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198篇 您的检索式:作者名="Muhammad KHALID"
    题名 作者 年代 出处 被引量
1基于波形相似度比较的线路快速纵联保护研究显示文摘针对基于工频量线路纵联保护动作速度受制于滤波算法数据窗以及抗干扰能力不足的问题,提出一种基于波形相似度比较的线路快速纵联保护算法。该方法利用故障发生后故障线路两侧波形间不一致形变的特征,通过Hausdorff距离算法对包括故障暂态时刻在内的任意时刻信号进行相似度比较,实现故障的快速识别和切除。该文结合算法特点提出对应的保护整定方法,并在整定的基础上分析算法的动作特性。针对原有Hausdorff距离算法受异常数据影响的缺陷,分析线路保护可能面临的异常数据特征,提出相应的改进策略。理论分析和仿真试验验证了所提算法的有效性和优越性。陈乐 薄志谦 林湘宁 魏繁荣 余梦琪 金能 Muhammad Shoaib Khalid 李正天 黄景光 邓科 2017中国电机工程学报2017,37,17:33
2考虑可转移负荷效率的风/光/柴/蓄孤岛微网日运行能量控制优化策略显示文摘大型负荷尤其是可转移负荷的效率–功率特性常常被忽视,因此考虑风/光/柴/蓄微网系统的运行调度是不经济的。该文提出一种考虑可转移负荷效率的风/光/柴/蓄微网能量控制优化策略。首先以典型的可转移负荷——反渗透型制淡设备为例,建立包含设备工作全程的淡水输入–产出模型,实时计算其功率–效率特性曲线。在考虑制淡设备功率特性、蓄电池寿命(使用成本)、柴油机工作效率等因素的基础上,以燃料及蓄电池使用成本最少为目标,提出一种风/光/柴/蓄微网系统的日运行能量控制优化策略。通过与两种典型微网能量控制方案进行比较,仿真结果验证在包含可转移负荷的微网场景中,针对各种可能的储能设备和燃料的使用成本组合,在淡水需求量一定时,所提策略均具有较好的成本优势,为包含可转移负荷的微网经济运行策略制定提供了全新的视角。魏繁荣 随权 林湘宁 李正天 陈乐 邓科 薄志谦 黄景光 Muhammad Shoaib Khalid Owolabi Sunday Adio 2018中国电机工程学报2018,38,4:34
3微生物碳酸盐岩的成因、分类以及问题与展望——来自华北地台寒武系微生物碳酸盐岩研究的启示显示文摘微生物碳酸盐岩以其漫长的地史分布、多样的产出环境、复杂的沉积构成和与微生物活动密切相关的特性而成为沉积学研究的焦点,同时也是沉积学研究的难点,被誉为'最难研究的沉积岩之一'。其研究的中心主要是钙化微生物席和微生物膜及其地质记录,即石化/成岩作用的产物。从成因着手,系统总结和梳理了2个类型的微生物群落,较薄的生物膜和较厚的微生物席,经过生物/有机矿化作用和石化/成岩作用形成微生物碳酸盐岩的过程。提出除微生物群落自身的复杂性和沉积过程的复杂性之外,多重状生物膜是导致微生物碳酸盐岩多样性的另外一个重要原因。以中国华北地台寒武系微生物碳酸盐岩的研究为基础,梳理了不同类型的微生物碳酸盐岩的沉积特征和分类依据。认为微生物碳酸盐岩应该置于Embry和Kloven描述的黏结岩类下,根据宏观组构可进一步分为叠层石、凝块石、核形石、层纹石和均一石5类,树形石不易独立成类而应归于凝块石。微生物碳酸盐岩为整个地质历史时期与微生物活动相关的生物/有机矿化作用过程研究提供了有用信息,不但是了解地球表层环境演变的一个重要窗口,而且还形成和储集了较大规模的油气,具有重要的科学意义和经济价值。王龙 Khalid Latif Muhammad Riaz 刘晓晔 2018地球科学进展2018,33,10:18
4基于隔直装置全局优化投切的直流偏磁治理方法显示文摘由于缺乏对直流电流全局分布的考虑,传统隔直装置投切方法容易造成区域内其他变压器出现中性点直流电流被动超标。为了有效地指导偏磁治理工作,提出一种基于隔直装置全局优化投切的偏磁治理方法。首先根据直流电位衰减规律确定交流系统建模范围,其次结合交流系统等效电阻网络、变电站与接地极地理位置分布情况,采用场–路耦合分析思想建立全局隔直装置优化投切数学模型,最后以全局中性点直流电流最大值最小为目标进行寻优,得到最优投切方案。通过宜昌地区电网实际参数验证所提方法(基于穷举法寻优)隔直效果优于传统方法,同时为了保证在交流系统规模扩大后寻优的效率,采用多种智能方法对优化问题进行求解,验证了智能算法同样可以实现趋近于穷举法的隔直效果。谢志成 林湘宁 李正天 郑颖 郭倩雯 Muhammad Shoaib Khalid Owolabi Sunday Adio 薄志谦 2017中国电机工程学报2017,37,24:16
5Distributed cooperative control of autonomous multi-agent UAV systems using smooth control显示文摘This paper addresses the cooperative control problem of multiple unmanned aerial vehicles(multi-UAV)systems.First,a new distributed consensus algorithm for second-order nonlinear multi-agent systems(MAS)is formulated under the leader-following approach.The algorithm provides smooth input signals to the agents’control channels,which avoids the chattering effect generated by the conventional sliding mode-based control protocols.Second,a new formation control scheme is developed by integrating smooth distributed consensus control protocols into the geometric pattern model to achieve three-dimensional formation tracking.The Lyapunov theory is used to prove the stability and convergence of both distributed consensus and formation controllers.The effectiveness of the proposed algorithms is demonstrated through simulation results.BELKACEM Kada MUNAWAR Khalid MUHAMMAD Shafique Shaikh 2020Journal of Systems Engineering and Electronics2020,31,6:16
6A survey on trust based detection and isolation of malicious nodes in ad-hoc and sensor networks显示文摘Adnan AHMED Kamalrulnizam ABU BAKAR Muhammad Ibrahim CHANNA Khalid HASEEB Abdul Waheed KHAN 2015Frontiers of Computer Science2015,9,2:15
7寒武纪芙蓉统均一石沉积组构及环境特征——以河北涞源长山组为例显示文摘均一石以隐晶质岩性、无纹层与凝块结构发育为特征,与叠层石、凝块石、树形石并列为典型的微生物岩。然而,由于均一石在1995年命名以来很少在地层记录中得到识别和描述,并且缺乏现代实例的类比物,使得关于均一石的报道极具研究价值。为研究华北地台寒武系均一石沉积组构与形成环境特征,系统性地针对河北涞源祁家峪剖面芙蓉统长山组均一石生物丘进行研究。芙蓉统长山组从下部陆棚相钙质泥岩向上变浅至浅缓坡相厚层块状泥晶灰岩,组成了一个淹没不整合型三级层序。三级层序顶部的浅缓坡相厚层块状泥晶灰岩层,代表强迫型海退过程沉积,其内部发育一系列米级均一石生物丘。研究结果表明,这些生物丘主体为致密泥晶及少量微量晶组成,其中可见到附枝菌(Epiphyton)、葛万菌(Girvanella)、肾形菌(Renalcis)等钙化微生物化石。这些钙化微生物(蓝细菌)化石的出现,代表了显生宙第一幕蓝细菌钙化作用事件的证据,同时间接的说明均一石生物丘形成于蓝细菌主导的微生物席的钙化作用过程之中。同时,生物丘内还局部集中发育底栖鲕粒与草莓状黄铁矿颗粒,表明了生物丘形成过程中复杂的微生物沉积作用机制。因此,河北涞源长山组顶部的均一石生物丘,尽管泥晶和微亮晶是其基本构成,但是各种钙化蓝细菌化石以及底栖鲕粒与草莓状黄铁矿颗粒的局部出现表明了在蓝细菌主导的微生物席中复杂的微生物活动信号,成为了解生物丘形成机制、显生宙第一幕蓝细菌钙化作用事件的典型实例。肖恩照 王皓 覃英伦 Khalid Latif Muhammad Riaz 2020沉积学报2020,38,1:11
8吕梁山东北缘寒武系层序地层划分--以文水苍尔会剖面为例显示文摘为研究山西吕梁山地区寒武纪地层的地层学与沉积学问题,根据山西文水苍尔会剖面寒武系地层叠置关系,将该剖面寒武系地层划分为8个三级层序。基于沉积相的变化规律和地层叠置关系的旋回性研究结果,苍尔会剖面存在两个特殊的地层学与沉积学现象:下部为霍山组砂岩直接覆盖在太古宙变质岩系上,其较为良好的出露与明显的地层接触关系,为探讨山西中部霍山组砂岩的地层归属问题提供依据;在该剖面崮山组、长山组、凤山组中分别发育不同的均一石生物丘,代表华北地台寒武纪晚期—奥陶纪中期'随着后生动物辐射,微生物碳酸盐也在增加'微生物碳酸盐复苏期的基本沉积样式。在新的寒武纪年代地层框架下,对山西文水苍尔会剖面进行层序地层划分,不但为研究华北寒武系生物丘沉积组构多样性提供参考实例,同时也为探讨山西中部地区前寒武—寒武巨大的古地理变迁提供实例。肖恩照 覃英伦 Muhammad Riaz Khalid Latif 姚琳 王皓 2017东北石油大学学报2017,41,5:10
9Effect of chromium on growth attributes in sunflower(Helianthus annuus L.)显示文摘Heavy metal soil pollution takes place when the metal concentration of soil exceeds natural background level and causes ecological destruction and deterioration of the environment.In the present study,a pot experiment was conducted to evaluate the effect of chromium-contaminated soil in sunflower(Helianthus annuus L.)growth attributes.Three different levels of chromium(Cr)i.e.,20, 40,and 60 mg/kg were applied to three varieties of sunflower(G-3,G-9,and G-59).The results of morphological,chemical,and yield parameters were recorded at crop maturity.The result showed that germination,root,and shoot lengths were decreased with increase in Cr concentrations.A gradual decrease was observed for various morphological parameters like root fresh and dry weights,shoot fresh and dry weights,and plant height with increase in Cr levels.A comparison among Cr treatments obtained a significant decrease in yield parameters as achenes/capitulum,achenes/plant,and 100 achenes weight in three varieties.Cr was significantly absorbed by roots but its transport to other parts of plants was slow,and uptake in seeds was much lower than in roots and shoots.FOZIA Andaleeb MUHAMMAD Anjum Zia MUHAMMAD Ashraf ZAFAR Mahmood Khalid 2008Journal of Environmental Sciences2008,20,12:9
10Role of flavonoids in plant interactions with the environment and against human pathogens-A review显示文摘Flavonoids are widely-distributed polyphenolic secondary metabolites with diverse biological activities in plants and benefit human health as protective dietary agents.They participate in plants' responses to harsh environmental conditions and effectively regulate the cell differentiation and growth.In plants,the majority of their functions are attributed to their strong antioxidative properties.Similarly,dietary flavonoids protect the human body against free radicals which are associated with the development of cancer and atherosclerosis.Plants rich in polyphenols have been used to cure various diseases because of their antibacterial,antiviral,antifungal and anticancer properties.This review summarizes the up-to-date research trends and development on flavonoids and its derivatives,working mechanisms and potential functions and applications particularly in relation to plant protection and human health.Towards the end,notable concluding remarks with a close-up look at the future research directions have also been presented briefly.Muhammad Khalid Saeed-ur-Rahman Muhammad Bilal HUANG Dan-feng 2019Journal of Integrative Agriculture2019,18,1:8
11微生物白云岩形成机制研究进展与存在问题显示文摘近年来,有关微生物白云岩沉淀作用机制的研究拓宽了沉积学中'白云岩问题'研究的视角。硫酸盐还原反应、产甲烷作用、有机分子水解等一系列可促进沉淀白云石的微生物代谢机制的发现,延伸了微生物白云石(岩)形成模式;有关可溶解硫化物催化白云石沉淀的研究,不但强调了硫酸盐还原反应机制,也为重新认识硫酸盐还原反应促进白云石沉淀机理提供了新线索。在现代环境中,微生物席内的原生白云石沉淀的发现,将微生物过程引入地表环境原生白云石沉淀作用和机理的研究,可能为寻找地层记录中的微生物白云石提供了更多有益的工作手段和思考途径。然而更加复杂的白云岩地层记录说明,运用微生物白云石去解释复杂的地质记录还存在着较多的局限性。肖恩照 隋明园 Khalid Latif Muhammad Riaz 2017大庆石油地质与开发2017,36,2:8
12河北涞源祁家峪剖面寒武系层序地层划分显示文摘河北涞源祁家峪剖面寒武系出露连续,层序界面清楚且沉积现象丰富,是进行华北地台寒武系层序划分的较为典型的剖面之一。在新的寒武系年代地层框架下,依据地层的叠置形式、纵向上的沉积相变化及其内部的旋回特征,将该剖面寒武系划分为8个三级层序。结果表明:研究区域从馒头组、毛庄组的'TST+HST'沉积序列转变为'CS+HST'的淹没不整合型层序序列,反映出从混积潮坪沉积序列向缓坡型碳酸盐台地的演化过程,也意味着华北地台寒武系碳酸盐台地从发展阶段向成熟阶段的重大转变;该剖面芙蓉统内部的竹叶状灰岩与长山组顶部、凤山组第1个三级层序顶部发育的均一石生物丘代表了华北地台寒武系末期'贫乏骨骼的风暴海'以及'随着后生动物辐射,微生物碳酸盐岩也在增加'两大特殊沉积现象较为典型的沉积样式。基于层序地层框架内的沉积相叠加方式和地层记录中旋回特征的描述,对河北涞源祁家峪剖面进行层序地层划分,将为探索华北地台在太行山北缘广泛分布的寒武系提供参考实例,也为今后更大区域范围的对比研究提供线索。肖恩照 隋明园 覃英伦 Khalid Latif Muhammad Riaz 王皓 2017大庆石油地质与开发2017,36,6:7
13应对全站采样信息缺失的应急保护系统显示文摘智能变电站的采样系统与GOOSE系统是两套相对独立的信息采集与传递系统。为了应对变电站全站采样信息缺失后变电站需立即退出运行或只能借助远后备保护进行完全非选择性保护的挑战,提出一种应对全站采样信息缺失的应急保护系统。该系统首先基于多端电流差动保护或方向保护原理界定大致故障区域,然后对双端和多端系统分别采用测量电抗百分比比较法和补偿电压相量推演比较法识别故障线路,并结合就地距离保护I段提出应对全站采样信息缺失的应急保护策略。理论分析与仿真结果表明:所提的应急保护系统可靠性及灵敏度高,具备对带过渡电阻故障的响应能力,能有效保障全站采样信息缺失后变电站继续运行及区域电网的安全稳定。金能 李正天 林湘宁 魏繁荣 陈乐 余梦琪 薄志谦 黄景光 Muhammad Shoaib Khalid 2017中国电机工程学报2017,37,8:7
14Advances in fungal-assisted phytoremediation of heavy metals:A review显示文摘Trace metals such as manganese(Mn),copper(Cu),zinc(Zn),and iron(Fe)are essential for many biological processes in plant life cycles.However,in excess,they can be toxic and disrupt plant growth processes,which is economically undesirable for crop production.For this reason,processes such as homeostasis and transport control of these trace metals are of constant interest to scientists studying heavily contaminated habitats.Phytoremediation is a promising cleanup technology for soils polluted with heavy metals.However,this technique has some disadvantages,such as the slow growth rate of metal-accumulating plant species,low bioavailability of heavy metals,and long duration of remediation.Microbial-assisted phytoremediation is a promising strategy for hyperaccumulating,detoxifying,or remediating soil contaminants.Arbuscular mycorrhizal fungi(AMF)are found in association with almost all plants,contributing to their healthy performance and providing resistance against environmental stresses.They colonize plant roots and extend their hyphae to the rhizosphere region,assisting in mineral nutrient uptake and regulation of heavy metal acquisition.Endophytic fungi exist in every healthy plant tissue and provide enormous services to their host plants,including growth enhancement by nutrient acquisition,detoxification of heavy metals,secondary metabolite regulation,and enhancement of abiotic/biotic stress tolerance.The aim of the present work is to review the recent literature regarding the role of AMF and endophytic fungi in plant heavy metal tolerance in terms of its regulation in highly contaminated conditions.Muhammad KHALID Saeed UR-RAHMAN Danial HASSANI Kashif HAYAT Pei ZHOU Nan HUI 2021Pedosphere2021,31,3:6
15应对不可预知型短路电流超标的主动响应型站域保护策略显示文摘针对电力系统可能存在的不可预知型短路电流超标风险,提出一种主动响应型站域集成保护策略。采用最小二乘短路电流超快速预测,闭锁保护出口以防止断路器强行分闸造成爆炸;并基于短路前后外部系统状态突变,实现无故障进线的背侧系统等值,从而预估短路电流限制措施实施效果,优选站域保护紧急跳闸方案。仿真结果验证所提策略的有效性,为电网不可预知型短路电流超标问题提供一种全新的保护解决思路。魏繁荣 马啸 林湘宁 李正天 陈乐 邓科 Muhammad Shoaib Khalid Owolabi Sunday Adio 2018中国电机工程学报2018,38,2:6
16巴基斯坦海域油气勘探方向探讨显示文摘为了寻找巴基斯坦海域油气勘探方向,对收集的大量文献资料进行了整理和分析,并对最新采集的柱状样进行了测试分析,发现巴基斯坦海域烃源岩普遍存在,而储集岩主要为始新统的生物礁和中新统的河道砂岩。巴基斯坦海域北部的马克兰增生楔物源可能主要为细碎屑岩,中新统的河道砂岩分布局限,油气勘探前景差;而在巴基斯坦海域东部的印度扇,中新统河道砂岩分布广,储集性能好。因此,巴基斯坦海域的油气勘探应以东部印度扇为勘探靶区,其主要的勘探层位应以陆架区中新统的河道砂岩和深水区始新统的礁灰岩为主。龚建明 廖晶 Muhammad Khalid 梁杰 陈建文 成海燕 孟明 2019海洋地质前沿2019,35,11:5
17考虑TCSC型故障限流器动态过程的距离保护整定方法显示文摘在含TCSC型故障限流器(thyristor-controlled series capacitor-based fault current limiter,TCSC-FCL)线路距离保护的整定中,通常将TCSC-FCL作为电抗器处理,忽略其动态阻抗特性,可能导致保护拒动/误动或速动性不足。针对上述问题,建立TCSC-FCL动态阻抗分析模型,对TCSC-FCL独有的首周波旁路模式下的阻抗时变特性进行分析,研究其从串补模式切换到限流模式的动态阻抗变化过程,提出TCSC-FCL动态阻抗特性函数表示方法,并提出基于动态偏移阻抗圆的距离保护整定策略,以消除TCSC-FCL动态阻抗特性对距离保护动作性能的影响。建立含TCSC-FCL的典型输电网模型,验证上述动态特性函数表示方法以及距离保护整定策略的正确性。魏繁荣 李慧 林湘宁 李正天 邓科 Muhammad Shoaib Khalid Owolabi Sunday Adio 2017中国电机工程学报2017,37,8:5
18和阻抗继电器的改进形式及其动作性能分析显示文摘现有高压输电线路保护对于单相高阻接地故障灵敏度不足,长期以来一直是继电保护领域的一个遗留问题。该文根据线路双端测量阻抗之和在正常运行及单相故障场景下的差异性,针对原有和阻抗继电器不能动态适应线路电容电流变化的缺陷,提出一种改进和阻抗继电器,并设计能够保障其区内全线高阻接地速动能力的自适应浮动门槛。仿真结果证明所提出的原理实现简单、无需双端信息同步,能够快速响应区内任意故障点单相高阻故障,具备适应系统非全相运行能力,在绝大多数情况下,耐受过渡电阻能力均能达到300Ω。通过与现有主保护配合使用,可显著提升高压输电线路保护对各种系统运行工况下单相高阻接地故障的响应能力。吕冉 李慧 刘鹏 林湘宁 童宁 李正天 黄景光 邓科 Owolabi Sunday Adio Muhammad Shoaib Khalid 韩雄辉 2018中国电机工程学报2018,38,7:5
19Estimation and inter-comparison of dust aerosols based on MODIS, MISR and AERONET retrievals over Asian desert regions显示文摘This study presents detailed analysis of spatiotemporal variations and trend of dust optical properties i.e., Aerosol Optical Depth(AOD) and Angstrom component over Asian desert regions using thirteen years of data(i.e., 2001–2013) retrieved from Aerosol Robotic Network(AERONET), Moderate Resolution Imaging Spectroradiometer(MODIS) and Multi-angle Imaging Spectroradiometer(MISR). These regions include Solar Village, Dunhuang and Dalangzadgad and are considered as origin of desert aerosols in Asia. Mann–Kendall trend test was used to show the trend of AOD. The relationship of AOD with weather parameters and general AOD trend over different wavelengths has also been shown. AOD's trend has been observed significant throughout the year in Solar Village, while in Dunhuang and Dalanzadgad the significant trend has been found only in peak period(March–June).Analysis show high values of AOD and low values of angstrom in Solar Village during peak period. In Chinese desert regions, high values of AOD have been found during peak period and low values in pre-peak period. Significant relationship has been observed between AOD and average temperature in Solar Village and Dalanzadgad whereas rainfall and wind speed showed no significant impact on AOD in all desert regions.Ammara Habib Bin Chen Bushra Khalid Saichun Tan Huizheng Che Tariq Mahmood Guangyu Shi Muhammad Tahir Butt 2019Journal of Environmental Sciences2019,31,2:5
20Molecular mechanism underlying Piriformospora indica-mediated plant improvement/protection for sustainable agriculture显示文摘The beneficial endophytic microorganisms have received significant attention in agriculture because of their exceptional capabilities to facilitate functions like nutrient enrichment,water status,and stress tolerance(biotic and abiotic).This review signifies the molecular mechanisms to better understand the Piriformospora indica-mediated plants improvement or protection for sustainable agriculture.P.indica,an endophytic fungus,belonging to the order Sebacinales(Basidiomycota),is versatile in building mutualistic associations with a variety of plants including pteridophytes,bryophytes,gymnosperms,and angiosperms.P.indica has enormous potential to manipulate the hormonal pathway such as the production of indole-3-acetic acid which in turn increases root proliferation and subsequently improves plant nutrient acquisition.P.indica also enhances components of the antioxidant system and expression of stress-related genes which induce plant stress tolerance under adverse environmental conditions.P.indica has tremendous potential for crop improvement because of its multi-dimensional functions such as plant growth promotion,immunomodulatory effect,biofertilizer,obviates biotic(pathogens)and abiotic(metal toxicity,water stress,soil structure,salt,and pH)stresses,phytoremediator,and bio-herbicide.Considering the above points,herein,we reviewed the physiological and molecular mechanisms underlying P.indica-mediated plants improvement or protection under diverse agricultural environment.The first part of the review focuses on the symbiotic association of P.indica with special reference to biotic and abiotic stress tolerance and host plant root colonization mechanisms,respectively.Emphasis is given to the expression level of essential genes involved in the processes that induce changes at the cellular level.The last half emphasizes critical aspects related to the seed germination,plant yield,and nutrients acquisition.Muhammad Khalid Saeed-ur-Rahman Danfeng Huang 2019Acta Biochimica et Biophysica Sinica2019,51,3:4
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