联用色谱数据的双窗口因子分析

利用组分光谱的特征信息,发展了一种能直接对联用色谱重叠峰中组分进行定性定量分析的新方法──双窗口因子分析（dualwindowfactoranalysis,DWPA）。该法可从多组分重叠峰中定性目标组分,且在未经其它组分的分辨下可直接对目标组分的光谱、色谱进行分辨。因此更适应于联用色谱对复杂体系中待测组分的定性定量分析。用该法成功地对4组分重叠峰进行了分析,实验结果令人满意。     

采用正弦微窗光栅的位移传感器

研制了一种新型的光栅位移传感器,它采用了一种被作者称为正弦微窗光栅的新元件作为指示光栅,用于消除光栅信号中的高次谐波,所为正弦微穿光栅是一种由许多微小的正弦穿孔排列组成的光栅。介绍了采用光学图形发生器和刻蚀镀膜工艺制造这种光栅的方法。并将制成的正弦微穿光栅用于光栅位移传感器的设计。实验表明,新型传感器能够很好地抑制光栅信号中的高次谐波,可将高次谐波总旧降至基波的２％以下。     

Synthesis of styrene–acrylonitrile random copolymers (SAN) and polyarylate block copolymers and the control of their mechanical properties by morphology generation

The idea of repulsion in random copolymers was applied to the miscibility modification between polystyrene (PS) and polyarylate (PAr) segments of PS–PAr block copolymer (PAr–PS–PAr). Acrylonitrile (AN), which has a large positive interaction parameter against styrene, was used as a miscibility modifier toward PAr segments. AN was introduced into the carboxyl terminated telechelic‐PS at AN wt % ranging from 12 to 37 wt %. Based on these telechelic acrylonitrile–styrene random copolymers (SAN_x's where x represents AN wt %), SAN_x and PAr block copolymers (PAr–SAN_x–PAr's) were synthesized. The miscibility of SAN_x and PAr segments was estimated from the results of DSC with Fox's equation and spin–spin relaxation time measured by pulsed NMR. These results evidenced that the miscibility between PS and PAr segments can be modified by introducing AN into PS segments. The estimated volume fraction of the interfacial layer between SAN_x and PAr segments was increased as x was increased toward 24 wt %, around which the predicted miscibility reaches a maximum. Above that AN wt %, it began to decrease. The flexural strength increased as the miscibility between SAN_x and PAr segments increased. In particular, when x was between 20 and 30 wt %, PAr–SAN_x–PAr exhibited three times larger flexural strength than PAr–PS–PAr. The fracture behavior changed from brittle to ductile, even though the telechelic SAN_x by themselves exhibited almost the same fracture strength as the telechelic PS. The results of dynamic mechanical measurements and the percolation model suggested that around these AN wt % the continuum matrices in PAr–SAN_x–PAr changed from SAN_x phase to a cocontinuous phase of SAN_x and PAr. From these results, PAr–SAN_x–PAr was explained to perform such a high flexural strength by this phase change in the continuum matrices. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 127–137, 2000     

Influence of Counter Pressure on Separation Performance in SDS-MEKC

The influence of a hydrostatic counter pressure on basic mobility equations in MEKC was analyzed theoretically and investigated experimentally. Taking into account the influence of counter pressure, the modified mobility equations predict a decreased migration time ratio t₀/t_MC, which was confirmed by results obtained in SDS-MEKC separation of a homologous series of n-alkyl phenyl ketones. As a result, the migration time window could be enlarged in a simple way without having to change the chemistry of the system. Although counter pressures reduce peak efficiency in MEKC by disturbing the plug profile, the concomitant enlargement of the migration time window compensates for this effect. Especially for later migrating compounds, peak resolution could be enhanced at moderate counter pressures. The overall peak capacities within the whole migration window increases slightly when applying counter pressures up to 10 mbar.     

双色中红外激光场延迟及相位调控产生水窗区间光子

理论研究了双色中红外激光场时间延迟及相位对高次谐波光谱的影响.结果表明：当激光延迟为-1.0 fs,激光相位为0.2π和0时,谐波截止能量可以得到有效延伸,并且获得一个超宽水窗区间谐波连续平台区.此外,谐波光谱的延伸与控制场波长关系不大,即,在上述激光延迟和相位下,控制场波长在2300 nm到2700 nm区间时都可获得水窗区谐波光谱.最后,叠加光谱连续区的谐波可获得35 as的水窗区孤立阿秒脉冲.     

基于Blackman窗函数的插值FFT在电网谐波信号分析中的应用

对插值快速傅里叶变换（FFT）算法在电网谐波参数估计的研究表明：窗函数的类型和宽度是影响插值FFT算法分析精度的主要原因．通过对常用窗函数和电网信号的分析,Blaekman窗适合分析电网信号,同时给出了基于Blackman窗的插值FFT算法．仿真结果表明,基于Blackman窗的插值FFT算法对电网谐波幅值、频率和相位的估计精度都达到了电能质量的国家标准．     

加窗后波前功率谱密度的计算值修正

 波前功率谱密度的数值计算会由于窗函数的使用引入较大的计算误差。通过对模拟的单一频率波前加窗前后的功率谱密度的理论计算,由傅里叶变换性质推导出了修正因子,并对波前频率与修正因子的关系进行了理论研究。结果表明,在一定的波前频率及误差范围内,对加汉宁窗后1维功率谱密度的计算结果乘上一个常量8/3即可实现简单有效地修正。     

Self-Assembled Multistable Scattering Mode for Versatile Energy-Saving Smart Windows

Smart windows are crucial to dynamic control over light transmission to fulfill various demands in energy saving, privacy, and information display; however, most present technologies still perform a single function (often tint or haze adjustment) and require continuous electricity for operation. In this study, novel self-assembled ionic liquid crystals (ILCs) doped with negative cholesteric liquid crystals (CLCs) to offer electrically switchable and stable scattering-mode light modulators are presented. The novel smectic A phase based on the ILCs exhibits high solubility in the adopted nematics, enhancing the LC device's performance in several ways, including improved homogeneity, stable alignment quality, prolonged stability, and simplified fabrication. The LC device can potentially offer a dynamically rapid switching function between stable transparent (imperfect fingerprint textures) states and stable scattering (focal conic textures with small domains) states by using external stimuli and highly maintained multistable states for prolonged periods, even when the external stimuli are removed. The LC device also offers polarization-independent scattering and transparent-mode LC light modulators, low operating voltage, excellent contrast, and broad viewing angles. Its versatility and outstanding field-off stability make it ideal for various applications such as smart lighting, building climate control, energy-saving displays, and augmented reality (AR) glasses.     

自由旋涡气动窗口全流场的数值模拟

建立自由旋涡气动窗口全流场仿真模型,对大密封压比气动窗口的全流场展开数值研究,得到自由旋涡气动窗口的流场结构,发现大密封压比气动窗口形成的自由旋涡射流在光束输出通道内无明显的波系结构.根据模拟结果对自由旋涡气动窗口的性能进行优化,对自由旋涡喷管上壁面型线进行二次粘性修正.优化自由旋涡射流场后,激光器输出光束通道内压力分布稳定上升;增加扩压器外端壁吹气1.19MPa、内端壁吹气1.68MPa时,自由旋涡射流总能提高,气动窗口密封压力从37.5torr降低至6torr.该研究结果对自由旋涡气动窗口技术的发展具有参考意义.     

利用烷基糖苷迁移和扩张共轭亚油酸囊泡pH窗口

脂肪酸囊泡(FAV)具有与脂质体类似的中空核壳结构, 且原料来源广泛, 绿色安全, 在包埋/缓释方面有重要意义. 但FAV对pH值依赖性强, pH窗口很窄并偏离生命体系适应pH范围, 限制了其作为包埋/缓释体在日用化学品及外用药等中的应用. 本文用绿色安全非离子表面活性剂烷基糖苷(APG)使共轭亚油酸(CLA)形成FAV的pH窗口从原先的8.0-9.0 迁移并扩张至6.0-8.0, 从而与生命体系适应pH值范围相匹配, 并探讨了改善FAV的pH值依赖性和敏感性的原理.