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Olefin Polymerization Behavior of Titanium(IV) Complexes with fluorinated and Non-fluorinated Aliphatic Phenoxyimine Ligands

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Chinese Journal of Polymer Science 2024年第1期42卷 52-62,I0007页

作者： Vladislav A.Tuskaev kasim f.magomedov Svetlana Ch.Gagieva Dmitry A.Kurmaev Yulia V.Nelyubina Evgenii K.Golubev Maria D.Evseeva Viktor G.Vasil'ev Galina G.Nikiforova Mikhail I.Buzin Vyacheslav S.Bogdanov Boris M.Bulychev Department of Chemistry M.V.Lomonosov Moscow State UniversityMoscow 119992Russian Federation A.N.Nesmeyanov Institute of Organoelement Compounds Russian Academy of SciencesMoscow119991Russian Federation Enikolopov Institute of Synthetic Polymer Materials Russian Academy of SciencesMoscow 117393Russian Federation

A series of Ti(Ⅳ) dichloride and dialkoxide com plexes with phenoxyimine ligands containing fluorinated and nonfluorinated aliphatic imine fragments have been *** molecular structures of complexes 1 and 4 were established by single-crystal X-ray diffraction *** complexes adopt a distorted octahedral coordination structure around the titanium atom and two oxygen atoms are situated in trans position while two nitrogen atoms and two outgoing ligands(Cl or iPrO) are situated in cis *** of activators(MMAO-12 and combinations Et_nAICl_(3-n)+Bu_(2)Mg) and outgoing ligand(Cl or iPrO) nature on the catalytic activity and properties of the resulting polymers was *** Ti complexes,despite the nature of the outgoing ligands(Cl or iPrO) in the presence of Al/Mg activators,was found to display a high ethylene polymerization activity in the range 1600-3830 kg_(polymer)·mol_(Ti)^(-1)·h^(-1)·atm^(-1) with a viscosity average molecular weight(M_v) value in the range 1.1×10~6-7.1×10~6 Dalton(Da).The resulting UHMWPE can be processed by a solventless method into high-strength and high-modulus oriented *** rheological characteristics of a polymer melt have been *** absence of a cross-over point did not allow to compare the values of the molecular weight distribution of polymers obtained on fluorinated and non-fluorinated pre-catalysts,however,the estimation of the entanglement density is in good agreement with the mechanical characteristics of oriented film *** activation with methylalumoxane,the activity of the com plexes decreased very significantly;however,a polymer with a molecular weight of about 12 million Da was *** the process of ethylene/octene-1 copolymerization,fluorine-containing precatalysts showed a clear advantage over non-fluorinated analogues both in activity and in comonomer content.

关键词： fI catalysts Titanium(IV) (Co)polymerization Al/Mg co-catalyst Ultra-high molecular weight polyethylene

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近红外激发PLNPs/UCNPs纳米复合材料的制备及其性能研究

近红外激发PLNPs/UCNPs纳米复合材料的制备及其性能研究

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作者：鲁克曼·喀斯木（Lukman kasim）喀什大学

学位级别：硕士

研究人员在新型多功能纳米材料的研发上付出了诸多努力,并将其广泛应用于生物医学领域。其中,长余辉发光材料和上转换发光材料在生物成像、生物传感和癌症治疗等领域的发展,具有潜在应用前景。但是,长余辉发光材料和上转换发光材料的开... 详细信息

研究人员在新型多功能纳米材料的研发上付出了诸多努力,并将其广泛应用于生物医学领域。其中,长余辉发光材料和上转换发光材料在生物成像、生物传感和癌症治疗等领域的发展,具有潜在应用前景。但是,长余辉发光材料和上转换发光材料的开发仍然面临着一些挑战。部分长余辉发光材料中能量的耗尽可以被光激励持续发光策略恢复,但大部分长余辉发光材料充电效率差,发射强度和穿透深度仍然受到限制,满足不了在体内重复激发以便用于长期成像应用的需求;上转换发光材料内部的非辐射能量损失和其他损耗机制的存在,导致发光效率较低,并且发光时间有限。基于以上问题,可以通过发射波长在近红外第二（NIR-II）生物窗口的长余辉发光材料来解决长余辉发光穿透深度受到限制的问题;通过将长余辉发光材料和上转换发光材料的结合来解决长期成像应用的需求。在第一项工作中,我们采用水热合成法,制备了发射波长位于NIR-II生物窗口的Ni2+掺杂镓酸锌Zn1+2xGa2-2xO4:Nix2+（ZGO:Ni）长余辉发光材料,ZGO:Ni在1000～1500nm之间出现宽带发射峰。系统地研究了不同煅烧温度和p H值以及Ni2+不同掺杂比例对ZGO:Ni发光特性的影响。采用XRD、TEM、EDS、荧光光谱仪进行测试,对制备的ZGO:Ni进行了表征,并研究了其光致发光性能、余辉发光性能和发光机理。结果显示,通过优化煅烧温度和p H值以及Ni2+的掺杂量,确定了当ZGO:Ni的煅烧温度为1000℃、p H值为8、Ni2+的掺杂量1%时发光性能最佳,发射波长位于1290 nm处。在第二项工作中,我们构建了Zn Ga2O4:Ni2+/Na Er f4:Yb3+,Mn2+（ZGO:Ni/UCNPs）上转换长余辉纳米复合材料。我们采用水热合成法,制备了激发源为980 nm激光、发射波长在600-700 nm范围内的Na Er f4:Yb3+,Mn2+上转换发光材料,基于荧光共振能量转移体系,通过共价键将Zn Ga2O4:Ni2+与Na Er f4:Yb3+,Mn2+结合。所得到的复合材料用980 nm激光激活后,在1290 nm处呈现持续发光。这是由于980 nm激光激发后,Na Er f4:Yb3+,Mn2+的发射光谱与Zn Ga2O4:Ni2+的激发光谱有良好的重叠,使得Na Er f4:Yb3+,Mn2+中的Er3+和Zn Ga2O4:Ni2+中的Ni2+之间发生荧光共振能量转移。ZGO:Ni/UCNPs上转换长余辉纳米复合材料的构建,解决了光激励持续发光策略不能满足体内重复激发以供长期成像应用需求的问题。此外,因为复合材料的激发（980nm）和发射（1290 nm）波长位于生物NIR-I、NIR-II生物窗口内,适合用于深层组织的生物成像,因此,该复合材料在体内生物成像方面有巨大的应用潜力。

关键词：长余辉发光上转换发光上转换长余辉发光 NIR-Ⅱ生物窗口

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Q-switched ytterbium doped fiber laser using multi-walled carbon nanotubes saturable absorber

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Chinese Optics Letters 2014年第3期12卷 41-44页

作者： N.kasim A.H.H.Al-Masoodi f.Ahmad Y.Munajat H.Ahmad S.W.Harun Advanced Photonics Science Institute Faculty of ScienceUniversity Technology Malaysia Photonics Research Centre University of Malaya Department of Electrical Engineering Faculty of EngineeringUniversity of Malaya

A Q-switched ytterbium-doped fiber laser （YDfL） is proposed and demonstrated using a newly developed multi-walled carbon nanotubes polyethylene oxide （MWCNTs-PEO） film as a passive saturable absorber （SA）. The saturable absorber is prepared by mixing the MWCNTs homogeneous solution into a dilute PEO polymer solution before it is left to dry at room temperature to produce thin film. Then the film is sandwiched between two fC/PC fiber connectors and integrated into the laser cavity for Q-switching pulse generation. The laser generates a stable pulse operating at wavelength of 1060.2 nm with a threshold pump power of 53.43 mW. The YDfL generates a stable pulse train with repetition rates ranging from 7.92 to 24.27 kHz by varying 980-nm pump power from 53.42 to 65.72 mW. At 59.55-mW pump power, the lowest pulse width and the highest pulse energy are obtained at 12.18 μs and 143.5 n J, respectively.

关键词： MWCNTs PEO length SA Q-switched ytterbium doped fiber laser using multi-walled carbon nanotubes saturable absorber

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Endoscopic Transsphenoidal Surgery for Pituitary Adenoma. Early Experience in Sohag University Hospitals

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Open Journal of Modern Neurosurgery 2021年第3期11卷 194-203页

作者： Karam Kenawy Ahmed Ismail Ibrahim Rezk Abdin K. kasim Department of Neurosurgery Sohag University Sohag Egypt Department of E.N.T Sohag University Sohag Egypt

Objective: To report the results of our first series of patients undergoing a purely endoscopic endonasal approach for pituitary surgery in Sohag University Hospitals. Patients and Methods: We reviewed 20 consecutive patients during the period from January 2017 to January 2020 with pituitary adenoma who underwent purely endoscopic transsphenoidal resection of their lesions. The patients’ clinical outcomes, degrees of tumor removal, and complications were reported. Results: There were 18 primary and 2 recurrent adenomas (19 nonfunctioning and 1 functioning GH secreting adenoma). The average degree of gross total removal for tumors was 70%, C.S.F leak occurred in 20%, diabetes insipidus in 10% and sellar hemorrhage in 5%. There was no post-operative mortality, vascular injury, sphenoiditis, septal perforation, epistaxis or general complication. Conclusion: A purely endoscopic approach for pituitary adenoma treatment is a safe and effective alternative to the traditional microscopic procedure.

关键词： Endoscopic Surgery Endonasal Pituitary Adenoma Transsphenoidal Outcome Complications

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Chemical Composition and Antibacterial Activity of Essential Oils from <i>Struchium sparganophora</i>Linn. Ktze Asteraceae

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Advances in Biological Chemistry 2014年第4期4卷 246-252页

作者： Lateef S. kasim Kafayat O. Olaleye A. B. fagbohun S. f. Ibitoye O. E. Adejumo Department of Pharmaceutical and Medicinal Chemistry Olabisi Onabanjo University Sagamu Nigeria

Struchium sparganophora Linn. Ktze Asteraceae is a culinary herb that is consumed in the Western part of Nigeria and has wide medicinal uses in traditional medicine. The present study was carried out to determine the chemical composition of the oils from its leaf and stem and their antibacterial activity. Essential oils were collected from the leaf and stem of Struchium sparganophora by hydrodistillation and analysed by GC and GC-MS. The antimicrobial activity was tested against Gram negative (G-ve) and Gram positive (G + ve) microorganisms obtained from the Medical Microbiology Unit, University College Hospital (UCH), Ibadan, Nigeria. forty-six compounds were identified in the leaf representing 95.3% of the total oil while fifty-five compounds were identified in the stem representing 93.5% of the oil. β-caryophyllene, Germacrene A, a-humulene and Germacrene D represented the major components in both oils. Antibacterial activity of the oils against certain strains of bacteria showed that the different concentrations of the oils (100 – 10,000 ppm) from the leaf had activity ranging from 9.0 ± 1.0 to 14.3 ± 2.55 mm while that from the stem had activity ranging from 18.5 ± 2.2 to 20.0 ± 0.0 mm for both *** G + ve microorganisms respectively.

关键词： Essential Oils β-Caryophyllene Germacrene A Antibacterial Activity

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维吾尔语词首音节元音声学分析1

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中文信息学报 2009年第5期23卷 114-118页

作者：孜丽卡木.哈斯木那斯尔江.吐尔逊吾守尔.斯拉木新疆大学信息科学与工程学院新疆乌鲁木齐830046 新疆大学数学与系统科学学院新疆乌鲁木齐830046 西安交通大学电子与信息工程学院陕西西安710049

该文利用"维吾尔语语音声学参数数据库",统计分析和归纳了维吾尔语词首音节元音的共振峰模式及其分布格局。声学元音图有多种画法,该文采用JOOS型声学元音图。这种元音图的特点是以f1为纵坐标,以f2为横坐标。这样绘制成的声学元音图与... 详细信息

该文利用"维吾尔语语音声学参数数据库",统计分析和归纳了维吾尔语词首音节元音的共振峰模式及其分布格局。声学元音图有多种画法,该文采用JOOS型声学元音图。这种元音图的特点是以f1为纵坐标,以f2为横坐标。这样绘制成的声学元音图与元音舌位图有很好的对应性。维语标准音词首音节中有[y,i,e,O,u,o,;,A]等8个元音。舌位前后的分布特点是:[u,o,A]为后元音,[y,i,e,O,;]为前元音;开口度(舌位高低)分布特点是:[y,i,u]为高元音,[e,O,o]为次高元音,[;]为次低元音,[A]为低元音.

关键词：计算机应用中文信息处理维吾尔语词首音节元音声学分析

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正交试验优化肉桂子中超声提取桂皮醛的工艺

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新疆医科大学学报 2013年第9期36卷 1278-1281页

作者：胡曙晨李莉李新霞热娜.卡斯木新疆医科大学药学院乌鲁木齐830011

目的优化肉桂子中超声提取桂皮醛的最佳工艺。方法以桂皮醛为对照品,采用高效液相法进行测定,以提取液中桂皮醛含量作为考察指标,对影响桂皮醛提取工艺的因素进行分析。通过单因素实验研究提取溶剂、料液比、超声提取时间、超声波功率... 详细信息

目的优化肉桂子中超声提取桂皮醛的最佳工艺。方法以桂皮醛为对照品,采用高效液相法进行测定,以提取液中桂皮醛含量作为考察指标,对影响桂皮醛提取工艺的因素进行分析。通过单因素实验研究提取溶剂、料液比、超声提取时间、超声波功率、超声提取次数对提取效果的影响,采用正交试验法优化最佳提取工艺条件。结果影响肉桂子中桂皮醛提取的主要因素是超声提取次数与超声波功率,正交试验表明最佳提取工艺参数为:超声波作用时间20min,料液比为1∶50,超声波作用功率350 W,超声波提取次数2次。通过验证实验,肉桂子中桂皮醛的含量为3.21%。结论采用正交试验优化的超声提取工艺,能有效提高肉桂子中桂皮醛的提取效率,具有良好的应用前景。

关键词：正交试验法超声肉桂子桂皮醛

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