AI 中文总结
研究通过太赫兹光谱和低温量热法，对不同Ca/Si比的硅酸钙水合物中玻色子峰进行表征。经校正后两种方法定位BP频率一致但强度不同，还获得相关长度和参数等。该双探针方法可用于其他无定形固体，为研究C-S-H性能提供新途径。
AI 中文摘要
玻色子峰（BP）是无序固体的一种普遍振动异常，在硬化水泥的粘结相硅酸钙水合物（C-S-H）中已被预测但未系统表征。基于初步的太赫兹调查，我们使用太赫兹时域光谱（THz-TDS）和低温量热法，对五个Ca/Si比（0.5-1.7）的BP进行了表征，这两种振动动力学探针补充了传统结构方法的静态图像。经布鲁格曼校正结晶杂质后，两种探针都将BP定位在1 THz附近；它们在频率上一致，但强度不同。太赫兹积分光谱权重和量热Cp/T3峰均随Ca/Si单调下降，而表观太赫兹峰高在Ca/Si = 1.0时最大，此时阻尼低且振子强度仍很大。这种解耦标志着硅酸盐链解聚和层间钙填充之间的结构转变。从BP我们获得了约1 nm（0.3-2 nm）的中程动力学相关长度和一个相干势弹性非均匀性参数，随着Ca/Si升高，该参数从γ = 0.98降至0.48；德拜归一化的BP频率（ν_BP/ν_D = 0.15-0.17）将C-S-H置于硅酸盐玻璃报道的范围内。因为γ控制局部结构重排的能垒分布，它提供了一个与C-S-H的固有蠕变和热传输相关的定量、成分分辨描述符，将纳米级振动动力学与混凝土的宏观耐久性联系起来。双探针玻色子峰方法可转移到其他无定形固体，包括低碳水泥的辅助胶凝材料。
英文摘要
The boson peak (BP), a universal vibrational anomaly of disordered solids, has been predicted but not systematically characterized in calcium silicate hydrate (C-S-H), the binding phase of hardened cement. Building on a preliminary terahertz survey, we characterize the BP across five Ca/Si ratios (0.5-1.7) using terahertz time-domain spectroscopy (THz-TDS) and low-temperature calorimetry, two probes of vibrational dynamics that complement the static picture of conventional structural methods. After Bruggeman correction for crystalline impurities, both probes locate the BP near 1 THz; they agree on frequency but diverge in intensity. The terahertz integrated spectral weight and the calorimetric Cp/T3 peak both fall monotonically with Ca/Si, whereas the apparent terahertz peak height is maximal at Ca/Si = 1.0, where damping is low and oscillator strength still substantial. This decoupling marks a structural crossover between silicate-chain depolymerization and interlayer calcium filling. From the BP we obtain a medium-range dynamical correlation length of order 1 nm (0.3-2 nm) and a coherent-potential elastic-heterogeneity parameter that decreases from gamma = 0.98 to 0.48 as Ca/Si rises; the Debye-normalized BP frequency (nu_BP/nu_D = 0.15-0.17) places C-S-H within the range reported for silicate glasses. Because gamma governs the distribution of energy barriers for local structural rearrangements, it provides a quantitative, composition-resolved descriptor relevant to the intrinsic creep and thermal transport of C-S-H, linking nanoscale vibrational dynamics to the macroscopic durability of concrete. The dual-probe boson-peak approach is transferable to other amorphous solids, including the supplementary cementitious materials of low-carbon cements.
