CdS@3DOM TiO2–ZrO2 composites with high efficiency photocatalytic properties prepared by template method combined with in-situ self-assembly technology

The three-dimensional ordered macroporous composites CdS@3DOM TiO₂–ZrO₂ were prepared by the template method combined with in-situ self-assembly technique. The composition, structure, morphology and surface physicochemical properties of composites were characterized by XRD, XPS, UV–vis/DRS, SEM, TEM, HR-TEM, PL, N₂ adsorption−desorption and EIS tests. The results show that CdS@3DOM TiO₂–ZrO₂ composites have strong light absorption in the visible region. And the in-situ self-assembled CdS particles in the composite do not destroy the excellent open pore structure, and the introduction of CdS further improves the charge separation efficiency. The results of multi-mode photocatalytic degradation of CdS@3DOM TiO₂–ZrO₂ show that the photocatalytic properties of CdS@3DOM TiO₂–ZrO₂ composites are obviously enhanced. In addition, the hydrogen production of CdS@3DOM TiO₂–ZrO₂ can reach 1323 μmol/g (8 h) in the photolysis of water experiment, which is 94.5 times than that of the commercially available P25, showing excellent photocatalytic performance.     

Fabrication of hybrid membrane of electrospun polycaprolactone and polyethylene oxide with shape memory property

Hybrid materials with nanostructure could exhibit a diverse range of applications as advanced functional materials. This research work, composite membranes with shape memory property based on biocompatible polycaprolactone and polyethylene oxide were successfully fabricated by using electrospinning technique. Electrospun fiber configuration is strongly related to the concentration of polymer and electric field strength. The hydrophilic property of hybrid membrane has been improved and water play a critical role in resulting lower its responsive temperature compared with dry membrane. The mechanism of shape memory PCL/PEO hybrid membrane at wet condition has been proposed.     

高沸醇木质素-季戊四醇改性松香树脂的合成

利用高沸醇木质素、季戊四醇合成松香改性树脂,测定了改性树脂的软化点、酸值、黏度、DSC-TGA曲线,并与原料松香进行比较。实验结果表明高沸醇木质素可以替代部分季戊四醇改性松香树脂,松香通过高沸醇木质素、季戊四醇的改性,产品的软化点、酸值、黏度以及耐热稳定性得到改善。研究结果还表明用高沸醇木质素制备松香改性树脂比木质素磺酸钙效果更好。     

Spin susceptibility and its relationship to structure in perchlorate doped polyacetylene in the intermediate dopant-concentration region

We present the results of ESR, thermoelectric power, and resistivity measurements for perchlorate doped polyacetylene. An anomaly similar to a spin-gap was observed in the spin susceptibility in the intermediate dopant-concentration region. Since a corresponding anomaly was not observed in the thermoelectric power, the comparison leads us to conclude that the anomaly is associated with spin–charge separation, in relation to the formation of charged soliton-like carrier, as a result of phase separation. The resistivity data show a decreasing tendency in the activation energy on the low-temperature side of the transition, suggesting a change in carrier transport. The absence of similar data in previous reports is discussed in terms of structural difference in polyacetylene chains. The low-temperature heat capacity measurement carried out as a function of the dopant-concentration revealed that the chain arrangement to form channels to accommodate the dopants is almost formed at the initiation of doping.     

Ultrasound propagation in two-layer gas flow

The ultrasonic signal propagation in two-layer gas flow was studied. The intensity degradation of the signal was observed while the signal was propagating through the air-hydrogen-air two-layer gas flowing system. The concentration of flowing hydrogen (H₂) gas was measured using ultrasound from the exterior of the pipe, and it was calculated that the intensity degradation of signal did not simply depend on the H₂ concentration, however, the intensity varied every second. Schlieren photography was taken to visualize the motion of H₂ gas after injecting into the flowing air of 2 m/s. It was observed that high concentration H₂ gas was flowing in the middle of the airflow without quick diffusion into the air. A two-dimensional air-H₂-air gas flow model was considered where 100% H₂ was flowing in the middle of the airflow, and the gas layers were separated by two fluctuated interfaces. According to the calculation using this model, only limited conditions of the signals can reach to the receiver due to the refraction at the fluctuating air-H₂-air gas interfaces while propagating. It was found that the receiver could hardly detect the signals; hence, the intensity of the signal looked degraded.     

银掺杂TiO2纳米管制备与性能研究

常压碱熔-水热法制备了银掺杂TiO2复合纳米管。氮吸附法测定其比表面积与原料相比,增加了2.3倍,达82m2/g。用XRD、TEM和XPS进行了表征。TiO2纳米管由锐钛矿相和金红石相组成,研究表明复合纳米管中银元素以金属银和氧化银状态共存。因长径比增大,其XRD衍射峰峰高和峰强均大幅度降低。UV-Vis吸收光谱显示,银掺杂TiO2复合纳米管的吸收光谱发生了红移,带边红移近40nm。这是因为在TiO2纳米管表面形成了肖特基结,TiO2禁带宽度之间形成了杂质能级,使其表观禁带宽度减小,有助于光生电子的迁移,减少电子-空穴复合;纳米管表面羟基氧(—OH)使其表面的酸性活性点增加,增强了价带中光生空穴的氧化能力。     

A research on the effect of different measuring configurations in Network RTK applications

The aim of this article is to try to determine whether there’s a statistically significant difference between coordinates obtained under different elevation angles and measuring epochs through different correction methods in Network Real Time Kinematic Applications. For this purpose, analysis of variance was used. When the statistical data obtained according to different variables are compared, the accuracy seems to be less in the direction of h coordinate axis. There is no a statistically significant difference among the values obtained according to different epoch numbers in all directions of the coordinate axes. The subsets formed according to satellite elevation angles show similar characteristics along Y and h coordinate axes while they differ 30° according to other angles in the direction of X coordinate axis. Based on the correction methods, while FKP and VRS method show different characteristics with respect to each other, MAC method shows similar characteristics compared to other methods.     

Verification of the impact of the used type of excitation noise in determining the acoustic properties of separating constructions

When measuring the acoustic properties of building constructions, a chain generating excitation noise, in which a generator generates the chosen type of noise, is used. White or pink noise is most often utilised. Standard STN ISO 140-4 recommends using white noise, whereas standard STN EN ISO 717-1 recommends pink noise. No reasonable science-based recommendations for the choice of noise are known. This study elucidates the impact of noise on the measurements of acoustic properties of building constructions.     

Preparation of carbon black via arc discharge plasma enhanced by thermal pyrolysis

Carbon black (CB) was prepared via arc discharge non-thermal plasma which was enhanced by thermal pyrolysis process, in which propane was cracked into CB with controlled structure and hydrogen. Argon was also introduced along with the propane. Detailed parameters like discharge current, argon flow rate, propane flow rate and cracking temperature were discussed in order to obtain optimal conditions for generating CB with high productivity, yield and well developed structure. The morphology of CB was characterized by scanning and transmission electron microscopy. X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy and BET surface area analysis were used to analyze the structure of CB. The results showed that the yield of CB could be 85.9% under optimal operating conditions; the spherical CB produced by this process possessed a narrow size distribution. Thermal pyrolysis began to significantly serve above 500 °C, and the yield under 700 °C was higher than that of plasma process without electrical heating assistance. Resistivity of the CB was decreased with increasing discharge current and pyrolysis temperature. Mechanism of CB formation in our process was assumed according to experimental phenomenon and the widely accepted formation mechanism of furnace-type CB.