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The convergence ball and error analysis of the two-step Secant method

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Applied Mathematics(A Journal of Chinese Universities) 2017年第4期32卷 397-406页

作者： LIN Rong-fei WU Qing-biao CHEN Min-hong KHAN yasir LIU Lu Department of Mathematics Taizhou University Department of Mathematics Zhejiang University Department of Mathematics Zhejiang Sci-Tech University

Under the assumption that the nonlinear operator has Lipschitz continuous divided differences for the first order,we obtain an estimate of the radius of the convergence ball for the two-step secant ***,we also provide an error estimate that matches the convergence order of the two-step secant *** last,we give an application of the proposed theorem.

关键词： two-step secant method estimate of radius convergence ball Lipschitz continuous

Maternal TMPRSS6 Gene Polymorphism rs855791SNP in Women with Preeclampsia

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Journal of Biosciences and Medicines 2023年第1期11卷 70-81页

作者： yasir I. B. Ahmed Hind S. Yagoub Mohamed A. Hassan Department of Haematology and Immunohematology Faculty of Medical Laboratory Sciences Omdurman Islamic University Omdurman Sudan Department of Medical Laboratory Technology College of Applied Medical Sciences Taibah University Medina Saudi Arabia Africa City of Technology Khartoum Sudan

Introduction: Preeclampsia can lead to several maternal and perinatal adverse effects. There are few published data on the association between transmembrane serine protease 6 (TMPRSS6) gene polymorphism and preeclampsia. Objective: To assess the association between TMPRSS6 gene polymorphism rs855791SNP in women with preeclampsia compared with healthy pregnant women. Method: A case-control study (60 women in each arm) was conducted at Saad Abuaela Maternity Hospital in Khartoum, Sudan. Sociodemographic and clinical data were gathered through a questionnaire. The participant was genotype for TMPRSS6 gene rs855791SNP using Polymerase Chain Reaction and Restriction Fragment Length Polymorphism (PCR-RFLP). The results were confirmed by DNA sequencing. Result: There was no significant difference in the median of age, parity, and body mass index. The distribution of the genotypes and alleles of TMPRSS6 rs855791 was consistent with the HWE. The overall TMPRSS6 rs855791 polymorphism was not significantly associated with preeclampsia. However, the proportion of heterozygotes (TC) was considerably higher in the women with preeclampsia (46.7%) than in the control group (23.3%) (p = 0.001;OR = 2.71;95% CI = 1.21 - 6.07). The proportion of homozygotes (TT) and T alleles was not significantly different between women with preeclampsia and the control group. Conclusion: The overall TMPRSS6 rs855791 polymorphism was not significantly associated with preeclampsia and healthy control.

关键词： Preeclampsia TMPRSS6 Gene Polymorphism rs855791SNP

Kappaphycus alvarezii waste biomass:A potential biosorbent for chromium ions removal

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Journal of Environmental Sciences 2011年第6期23卷 918-922页

作者： Oon Lee Kang Nazaruddin Ramli Mamot Said Musa Ahmad Suhaimi Md yasir Arbakariya Ariff School of Chemical Sciences and Food Technology Faculty of Science and TechnologyUniversiti Kebangsaan Malaysia43600 BangiSelangorMalaysia School of Sciences and Technology Universiti Malaysia Sabah88400 Kota KinabaluSabahMalaysia Faculty of Biotechnology and Biomolecular Science Universiti Putra Malaysia43400 SerdangSelangorMalaysia

The Cr（III） sorption experiments onto Kappaphycus alvarezii waste biomass were conducted at different pH values（2-6） under the conditions of initial metal concentration of 10-50 mg/L and the chemical compositions of Cr-Cu and *** Cr（III） sorption capacities were slightly dependent on pH,and the maximum sorption capacity was 0.86 mg/g at pH *** sorption capacities increased with increase in the initial metal concentration,whereas it was suppressed by the presence of Cu（II） and Cd（III） in the *** Cr（III） sorption equilibrium was evaluated using Langmuir,Freundlich and BET *** sorption mechanisms were characterised using scanning electron microscopy and Fourier transform infrared *** main mechanisms were ion exchange coupled with a complexation *** alvarezii waste biomass represents a potential for Cr（III） ion removal from aqueous solution.

关键词： biosorption chromium Kappaphycus alvarezii

CLASSIFICATION OF CUBIC PARAMETERIZED HOMOGENEOUS VECTOR FIELDS

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Journal of Systems Science & Complexity 2002年第2期15卷 125-138页

作者： Kamal H yasir Tang Yun Department of Mathematical Science Tsinghua University 北京 100084

Abstract. In this paper the cubic homogeneous parameterized vector fields aJre *** classification of the phase portrait near the critical point is presented. This classifica- tion is an extension of the result given b... 详细信息

关键词：二次微分方程各向同性矢量场矢量场分类

Incidence and clinical presentation of portal vein thrombosis in cirrhotic patients

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Hepatobiliary & Pancreatic Diseases International 2016年第5期15卷 499-503页

作者： yasir Furkan Cagin Yahya Atayan Mehmet ali Erdogan Firat Dagtekin Cemil Colak Division of Gastroenterology Medical Faculty Inonu University Malatya 44280 Turkey Division of Internal Medicine Medical Faculty Inonu University Malatya 44280 Turkey Division of Biostatistics and Medical Informatics Colak C Medical Faculty Inonu University Malatya 44280 Turkey

BACKGROUND: Portal vein thrombosis (PVT) is due to many risk factors, but its pathogenesis is still not clearly understood. To identify the risk factors for PVT, we analyzed the clinical characteristics and complications associated with PVT in cir-rhotic patients. METHODS: We studied patients with liver cirrhosis who were admitted to our unit from April 2009 to December 2014. The patients were divided into the PVT and non-PVT groups, and were compared by variables including gender, age, the etiology of cirrhosis, stage of cirrhosis, complications, imaging, and treatment. RESULTS: PVT was found in 45 (9.8%) of 461 cirrhotic pa-tients admitted to our hospital. Most patients (45.9%) had hepatitis B virus (HBV)-related cirrhosis, with a similar dis-tribution of etiologies between the groups. However, there was no positive relationship between PVT and etiologies of cirrhosis. Most patients (71.5%) were in the stage of hepatic decompensation. No statistically signiifcant differences were found in complications including esophageal varices, ascites, and hepatic encephalopathy between the groups. However, there was a signiifcant positive correlation between hepatocel-lular carcinoma (HCC) and PVT (Pal vein and/or portal branches, 37.8% were diagnosed on ultrasound. CONCLUSIONS: The incidence of PVT was 9.8%, mainly in patients with HBV-related cirrhosis. The development of PVT was associated with the severity of liver disease and HCC.

关键词： portal vein thrombosis cirrhosis clinical presentation

Ultra-Low Power 1 Volt Small Size 2.4 GHz CMOS RF Transceiver Design for Wireless Sensor Node

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Journal of Beijing Institute of Technology 2018年第4期27卷 584-591页

作者： Muhammad yasir Faheem Shun'an Zhong Abid ali Minhas Muhammad Basit Azeem School of Information and Electronics Beijing Institute of TechnologyBeijing College of Computer and Information Systems Al Yamamah University Department of Mechatronics Engineering University of Engineering and Technology

Ultra-low power transceiver design is proposed for wireless sensor node used in the wireless sensor network（WSN）.Typically,each sensor node contains a transceiver so it is required that both hardware and software designs of WSN node must take care of energy consumption during all modes of operation including active/sleep modes so that the operational life of each node can be increased in order to increase the lifetime of *** current declared size of the wireless sensor node is of millimeter order,excluding the power source and crystal *** have proposed a new 2.4 GHz transceiver that has five blocks namely XO,PLL,PA,LNA and *** proposed transceiver incorporates less number of low-drop outs（LDOs）*** size of the transceiver is reduced by decreasing the area of beneficiary components up to 0.41 mm;of core area in such a way that some functions are optimally distributed among other *** proposed design is smaller in size and consumes less power,also been reduced to 1 *** transceiver is most efficient and will be fruitful for the wireless networks as it has been designed by considering modern requirements.

关键词： low-drop outs(LDOs) transceiver metal oxide semiconductor field effect transistor(MOSFET) wireless sensor networks(WSN)

利用多角度反射数据估算不同物种不同叶片的含水量

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利用多角度反射数据估算不同物种不同叶片的含水量

作者：亚斯（Qazi Muhammad yasir）东北师范大学

学位级别：硕士

目前,主要的科学问题之一是了解和量化全球气候变化对地球系统的影响。其中一个挑战是了解陆地生态系统的作用和它们可能发生的变化。在这方面,植物叶片的含水量和植物的水分利用效率研究具有重要意义。叶片含水量是植物的重要生物化学... 详细信息

目前,主要的科学问题之一是了解和量化全球气候变化对地球系统的影响。其中一个挑战是了解陆地生态系统的作用和它们可能发生的变化。在这方面,植物叶片的含水量和植物的水分利用效率研究具有重要意义。叶片含水量是植物的重要生物化学组分,也是植物蒸腾作用的主要限制因素,与多种生理过程和生态系统状态密切相关。植被含水量的时空变化对于监测植物的生理状态至关重要。叶片层面的植被含水量可以通过遥感数据进行估计,在这之前,首先要建立准确的方法来估算叶片含水量。光学遥感提供了一种简单而多样的方法,利用多角反射率测量来准确估计含水量信息。由于叶片的反射光谱在近红外(NIR)和短波红外(SWIR)波长范围内存在水吸收带,因此我们可以通过电磁波谱正确地估算叶片含水量。本文在详细分析叶片含水量光谱特征的基础上,提出了用于估计叶片含水量的新指数。由于叶子有不同的角度方向,而高空间分辨率的数据可以收集到单个叶子的微小区域,因此,在研究时有必要考虑叶子的多角反射。叶片产生的多角度反射的分布和大小主要由叶片表面的镜面反射控制,然而,镜面反射与叶子的生化特征无关。在本研究中,350-2500 nm范围的多角度反射测量被用来研究叶片等效水厚度(EWT)、重量水含量(GWC)和植物水浓度(PWC)之间的关系。本研究使用了长春东北师范大学植物园中10种不同物种的256个叶子样本作为校准数据集,并使用了683个来自不同品种的叶片样本进行验证,包括93年叶片光学特性实验(LOPEX93)、ANGERS和多角度数据集,分别包含330、275和78个叶片样本。以往的研究中,研究者们基于多角度光谱提出了多种形式的各种指数。为了,本研究同样多角度反射测量分析叶片的含水量,评估了三种不同形式的高光谱指数,包括简单比值植被指数(SR)、归一化植被指数(ND)和双差值植被指数(datt类型的指数)。因为这些指数大多是基于植物物种的两个或三个特定波段,测量起来很容易,也不太费时。本研究首先对比了EWT、PWC和GWC与十个不同光谱指数之间的关系,发现基于多角度测量提出的datt类型指数(R-R)/(R-R)表现最好。为了进一步分析现有指数的表现,本研究选择了EWT、PWC和GWC的五个指数,分析它们在校准数据集上的表现。结果显示只有R/R、(R-R)/(R-R)和(R-R)/(R-R)与EWT表现出良好的相关性。本研究主要在校准数据集中应用了两种方法,一种是线性回归,另一种是非线性回归模型。最终为每个指标(EWT,PWC,GWC)确定了两个指数:EWT的线性形式的指数是(R-R)/(R-R),非线性形式的指数是(R-R)/(R-R);PWC的线性形式的指数是(R-R)/(R-R),PWC非线性形式的指数是(R-R)/(R-R);GWC的线性和非线性指数均为(R-R)/(R-R)。然后,本研究进一步分析了数据,以便基于本研究的数据找出一个新的三波段形式(R1-R2/R1-R3)的植被指数。基本上,我们采用的方法是为三种类型的指标,即EWT、PWC和GWC找出最佳指数,因此对于每个指标,我们在线性回归模型和非线性回归模型的基础上选择了两个指数。结果显示EWT R>0.94,PWC R>0.71,而GWC R>0.8,所有指数均显示较好的可决系数。然后,通过可决系数和均方根误差值,选择在主平面上的叶片多角度反射(范围为-60到60)的表现最佳的指数,结果显示EWT指标的表现最好,对应的线性和非线性EWT指数分别为(R-R)/(R-R)和(R-R)/(R-R)。本研究中使用的已发表的光谱指数中,除了R/R,(R-R)/(R-R)和(R-R)/(R-R)植被指数外,其他指数指数在多角度建模数据集中与叶片含水量相关关系非常弱。同时,重量水分含量(GWC)和植物水分浓度(PWC)这两个指标表现出很强的相关性,但EWT的相关性最强。此外,当使用LOPEX、ANGERS和多角度数据集验证PWC和GWC指数的可靠性和准确性时,PWC和GWC只在多角度数据库中显示出良好的结果,因为在在多角度验证数据集与校准数据集存在重复的物种,只有少数物种不同。结合三个指标在多角度验证数据集验证上的表现,EWT的指数表现出最优的结果,RMSE为0.0043(g/cm),PWC的RMSE为0.0061(g/g),GWC的RMSE为0.0054(g/g)。因此,我们得出结论,EWT的指数在所有三个验证数据集(包括LOPEX、ANGERS和多角度数据集)中都表现非常好。而其他两个指标,即PWC和GWC,除了多角度数据集外,在RMSE方面表现得并不明显。本研究提出的高光谱指数在EWT方面的表现超过了其他指数的表现,它已被LOPEX、ANGERS和多角数据集所验证。最后,本研究表明,三波段组合(R-R)/(R-R)的植被指数类型可用于估算EW

关键词： EWT PWC GWC 反射率遥感高光谱指数

Microstructure and Mechanical Properties of Fe-based Amorphous Composite Coatings Reinforced by Stainless Steel Powders

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Journal of Materials Science & Technology 2015年第1期31卷 43-47页

作者： H.Zhou C.Zhang W.Wang M.yasir L.Liu School of Materials Science and Engineering State Key Lab for Materials Processing and Die &Mould TechnologyHuazhong University of Science and Technology Huazhong University of Science and Technology Research Institute in Shenzhen

In this study,a few Fe-based amorphous matrix composite coatings reinforced with various portions(4,8 and16 vol.%) of 31 6L stainless steel powders have been successfully produced through high velocity oxy-fuel(HVOF) *** microstructure of the composite coatings was systematically characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM) and transmission electron microscopy(TEM).The main structure of composite coatings remained amorphous while 31 6L stainless steel splats were distributed homogeneously in the amorphous matrix and well connected with surrounding amorphous *** strength of coatings to the substrate was determined by 'pull-off' tensile *** results revealed that the31 6L stainless steel phase effectively improved the bonding strength of amorphous coatings,which is mainly contributed by the strong metallurgical bonding between stainless steel and amorphous *** addition of31 6L stainless steel also enhanced the ductility and fracture resistance of the coatings due to the ductile stainless steel phases,which can arrest crack propagation and increase energy dissipation.

关键词： Thermal spraying Fe-based amorphous coating Stainl

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四叶草形超宽带漫散射编码超表面

雷达学报（中英文） 2021年第3期10卷 382-390页

作者： yasir Saifullah 杨国敏徐丰复旦大学电磁波信息科学教育部重点实验室上海200433

该文提出了一种结构新颖的四叶草形编码超表面,并利用该超表面实现了超宽带漫散射。所提出的编码超表面具有旋转对称性,它对x极化和y极化波产生相似的反射特性。为了实现1比特编码超表面,该文设计了在15.5~40.5 GHz的频率范围内且相位差... 详细信息

该文提出了一种结构新颖的四叶草形编码超表面,并利用该超表面实现了超宽带漫散射。所提出的编码超表面具有旋转对称性,它对x极化和y极化波产生相似的反射特性。为了实现1比特编码超表面,该文设计了在15.5~40.5 GHz的频率范围内且相位差为180°±37°的两个超表面单元。采用优化算法得到阵列中单元的最佳排列,从而实现了宽带RCS的缩减。四叶草形编码超表面可以在15.5~26.5 GHz和30.5~40.5 GHz这两个频带内实现10 dB的RCS缩减。该文加工了该编码超表面并与仿真结果进行了比较,从而有效验证了所设计的四叶草形编码超表面可以在宽频带内实现RCS的缩减。

关键词：编码超表面水循环算法雷达散射截面漫散射四叶草形