Porous graphene oxide-based carbon artefact with high capacity for methylene blue adsorption

A three-dimensional porous graphene oxide (PGO) material prepared by hydrothermal method was selected to adsorb methylene blue (MB), which demonstrates a high MB adsorption capacity, up to 1100 mg g^?1 in alkaline solution at room temperature. The influences of different pore structures and different contents of oxygen-containing functional groups on MB adsorption behaviors were studied in detail, which indicated that the high MB adsorption capacity is mainly ascribed to the synergistic effect of the large number of oxygen-containing functional groups and the interconnected 3D porous network. Moreover, based on the investigation on the adsorption kinetics and the effect of pH value on MB adsorption, we propose a two-step adsorption kinetics for PGO, which involved in two interactions between MB molecular and porous graphene oxide-based carbon: electrostatic force and π-π stacking. Besides, the calculation of the activation energies indicates that chemisorption dominates the adsorption for PGO in comparison with physisorption for three-dimensional porous graphene materials which has low adsorption capacity because of the removal of functional groups. The results are of great significance for the design and environmental applications of PGO as a promising adsorbent material for water purification.     

Synthesis and aggregation properties of amphiphilic mono and bisadducts of fullerene in aqueous solution

New amphiphilic[60]fullerene monoadduct TPF and bisadducts BTPF were synthesized and well-characterized. Their aggregation properties in aqueous solution was investigated by UV-vis and TEM methods. In aqueous solution, monoadduct TPF forms irregularly shaped and some rod-like aggregates, whereas bisadducts BTPF gives sphadcal aggregates with diameters of 50-150 rim. It indicated that the aggregation properties of amphiphilic fullerene derivatives depend on the number of hydrophilic     

Toeplitz Operators from One Fock Space to Another

In this paper, we study Toeplitz operators T _μ from one Fock space \({F^{p}_{\alpha}}\) to another \({F^{q}_{\alpha}}\) for 1 < p, q < ∞ with positive Borel measures μ as symbols. We characterize the boundedness (and compactness) of \({T_\mu: F^{p}_{\alpha} \to F^{q}_{\alpha}}\) in terms of the averaging function \({\widehat{\mu}_r}\) and the t-Berezin transform \({\widetilde{\mu}_t}\) respectively. Quite differently from the Bergman space case, we show that T _μ is bounded (or compact) from \({F^{p}_{\alpha}}\) to \({F^{q}_{\alpha}}\) for some p ≤ q if and only if T _μ is bounded (or compact) from \({F^{p}_{\alpha}}\) to \({F^{q}_{\alpha}}\) for all p ≤ q. In order to prove our main results on T _μ , we introduce and characterize (vanishing) (p, q)-Fock Carleson measures on C ⁿ .     

多光束泵浦中红外激光器

为了获得高功率高效率3 m～5 m中红外激光输出,利用双声光调Q晶体,通过高重复频率驱动调Q同步技术和LD侧面泵浦双棒串接技术,获得高功率高光束质量1.06 m激光双端输出,外置起偏器获得4束激光输出,利用波片偏振旋光原理,实现4束偏振态一致的激光输出,泵浦非线性晶体PPLT进行频率变换,实现高功率3 m～5 m中红外激光输出。在电源输入电流30 A、调Q驱动频率10 kHz的条件下,获得最高功率10.6 W的3.9 m中红外激光,1.06 m～3.9 m转化效率为9.5%。实验结果表明:通过双声光调Q技术和LD侧面泵浦双棒串接技术,可以实现4束高重复频率窄脉宽1.06 m偏振激光输出,泵浦PPLT可获得高功率3.9 m中红外激光输出。     

Study on the Nonisothermal Crystallization Kinetics of Poly(Vinylidene Fluoride)/Tributyl Citrate Blends Via Thermally Induced Phase Separation

The nonisothermal crystallization kinetics of poly (vinylidene fluoride) (PVDF) in PVDF/tributyl citrate (TBC) blends having undergone thermally induced phase separation were investigated through differential scanning calorimetry measurements. Ozawa theory, Mo's method and Kissinger model were used to analyze the kinetics of the nonisothermal crystallization process. The Ozawa theory failed to describe the crystallization behavior of PVDF in the PVDF/TBC blends, whereas the Mo model was able to describe the nonisothermal crystallization process fairly well. The crystallization activation energy was determined by the Kissinger method, and was in the range of 90–165 kJ/mol.     

Optical Observation of Lung Cancer With Attenuated Total Reflectance–Fourier Transform Infrared Microscope (ATR-FTIR) and Confocal Raman Microscope

ABSTRACT

Optical observation of lung cancer tissues using attenuated total reflectance–Fourier transform infrared microscope (ATR-FTIR) and confocal Raman microscope were performed. A total of six malignant tissues, seven tissues adjacent to cancer, and nine normal tissues from nine patients with known lung cancer were studied. High-quality spectra from human tissues were obtained only in a few seconds. The results revealed that some of the spectral characteristics varied significantly between normal and malignant tissues, that is, IR peak positions, Raman shift, and the spectral intensities. Differences in positions of 10 main peaks in IR shifts and 13 main peaks in Raman shifts were listed, and the intensity changes were also studied between the malignant and normal tissues. The ratios of 1453-cm^?1/1645-cm^?1 intensity in IR spectrum and 1245-cm^?1/1571-cm^?1 intensity in Raman spectrum were found with the most significant difference (p < 0.0001 and p < 0.05 separately) in statistics and may be used in combination to differentiate the normal and malignant tissues. ATR-FTIR spectrum and Raman spectrum were mutually complementary in the observation of many materials and were both found with high sensitivities and spatial resolutions in the observation of human tissues. This study will be helpful to developing rapid and accurate cancer detection techniques in future clinical diagnosis.     

干涉和衍射的联系与区别

通过理论分析得出双缝实验中空间光场的分布是干涉与衍射共同作用的结果.在形成条件、分布规律以及数学处理方法上说明了干涉和衍射的区别与联系.     

Measuring,modelling and optimising an embedded rail track

A finite element (FE) model and a boundary element (BE) model have been developed to predict the decay rate, vibration and noise responses of an embedded rail track. These models are validated using measured results. The optimisation of the embedded rail track is conducted using these calculated models. The results indicate that the optimised cross-section of the gutter for the embedding rail can significantly reduce the radiated noise of the embedded rail track. The embedded rail track using the I-shaped cross-section gutter reduces the radiated noise of the track by at least by 3 dB(A). Furthermore, combining the material parameter optimisation with the gutter cross-section optimisation can further reduce the radiated noise of the embedded rail track. Increasing the Young’s modulus of the rail pad in the embedded rail track with the I-shaped cross-section gutter can result in a radiated noise reduction of 4 dB(A).     

Wintersweet Branch‐Like C/C@SnO2/MoS2 Nanofibers as High‐Performance Li and Na‐Ion Battery Anodes

Structure and morphology of molybdenum disulfide (MoS₂) play an important role in improving its reversible lithium storage and sodium storage as anodes. In this study, a facile method is developed to prepare C/C@SnO₂/MoS₂ nanofibers with MoS₂ nanoflakes anchoring on the core–shell C/C@SnO₂ nanofibers through hydrothermal reaction. By adjusting the concentration of MoS₂ precursors, the synthesized MoS₂ with different slabs dimensions, size, and morphologies are obtained, constituting budding and blooming wintersweet branch‐like composite structure, respectively. Owing to scattered MoS₂ nanoparticles and sporadic MoS₂ nanoflakes, the budding wintersweet branch‐like composite nanofibers processes less slabs of staking in number and large specific surface area. Benefiting from the exposed C@SnO₂ shell layer, the synergistic effect among SnO₂, carbon, and MoS₂ is strengthened, which maximizes the advantage of each material to exhibit stable specific capacities of 650 and 230 mAh g^?1 for Li‐ion batteries and Na‐ion batteries after 200 cycles.