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三种脱敏剂对全酸蚀粘结剂牙本质粘结强度和界面形态的影响

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牙体牙髓牙周病学杂志 2012年第4期22卷 227-230页

作者：邹璇赵三军李芳陈吉华第四军医大学口腔医学院陕西西安710032

目的:研究、比较三种脱敏剂对全酸蚀粘结剂牙本质粘结强度及其粘结界面形态的影响。方法:选择12个无龋损离体人磨牙,磨除牙合面釉质,用600目碳化硅砂纸在流水下预备出有统一玷污层的牙本质粘结面后,随机分为4组,分别用去离子水(对照组)... 详细信息

目的:研究、比较三种脱敏剂对全酸蚀粘结剂牙本质粘结强度及其粘结界面形态的影响。方法:选择12个无龋损离体人磨牙,磨除牙合面釉质,用600目碳化硅砂纸在流水下预备出有统一玷污层的牙本质粘结面后,随机分为4组,分别用去离子水(对照组)和3种脱敏剂(Hybrid Coat、Gluma、极固宁)进行脱敏处理后,应用Single Bond 2在面粘结4 mm树脂。然后将每个牙垂直于粘结面切割出12个1.0 mm×1.0 mm×4.0 mm的粘结试件,分别在SEM下观察其粘结界面微观形态并进行微拉伸强度(μTBS)测试。结果:HybridCoat组粘结强度最高((14.81±3.87)MPa,随后依次为去离子水组(13.39±4.67)MPa、Gluma组(12.76±2.96)MPa和极固宁组(10.48±4.32)MPa,各组间两两比较,极固宁组明显低于其他3组(P﹤0.05),其他3组间相比均无显著性差异(P﹥0.05);Hybrid Coat组形成的树脂突大部分>35μm,长而密集;Gluma组形成的树脂突长7～35μm;极固宁组形成的树脂突长20～35μm,较稀疏。结论:Hybrid Coat和Gluma对全酸蚀粘结剂牙本质粘结强度无明显影响,而极固宁则明显降低其粘结强度。

关键词：牙本质脱敏剂微拉伸强度扫描电镜

Effects of ultrasonic-assisted extraction on bioactive compounds,volatile flavors and antioxidant activities of vine tea water extracts

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Traditional Medicine Research 2025年第1期10卷 73-81页

作者： Xiao-Long Zhou Wei-Jin Jiang Ji Yu Mao-jun Yao Yun-Tong li Hunan Provincial Key Laboratory of Research Resource Mining and High-valued Utilization on Edible&Medicinal PlantCollege of Chemistry and Chemical EngineeringJishou UniversityJishou 416000China Hunan Gaoge Dairy Co. Ltd.Changsha 410000China

Background:Ampelopsis grossedentata,vine tea,which is the tea alternative beverages in *** vine tea processing,a large amount of broken tea is produced,which has low commercial ***:This study investigates the influence of different extraction methods(room temperature water extraction,boiling water extraction,ultrasonic-assisted room temperature water extraction,and ultrasonic-assisted boiling water extraction,referred to as room temperature water extraction(RE),boiling water extraction(BE),ultrasonic assistance at room temperature water extraction(URE),and ultrasonic assistance in boiling water extraction(UBE))on the yield,dihydromyricetin(DMY)content,free amino acid composition,volatile aroma components,and antioxidant properties of vine tea ***:A notable influence of extraction temperature on the yield of vine tea extracts(P<0.05),with BE yielding the highest at 43.13±0.26%,higher than that of RE(34.29±0.81%).Ultrasound-assisted extraction significantly increased the DMY content of the extracts(P<0.05),whereas DMY content in the RE extracts was 59.94±1.70%,that of URE reached 66.14±2.78%.Analysis revealed 17 amino acids,with L-serine and aspartic acid being the most abundant in the extracts,nevertheless ultrasound-assisted extraction reduced total free amino acid *** chromatography-mass spectrometry analysis demonstrated an increase in the diversity and quantity of compounds in the vine tea water extracts obtained through ultrasonic-assisted ***,69 and 68 volatile compounds were found in URE and UBE extracts,which were higher than the number found in RE and BE *** vitro,antioxidant activity assessments revealed varying antioxidant capacities among different extraction methods,with RE exhibiting the highest DPPH scavenging rate,URE leading in ABTS•+free radical scavenging,and BE demonstrating superior ferric ion reducing antioxidant ***:The findings suggest that extraction methods signi

关键词： vine tea dihydromyricetin ultrasonic-assisted extraction volatile aroma components

Hadronic Scenarios for Gamma-Ray Emission from Three Supernova Remnants Interacting with Molecular Clouds

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Chinese Physics Letters 2014年第4期31卷 206-209页

作者： YU Huan fang jun ZHANG li Department of Physics Yunnan University Kunming 650091 Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming 650011

GeV γ-rays detected with the large area telescope on board the Fermi Gamma-ray space telescope in the direc- tion of HB21, MSH 17-39 and G337.0-0.1 have been recently reported. The three supernova remnants （SNRs） show interactions with molecular clouds, and they are effective gamma-ray emitters as the relativistic protons accelerated by the SNR shocks inelastically colliding with the dense gas in the clouds. The origin of the observed γ-rays for the three remnants is investigated in the scenario of the diffusive shock acceleration. In the model, a part of the SNR shock transmits into the nearby molecular clouds, and the shock velocity is greatly reduced. As a result, a shock with a relatively low Alfven Mach number is generated, and the spectra of the accelerated protons and thee＇γ-ray photons produced via proton-proton interaction can be obtained. The results show that the observed γ-ray spectra for the three SNRs interacting with the molecular clouds can be reproduced. It can be concluded that the hadronic origin of the γ-rays for the three SNRs is approved, and the ability of SNR shocks to accelerate protons is also supported.

关键词： Clouds Hadronic large area telescope

基于地理信息系统的重庆市自然灾害综合区划及评价

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西南师范大学学报（自然科学版） 2003年第4期28卷 627-632页

作者：蒋勇军况明生李林立冯绍国方佳军高方立何凌云曹晓林杨定中西南师范大学资源环境科学学院重庆400715 重庆市人民政府救灾办公室重庆400015

从孕灾环境、自然致灾因子和承灾体3个方面选取区划指标,通过地理信息系统(GIS)空间分析,分别得到重庆市孕灾环境敏感度图、自然致灾因子危险度图和区域承灾体脆弱度图;将上述3幅图进行叠加分析,得到重庆市自然灾害区划的基本单元,然后... 详细信息

从孕灾环境、自然致灾因子和承灾体3个方面选取区划指标,通过地理信息系统(GIS)空间分析,分别得到重庆市孕灾环境敏感度图、自然致灾因子危险度图和区域承灾体脆弱度图;将上述3幅图进行叠加分析,得到重庆市自然灾害区划的基本单元,然后对基本单元属性数据库的数据处理,根据拟定的区划原则,采用"自下而上"的区划定量分析方法并结合"自上而下"的区划方法对重庆市自然灾害进行区划,得到4个自然灾害区;从属性数据库中提取相关属性数据,得到每个自然灾害区的基本特征;最后,分别对每个自然灾害区的自然灾害、环境以及社会经济情况进行详细的评价.

关键词：重庆自然灾害综合区划地理信息系统孕灾环境自然致灾因子承灾体灾害评价

Evaluation of numerical ablation model for charring composites

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Science China(Technological Sciences) 2019年第8期62卷 1322-1330页

作者： li Wei ZHANG jun fang GuoDong li WeiJie liANG jun MENG SongHe Science and Technology on Advanced Composites in Special Environments Key Laboratory Harbin Institute of Technology Harbin 150001 China Institute of Advanced Structure Technology Beijing Institute of Technology Beijing 100081 China

Charring composites are widely used in the thermal protection system(TPS) to consume the intense aerodynamic heating during vehicle reentry. The ablation and thermal responses for the charring composites can be studied by using a numerical ablation model, in which the surface ablation and volume ablation could be taken into account. The coupling interactions among temperature, gas motion and interior pressure producing the pyrolysis gas could make the computation more complicated. A multi-physics model is developed to simulate the thermal response coupled with volume ablation and surface ablation. After studying four typical ablation cases, the model is validated, and then the heat transfer mechanisms in ablation are investigated. It is found that the viscous dissipation energy by the motion of pyrolysis gas can be neglected in the simulation. Also, the flow of pyrolysis gas plays an important role in the temperature response, especially under high heat flux condition.

关键词： ablation charring composites numerical model coupling

An Evaluation Framework for Virtual Articulatory Movements Based on Medical Video

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Chinese Journal of Electronics 2019年第3期28卷 585-592页

作者： li Rui YU jun li Xian fang Peng WANG Zengfu Department of Automation University of Science and Technology of China Institute of Intelligent Machines Chinese Academy of Sciences

An important aspect of a Speech tutoring aimed talking-head system(STTS) is the accuracy of produced articulatory movements. little work has been done for the Articulatory movements’ accuracy(AMA)evaluation in STTSs. Although subjective evaluation is reliable, it is time consuming and inconvenient. The traditional objective evaluation is comparing the motion of several points on the surface of the synthetic articulator to the Electromagnetic articulography(EMA) data which describes the motion of corresponding points on the articulatory surface of a speaker. The EMA information is too limited to describe the whole shape changing of deformable articulators for a speech process. To solve this problem, we propose a substantially different objective evaluation method based on a separately recorded medical video. The synthetic articulatory shapes in a speech process are compared to the corresponding shapes tracked from the medical video. This method is translation,rotation, and scaling invariant which allows the comparison of the shapes from the synthetic tongue and the medical images. The time difference problem of synthesis results and medical video is solved by introducing Dynamic time warping(DTW) to the proposed method. Experimental results demonstrate that our method has the ability to evaluate the deformation shape accuracy from an entire articulation process. The comparison results suggest that our method is more accurate than the traditional method especially for deformable articulators.

关键词： Accuracy evaluation Medical video Articulatory animation Speech tutoring aimed talkinghead system

p38 MAPK is a Component of the Signal Transduction Pathway Triggering Cold Stress Response in the MED Cryptic Species of Bemisia tabaci

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Journal of Integrative Agriculture 2012年第2期11卷 303-311页

作者： li fang-fang XIA jun li jun-min liU Shu-sheng WANG Xiao-wei Key Laboratory of Agricultural Entomology Ministry of Agriculture/Institute of Insect SciencesZhejiang UniversityHangzhou 310029P.R.China

Cold stress responses help insects to survive under low temperatures that would be lethal *** phenomenon might contribute to the invasion of some Bemisia tabaci cryptic species from subtropical areas to temperate ***,the molecular mechanisms regulating cold stress responses in whitefly are yet ***-activated protein kinases（MAPKs）which including p38,ERK,and JNK,are well known for their roles in regulating metabolic responses to cold stress in many *** this study,we explored the possible roles of the MAPKs in response to low temperature stresses in the Mediterranean cryptic species（the Q-biotype）of the *** species ***,we cloned the p38 and ERK genes from the whitefly cDNA ***,we analyzed the activation of MAPKs during cold stress in the Mediterranean cryptic species by *** cold stress,the level of phospho-p38 increased but no significant change was observed in the phosphorylation of ERK and JNK,thus suggesting that the p38 might be responsible for the defense response to low temperature ***,we demonstrated that：i）3 min chilling at 0°C was sufficient for the activation of p38 MAPK pathway in this whitefly;and ii）the amount of phosphorylated p38 increased significantly in the first 20 min of chilling,reversed by 60 min,and then returned to the original level by 120 *** together,our results suggest that the p38 pathway is important during response to low temperature stress in the Mediterranean cryptic species of the *** species complex.

关键词： Bemisia tabaci cold stress MAPK p38 phosphorylation signal transduction

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数字通信中的盲多径衰落信道估计与均衡

湘潭师范学院学报（自然科学版） 2004年第3期26卷 38-41页

作者：饶伟栋李方军李海吉首大学数学与计算机科学系湖南吉首416000

建立一个过采样的的多径衰落信道的FIR滤波器模型 ,提出了一种基于子空间过采样的多径衰落信道盲估计算法 ,并在信道估计的基础上用迫零算法实现信道均衡。试验仿真表明 ,该方法能有效地估计出信道 ,并能有效地提高系统的容量和利用率。

关键词：数字通信系统信道子空间特征值分解噪声迫零算法

Particle breakage and the mobilized drained shear strengths of sand

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Journal of Mountain Science 2016年第8期13卷 1481-1488页

作者： YU fang-wei SU li-jun Institute of Mountain Hazards and Environment Chinese Academy of Sciences Department of Civil Engineering The University of Tokyo

This paper presents particle breakage and the mobilized drained shear strengths of sand with the purpose of clarifying the influence of particle breakage on the mobilized shear strengths of sand. Several drained triaxial tests were carried out on Silica sand No.5 under 3 MPa confining pressure to produce the pre-crushed sands in simulating the high- pressure shear process on soil to result in particle breakage, and then the pre-crushed sands were re- sheared in series of drained triaxial tests to investigate the mobilized strengths of the pre-crushed sands in detecting the influence of particle breakage. It was found that, by deteriorating strain-stress behavior, particle breakage resulted in change of stress-dilataney behavior in translation and rotation of the relation of the dilatancy factor and the effective principal stress ratio. For a given initial void ratio, particle breakage resulted in impairment of dilatancy behavior of soil to be more contractive in deterioration of the mobilized friction angle and the mobilized dilatancy angle and reduction of void ratio. However, particle breakage resulted in increase of the mobilized basic friction angle especially before failure. In addition, the influence of particle breakage on the mobilized strengths was revealed to be influenced by the shear stress-strain state.

关键词： Particle breakage Mobilized strengths Friction Dilatancy Void ratio Sand