Biomass Cell Wall Component Structural Interpretation and Bonding Mechanism

生物质转化为高值化材料的关键一步是对组分进行清洁温和分离,然后将分离后的组分进行生物和化学转化,获得高性能材料。然而,由于生物质结构复杂,人们对其了解的局限导致对它们有效分离缺乏理论上的指向,使得目前的分离技术多是一种工艺层面的探索。迄今为止,尚没有高效的集成化生物质清洁分离技术体系,即在一个工艺过程中将生物质不同的组分能以较完整的分子结构形式清洁有效分离出来。由于生物质现代转化利用途径需要在保持较完整结构的基础上将主要组分清洁有效分离开来,然后对不同组分进行有目的的转化利用。因此,尽管生物质组分转化利用有广阔的应用前景,但生物质组分的清洁有效分离仍是一个瓶颈限制,是一个难点问题。生物质组分分离的关键是将断裂木质素组分和半纤维素组分之间的结合键或有选择性断裂木质素分子内的结合键,进一步达到清洁分离组分的目的。该研究拟从生物质组分间化学结合键的差异性以及空间构型的差异性中寻找其对不同差异介质环境中的反应机制,从而进一步提出氧基化学分离新途径的导向指引,即利用木质素侧链的α、β、γ-与半纤维素组分之间的酯键等结合键或木质素分子内不同化学键对不同微差异介质环境中化学体系中O2分子的敏感性不同,探索其可能的分子内或分子外结合键的断裂途径,从而实现清洁温和分离纤维素、半纤维素和木质素组分的目的,为生物质的高值化利用奠定基础。The key procedure of converting the biomass into high value materials is to separate the fractions clean and moderately and then to conduct the biological or chemical conversion of the separated fractions to obtain the high value materials. However, it, the lack of theoretical guide of effective separation on account of the limitation of our acquirement about the complexity of biomass structure, makes the separation technology become an exploration on process level. So far, there is no efficient integrated system for clean separation, which can separates different fractions at a fairly complete molecular structure clean and effectively in a process. The way of modern biomass utilization needs to separate its fractions clean and effectively under the premise of a fairly complete molecular structure and then carry out the purposeful conversion and utilization of different fractions. Despite the biomass conversion and utilization have broad application prospects, the clean and effective separation is still a bottleneck restriction and a difficult problem. The key to the separation of biomass components is to break the bond between lignin and hemicellulose or to selectively break the intramolecular bond among lignin achieving the purpose of clean separation. This study intends to find the reaction mechanism under different medium environment from the differences of the bonds among the fractions and the differences of spatial configuration, and then propose an orientation guidance of oxygen chemical separation. Scilicet, making use of the different sensitivities to O2 of different bonds, which between lignin side chain of alpha, beta, gamma- and bonds among hemicellulose fractions, such as easter bond, or intramolecular bond among lignin molecules, to explore the possible fracture way in or between the molecular. Furthermore, on the basis of the above work, this study intends to achieve the purpose of a clean and moderate separation of cellulose, hemicellulose and lignin fractions, laying a foundation for high value utilization of biomass

Ti-6Al-7Nb合金与口腔常用合金间电偶腐蚀的研究

目的：评价Ti-6Al-7Nb合金与3种口腔常用合金在人工唾液中的电偶腐蚀性。方法：运用电化学方法测量Ti-6Al-7Nb合金与纯钛（TA2型）、Ni-Cr烤瓷合金、Co-Cr合金4种金属材料在人工唾液中的自腐蚀电位（Ecorr）塔菲尔曲线,并测量Ti-6Al-7Nb合金与其他3种金属组成电偶对后的电偶电流密度值,分析Ti-6Al-7Nb合金与不同金属偶合后的耐电偶腐蚀能力。结果：Ti-6Al-7Nb合金、TA2、Co-Cr合金和Ni-Cr烤瓷合金的Ecorr值（mV）分别为-111.8±0.02、-156.6±0.03、-246.2±0.07和-298±0.08,两两比较均有显著性差异（P〈0.01）;Ti-6Al-7Nb合金与TA2、Co-Cr合金和Ni-Cr烤瓷合金组成电偶对后测得的电偶电流密度值（μA/cm^2）分别为0.46±0.21、1.37±0.90和2.25±1.52,两两比较均有显著性差异（P〈0.01）。结论：Ti-6Al-7Nb合金在人工唾液环境中具有良好的耐腐蚀性能,与牙科常用合金偶合后不会有电偶腐蚀发生

Ti-6Al-7Nb合金与口腔常用合金间电偶腐蚀的研究

目的：评价Ti-6Al-7Nb合金与3种口腔常用合金在人工唾液中的电偶腐蚀性。方法：运用电化学方法测量Ti-6Al-7Nb合金与纯钛（TA2型）、Ni-Cr烤瓷合金、Co-Cr合金4种金属材料在人工唾液中的自腐蚀电位（Ecorr）塔菲尔曲线,并测量Ti-6Al-7Nb合金与其他3种金属组成电偶对后的电偶电流密度值,分析Ti-6Al-7Nb合金与不同金属偶合后的耐电偶腐蚀能力。结果：Ti-6Al-7Nb合金、TA2、Co-Cr合金和Ni-Cr烤瓷合金的Ecorr值（mV）分别为-111.8±0.02、-156.6±0.03、-246.2±0.07和-298±0.08,两两比较均有显著性差异（P〈0.01）;Ti-6Al-7Nb合金与TA2、Co-Cr合金和Ni-Cr烤瓷合金组成电偶对后测得的电偶电流密度值（μA/cm^2）分别为0.46±0.21、1.37±0.90和2.25±1.52,两两比较均有显著性差异（P〈0.01）。结论：Ti-6Al-7Nb合金在人工唾液环境中具有良好的耐腐蚀性能,与牙科常用合金偶合后不会有电偶腐蚀发生

Association of dynamic functional connectivity with bilateral precuneus at resting-state with obsessive-compulsive disorder

目的:探讨强迫症患者在静息状态下双侧楔前叶动态功能连接（dynamic functional connectivity，dFC）的模式。方法:对符合ICD-10诊断标准的50例强迫症患者（患者组）和50名健康对照者（对照组）进行全脑静息态功能磁共振成像（functional magnetic resonance imaging，fMRI）扫描。采用基于全脑体素的dFC分析强迫症患者静息状态下双侧楔前叶dFC模式；采用皮尔逊相关分析方法，探讨强迫症患者异常dFC值与临床症状之间的关系；采用支持向量机分析方法，探索异常的dFC值是否可以用于识别强迫症。结果:与健康对照组比较，患者组左侧楔前叶与左侧内侧前额叶皮质（0.23&plusmn;0.02与0.26&plusmn;0.03， t=-6.23， P&lt;0.05，GRF校正）、左侧楔叶（0.24&plusmn;0.03与0.28&plusmn;0.04， t =-5.30， P&lt;0.05，GRF校正）、左侧中央旁小叶（0.23&plusmn;0.03与0.27&plusmn;0.04， t =-5.36， P&lt;0.05，GRF校正）dFC值降低，右侧楔前叶与左侧中央后回（0.23&plusmn;0.04与0.27&plusmn;0.04， t =-5.12， P&lt;0.05，GRF校正）dFC值降低；患者组降低的左侧楔前叶与左侧内侧前额叶皮质dFC值（ r=0.289， P&lt;0.05，未校正）与Y-BOCS总分呈正相关，降低的右侧楔前叶与左侧中央后回dFC值与Y-BOCS总分（ r=0.292， P&lt;0.05，未校正）、强迫思维因子分（ r=0.304， P&lt;0.05，未校正）呈正相关；降低的右侧楔前叶与左侧中央后回dFC值的受试者操作特征曲线的曲线下面积为0.856，约登指数为0.52，敏感度为100%，特异度为52%。 结论:静息状态下，强迫症患者双侧楔前叶dFC降低；降低的右侧楔前叶与左侧中央后回dFC值可能对于强迫症的识别有提示作用。</p

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel

JUNO sensitivity on proton decay p → ν K + searches*

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the $p\to \bar{\nu} K^+$ mode with JUNO is investigated. The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar{\nu} K^+$ is 36.9% ± 4.9% with a background level of $0.2\pm 0.05({\rm syst})\pm$$0.2({\rm stat})$ events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is $9.6 \times 10^{33}$ years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies