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枯草芽孢杆菌YZ-1突变体库构建与产表面活性素优势菌株筛选

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西南农业学报 2024年

作者：万莉何月秋谢鑫欣刘迎龙何鹏搏 mUNIR shahzad 吴毅歆何鹏飞云南农业大学农学与生物技术学院云南农业大学植物保护学院

【目的】拟通过构建高效杀虫枯草芽孢杆菌YZ-1的转座突变体库，从中筛选出高产表面活性素的突变体菌株，为后续YZ-1的表面活性素合成调控机制解析和开发利用提供前期材料。【方法】利用携带转座子TnYLB-1和温敏型复制蛋白的穿梭载体pmar... 详细信息

【目的】拟通过构建高效杀虫枯草芽孢杆菌YZ-1的转座突变体库，从中筛选出高产表面活性素的突变体菌株，为后续YZ-1的表面活性素合成调控机制解析和开发利用提供前期材料。【方法】利用携带转座子TnYLB-1和温敏型复制蛋白的穿梭载体pmarA转化YZ-1，通过50 ℃温度诱导转座子转座、抗性培养复筛以及特异性PCR扩增验证，构建YZ-1菌株的转座突变体库。组合使用血平板法初筛、溴百里香酚蓝比色法复筛及HPLC定量检测，从突变体库中筛选表面活性素合成显著增强的突变体。【结果】通过自然转化成功地将pmarA质粒导入枯草芽孢杆菌YZ-1中，获得含有3000株转座突变子的YZ-1突变体库，从中筛选出11株表面活性素合成增强的候选菌株。HPLC检测显示与YZ-1野生型相比，表面活性素合成增强和相似的突变体有5株（m1、m6、m7、m8及m9），显著下降有6株（m2、m3、m4、m5、m10及m11），其中表面活性素产量最高的m8突变体为282.4 mg/L较野生型增加了13.7%，而最低的m2菌株为47.53 mg/L，较野生型下降了80.9%。【结论】增设抗性复筛培养可提高YZ-1突变体库的正确率。基于血平板培养和溴百里香酚蓝比色的高通量筛选与HPLC定量检测的YZ-1表面活性素增强型突变体筛选结果不理想，还需进一步改进。

关键词：枯草芽孢杆菌表面活性素 TnYLB-1转座子 pmarA质粒 Himar1转座元件

Fragmentation Cross Sections of 158 AGeV Pb Projectiles

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Chinese Physics Letters 2007年第10期24卷 2800-2803页

作者： G. Sher m.I. shahzad m. Hussain Physics Division PINSTECH Islamabad Pakistan Department of Physics University of the Punjab Lahore Pakistan

We investigate the fragmentation cross sections of 158 AGeV ^207Pb projectile interacting with different targets using CR39 nuclear track detectors. The exposure is made at SPS beam facility of CERN. The detectors are chemically etched to obtain data in the form of etched cone length. The nuclear and electromagnetic contributions to the measured total charge-changing cross sections are investigated. The estimated results are compared with those found in the literature for similar research work.

关键词： coated conductor buffer layer self-epitaxy CeO2

morphology and ontogeny of directly differentiating shoot buds and somatic embryos in Santalum album L.

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Journal of Forestry Research 2019年第4期30卷 1179-1189页

作者： Rakhshanda Akhtar Anwar shahzad Plant Biotechnology Section Department of BotanyAligarh Muslim University

Santalum album *** a commercially important tree that yields essential oil of high medicinal *** research through organogenesis and embryogenesis has been documented but no report depicts comparative ontogeny of directly differentiating shoot buds(SB)and somatic embryos(SE).In the present study aseptic seedling derived hypocotyl segments(HC)and hypocotyl+root junction(HC+R)were used to induce SBs and SEs,*** differences between the structures were confirmed using scanning electron microscopy and histological *** medium containing 6-benzyladenine or BA(2.5μm)produced highest number of direct SB,while mS+BA(7.5μm)proved suitable for higher frequency of SE *** differentiating structures attained growth when transferred to mS medium containing a combination of BA and anaphthalene acetic acid or silver nitrate(AgNO3).A combination of indole-3-butyric acid and silver nitrate(AgNO3)in half-strength woody plant medium and lesser osmotic concentration(2%sucrose),induced rhizogenesis.

关键词： Direct somatic embryos Emblings Histology Hypocotyl Ontogenic

mass dependence of pion-induced fission cross sections on the level density parameter

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Chinese Physics C 2012年第9期36卷 831-835页

作者： Zafar Yasin Warda Iram m.Ikram shahzad Physics Division PINSTECHP.O.NiloreIslamabadPakistan Physics Department Islamia UniversityBahawalpurPakistan

Fission probabilities and fission cross sections strongly depend on the mass number of the target and energy of the projectile. In this research work, a cascade-exciton model （using CEm95 computer code） has been implemented to observe the dependence of pion-induced fission cross sections and fission probabilities on the target mass and ratio of the level density parameter in fission to neutron emission. The analysis has been performed for both the positive and negative pions as the projectile at 80, 100 and 150 meV energies. The computed cross sections satisfactorily reproduced the experimental findings when compared with the available experimental data in the literature. We observed a smooth dependence at 150 meV, and a sharper dependence at 80 and 100 meV pion energy, in the fissility region above 29.44.

关键词： CEm95 fission cross section level density parameter

matter accretion onto Einstein-aether black holes via well-known fluids

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Chinese Physics C 2020年第6期44卷 182-196页

作者： m.Umair shahzad Rafaqat Ali Abdul Jawad Shamaila Rani Department of mathematics University of OkaraOkaraPakistan Department of mathematics COMSATS University IslamabadLahore-CampusPakistan

We study matter accretion onto Einstein-aether black holes by adopting the Hamiltonian *** general solution of accretion is discussed using the isothermal equation of *** types of fluids are considered,including ultra-relativistic,ultra-stiff,sub-relativistic,and radiation fluids,and the accretion process onto Einstein-aether black holes is *** behavior of the fluid flow and the existence of critical points is investigated for Einstein-aether black *** further discuss the general expression and behavior of polytropic fluid onto Einstein-aether black *** most important feature of this work is the investigation of the mass accretion rate of the above-mentioned fluids and the comparison of our findings with the Schwarzschild black hole,which generates particular ***,the maximum mass accretion rate occurs near the Killing and universal horizons,and the minimum accretion rate lies between them.

关键词： black hole accretion homo-clinic orbits

Structural and magnetic Properties of Chemically Synthesized Pd-modified NiFe2O4 Nanoparticles

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Chinese Journal of Chemical Physics 2016年第2期29卷 245-248,I0002页

作者： Shahid Aatiq Shahid m. Ramay Asif mahmood SairaRiaza shahzad Naseem 巴基斯坦旁遮普邦大学固体物理卓越中心拉合尔100190 沙特阿拉伯沙特国王大学理学院物理与天文学系利雅得11421 沙特阿拉伯沙特国王大学工程学院化学工程系利雅得11421

magnetic nanoparticles of NiFe2O4-Pd composites have been synthesized using a simple, low cost, sol-gel auto-combustion method. As-prepared samples were sintered at 800℃ for 6 h in order to develop the crystalline phase. X-ray diffraction confirmed the spinel structure of the ferrite samples. Structural morphology and size of the nanoparticles were evaluated using a field emission scanning electron microscope. magnetic hysteresis loops were obtained at 300 and 100 K using a physical properties measurement system. The value of saturation magnetization was observed to decrease at the temperatures with the increase of Pd contents up to 5% but then a sudden rise in saturation magnetization was observed for the addition of 10% Pd in NiFe2O4.

关键词： magnetic nanoparticles Sol-gel auto-combustion Low temperature magneticproperty

Application of 0D model of blood flow to study vessel abnormalities in the human systemic circulation: An in-silico study

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International Journal of Biomathematics 2018年第8期11卷 217-234页

作者： R. Gul A. shahzad m. Zubair COmSATS Institute of Information Technology Abbottabad Pakistan

In this paper, a multi-compartment 0D model of the blood flow is considered to study the vessel abnormalities (stenoses and aneurysms) in the human systemic circulation (SC). In the complete SC, different levels of stenosis and aneurysms are artificially created by decreasing and increasing the vessel diameters respectively and their effects on pressure and flow are studied using sensitivity analysis (SA). Normalized local sensitivity analysis (LSA) is used to study the impact of stenosis and aneurysms on pressure and flow wave pattern. Furthermore, global sensitivity analysis (GSA), Sobol's method is used to quantify the overall influence of stenoses and aneurysms in the complete SC. The results of global sensitivity analysis revealed that the impact of both stenoses and aneurysms is strong within the individual structures (arm. legs, carotid bifurcation, aorta), while, aortic stenoses and aneurysms have effect on almost all downstream nodes. moreover, the study could be useful for medical doctors, teachers and students to observe the hemodynamical changes in the SC with respect to vessel abnormalities, which could further help in making any clinical decision for patients having different levels of vessel abnormalities in any part or structure of the SC.

关键词： 0D model systemic circulation sensitivity analysis stenosis aneurysms

Analytical Solution for Time-dependent Flow of a Third Grade Fluid Induced Due to Impulsive motion of a Flat Porous Plate

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Acta mathematicae Applicatae Sinica 2015年第3期31卷 757-766页

作者： Taha Aziz F.m.mahomed Azeem shahzad Asim Aziz School of Computational and Applied mathematics DST-NRF Centre of Excellence in Mathematical and Statistical Sciences Differential Equations Continuum Mechanics and Applications University of the Witwatersrand School of Natural Sciences National University of Sciences and Technology Department of mathematics Quaid-i-Azam University Department of Basic Sciences and Humanities National University of Sciences and Technology College of Electrical and Mechanical Engineering

The aim of the present communication is to discuss the analytical solution for the unsteady flow of a third grade fluid which occupies the space y 〉 0 over an infinite porous plate. The flow is generated due to the motion of the plate in its own plane with an impulsive velocity V（t）. Translational symmetries in variables t and y are utilized to reduce the governing non-linear partial differential equation into an ordinary differential equation. The reduced problem is then solved using homotopy analysis method（HAm）. Graphs representing the solution are plotted and discussed and proper conclusions are drawn.

关键词： third grade fluid Porous plate translational symmetries Homotopy analysis method(HAm)

A novel laminated metal composite with superior interfacial bonding composed of ultrahigh strength maraging steel and 316L stainless steel

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Journal of Iron and Steel Research International 2020年第4期27卷 433-439页

作者： Le Zhang Wei Wang m.Babar shahzad Yi-yin Shan Ke Yang Institute of metal Research Chinese Academy of SciencesShenyang 110016LiaoningChina School of materials Science and Engineering University of Science and Technology of ChinaHefei 230026AnhuiChina Key Laboratory of Nuclear materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016LiaoningChina

A 5-layer laminated metal composite composed of ultrahigh-strength maraging steel and ductile 316L stainless steel was fabricated by hot pressing in vacuum and post-heat *** characterization on hierarchical structure of the composite before and after heat treatment was made by optical microscopy,scanning electron microscopy and electron back-scattered diffraction technique,***,the difference of mechanical performance on both sides of the interface was characterized by nano-hardness *** tensile test showed that superior interfacial bonding was achieved due to the micro-‘bite’structure between the two steels without obvious defects or oxides at the interface and with coordinated deformation of the two ***,a laminated metal composite consisting of two different constituents with extreme difference in strength can be well fabricated.

关键词： maraging steel Austenitic stainless steel Laminated metal composite Hierarchical structure Interfacial