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1843篇 您的检索式:作者名="Haider"
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1甲醛诱导Tau蛋白形成“孔道样”聚集结构显示文摘尽管Lin等(University of California,Santa Barbara)就蛋白构象病中细胞死亡的机制提出了'非特异性淀粉样离子通道'(aspecific amyloid ion channels)学说,但到目前为止,尚未发现神经Tau蛋白能形成'孔道样'聚集结构,也未寻找到可以导致蛋白质形成'孔道样'聚集结构的诱导剂.依据本实验室提出的'散发性老年痴呆发生发展中的内源性甲醛慢性损伤'假说,采用一定浓度的甲醛与Tau蛋白进行温育,观察到甲醛可以明显诱导Tau蛋白分子聚集并形成淀粉样沉积物,同时也观察到了Tau蛋白'孔道样'聚集结构.上述结果为探索甲醛诱导Tau蛋白错误折叠形成的产物导致细胞代谢障碍和死亡的机制提供了新的研究思路.NAQVI Sajjad Haider 王维山 苗君叶 赫荣乔 2010生物化学与生物物理进展2010,37,11:21
2Preliminary experience with drug-coated balloon angioplasty in primary percutaneous coronary intervention显示文摘We evaluated the clinical feasibility of using drugcoated balloon(DCB) angioplasty in patients undergoingprimary percutaneous coronary intervention(PPCI). Between January 2010 to September 2014,89 STelevation myocardial infarction patients(83% male,mean age 59 ± 14 years) with a total of 89 coronary lesions were treated with DCB during PPCI. Clinical outcomes are reported at 30 d follow-up. Left anterior descending artery was the most common target vessel for PCI(37%). Twenty-eight percent of the patients had underlying diabetes mellitus. Mean left ventricular ejection fraction was 44% ± 11%. DCB-only PCI was the predominant approach(96%) with the remaining 4% of patients receiving bail-out stenting. Thrombolysis in Myocardial Infarction(TIMI) 3 flow was successfully restored in 98% of patients. An average of 1.2 ± 0.5 DCB were used per patient,with mean DCB diameter of 2.6 ± 0.5 mm and average length of 23.2 ± 10.2 mm. At 30-d follow-up,there were 4 deaths(4.5%). No patients experienced abrupt closure of the infarctrelated artery and there was no reported target-lesion failure. Our preliminary experience showed that DCB angioplasty in PPCI was feasible and associated with a high rate of TIMI 3 flow and low 30-d ischaemic event.Hee Hwa Ho Julian Tan Yau Wei Ooi Kwok Kong Loh Than Htike Aung Nwe Tun Yin Dasdo Antonius Sinaga Fahim Haider Jafary Paul Jau Lueng Ong 2015World Journal of Cardiology2015,7,6:14
3Whole-Genome Resequencing of a Worldwide Collection of Rapeseed Accessions Reveals the Genetic Basis of Ecotype Divergence显示文摘Rapeseed (Brassica napus),an important oilseed crop,has adapted to diverse climate zones and latitudes by forming three main ecotype groups,namely winter,semiwinter,and spring types. However,genetic variations underlying the divergence of these ecotypes are largely unknown. Here,we report the global pattern of genetic polymorphisms in rapeseed determined by resequencing a worldwide collection of 991 germplasm accessions.A total of 5.56 and 5.53 million singlenucleotide polymorphisms (SNPs)as Well as 1.86 and 1.92 million InDels were identified by mapping reads to the reference genomes of 'Darmor-bzh'and 'Tapidor,'respectively.We generated a map of allelic drift paths that shows splits and mixtures of the main populations,and revealed an asymmetric evolution of the two subgenomes of B.napus by calculating the genetic diversity and linkage disequilibrium parameters.Selective-sweep analysis revealed genetic changes in genes orthologous to those regulating various aspects of plant development and response to stresses.A genome-wide association study identified SNPs in the promoter regions of FLOWERING LOCUS T and FLOWERING LOCUS C orthologs that corresponded to the different rapeseed ecotype groups. Our study provides important insights into the genomic footprints of rapeseed evolution and flowering-time divergence among three ecotype groups,and will facilitate screening of molecular markers for accelerating rapeseed breeding.Dezhi Wu Zhe Liang Tao Yan Ying Xu Lijie Xuan Juan Tang Gang Zhou Ulrike Lohwasser Shuijin Hua Haoyi Wang Xiaoyang Chen Qian Wang Le Zhu Antony Maodzeka Nazim Hussain Zhilan Li Xuming Li Imran Haider Shamsi Ghulam Jilani Linde Wu Hongkun Zheng Guoping Zhang Boulos Chalhoub Lisha Shen Hao Yu Lixi Jiang 2019Molecular Plant2019,12,1:10
4Watering techniques and zero-valent iron biochar pH effects on As and Cd concentrations in rice rhizosphere soils,tissues and yield显示文摘Zero-valent iron amended biochar(ZVIB)has been proposed as a promising material in immobilizing heavy metals in paddy fields.In this study,the impacts of p H of ZVIB(p H 6.3 and p H 9.7)and watering management techniques(watering amount in the order of CON(control,5/72)>3/72>1-3/72>3/100>1/72,with 5/72,for example,representing irrigation given to 5 cm above soil surface in 72 hr regular interval)on As and Cd bioavailability for rice and its grain yield(Yield BR)were investigated in a pot experiment.Brown rice As(As BR)content was irrelative to the watering treatments,while significantly decreased(>50%)with the addition of both ZVIB materials.The diminutions of brown rice Cd(Cd BR)content as well as the Yield BR were highly dependent on both the soil amendment materials’p H and watering amount.Among all the watering treatments,3/72 treatment(15%less irrigation water than the CON)with ZVIB 6.3 amendment was the optimum fit for simultaneous reduction of As BR(50%)and Cd BR contents(19%)as well as for significant increment(12%)of the Yield BR.Although high pH(9.7)ZVIB application could also efficiently decrease As and Cd contents in brown rice,it might risk grain yield lost if appropriate(e.g.3/72 in our study)watering management technique was not chosen.Therefore,ZVIB would be an environmentally friendly option as an amendment material with proper selection of watering management technique to utilize As and Cd co-contaminated arable soils safely for paddy cultivation.Md Shafiqul Islam Yali Chen Liping Weng Jie Ma Zulqarnain Haider Khan Zhongbin Liao Abdoul Salam Issiaka Abdoul Magid Yongtao Li 2021Journal of Environmental Sciences2021,33,2:9
5云南不同生态区玉米害虫优势种及其天敌优势种的种群动态显示文摘通过对滇东北温凉地区和滇南暖热地区夏玉米田害虫及其天敌种群的系统调查,明确了云南南北两地玉米上的害虫优势种及其天敌优势种的发生动态规律,以期为玉米害虫的预测预报及防治提供理论依据。结果表明,滇东北昭通地区害虫优势种是玉米蚜,发生高峰期为抽雄散粉期和蜡熟期;天敌优势种是异色瓢虫,发生高峰期滞后于玉米蚜。滇南普洱地区玉米抽雄散粉期之前害虫优势种为黄脸油葫芦,发生高峰期为小喇叭口期;抽雄散粉期之后害虫优势种是玉米蚜,发生高峰期为完熟期;天敌优势种是异色瓢虫和黑带食蚜蝇,两种天敌的发生高峰期和玉米蚜吻合。因此,昭通地区防治重点为玉米蚜,防治适期为玉米抽雄散粉期之前。普洱地区防治重点为黄脸油葫芦,可从从苗期开始采取防治措施;玉米蚜的发生时间较晚、为害较轻,可在玉米吐丝期之后对其进行防治。田间施药的时间应注意避开天敌的发生高峰期。禹田 贾永超 柴正群 吴迪 Nawaz Haider Bashir 马丽 陈国华 李强 2018中国植保导刊2018,38,9:9
6Risk factors for colonoscopic perforation: A population-based study of 80118 cases显示文摘AIM: To assess the incidence and risk factors associated with colonic perforation due to colonoscopy. METHODS: This was a retrospective cross-sectional study. Patients were retrospectively eligible for inclusion if they were 18 years and older and had an inpatient or outpatient colonoscopy procedure code in any facility within the Geisinger Health System during the period from January 1, 2002 to August 25, 2010. Data are presented as median and inter-quartile range, for continuous variables, and as frequency and percentage for categorical variables. Baseline comparisons across those with and without a perforation were made using the two-sample t -test and Pearson's χ2 test, as appropriate.RESULTS: A total of 50 perforations were diagnosed out of 80118 colonoscopies, which corresponded to an incidence of 0.06% (95%CI: 0.05-0.08) or a rate of 6.2 per 10000 colonoscopies. All possible risk factors associated with colonic perforation with a P -value < 0.1 were checked for inclusion in a multivariable logbinomial regression model predicting 7-d colonic perforation. The final model resulted in the following risk factors which were significantly associated with risk of colonic perforation: age, gender, body mass index, albumin level, intensive care unit (ICU) patients, inpatient setting, and abdominal pain and Crohn's disease as indications for colonoscopy. CONCLUSION: The cumulative 7 d incidence of colonic perforation in this cohort was 0.06%. Advanced age and female gender were significantly more likely to have perforation. Increasing albumin and BMI resulted in decreased risk of colonic perforation. Having a colonoscopy indication of abdominal pain or Crohn's disease resulted in a higher risk of colonic perforation. Colonoscopies performed in inpatients and particularly the ICU setting had substantially greater odds of perforation. Biopsy and polypectomy did not increase the risk of perforation and only three perforations occurred with screening colonoscopy.Uzair Hamdani Raza Naeem Fyeza Haider Pardeep Bansal Michael Komar David L Diehl H Lester Kirchner 2013World Journal of Gastroenterology2013,19,23:9
7Ciprofloxacin adsorption from aqueous solution onto chemically prepared carbon from date palm leaflets显示文摘A chemically prepared carbon was synthesized from date palm leaflets via sulphuric acid carbonization at 160℃.Adsorption of ciprofloxacin(CIP) from aqueous solution was investigated in terms of time,pH,concentration,temperature and adsorbent status(wet and dry).The equilibrium time was found to be 48 hr.The adsorption rate was enhanced by raising the temperature for both adsorbents,with adsorption data fitting a pseudo second-order model well.The activation energy,E a,was found to be 17 kJ/mol,indicating a diffusion-controlled,physical adsorption process.The maximum adsorption was found at initial pH 6.The wet adsorbent showed faster removal with higher uptake than the dry adsorbent,with increased performance as temperature increased(25-45℃).The equilibrium data were found to fit the Langmuir model better than the Freundlich model.The thermodynamic parameters showed that the adsorption process is spontaneous and endothermic.The adsorption mechanism is mainly related to cation exchange and hydrogen bonding.El-Said Ibrahim El-Shafey Haider Al-Lawati Asmaa Soliman Al-Sumri 2012Journal of Environmental Sciences2012,24,9:9
8Crop diversity and pest management in sustainable agriculture显示文摘Large-scale crop monocultures facilitate the proliferation and increasing prevalence of diseases and pest insects.Many studies highlight the impacts of plant diversification upon pathogens,and the population dynamics of insects and beneficial organism in agricultural ecosystems.These studies provide evidence that habitat manipulation techniques such as intercropping,relay,and rotation can significantly improve disease and pest management.This review introduces the concept of crop diversity,considers recent insights and mechanisms underlying crop diversity,and discusses its potential for improving sustainable agricultural practices.Recently,the phytobiomes resulting from increased crop diversity are increasingly recognized for their contribution to disease and pest control.Further,understanding the interactions between pathogens or pests with their host phytobiome may lead to novel options for the prevention of pests.Recent advances in the agricultural systems include:(i)a better understanding of the mechanisms of interactions between crop species and genotypes;(ii)ecological progress including a better understanding of the context-dependency of those interactions;and(iii)the role of microtopographic variation in agricultural systems for priming basal resistance to multiple pests and pathogens by intercropped crops.We also highlight recent progress in China and the potential options for habitat management and design that enhance the ecological role of biodiversity in agroecosystems.HE Han-ming LIU Li-na Shahzad Munir Nawaz Haider Bashir WANG Yi YANG Jing LI Cheng-yun 2019Journal of Integrative Agriculture2019,18,9:8
9Comparison of perceived pain and patients’ satisfaction with traditional local anesthesia and single tooth anesthesia: A randomized clinical trial显示文摘BACKGROUND Contemporary innovations in the area of local anesthesia have attempted to provide an absolutely pain free experience for patients.Since the introduction of Computer-Controlled Local Anesthetic Delivery Systems to dentistry,many studies have compared its efficacy and safety to conventional anesthesia.However,very few studies have compared single tooth anesthesia(STA)and traditional local anesthesia.AIM To compare pain rating,changes in blood pressure,and heart rate during the local anesthetic injection.The secondary objectives were to measure the patients’level of satisfaction and the differences in anesthetic efficiency between the STA system and traditional local infiltration.METHODS A randomized controlled trial was conducted and a total of 80 patients with dental restorative needs were enrolled for the study.The patients were evaluated for their general physical status and oral clinical findings before enrollment.Information regarding perceived pain,changes in heart rate and blood pressure,and patients’satisfaction was collected using an electronic data form and was analyzed using paired and unpaired t-tests.RESULTS No significant difference was noted in perceived pain(P=0.59)and systolic blood pressure(P=0.09)during anesthetic injection using both traditional and STA techniques.STA patients had a significantly higher heart rate during anesthesia,although a statistically significant difference was noted among the traditional anesthesia and the STA groups even before anesthesia.During the restorative procedure,less pain was perceived by STA patients on the Wong-Baker FACES pain scale,which was statistically significant(P<0.001).Analyses of post-procedure patient responses showed that STA patients had a significantly better treatment experience and preferred to have the same method of injection in the future(P=0.04).CONCLUSION STA system can provide less painful and more comfortable restorative treatment procedures in comparison to the traditional infiltration technique.Mohammad I Al-Obaida Mehdiya Haider Rawan Hashim Wafa AlGheriri Sree Lalita Celur Samar A Al-Saleh Ebtissam M Al-Madi 2019World Journal of Clinical Cases2019,7,19:8
10基于公式递推法的可变计算位宽的循环冗余校验设计与实现显示文摘循环冗余校验(CRC)与信道编码的级联使用,可以有效改善译码的收敛特性。在新一代无线通信系统,如5G中,码长和码率都具有多样性。为了提高编译码分段长度可变的级联系统的译码效率,该文提出一种可变计算位宽的CRC并行算法。该算法在现有固定位宽并行算法的基础上,合并公式递推法中反馈数据与输入数据的并行计算,实现了一种高并行度的CRC校验架构,并且支持可变位宽的CRC计算。与现有的并行算法相比,合并算法节省了电路资源的开销,在位宽固定时,资源节约效果明显,同时在反馈时延上也有将近50%的优化;在位宽可变时,电路资源的使用情况也有相应的优化。陈容 陈岚 WAHLA Arfan Haider 2020电子与信息学报2020,42,5:7
11刀额新对虾主要过敏原蛋白的肽指纹图谱鉴定与分析显示文摘以我国常见的刀额新对虾为研究对象,旨在获得其主要过敏原的氨基酸序列等基础数据,增加对虾类过敏原的认识和理解。分离和纯化了分子量为36 kD的虾主要过敏原蛋白,利用激光辅助解析/飞行时间质谱对其进行肽质量指纹图谱鉴定,并对鉴定的结果采用Mascot搜索引擎在NCBInr数据库上进行搜索。结果表明刀额新对虾主要过敏原蛋白与斑节对虾原肌球蛋白匹配分值最高为268,吻合肽段27条,序列覆盖率为65%;与其它无脊椎动物如腐食酪螨、衣鱼等的原肌球蛋白的序列覆盖率也很高,分别达到了51%和53%。这一结果不仅表明了刀额新对虾与其它甲壳类海产品过敏原存在着高度同源性,而且为其与甲壳类及其它无脊椎动物主要过敏原之间存在严重交叉反应的现象提供了理论依据。林洪 郑礼娜 李振兴 Samee Haider 2009中国海洋大学学报(自然科学版)2009,39,5:6
12Detection of Tocopherol in Oilseed Rape (Brassica napus L.) Using Gas Chromatography with Flame Ionization Detector显示文摘The variation among Chinese genotypes of Brassica napus L.for seed tocopherols content and their analysis using gas chromatography has not been comprehensively reported till to date.In the present study,the tocopherol contents of four Chinese genotypes of Brassica napus L.,namely,Gaoyou 605,Zhejiang 619,Zheshuang 758,and Zheshuang 72,were evaluated using three modified sample preparation protocols(P1,P2,and P3) for tocopherol extraction.These methods were distinguished as follows.Protocol one(P1) included the evaporation of solvent after extraction without silylation.Protocol two(P2) followed the direct supernatant collection after overnight extraction without drying and silylation.Protocol three(P3) included trimethylsilylation with N,O-bis(trimethylsilyl) trifluoroacetamide.Genotypic comparison of tocopherol and its isoforms revealed that Gaoyou 605 was dominant over the other genotypes with(140.5±10.5),(316.2± 9.2),and(559.1±24.3) μg g-1 of seed meal α-,γ-,and total(T-) tocopherol,respectively,and a 0.44±0.04 α-to γ-tocopherol ratio.The comparison of the sample preparation protocols,on the other hand,suggests that P3 is the most suitable method for the tocopherol extraction from Brassica oilseeds and for the analysis of tocopherols using gas chromatography flame ionization detector(GC-FID).Trimethylsilylation is the key step differentiating P3 from P1 and P2.Variations detected in tocopherol contents among the Chinese rapeseed(B.napus) genotypes signify the need to quantify a wide range of rapeseed germplasm for seed tocopherol dynamics in short and crop improvement in long.Nazim Hussain Zahra Jabeen LI Yuan-long CHEN Ming-xun LI Zhi-lan GUO Wan-li Imran Haider Shamsi CHEN Xiao-yang JIANG Li-xi 2013Journal of Integrative Agriculture2013,12,5:6
13参量阵浅地层剖面仪在海底羽状流探测中的应用--以ATLAS P70在马克兰海域调查为例显示文摘海底渗漏的羽状流是沉积层赋存天然气水合物的重要证据之一,基于非线性水声学原理的参量阵浅地层剖面仪作为海洋探测的重要设备,对于获得羽状流在水体中的物性特征和渗漏点的浅地层信息有着重大意义.本文根据ATLAS P70浅地层剖面仪在马克兰海域调查中得到的浅地层剖面数据,结合多道地震数据、多波束数据以及地质样品等资料,刻画了研究区内羽状流形态特征,分析了羽状流区海底地层流体运移的通道以及近海底微地形地貌特征.通过研究发现在羽状流区伴随泥火山喷发,自生碳酸盐岩发育,剥蚀海底松散沉积物形成大小不一的麻坑,滋生生物群落等特征.反映在浅剖初始高频(20 kHz)数据界面上羽状流表现为柱状浑浊反射异常,形态呈火焰状,高度由80 m到1500 m不等;对应在次级低频(4 kHz)信号界面可以清晰显示流体渗漏的浅地层结构特征,从中不仅可以识别出流体的运移通道,如泥火山和管状通道等,而且揭示了流体逸散的残留地貌,如麻坑构造和海底滑坡等.本文依托参量阵浅地层剖面数据,对巴基斯坦马克兰海域羽状流有了较全面的认识,为天然气水合物的研究垫定了基础.单晨晨 邓希光 温明明 冯强强 Syed Waseem Haider 黄伟 2020地球物理学进展2020,35,3:6
14Appraisal of Biofertilizers in Rice: To Supplement Inorganic Chemical Fertilizer显示文摘A field experiment was carried out to evaluate the feasibility of inoculating rice seedlings with biofertilizers(Azospirillum and Trichoderma) in order to reduce the use of chemical inorganic nitrogen(N)fertilizer on rice variety BU Dhan 1. The plant performances were better when 25% less inorganic N was applied with Trichoderma and combined application of Trichoderma and Azospirillum. Plants contained the highest chlorophyll concentrations when they were treated with 75% N + Trichoderma. Considering the yield attributes, 75% N + Trichoderma and 75% N + Trichoderma + Azospirillum performed similar to the control. The grain yield of rice was similar to the recommended dose even with 25% less N application. Application of Trichoderma resulted higher yield, followed by combined application with Azospirillum. Results revealed the greater scope of applying biofertilizer(Trichoderma) to supplement chemical N fertilizer with optimum yield of rice.Haider Iqbal KHAN 2018Rice science2018,25,6:6
15菲律宾蛤仔过敏原可视化抗体微阵列玻片的检测方法显示文摘采用辣根过氧化物酶(HRP)与3,3′,5,5′—四甲基联苯胺(TMB)—H2O2作为信号示踪系统,建立了一种可视化抗体微阵列检测菲律宾蛤仔过敏原的方法。对孵育时间、抗体浓度等免疫条件进行了优化。采用改良双抗体夹心法,将菲律宾蛤仔过敏原的兔多克隆抗体固定于琼脂糖三维芯片上,依次加入待检样品、菲律宾蛤仔鼠多克隆抗体和HRP-羊抗鼠IgG,孵育后加TMB显色,肉眼观察后,用平板扫描仪获取扫描图象,采用GenePixPro6.0软件分析灰度值。试验结果表明,该方法最低可检出10ng/mL的菲律宾蛤仔过敏原,片内平均变异系数(CV)为5.99%,片间为10.3%;香肠及蟹棒中3个不同浓度的加标回收率为73.54%~95.44%;4℃存放4个月内抗体微阵列玻片活性保持稳定。该方法不需要大型精密仪器,结果直观可见,可以发展为对多种过敏原进行同时检测,具有良好的实用和推广价值。李小燕 李振兴 林洪 SAMEE Haider 张轶群 2010水产学报2010,34,3:6
16Anti-allergic effects of ethanol extracts from brown seaweeds显示文摘Ethanol extracts of brown seaweeds from Pakistan and China were isolated and compared for their antiallergenic activities. They included Sargassum tennerimum (ST) and Sargassum cervicorne (SC) from Pakistan, and Sargassum gramini- folium turn (SG), Sargassum thunbergii (STH), and Laminaria japonica (LJ) from China. The ethanol extracts of these brown seaweeds were optimized at 85% (v/v) ethanol for the maximum yield of phlorotannin, an inhibitor against hyaluronidase. Total phlorotannins contained in the crude extracts were measured as 1.71% (SG), 0.74% (STH), 0.97% (LJ), 3.30% (SC), and 5.06% (ST). The 50% inhibitory concentrations (IC50) of Pakistani SC and ST were 109.5 and 21 μg/ml, respectively, lower than those of Chinese SG, STH, and LJ (134, 269, and 148 μg/ml, respectively). An antiallergic drug, disodium cromoglycate (DSCG), had an IC50=39 μg/ml, and a natural inhibitor of hyaluronidase, catechin, had an IC50=20 μg/ml. The IC50 of ST extract was found similar to that of catechin (21 vs 20 μg/ml) and lower than that of DSCG (21 vs 39 μg/ml). This suggests that ST is a potent inhibitor of hyaluronidase, indicating a promising future development of natural antiallergic medicines or functional foods.Haider SAMEE Zhen-xing LI Hong LIN Jamil KHALID Yong-chao GUO 2009Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)2009,10,2:6
17中国荷斯坦牛CSN3基因多态性及其与泌乳性状的关联性显示文摘【目的】研究中国荷斯坦牛CSN3基因的多态性,并探索其与泌乳性状的关系。【方法】采用DNA测序方法,对565头中国荷斯坦牛CSN3基因进行群体变异分析,将检测到的单核苷酸多态性(SNP)位点与中国荷斯坦牛泌乳性状进行关联性分析,同时分析不同双倍型对中国荷斯坦牛泌乳性状的影响。【结果】从中国荷斯坦牛CSN3基因中共检测到4个SNP位点,分别为g.463A>G、g.1012A>C、g.2015T>A和g.2396A>T,除g.2396A>T外,其余3个SNPs位点与中国荷斯坦牛泌乳性状紧密关联,其中g.463A>G、g.2015T>A均可以显著影响乳脂率和乳蛋白率,g.1012A>C可以显著影响乳脂率。双倍型关联性分析发现,H14H14的乳脂率显著或极显著高于其他双倍型。【结论】CSN3基因可以作为中国荷斯坦牛泌乳性状的候选基因用于标记辅助选择。胡言 桂林生 余横伟 Haider Abbas Raza 昝林森 2018西北农林科技大学学报(自然科学版)2018,46,3:5
18Evaluation of 1.2 kV SiC MOSFETs in Multilevel Cascaded H-bridge Three-phase Inverter for Medium-voltage Grid Applications显示文摘A study is conducted to evaluate 1.2 kV silicon-carbide(SiC)MOSFETs in a cascaded H-bridge(CHB)three-phase inverter for medium-voltage applications.The main purpose of this topology is to remove the need for a bulky 60 Hz transformer normally used to step up the output signal of a voltage source inverter to a medium-voltage level.Using SiC devices(1.2-6.5 kV SiC MOSFETs)which have a high breakdown voltage,enables the system to meet and withstand the medium-voltage stress using only a minimal number of cascaded modules.The SiC-based power electronics when used in the presented topology considerably reduce the complexity usually encountered when Si devices are used to meet the medium-voltage level and power scalability.Simulation and preliminary experimental results on a low-voltage prototype verifies the nine-level CHB topology presented in this study.Haider Mhiesan Janviere Umuhoza Kenneth Mordi Chris Farnell H.Alan Mantooth 2019Chinese Journal of Electrical Engineering2019,5,2:5
19PLC指令表程序的一种语法分析方法及其在代码静态测试上的应用显示文摘可编程逻辑控制器(PLC)是工业控制领域中广泛使用的自动控制装置。由于PLC程序缺乏具有普适性的测试工具,开发人员往往只能采用人工方式排查代码错误,导致测试效率低下。工业用户亟需一种标准化PLC代码检测方法,自动完成PLC程序语法检测与分析。该文以IEC61131-3标准为基础,建立基于Backus-Naur范式(BNF)的指令表语法模型。基于该模型构造抽象语法树,进而设计出一种具有线性复杂度的PLC指令表代码语法检测算法。利用2段控制工程中的PLC指令表代码对所提出的算法与商用软件CODESYS Static Analysis进行对比测试,验证了所提算法的可用性。李学良 赵千川 杨文 Syed Naeem HAIDER 2021清华大学学报(自然科学版)2021,61,10:5
20Interactions of cadmium and aluminum toxicity in their effect on growth and physiological parameters in soybean显示文摘The effect of Al and Cd on the growth, photosynthesis, and accumulation of Al, Cd and plant nutrients in two soybean genotypes were determined using hydroponic culture. There were six treatments: pH 6.5; pH 4.0; pH 6.5+1.0 μmol/L Cd; pH 4.0+1.0 μmol/L Cd; pH 4.0+150 μmol/L Al; pH 4.0+1.0 μmol/L Cd+150 μmol/L Al. The low pH (4.0) and Al treatments caused marked reduction in root length, shoot height, dry weight, chlorophyll content (SPAD value) and photosynthetic rate. Al-sensitive cv. Zhechun 2 accumulated comparatively more Al and Cd in plants than Al-tolerant cv. Liao 1. Compared with pH 6.5, pH 4.0 resulted in significant increase in Cd and Al concentration in plants. Combined application of Cd and Al enhanced their accu-mulation in roots, but caused a reduction in shoots. The concentrations of all 10 nutrients (P, K, Ca, Mg, Fe, Mn, Cu, Zn and B), except Mo were also increased when plants were exposed to pH lower than pH 6.5. Al addition caused a reduction in the con-centration of most nutrients in plant roots and shoots; but K, Mn and Zn in roots were increased. Treatments with Cd alone or together with Al reduced the concentrations of all the plant nutrients in plants. Al-sensitive genotype Zhechun 2 has lower nutrient concentration than Al-tolerant genotype Liao 1. The current findings imply that Al and Cd are synergistic in their effect on plant growth, physiological traits and nutrient uptake.SHAMSI Imran Haider JILANI Ghulam 2007Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)2007,8,3:5
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