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m, argest adjacency, signless Laplacian, and Laplacian H-eigenvalues of loose paths

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Frontiers of Mathematics in China 2016年第3期11卷 623-645页

作者： Junjie YUE Liping zhang mei LU Department of Mathematical Sciences Tsinghua University Beijing 100084 China State Key Laboratory of Space Weather Chinese Academy of Sciences Beijing 100910 China

We investigate k-uniform loose paths. We show that the largest H- eigenvalues of their adjacency tensors, Laplacian tensors, and signless Laplacian tensors are computable. For a k-uniform loose path with length l≥ 3, we show that the largest H-eigenvalue of its adjacency tensor is （（1 ＋ √-5）/2）2/k when = 3 and ）λ（A） = 31/k when g = 4, respectively. For the case of l ≥ 5, we tighten the existing upper bound 2. We also show that the largest H-eigenvalue of its signless Laplacian tensor lies in the interval （2, 3） when l≥ 5. Finally, we investigate the largest H-eigenvalue of its Laplacian tensor when k is even and we tighten the upper bound 4.

关键词： H-eigenvalue hypergraph adjacency tensor signless Laplaciantensor Laplacian tensor loose path

高弹EPE泡沫两自由度连续冲击包装动力学响应研究

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包装工程 2024年第19期45卷 318-324页

作者：陈家璇周卫中张美林志杨卢富德湖南工业大学包装与材料工程学院湖南株洲412007 金华市捷特包装有限公司浙江金华321000

目的基于产品在包装运输过程中经常遭受多次跌落冲击,探究两自由度高弹EPE泡沫包装在连续冲击载荷下的动力学响应。方法以密度为34kg/m3的EPE泡沫为研究对象,建立高弹泡沫本构方程,并通过ABAQUS构建两自由度高弹泡沫包装系统有限元模型... 详细信息

目的基于产品在包装运输过程中经常遭受多次跌落冲击,探究两自由度高弹EPE泡沫包装在连续冲击载荷下的动力学响应。方法以密度为34kg/m3的EPE泡沫为研究对象,建立高弹泡沫本构方程,并通过ABAQUS构建两自由度高弹泡沫包装系统有限元模型,并进行有限元模拟。利用ABAQUS中的Hyperform模型和Mullins效应来模拟高弹泡沫产品在连续冲击载荷下的加速度响应。结果通过对比试验和仿真结果可知,两自由度高弹EPE泡沫包装系统在连续冲击下,其产品加速度变化趋势明显,且泡沫的软化效应会降低其缓冲性能。结论在两自由度包装系统中,冲击对底层产品的影响持续时间较长,并且冲击作用会导致泡沫出现软化现象。在泡沫压实阶段,应力会急剧上升。

关键词：两自由度 EPE高弹泡沫连续冲击有限元分析

黄厚止泻滴丸对溃疡性结肠炎小鼠肠黏膜屏障及肠道菌群的影响

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中国中西医结合消化杂志 2024年第7期32卷 586-593页

作者：张震梅艳侯明星内蒙古医科大学附属医院胃肠外科呼和浩特010000 内蒙古自治区人民医院健康管理中心

目的:评估黄厚止泻滴丸对溃疡性结肠炎小鼠肠黏膜屏障以及肠道菌群的影响。方法:将Balb/c小鼠随机进行分组,分为空白组、模型组、黄厚低剂量组、黄厚中剂量组、黄厚高剂量组以及美沙拉嗪对照组,每组6只。除空白组外,其余各组均进行造模... 详细信息

目的:评估黄厚止泻滴丸对溃疡性结肠炎小鼠肠黏膜屏障以及肠道菌群的影响。方法:将Balb/c小鼠随机进行分组,分为空白组、模型组、黄厚低剂量组、黄厚中剂量组、黄厚高剂量组以及美沙拉嗪对照组,每组6只。除空白组外,其余各组均进行造模,造模成功后应用相应组别的药物进行喂养,2周后取出小鼠结肠并收集肛门附近的粪便冻存。应用Western blot方法检测紧密连接蛋白,应用16sRNA检测粪便菌群并进行对比分析。结果:与空白组比较,模型组紧密连接蛋白claudin-1、ZO-1、occludin的表达水平显著降低(P<0.01);与模型组比较,黄厚止泻滴丸各分组中紧密连接蛋白claudin-1、ZO-1、occludin的含量均明显提高(P<0.05),进一步对比可见黄厚中剂量组效果良好。α多样性及物种差异分析显示各组菌群组成差异较大,进一步分析可知模型组小鼠肠道中的拟杆菌门减少,变形菌门增加。β多样性分析、物种组成热图及LefSe分析可见3组中的物种差异较大,由ZIPI图可知各组菌群中丰度最高的5种关键物种分别为厚壁菌门、拟杆菌门、变形菌门、软壁菌门及疣微菌门。功能潜能预测发现核心菌群主要影响氨基酸、核苷酸、修复基团、电子载体和维生素的合成,也影响碳水化合物、羧酸盐以及核苷和核苷酸的降解。结论:黄厚止泻滴丸可提高溃疡性结肠炎结肠组织中claudin-1、occludin和ZO-1的含量,改善溃疡性结肠炎小鼠肠道的通透性;促进益生菌和共生菌群的生长,抑制机会性致病菌或有害菌的定植,维持肠道菌群的稳态;并通过改变核心菌群的数量以影响合成、降解等生物过程进而治疗溃疡性结肠炎。

关键词：溃疡性结肠炎黄厚止泻滴丸肠黏膜屏障肠道菌群

大蒜挥发油的提取工艺优化及GC-MS成分分析

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化学工程师 2024年第9期38卷 13-17页

作者：师白梅贾晓妮郭晓利翟云会张雅欣西安文理学院化学工程学院西安市食品安全检测与风险评估重点实验室陕西西安710065 西安市精神卫生中心中心实验室陕西西安710100

目的优化大蒜挥发油的提取工艺,并进行GC-MS分析。方法采用响应面法对大蒜挥发油的提取工艺进行优化,并采用GC-MS对其进行成分分析。结果最佳提取工艺:萃取温度为36℃、料液比为1∶4(g∶mL)、蒸馏时间为3h。采用GC-MS共检测出21个挥发... 详细信息

目的优化大蒜挥发油的提取工艺,并进行GC-MS分析。方法采用响应面法对大蒜挥发油的提取工艺进行优化,并采用GC-MS对其进行成分分析。结果最佳提取工艺:萃取温度为36℃、料液比为1∶4(g∶mL)、蒸馏时间为3h。采用GC-MS共检测出21个挥发性成分,多为硫醚类化合物。结论该提取工艺可有效提取大蒜的功能提取物,并通过GC-MS鉴定出大蒜的化学成分,为大蒜的药食两用提供理论基础。

关键词：大蒜挥发油水蒸气蒸馏法响应曲面法成分分析

Total synthesis of cyclic heptapeptide euryjanicin B

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Chinese Chemical Letters 2011年第6期22卷 631-634页

作者： Chun mei zhang Jun Xiang Guo Liang Wang xiao Yun Chai Hong Gang Hu Qiu Ye Wu Department of Organic Chemistry School of PharmacySecond Military Medical UniversityShanghai 200433China School of Pharmacy Yantai UniversityYantai 264005China

The first synthesis of the naturally occurring cyclic peptide euryjanicin B has been achieved.A general method was described to synthesize the cyclic peptide by a two-step solid-phase/solution synthesis *** the amino acids in this study are L-configuration. The linear heptapeptide was assembled by standard Fmoc chemistry on solid-phase and subsequently cyclization was carried out by solution method.

关键词： Cyclic peptide Solid-phase synthesis Cyclization Purification Euryjanicin B

A Multi-Objective Optimization Method of Initial Virtual Machine Fault-Tolerant Placement for Star Topological Data Centers of Cloud Systems

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Tsinghua Science and Technology 2021年第1期26卷 95-111页

作者： Wei zhang xiao Chen Jianhui Jiang the School of Software Engineering Tongji UniversityShanghai 201804China

Virtualization is the most important technology in the unified resource layer of cloud computing *** placement and dynamic management are two types of Virtual Machine(VM)management *** dynamic management is based on the structure of the initial VM placement,and this initial structure will affect the efficiency of VM dynamic *** a VM fails,cloud applications deployed on the faulty VM will crash if fault tolerance is not *** this study,a model of initial VM fault-tolerant placement for star topological data centers of cloud systems is built on the basis of multiple factors,including the service-level agreement violation rate,resource remaining rate,power consumption rate,failure rate,and fault tolerance ***,a heuristic ant colony algorithm is proposed to solve the *** service-providing VMs are placed by the ant colony algorithms,and the redundant VMs are placed by the conventional heuristic *** experimental results obtained from the simulation,real cluster,and fault injection experiments show that the proposed method can achieve better VM fault-tolerant placement solution than that of the traditional first fit or best fit descending method.

关键词： cloud computing virtual machine placement fault tolerance multi-objective optimization heuristic ant colony algorithm

用于痕量监测Zr^(4+)、Cr_(2)O_(7)^(2-)、Fe^(3+)、HPO_(4)^(2-)和指纹识别的功能化Eu^(3+)/Tb^(3+)配位聚合物荧光探针的构筑

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无机化学学报 2024年第2期40卷 441-450页

作者：王思璐张凤凤张成王潇唐龙岳二林王记江侯向阳延安大学化学与化工学院延安716000

采用芳香族π共轭及含氮原子有机连接剂,合成同构铽、铕发光配位聚合物(CPs){[Eu(PLIA)_(1.5)(H_(2)O)_(2)]·H_(2)O}_(n)(1)和{[Tb(PLIA)_(1.5)(H_(2)O)_(2)]·H_(2)O}_(n)(2),其中H_(2)PLIA=5-((吡啶-4-基甲基)氧基)苯-1,3-二甲酸。对合成的配合物进行了结构测定、表征和荧光痕量识别实验研究。2个同构配合物具有理想的三维框架结构,π…π堆积及氢键等弱相互作用增强了其化学稳定性;表征显示配位聚合物1和2具有良好的荧光性质、结晶性、热力学稳定性及结构完整性,可作为荧光传感的材料。1和2对水溶液中的Zr^(4+)、Cr_(2)O_(7)^(2-)和Fe^(3+)、HPO_(4)^(2-)具有选择性好、灵敏度高的荧光识别能力,其检出限分别为0.139μmol·L^(-1)(1,Zr^(4+))、0.626μmol·L^(-1)(1,Cr_(2)O_(7)^(2-))、0.430μmol·L^(-1)(2,Fe^(3+))、1.36μmol·L^(-1)(2,HPO_(4)^(2-))。探究了1和2作为探针的荧光猝灭机理。更有趣的是,1和2具有指纹识别性能,其荧光指纹纹路清晰连贯,细节明显,可被清晰观察。

关键词： Eu^(3+)/Tb^(3+)配位聚合物合成表征荧光探针指纹识别

Flight parameter calculation method of multi-projectiles using temporal and spatial information constraint

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Defence Technology（防务技术） 2023年第1期19卷 63-75页

作者： Han-shan Li xiao-qian zhang School of Electronic and Information Engineering Xi'an Technological UniversityXi'an710021China

The dynamic parameters of multiple projectiles that are fired using multi-barrel weapons in highfrequency continuous firing modes are important indicators to measure the performance of these *** characteristics of multiple projectiles are high randomness and large numbers launched in a short period of time,making it very difficult to obtain the real dispersion parameters of the projectiles due to the occlusion or coincidence of multiple *** six intersecting-screen testing system,in this paper,we propose an association recognition and matching algorithm of multiple projectiles using a temporal and spatial information constraint *** extract the output signal from each detection screen and then use the wavelet transform to process the output *** present a method to identify and extract the time values on which the projectiles pass through the detection screens using the wavelet transform modulus maximum *** then use the correlation of the output signals of three parallel detection screens to establish a correlation coefficient recognition constraint function for the multiple *** on the premise of linear projectile motion,we establish a temporal and spatial constraint matching model using the projectile’s position coordinates in each detection screen and the projectile’s time constraints within the multiple intersecting-screen *** then determine the time values of the multiple projectiles in each detection screen using an iterative search cycle registration,and finally obtain the flight parameters for the multiple projectiles in the presence of *** proposed method and algorithm were verified experimentally and can solve the problem of uncertainty in projectiles flight parameter under different multiple projectile firing states.

关键词： Six detection screen array Multi-projectile Recognition and matching Temporal and spatial information constraint Wavelet transform

Tsaokols A and B,unusual flavanol-monoterpenoid hybrids asα-glucosidase inhibitors from Amomum tsao-ko

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Chinese Chemical Letters 2021年第3期32卷 1202-1205页

作者： xiao-Feng He Ji-Jun Chen Tian-Ze Li Jing Hu Xu-Ke zhang Yuan-Qiang Guo Xue-mei zhang Chang-An Geng State Key Laboratory of Phytochemistry and Plant Resources in West China Kunming Institute of BotanyChinese Academy of SciencesYunnan Key Laboratory of Natural Medicinal ChemistryKunming 650201China College of Pharmacy and Tianjin Key Laboratory of Molecular Drug Research Nankai UniversityTianjin 300071China University of Chinese Academy of Sciences Beijing 100049China

Tsaokols A(1)and B(2),two complicated flavanol-monoterpenoid hybrids,were isolated from the dried fruits of Amomum tsao-ko under the guidance of LCMS and *** structures were determined by extensive spectroscopic analyses and electronic circular dichroism(ECD)*** 1 and2 shared a flavanol backbone fused with 5/7 and 5/6 bicyclic monoterpenoid scaffolds,which were biogenetically condensed by Michael addition and *** 1 and 2 exhibited significantα-glucosidase inhibitory activity with IC_(50)values of 18.8 and 38.6μmol/L(acarbose,IC_(50)=213μmol/L).Docking study supported the strong interactions of 1 and 2 bonding with enzyme by mainly hydrophobic and hydrogen-bond *** 1 and 2 could be fast distinguished by the diagnostic ions at m/z 289 and 313 in negative MS^(2)experiments.

关键词： Amomum tsao-ko Zingiberaceae Flavanol-monoterpenoid hybrids α-Glucosidase inhibitors