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Pebax/MWCNTS-NH2混合基质膜及其二氧化碳/氮气分离性能

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Pebax/MWCNTS-NH2混合基质膜及其二氧化碳/氮气分离性能

作者： Muhammad mujahid 天津大学

学位级别：硕士

在烟气分离领域,混合基质膜的研究和应用有着巨大的发展空间。膜分离的渗透性和选择性之间存在相互制约的平衡关系,这一直是难以解决的问题,而混合基质膜则可同时有效提升膜的渗透性和选择性。混合基质膜中无机填料的合理设计、填料与... 详细信息

在烟气分离领域,混合基质膜的研究和应用有着巨大的发展空间。膜分离的渗透性和选择性之间存在相互制约的平衡关系,这一直是难以解决的问题,而混合基质膜则可同时有效提升膜的渗透性和选择性。混合基质膜中无机填料的合理设计、填料与聚合物良好的相容性以及填料在聚合物中的均匀的分散性,都是影响膜的形态和分离性能的重要因素。本文探索了不同溶剂对填料分散度的影响,从而制备出无缺陷的平板混合基质膜。采用扫描电子显微镜对膜材料的横截面形貌进行了观察分析。还采用X射线衍射和傅立叶变换红外分析对膜材料进行了表征。分别在环境温度和低于室温的温度下对采用不同溶剂制得的膜进行CO,N气体渗透测试,以研究溶剂对膜渗透性能的影响。研究了摩尔体积,沸点和溶解度等溶剂参数,以及结晶度,d间距和自由体积分数等膜特性参数。实验结果表明,用高摩尔体积溶剂制备的膜比其他溶剂制备的膜效率更高。综合考虑不同参数(溶剂摩尔体积、无分离体积、膜的结晶度)之间的相互制约的影响,Pebax/MWCNTs-NH MMMs的通透性和选择性参数最优化结果分别可达到405 Barrer和51。此外,在亚环境条件下检查膜分离性能,发现随着温度的降低,CO/N选择性增加到80.

关键词：混合基质膜 CO2捕捉选择性渗透性

经食道超声心动图在室间隔缺损微创封堵术中的应用

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经食道超声心动图在室间隔缺损微创封堵术中的应用

作者： Haroon mujahid 山东大学

学位级别：硕士

目的：室间隔缺损是最常见的先天性心脏病之一。本研究通过分析经食道超声心动图在探头辅助下微创封堵室间隔缺损手术中的应用和结果,表明经食道超声心动图的在室间隔缺损微创封堵术中的临床价值。方法：选择2010年的6月～2012年的3... 详细信息

目的：室间隔缺损是最常见的先天性心脏病之一。本研究通过分析经食道超声心动图在探头辅助下微创封堵室间隔缺损手术中的应用和结果,表明经食道超声心动图的在室间隔缺损微创封堵术中的临床价值。方法：选择2010年的6月～2012年的3月在我院诊断为室间隔缺损的50例患者,根据患者的性别、年龄、体重以及缺损类型分为不同的小组。经食道超声心动图用来观察室间隔缺损的位置、类型、大小并帮助选择合适的Amplatzer封堵器。手术过程中,经食道超声心动图用来帮助找到荷包的合适位置并指导鞘管的进入与封堵器的释放,术后利用彩色多普勒观测有无分流存在,立刻评估临床效果,并在室间隔缺损封堵后监测有无并发症。结果： 50例患者中,25例患者采用实体探头来辅助手术的进行,20例患者采用空心探头,5例患者采用了没用探头辅助的直接手术的方法。所有患者在术前术后均采用经胸超声心动图以及经食道超声心动图。与经胸超声心动图相比,经食道超声心动图显示的结果更有利于手术的成功,可以多层面的观察评估封堵后的封堵器的大小、形状、是否稳定以及是否有残余分流和溶血现象。50例患者手术均获成功,术后仅两例患者出现1mm的残余分流。所有患者术后三到四天均出院,一年后经食道超声心动图随访,未出现Amplatzer脱落、溶血、房室传导阻滞等并发症。结论：：随着探头辅助下的微创室间隔缺损闭合手术方法的改进,经食道超声心动图术中监测能进一步评估缺损的大小,形态,与周围组织的关系,为进一步确认室间隔缺损诊断提供了更加准确信息。经食道超声心动图在探头辅助下的室间隔缺损闭合微创手术中发挥着重要作用,成为更加简单、可行以及高成功率的手术方法。

关键词：经食道超声心动图经胸超声心动图室间隔缺损微创封堵术

Laparoscopic Transabdominal Preperitoneal Mesh Hernioplasty: A Medical College Experience

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Surgical Science 2016年第2期7卷 107-113页

作者： Mushtaq Chalkoo mujahid Ahmad Mir Hilal Makhdoomi Department of General Surgery Government Medical College Srinagar India

Objectives: To determine the feasibility and patient’s outcome of laparoscopic transabdominal preperitoneal mesh hernioplasty for inguinal hernias. Patients and Methods: This study was carried out from March 2011 to April 2014. A total of 130 patients underwent laparoscopic transabdominal preperitoneal mesh hernioplasty (TAPP) for uncomplicated inguinal hernia. Of this, 10 patients presenting with bilateral inguinal hernias were operated in the single sitting. A 15 cm × 12 cm polypropylene mesh was used in all cases. Operative morbidity, postoperative pain, seroma formation, evidence of superficial infection, chronic groin pain and hernia recurrence were noted. The majority of the patients were discharged within 24 hours and follow-up was done at 1 week, 1 month, and 6 months. Results: 130 patients presenting with uncomplicated inguinal hernias were operated over a period of three years in the department of surgery, Govt. Medical College Srinagar. The mean age of the patients was 39.18 years (range: 18 - 70 years). The median duration of operation was 48.5 minutes (range: 18 - 120 minutes). None of the procedure was converted to open inguinal hernia repair. Postoperative pain was observed in 9.23% of the cases and was easily controlled by oral analgesics. Six patients (4.62%) developed seroma, out of which one required aspiration while others settled conservatively. Two patients (1.54%) developed wound infection and one patient (0.77%) had recurrence. None of the patients developed scrotal hematoma or neuralgia. Return to normal activity after TAPP repair was found to be after a median of 16.1 days. Conclusion: Transabdominal preperitoneal repair for inguinal hernia using proline mesh may be a safe and effective procedure with low morbidity, early return to normal activity and with a very low recurrence after six months follow-up.

关键词： Inguinal Hernias Laparoscopy Transabdominal Preperitoneal Hernia Repair Feasibility Complications

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变工况双螺杆泵水力性能及流场特性研究

变工况双螺杆泵水力性能及流场特性研究

作者： mujahid Rasheed 西安理工大学

学位级别：硕士

双螺杆泵是一种旋转容积式泵,具有增压能力强、工况适应性好,且能够输送高粘流体的优点,在液压、化工等领域得到广泛应用。然而,其水力效率相对于离心泵还较低,一方面是由于当前理论及数值模型对其工作性能的预测精度不够,导致对其结构... 详细信息

双螺杆泵是一种旋转容积式泵,具有增压能力强、工况适应性好,且能够输送高粘流体的优点,在液压、化工等领域得到广泛应用。然而,其水力效率相对于离心泵还较低,一方面是由于当前理论及数值模型对其工作性能的预测精度不够,导致对其结构和工况优化程度较低;另一方面是对其内部流动机理还不清楚,难以提出高性能的优化方案。因此,本文采用动网格技术,采用PUMPLINX对一双吸式双螺杆混输泵进行了数值模拟,搭建了实验平台测试了其工作性能,对其精度进行了验证,分析了出口压力、转速和间隙参数对其水力性能和流场特性的影响。主要研究内容和结论总结如下。(1)通过数值模拟和实验研究了出口压力对其性能和流场的影响。结果表明:随着出口压力的增大,双螺杆泵的流量、容积效率和水力效率均降低,泵的功率增大。出口压力的增大导致泵的泄漏量增大,泄漏损失增加,效率降低。螺杆泵各个工作腔内的压力分布均匀,间隙内的压力呈线性分布,从吸入侧至排出侧其压力呈现阶梯状上升,左右两侧工作腔内的压力呈对称分布。随着出口压力的增加,三个间隙的泄漏速度都随齿腔间的压差增大而升高。排液腔出口处阴阳转子的交替射流引发排液管内出现四个对称的涡;随着压力的升高,流量降低,射流量减低,涡的面积和强度降低。(2)基于数值模拟和试验结果,研究了转速对其性能和流场的影响。结果表明:流量、功率、容积效率和水力效率随着转速的增加而增加。性能升高的原因在于其相对泄漏随着转速的升高而降低。转速对腔内压力分布的影响较小,因此间隙内泄漏速度随转速的变化也不大,但由于转速的提高,泄漏的时间降低,相对泄漏量降低。当转速提高时,流量增大,工作腔内流体速度升高,最后一个工作腔出口的射流速度增大,导致出口管内的速度、涡强度和面积增大。(3)采用数值模型计算了三种间隙同时从0.1mm增大至0.16mm时螺杆泵的水力性能和内部流场,分析了间隙对其性能和流场的影响规律。结果表明:间隙对双螺杆泵的性能具有显著影响,当间隙从0.1mm增大至0.16mm时,容积效率下降了 15%,水力效率下降了 9%。齿顶的泄漏速度随间隙尺寸先增大后降低,在0.14mm时达到最大值。随着间隙的增大,泄漏量升高,排液腔的流量降低,其排液管中的涡的强度也降低,在间隙为0.1mm时,涡最大,在0.16mm时,涡消失。

关键词：双螺杆泵结构化动态网格水力性能间隙瞬态流场泄漏流

AP1000非能动安全壳冷却系统热工水力性能分析

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AP1000非能动安全壳冷却系统热工水力性能分析

作者： TALHA BIN mujahid 华北电力大学(北京)

学位级别：硕士

核反应堆安全壳建筑的设计至关重要,其用于提高核电站的安全性。由于如TMI,切尔诺贝利和福岛县的核事故,核电发展中的消极观念越来越受到重视。为了改善的新一代核电站的安全性,非能动系统被广泛使用,AP1000中的非能动安全壳冷却系统就... 详细信息

核反应堆安全壳建筑的设计至关重要,其用于提高核电站的安全性。由于如TMI,切尔诺贝利和福岛县的核事故,核电发展中的消极观念越来越受到重视。为了改善的新一代核电站的安全性,非能动系统被广泛使用,AP1000中的非能动安全壳冷却系统就是这类系统的典例之一。它的作用是在冷却剂丧失（LOCA）,主蒸汽管道破裂（MSLB）等事故发生时,将安全壳内产生的热量转移到大气中,并将容器内的压力保持在阈值以下。系统设计和安全分析需要一个模拟系统行为的合适模型,并采用多卷集总参数方法来分析容器完整性并研究假定的冷却剂失水事故（LOCA）和主蒸汽管道断裂（MSLB）事故。然而,对研究安全壳中的T-H特性很重要的温度和压力分布却不能用这种模型详细描述。在本研究中,Matlab软件被使用于建立基于集总参数法的PCCS模型,并与WGOTHIC的计算结果进行比较,说明该点模型具有可靠性。然后对输入参数进行过滤,选择中断的气温,风速和排放数据作为研究对象计算,并分析了基于不同输入参数组合的结果。再将这些结果与西屋设计控制文件（DCD）2002中的结果进行比较。通过分析计算结果表明,在LOCA下,气温和风速会影响峰值出现的时间。温度越低,压力峰值出现越晚。此外,还使用ANSYS FLUENT对LOCA进行模拟,并进行分析。在研究的第二阶段,LOCA的T-H分析是通过考虑PCCS中的降膜蒸发的热量去除因子来进行的。为此应用了 ANSYS FLUENT中的Eulerian Wall Film模型来研究上述现象。分析了 PCCS外部气流路径中液膜和蒸汽混合气体之间的传质,并表现出其良好的性能。

关键词：非能动安全壳冷却系统 AP1000 DBA MATLAB FLUENT

Scattering of the Radial Focusing Mass-Supercritical and Energy-Subcritical Nonlinear Schrödinger Equation in 3D

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Advances in Pure Mathematics 2013年第1期3卷 164-171页

作者： mujahid Abd Elmjed M-Ali Amadu Fullah Kamara Department of Mathematics Faculty of Education Kassala University Kassala Sudan Department of Mathematics Faculty of Pure and Applied Sciences Fourah Bay College University of Sierra Leone Freetown Sierra Leone

This paper studies the global behavior to 3D focusing nonlinear Schrodinger equation (NLS), the scaling index here is (0 详细信息

This paper studies the global behavior to 3D focusing nonlinear Schrodinger equation (NLS), the scaling index here is (0

关键词： NLS Blows-Up in Finite Time Supremum Precompactness

Analysis of diabetic foot ulcers in a tertiary care hospital-a clinico-microbiological perspective

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海南医学院学报 2010年第2期16卷 165-170,180页

作者： Shazi Shakil Shaista Alvi mujahid Beg Asad U.Khan Interdisciplinary Biotechnology Unit Aligarh Muslim University Aligarh Department of Medicine JN Medical University Aligarh Muslim University Aligarh

Objective:To assess potential risk factors for diabetic foot ulcers infected with multidrug-resistant-organisms(MDROs)and to investigate antibiotic susceptibility patterns and extended-spectrum-β-lactamase(ESBL)-production in bacteria isolated from these ***:Seventy-seven diabetic foot ulcer-patients were studied in a consecutive ***-four study factors were recorded for each *** were obtained by scraping the ulcer base or the deep portion of the wound edge with a sterile *** soft tissue specimens were quickly sent to the laboratory and processed for microbial ***-negative bacterial isolates were tested for ESBL production by double-disc-diffusion *** association of study variables with MDRO and non-MDRO infection status of ulcers was tested by Student's t test or Fisher's exact test using SPSS(version 11.5,Chicago).Results:An alarming number of patients were MDRO-positive(72.7%).ESBL-positive strains constituted 19.8% of total *** isolates identified as methicillin-resistant Staphylococcus aureus(MRSA)and vancomycin-resistant Staphylococcus aureus(VRSA),were 3.7%(n=8)and 0.5%(n=1)***-two study factors were found to be significantly associated with MDRO infection status of ulcers in the univariate *** logistic regressions proved that MDRO status was the only significant,independent predictor of glycemic control(Odds ratio = 4.22,P<0.01).Conclusion:It is concluded that MDRO infected patients have poor glycemic *** and linezolid can be suggested as the drugs of choice in the described setting.

关键词：糖尿病有机体 β-内酰胺酶菌株

Plant Long ncRNAs: A New Frontier for Gene Regulatory Control

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American Journal of Plant Sciences 2013年第5期4卷 1038-1045页

作者： Jian Zhang Hana mujahid Yuxuan Hou Babi R. Nallamilli Zhaohua Peng Department of Biochemistry Molecular Biology Entomology and Plant Pathology Mississippi State University Mississippi State USA.

Long non-coding RNA (lncRNA) refers to an over 200 nt functional RNA molecule that will not be translated into protein. Previously thought to be dark matters of the genome, lncRNAs have been gradually recognized as crucial gene regulators. Although tremendous progress has been made in animals and human, the study of lncRNAs in plant is still in its infancy. Here, we reviewed the biogenesis and regulation mechanisms of lncRNAs and summarized the achievements that have been made in plant lncRNA identification and functional characterization. Genome-wide identification has uncovered large amount of lncRNAs in Arabidopsis, Rice, Maize and Wheat, and more information from other plant species will be expected with the aid of deep sequencing technologies. Similar to other species, LncRNA-mediated gene regulation also widely exists in plants, even though only a few functionally characterized examples are available. Up to now, at least four divergent lncRNA-mediated regulation mechanisms have been unraveled, including target mimicry, transcription interference, PRC2 associated histone methylation and DNA methylation. lncRNAs may be involved in the regulation of flowering, male sterility, nutrition metabolism, biotic and abiotic stress response in plants.

关键词： Long Non-Coding RNA Plants Polycomb Repressing Complex 2 Gene Regulation

Pattern of bony injuries among civilian gunshot victims at tertiary care hospital in Karachi, Pakistan

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Chinese Journal of Traumatology 2015年第3期18卷 161-163页

作者： Ghulam Mustafa Kaim Khani Syed mujahid Humail Kamran Hafeez Naveed Ahmed Department of Orthopedics Dow International Medical College Dow University of Health Sciences Karachi Sindh 74800 Pakistan Department of Orthopedics Civil Hospital Dow University of Health Sciences Karachi Sindh 74800 Pakistan

Purpose： Firearm injuries impose a continuous economic burden on society and hospital resources. The aim of this study was to assess the pattern of bony injuries among victims of gunshots. Methods： A retrospective study was conducted in the Department of Orthopedics, Dow University of Health Sciences and Civil Hospital l〈arachi from January 2011 to December 2012. Patients with isolated bony injuries were included while patients with other systemic injuries were excluded. Results： There were 90 cases and the majority of them were male （84.4%）. Mean age was （32.52 ± 10.27） years. Most of the patients （72.2%） belong to the younger age group. A low velocity weapon was used in 61 （67.8%） cases and a high velocity weapon was used in 29 （32.2%） cases. Armed robbery （64.4%） was the cause of conflict in more than half of the cases. Lower limb was involved in 72.2%. Fifty eight （64.4%） patients remained hospitalized for 15-20 days and others for more than 20 days. Internal fixation with intramedullary nailing was done in 35 patients while K-wire was used in 5 patients. Fifty patients were managed with external fixation, either uniplanar or multiplanar ilizarov. Deep wound infection and nonunion were observed more often in high velocity injuries. Conclusion： Armed robbery was the leading cause of gunshot bony injuries in our hospital. Young males were victimized in a majority of cases. High velocity injuries were associated with more complications.

关键词： Gunshot bony injuries Robbery Extremity fractures