二维表格实时协同编辑系统的一致性维护

二维电子表格是应用最为广泛的计算机应用程序之一,随着大数据和云计算的兴起,对二维电子表格的协同编辑需求也日益增长,而CRDT(无冲突复制数据类型)作为近年来被提出的一致性维护方法,基于它的二维电子表格协同编辑方法在以前的文献中很少被研究.本文提出了一种基于CRDT的同步方法,通过检测操作间的关系,调用相应的冲突消解函数,以实现表格协同文档的一致性维护.本文首先定义了4种操作关系:1)正交冲突关系、一维冲突关系、互斥关系和相容关系;2)提出了一种基于CRDT框架下的冲突消解方案来处理这4种操作关系;3)从理论上分析了本文所提出算法的时间复杂度和空间复杂度;4)通过理论证明和实例研究,验证了该算法的正确性,同时本文还开发了Web端的在线表格协同编辑系统Co-Table,进一步证实了算法的正确性.

水热法制备羟甲基化木质素工艺研究

为了改进碱木质素羟甲基化的制备方法,采用水热法对碱木质素(Lig)进行羟甲基化改性,利用FT-IR半定量法测得的羟甲基含量作为参考指标,并结合产率,确定了最佳工艺条件为:反应温度100℃、反应时间2 h、m(Lig)∶m(HCHO)为6∶1,m(Lig)∶m(NaOH)为24∶1,该工艺条件下所得羟甲基化木质素(Lig—OH)的羟甲基相对含量为0.95,比改性前Lig增加了0.27,产率为98.3%。核磁共振氢谱(1 H NMR)与热失重(TGA)的分析结果表明Lig—OH的羟甲基含量和酚羟基均有所提高,且其初始降解温度(t 5%)较Lig提高了38℃,500℃下的残留量更是提高了33.6%,所得羟甲基化木质素表现出良好的热稳定性能和成炭能力,有望作为成炭剂用于膨胀型阻燃高分子材料领域。

当代大学生社会主义核心价值观的思考

思想政治教育是大学教育的重要组成部分,如何在社会主义核心价值观的培养中,促进青年大学生的全面发展,是深化教育教学改革的重要内容。本文立足当代大学生的特点,分析了当代大学生社会主义核心价值观培养的重要性,阐述了当前大学生社会主义核心价值观培养所存在的问题,并在此基础之上,从创新教育机制、优化培养方法、创设培养环境等方面,具体论述了当代大学生社会主义核心价值观的培养策略。

Line identification of extreme ultraviolet (EUV) spectra from low-Z impurity ions in EAST tokamak plasmas

Extreme ultraviolet(EUV) spectra emitted from low-Z impurity ions in the wavelength range of10–500Å were observed in Experimental Advanced Superconducting Tokamak(EAST)discharges. Several spectral lines from K-and L-shell partially ionized ions were successfully observed with sufficient spectral intensities and resolutions for helium, lithium, boron, carbon,oxygen, neon, silicon and argon using two fast-time-response EUV spectrometers of which the spectral intensities are absolutely calibrated based on the intensity comparison method between visible and EUV bremsstrahlung continua. The wavelength is carefully calibrated using wellknown spectra. The lithium, boron and silicon are individually introduced for the wall coating of the EAST vacuum vessel to suppress mainly the hydrogen and oxygen influxes from the vacuum wall, while the carbon and oxygen intrinsically exist in the plasma. The helium is frequently used as the working gas as well as the deuterium. The neon and argon are also often used for the radiation cooling of edge plasma to reduce the heat flux onto the divertor plate. The measured spectra were analyzed mainly based on the database of National Institute of Standards and Technology. As a result, spectral lines of He Ⅱ, Li Ⅱ–Ⅲ, B Ⅳ–Ⅴ, C Ⅲ–Ⅵ, O Ⅲ–Ⅷ, Ne Ⅱ–Ⅹ,Si Ⅴ–Ⅻ, and Ar Ⅹ–XVI are identified in EAST plasmas of which the central electron temperature and chord-averaged electron density range in Te0=0.6–2.8 keV and ne=(0.5–6.0)×1019 m-3, respectively. The wavelengths and transitions of EUV lines identified here are summarized and listed in a table for each impurity species as the database for EUV spectroscopy using fusion plasmas.

Reduction of impurity confinement time by combined heating of LHW and ECRH in EAST

The core impurity confinement properties are experimentally investigated in the Experimental Advanced Superconducting Tokamak(EAST)plasma heated by lower hybrid wave(LHW)and electron cyclotron resonance heating(ECRH)(LHW+ECRH).It is shown that the impurity confinement time(τ_(imp))in the L-mode plasma jointly heated by LHW and ECRH is weakly dependent on electron density but strongly dependent on the heating power,thus it is shorter than that in LHW-only heated L-mode plasma with the similar plasma parameters.The combined heating of LHW and ECRH can reduce the collisionality and indicates a more effective heating method for coreτimp reduction and normalized poloidal beta(βP)^(im)provement.It should be emphasized that in this highβ_P operation window the small ELM regime can be accessed,and an L-mode levelτ_(imp)(40 ms-80 ms)and highβ_N(~1.7)can be obtained simultaneously.It means that this typical small ELMy H-mode regime has an advantage in avoiding the serious tungsten accumulation,and will be competitive in future long-pulse steady-state and high-performance operation with high-Z material plasma-facing components.

Tungsten control in type-I ELMy H-mode plasmas on EAST

The first experimental investigation of the tungsten behavior in ELMy H-mode plasmas with co-/counter neutral beam injection(NBI)and unfavor-able/favorable B t was performed on EAST.Tungsten was found to accumulate easily in ELMy H-mode plasma with co-NBI heating and unfavorable B t.Thus,in this case the tungsten concentration can exceed 10^(-4),resulting in degradation of the plasma confinement and periodic H–L transitions.To reduce the tungsten concentration in steady-state type-I ELMy H-mode operation,counter-NBI is applied to modify the density and temperature and brake the plasma toroidal rotation.The applied counter-NBI decreases the PHZ+E_(r) inward pinch velocity and rever-ses the direction of neoclassical inward convection,thus decreasing the tungsten concentration from-7×10^(-5) to-2×10^(-5) in type-I ELMy H-mode plasma with favorable B_(t).A comparison of the effects of different B_(t) directions on the tungsten behavior also shows that favor-able B_(t) is beneficial for reducing the tungsten concentration in the core plasma.These results imply that counter-NBI with favorable B_(t) can effectively prevent tungsten accu-mulation and expand the operating window for exploring steady-state type-I ELMy H-mode operation of EAST.

基于单线激光雷达的自适应车辆高度检测算法的研究

针对道路超高车辆频繁碰撞桥涵,对行车安全构成严重威胁的现状,提出一种创新性解决方案。设计并实施一种基于单线激光雷达的自适应车辆高度检测算法。该算法利用激光二维扫描技术自动辨识地面并准确计算车辆高度,实验显示,算法能够将车辆高度的检测误差控制在±2 cm之内,且在连续监测中,实现了100%的检出率和0%的误报率。一旦发现超高车辆,系统立即输出信号,供视频追踪、证据保存或触发声光报警等后续措施使用。这些成果证明了该算法在车辆限高领域的高度精准性和可靠性,同时凭借其稳定性、适应性、低成本和易维护性,在该领域具有重要的应用价值。