量技术,以及思考荷质比作为衡量指标的意义等方面探讨了可进行深入研究的方向。中国农业航空静电喷雾技术研究特别在植保无人机静电喷雾技术方面的研究与应用有很大的发展空间,可参考国外经验,围绕航空静电喷雾技术的基础性研究、田间试验、成果转化、示范推广和服务指导全方面制定发展规划,把单一强调对雾滴带电的实现转向对技术系统的整体研究。张亚莉 黄鑫荣 王林琳 邓继忠 曾文 兰玉彬 Muhammad Naveed Tahir 2021农业工程学报2021,37,6:7
3Estimating the basic reproductive ratio for the Ebola outbreak in Liberia and Sierra Leone显示文摘Background:Ebola virus disease has reemerged as a major public health crisis in Africa,with isolated cases also observed globally,during the current outbreak.Methods:To estimate the basic reproductive ratio R0,which is a measure of the severity of the outbreak,we developed a SEIR(susceptible-exposed-infected-recovered)type deterministic model,and used data from the Centers for Disease Control and Prevention(CDC),for the Ebola outbreak in Liberia and Sierra Leone.Two different data sets are available:one with raw reported data and one with corrected data(as the CDC suspects under-reporting).Results:Using a deterministic ordinary differential equation transmission model for Ebola epidemic,the basic reproductive ratio R0 for Liberia resulted to be 1.757 and 1.9 for corrected and uncorrected case data,respectively.For Sierra Leone,R0 resulted to be 1.492 and 1.362 for corrected and uncorrected case data,respectively.In each of the two cases we considered,the estimate for the basic reproductive ratio was initially greater than unity leading to an epidemic outbreak.Conclusion:We obtained robust estimates for the value of R0 associated with the 2014 Ebola outbreak,and showed that there is close agreement between our estimates of R0.Analysis of our model also showed that effective isolation is required,with the contact rate in isolation less than one quarter of that for the infected non-isolated population,and that the fraction of high-risk individuals must be brought to less than 10%of the overall susceptible population,in order to bring the value of R0 to less than 1,and hence control the outbreak.Adnan Khan Mahim Naveed Muhammad Dur-e-Ahmad Mudassar Imran 2015Infectious Diseases of Poverty2015,4,1:5
4Effect of seedling age and water depth on morphological and physiological aspects of transplanted rice under high temperature显示文摘To study the effect of high temperature, rice seedlings 20, 30, 40 and 50 d were kept at 5, 10, 15 and 20 cm water depth in a water pool. Meteorological findings indicated that water temperature varied up to 10 cm but became stable below this depth. Deep water inflicted higher tiller mortality, minimal increase in dry weight of aerial parts and leaf area, decrease in root length, and decrease in root dry weight especially at 20 cm water depth and produced an unbalanced T/R ratio (top versus root dry weight). However, deep water tended to increase plant length. These parameters, however, excel in shallow water. Older seedlings, with the exception of root dry weight, could not perform well compared to young seedlings in all physiological and morphological aspects. The study revealed that seedlings, particularly young ones, stand well in shallow water and can cope with high temperature.KHAKWANI Abdul Aziz SHIRAISHI Masaaki ZUBAIR Muhammad BALOCH Mohammad Safdar NAVEED Khalid AWAN Inayatullah 2005Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)2005,6,5:4
5Gene-gene,gene-environment,gene-nutrient interactions and single nucleotide polymorphisms of inflammatory cytokines显示文摘Inflammation plays a significant role in the etiology of type 2 diabetes mellitus(T2DM).The rise in the pro-inflammatory cytokines is the essential step in glucotoxicity and lipotoxicity induced mitochondrial injury,oxidative stress and beta cell apoptosis in T2 DM.Among the recognized markers are interleukin(IL)-6,IL-1,IL-10,IL-18,tissue necrosis factor-alpha(TNF-α),C-reactive protein,resistin,adiponectin,tissue plasminogen activator,fibrinogen and heptoglobins.Diabetes mellitus has firm genetic and very strong environmental influence; exhibiting a polygenic mode of inheritance.Many single nucleotide polymorphisms(SNPs) in various genes including those of pro and antiinflammatory cytokines have been reported as a risk for T2 DM.Not all the SNPs have been confirmed by unifying results in different studies and wide variations have been reported in various ethnic groups.The inter-ethnic variations can be explained by the fact that gene expression may be regulated by gene-gene,gene-environment and gene-nutrient interactions.This review highlights the impact of these interactions on determining the role of single nucleotide polymorphism of IL-6,TNF-α,resistin and adiponectin in pathogenesis of T2 DM.Amina Nadeem Sadaf Mumtaz Abdul Khaliq Naveed Muhammad Aslam Arif Siddiqui Ghulam Mustafa Lodhi Tausif Ahmad 2015World Journal of Diabetes2015,6,4:4
6Location-allocation modeling for emergency evacuation planning with GIS and remote sensing:A case study of Northeast Bangladesh显示文摘This work developed models to identify optimal spatial distribution of emergency evacuation centers(EECs)such as schools,colleges,hospitals,and fire stations to improve flood emergency planning in the Sylhet region of northeastern Bangladesh.The use of location-allocation models(LAMs)for evacuation in regard to flood victims is essential to minimize disaster risk.In the first step,flood susceptibility maps were developed using machine learning models(MLMs),including:Levenberg-Marquardt back propagation(LM-BP)neural network and decision trees(DT)and multi-criteria decision making(MCDM)method.Performance of the MLMs and MCDM techniques were assessed considering the area under the receiver operating characteristic(AUROC)curve.Mathematical approaches in a geographic information system(GIS)for four well-known LAM problems affecting emergency rescue time are proposed:maximal covering location problem(MCLP),the maximize attendance(MA),p-median problem(PMP),and the location set covering problem(LSCP).The results showed that existing EECs were not optimally distributed,and that some areas were not adequately served by EECs(i.e.,not all demand points could be reached within a 60-min travel time).We concluded that the proposed models can be used to improve planning of the distribution of EECs,and that application of the models could contribute to reducing human casualties,property losses,and improve emergency operation.Mahfuzur Rahman Ningsheng Chen MdMonirul Islam Ashraf Dewan Hamid Reza Pourghasemi Rana Muhammad AliWashakh Nirdesh Nepal Shufeng Tian Hamid Faiz Mehtab Alam Naveed Ahmed 2021Geoscience Frontiers2021,12,3:3
7二硫化钼-还原氧化石墨烯复合材料用作高稳定性燃料电池阴极催化剂载体(英文)显示文摘碳黑是质子交换膜燃料电池中最常用的电催化剂载体材料.然而,由于燃料电池内部环境苛刻(强酸性、强氧化性、湿度大、温度高、电位高等),碳材料易被氧化腐蚀,同时还可能进一步引起Pt催化剂颗粒脱落和团聚,造成催化剂性能衰减,继而影响电池性能与稳定性.为了克服碳载体腐蚀的问题,提高碳材料的石墨化程度是一种可行方法,然而,石墨化程度提高的同时伴随着含氧官能团的减少,这减少Pt离子的沉积位点,造成Pt团聚和颗粒过大等问题,导致催化剂质量比活性过低.另一种方法是开发金属氧化物(WO3, TiO2)、金属氮化物(Mo2N, CrN)、金属碳化物(WC)和导电聚合物(PANI)等非碳载体.然而,这些载体材料的电导率远低于碳,造成催化剂活性较低,只适用于高温和使用强氧化剂(如纯氧、双氧水)等特殊工况.针对上述问题,本文设计合成了二硫化钼-还原氧化石墨烯(MoS2-rGO)复合材料作为燃料电池阴极催化剂的载体材料,利用MoS2的高稳定性及还原氧化石墨烯优异的导电性能与适量的含氧官能团,实现了Pt颗粒的均匀沉积并提高了催化剂活性与稳定性.XRD表征结果显示,使用溶剂热法制备的复合材料同时具有石墨烯与二硫化钼的特征峰,证实MoS2-rGO成功合成.XPS结果进一步证实了六价钼向四价钼及氧化石墨烯向还原氧化石墨烯的转变. TEM与HRTEM显示, MoS2以多层形式存在并成功沉积在rGO表面,和rGO相互搭接形成了连续的电子传输网络,保证了载体良好的导电能力.使用改进的乙二醇还原法制得MoS2-rGO负载Pt催化剂(Pt/MoS2-rGO), TEM显示Pt颗粒均匀分布在载体表面,且Pt颗粒平均粒径为3.2 nm.这主要归功于MoS2充分暴露的活性边缘及rGO表面存在的适量含氧官能团为Pt离子提供了充足的沉积位点.电化学测试显示,在催化ORR反应中, Pt/MoS2-rGO相比于碳载铂(Pt/C)具有更高的起始还原电位,表明MoS2-rGO载体有助于Pt催化剂活性的提升.此外,经历10000圈加速衰减循环后, Pt/C电化学活性面积损失57.6%.相比之下, Pt/MoS2-rGO活性面积损失为46.2%.同时,衰减后Pt/MoS2-rGO半波电位高于Pt/C,进一步确认基于复合载体的Pt催化剂具有更好的稳定性.Muhammad Tuoqeer Anwar 闫晓晖 Muhammad Rehman Asghar Naveed Husnain 沈水云 罗柳轩 程晓静 魏光华 章俊良 2019Chinese Journal of Catalysis2019,40,8:3
8Optical spin-symmetry breaking for high-efficiency directional helicity-multiplexed metaholograms显示文摘Helicity-multiplexed metasurfaces based on symmetric spin–orbit interactions (SOIs) have practical limits because they cannot provide central-symmetric holographic imaging. Asymmetric SOIs can effectively address such limitations, with several exciting applications in various fields ranging from asymmetric data inscription in communications to dual side displays in smart mobile devices. Low-loss dielectric materials provide an excellent platform for realizing such exotic phenomena efficiently. In this paper, we demonstrate an asymmetric SOI-dependent transmission-type metasurface in the visible domain using hydrogenated amorphous silicon (a-Si:H) nanoresonators. The proposed design approach is equipped with an additional degree of freedom in designing bi-directional helicity-multiplexed metasurfaces by breaking the conventional limit imposed by the symmetric SOI in half employment of metasurfaces for one circular handedness. Two on-axis, distinct wavefronts are produced with high transmission efficiencies, demonstrating the concept of asymmetric wavefront generation in two antiparallel directions. Additionally, the CMOS compatibility of a-Si:H makes it a cost-effective alternative to gallium nitride (GaN) and titanium dioxide (TiO2) for visible light. The cost-effective fabrication and simplicity of the proposed design technique provide an excellent candidate for high-efficiency, multifunctional, and chip-integrated demonstration of various phenomena.Muhammad Ashar Naveed Muhammad Afnan Ansari Inki Kim Trevon Badloe Joohoon Kim Dong Kyo Oh Kashif Riaz Tauseef Tauqeer Usman Younis Murtaza Saleem Muhammad Sabieh Anwar Muhammad Zubair Muhammad Qasim Mehmood Junsuk Rho 2021Microsystems & Nanoengineering2021,7,2:3
9In vivo screening of essential oils of Skimmia laureola leaves for antinociceptive and antipyretic activity显示文摘Objective:To study the screening of essential oils of Skimmia laureola leaves(SLO)for acute toxicity,antinociceptive,antipyretic and anticonvulsant activities in various animal models.Methods:SLO were extracted using modified Clevenger type apparatus.Acute toxicity test was used in mice to observe its safety level.Antinociceptive activity of SLO was evaluated in acetic acid induced writhing and hot plate tests.Yeast induced hyperthermic mice and pentylenetetrazole induced convulsive mice were used for the assessment of its antipyretic and anticonvulsant profile respectively.Results:Substantial safety was observed for SLO in acute toxicity test.SLO showed a high significant activity in acetic acid induced writhing test in a dose dependent manner with maximum pain attenuation of 68.48%at 200 mg/kg i.p.However,it did not produce any relief in thermal induced pain at test doses.When challenged against pyrexia evoked by yeast,SLO manifested marked amelioration in hyperthermic mice,dose dependently.Maximum anti-hyperthermic activity(75%)was observed at 200 mg/kg i.p.after 4 h of drug administration.Nevertheless,SLO had no effect on seizures control and mortality caused by pentylenetetrazole.Conclusions:In vivo studies of SLO showed prominent antinociceptive and antipyretic activities with ample safety profile and thus provided pharmacological base for the traditional uses of the plant in various painful conditions and pyrexia.Additional detail studies are required to ascertain its clinical application.Naveed Muhammad Barkatullah Muhammad Ibrar Haroon Khan Muhammad Saeed Amir Zada Khan Waqar Ahmad Kaleem 2013Asian Pacific Journal of Tropical Biomedicine2013,3,3:2
10Anti-nociceptive, anti-inflammatory and sedative activities of the extracts and chemical constituents of Diospyros lotus L.显示文摘Ghias Uddin Abdur Rauf Bina S. Siddiqui Naveed Muhammad Ajmal Khan Syed Uzair Ali Shah 2014Phytomedicine2014,,:1
11Evaluation of n -hexane extract of Viola betonicifolia for its neuropharmacological properties显示文摘Naveed Muhammad Muhammad Saeed Haroon Khan Ikramul Haq 2013Journal of Natural Medicines2013,,1:1
12Dynamic Stability Improvement of Decentralized Wind Farms by Effective Distribution Static Compensator显示文摘Dynamic instability of decentralized wind energy farms is a major issue to deliver continuous green energy to electricity consumers.This instability is caused by variations of voltage and frequency parameters due to intermittencies in wind power.Previously,droop control and inverter-based schemes have been proposed to regulate the voltage by balancing reactive power,while inertial control,digital mapping tech-nique of proportional-integral-differential(PID)controller and efficiency control strategy have been developed to regulate the frequency.In this paper,voltage stability is improved by a new joint strategy of distribution static compensator(DSTATCOM)six-pulse controller based reactive power management among decentralized wind turbines and controlled charging of capacitor bank.The frequency stability is ensured by a joint coordinated utilization of capacitor bank and distributed wind power turbines dispatching through a new DSTATCOM six-pulse controller scheme.In both strategies,power grid is contributed as a backup source with less priority.These new joint strategies for voltage and frequency stabilities will enhance the stable active power delivery to end users.A system test case is developed to verify the proposed joint strategies.The test results of the proposed new schemes are proved to be effective in terms of stability improvement of voltage,frequency and active power generation.Muhammad Naveed Naz Saqif Imtiaz Muhammad Kamran Liaquat Bhatti Waseem Qaiser Awan Muhammad Siddique Ashfaq Riaz 2021Journal of Modern Power Systems and Clean Energy2021,9,3:1
13Determination of Antioxidant Activity and Total Anthocyanin Contents of Extracts from Pulp and Peel of Malus domestica显示文摘HAJI Muhammad Shoaib Khan NAVEED Akhtar 2012Asian Journal of Chemistry2012,24,6:1
14CFD applications in various heat exchangers design: A review显示文摘Muhammad Mahmood Aslam Bhutta Nasir Hayat Muhammad Hassan Bashir Ahmer Rais Khan Kanwar Naveed Ahmad Sarfaraz Khan 2011Applied Thermal Engineering2011,,:1
15Muscle Relaxant and Sedative- Hypnotic Activities of Extract of Viola betonicifolia in Animal Models Supported by Its Isolated Compound,4-Hydroxy Coumarin显示文摘Naveed Muhammad Mohammad Saeed 2013Journal of Chemistry2013,7,2:1
16Finite time H∞ filtering for uncertain discrete time switching systems显示文摘Muhammad Naveed Iqbal Jian Xiao Weiming Xiang 2013Trans of the Institute of Measurement and Control2013,35,6:1
17Vibration analysis of damaged and undamaged steel structure systems: cantilever column and frame显示文摘This paper presents the experimental and numerical studies conducted on a steel column and a steel frame structure using free vibration analysis.The effects of damages on structures were investigated,which were simulated by introducing multiple cracks at different locations in the experimental and numerical models.The acceleration responses of the test models,were recorded through an accelerometer,and were used to calibrate the numerical models developed in finite element based software.Modal frequencies of damaged and undamaged structures were compared and analyzed,to derive relationships for damaged and undamaged structures’frequencies in terms of crack depth.It was found that,due to the presence of cracks,the mechanical properties of a structure changes,whereby,the modal frequencies decrease.An approximately linear trend was observed for the frequency decrease with the increase in crack depth,which was also confirmed by the numerical models.The derived relationships were extended to further develop a mechanics-based damage scale for steel structures,to help facilitate structural health monitoring and screening of vulnerable structures.Muhammad Abuzar Khan Kareem Akhtar Naveed Ahmad Feroz Shah Naeem Khattak 2020Earthquake Engineering and Engineering Vibration2020,19,3:1
18Root cause analysis of primary reformer catastrophic failure: A case study显示文摘Naveed Ramzan Shahid Naveed Muhammad Rizwan 2011Process Safety Progress2011,30,1:1
19Temperature trends and elevation dependent warming during 1965-2014 in headwaters of Yangtze River, Qinghai Tibetan Plateau显示文摘The understanding of temperature trends in high elevation mountain areas is an integral part of climate change research and it is critical for assessing the impacts of climate change on water resources including glacier melt, degradation of soils, and active layer thickness. In this study, climate changes were analyzed based on trends in air temperature variables(Tmax, Tmin, Tmean), and Diurnal Temperature Range(DTR) as well as elevation-dependent warming at annual and seasonal scales in the Headwaters of Yangtze River(HWYZ), Qinghai Tibetan Plateau. The Base Period(1965-2014) was split into two subperiods;Period-Ⅰ(1965-1989) and Period-Ⅱ(1990-2014) and the analysis was constrained over two subbasins;Zhimenda and Tuotuohe. Increasing trends were found in absolute changes in temperature variables during Period-Ⅱ as compared to Period-Ⅰ.Tmax, Tmin, and Tmean had significant increasing trends for both sub-basins. The highest significant trends in annual time scale were observed in Tmin(1.15℃ decade-1) in Tuotuohe and 0.98℃ decade-1 in Zhimenda sub-basins. In Period-Ⅱ, only the winter season had the highest magnitudes of Tmax and Tmin0.58℃ decade-1 and 1.26℃ decade-1 in Tuotuohe subbasin, respectively. Elevation dependent warming analysis revealed that Tmax, Tmin and Tmean trend magnitudes increase with the increase of elevations in the middle reaches(4000 m to 4400 m) of the HWYZ during Period-Ⅱ annually. The increasing trend magnitude during Period-Ⅱ, for Tmax, is 1.77, 0.92, and 1.31℃ decade-1, for Tmin 1.20, 1.32 and 1.59℃ decade-1,for Tmean 1.51, 1.10 and 1.51℃ decade-1 at elevations of4066 m, 4175 m and 4415 m respectively in the winter season. Tmean increases during the spring season for> 3681 m elevations during Period-Ⅱ, with no particular relation with elevation dependency for other variables. During the summer season in Period Ⅱ, Tmax, Tmin, Tmean increases with the increase of elevations(3681 m to 4415 m) in the middle reaches of HWYZ. Elevation dependent warming(EDW), the study concluded that magnitudes of Tmin are increasing significantly after the 1990s as compared to Tmax in the HWYZ. It is concluded that the climate of the HWYZ is getting warmer in both sub-basins and the rate of warming was more evident after the 1990s. The outcomes of the study provide an essential insight into climate change in the region and would be a primary index to select and design research scenarios to explore the impacts of climate change on water resources.Naveed AHMED WANG Gen-xu Adeyeri OLUWAFEMI Sarfraz MUNIR HU Zhao-yong Aamir SHAKOOR Muhammad Ali IMRAN 2020Journal of Mountain Science2020,17,3:1
20Spatiotemporal Changes in NDVI and Its Driving Factors in the Kherlen River Basin显示文摘Vegetation is an important factor linking the atmosphere,water,soil,and biological functions,and it plays a specific role in the climate change response and sustainable development of regional economies.However,little information is available on vegetation vulnerability and its driving mechanism.Therefore,studying temporal and spatial change characteristics of vegetation and their corresponding mechanisms is important for assessing ecosystem stability and formulating ecological policies in the Kherlen River Basin.We used Moderate-resolution Imaging Spectroradiometer(MODIS)normalized difference vegetation index(NDVI)remote sensing images from 2000 to 2020 to analyse temporal changes in NDVI with the autoregressive moving average model(ARMA)and the breaks for additive season trend(BFAST)in the basin and to assess natural,anthropogenic and topographic factors with the Geodetector model.The results show that:1)the long NDVI time series remained stable in the Kherlen River Basin from 2000 to 2020,with a certain significant mutation period from 2013 to 2017;2)the coefficient of variation(CV)in the analysis of the spatial NDVI was generally constant,mainly at the level of 0.01–0.07,and the spatial NDVI change was minimally impacted by external interference;and 3)temperature and precipitation are the key factors affecting the NDVI in the basin,and changes in local hydrothermal conditions directly affect the local NDVI.The results of this study could provide a scientific basis for the effective protection of the ecological environment and will aid in understanding the influence of vegetation change mechanisms and the corresponding factors.MUHAMMAD Naveed HE Hongshi ZONG Shengwei DU Haibo SATTI Zulqarnain TAN Xinyuan QAZI Muhammad Yasir 2023Chinese Geographical Science2023,33,2:1
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