Near Infrared Spectroscopy of the Cretaceous Red Beds in Inner Mongolia DongshengmiaoSCIEI北大核心CSCD

Take the cores and surface weathered soil from the Cretaceous red beds in the western of Dongshengmiao mine of Inner Mongolia and analysis with near-infrared spectroscopy. The result shows that near-infrared spectroscopy can identify mineral quickly through the characteristic absorption peaks of each group. The Cretaceous red beds in the western of Dongshengmiao mine is argillaceous cementation, it is mainly composed of quartz, feldspar, montmorillonite, illite, chlorite, muscovite etc, the mineral composition is mainly affected by the upstream source area. The clay mineral like montmorillonite water swelling and uneven drying shrinkage expands the original crack and creates new cracks, reduces its strength, which is the mainly reason of its disintegration. According to the composition of clay mineral, we speculate its weathering process is mainly physical weathering, the climate during the weathering is cold and dry. The results can not only improve the geological feature of the mining area, but also show that the near-infrared spectroscopy technology can analyze the mineral composition of soil and rock effectively on the basis of Mineral spectroscopy, which demonstrates the feasibility of the near-infrared spectroscopy can analyze minerals in soil and rock quickly, that shows the feasibility in geology study, provides new ideas for the future research of soil and rock.     

Main Components of Xinjiang Lavender Essential Oil Determined by Partial Least Squares and Near Infrared SpectroscopySCIEI北大核心CSCD

This work was undertaken to establish a quantitative analysis model which can rapid determinate the content of linalool, linalyl acetate of Xinjiang lavender essential oil. Totally 165 lavender essential oil samples were measured by using near infrared absorption spectrum(NIR), after analyzing the near infrared spectral absorption peaks of all samples, lavender essential oil have abundant chemical information and the interference of random noise may be relatively low on the spectral intervals of 7100-4 500 cm(-1). Thus, the PLS models was constructed by using this interval for further analysis. 8 abnormal samples were eliminated. Through the clustering method, 157 lavender essential oil samples were divided into 105 calibration set samples and 52 validation set samples. Gas chromatography mass spectrometry (GC-MS) was used as a tool to determine the content of linalool and linalyl acetate in lavender essential oil. Then the matrix was established with the GC-MS raw data of two compounds in combination with the original NIR data. In order to optimize the model, different pretreatment methods were used to preprocess the raw NIR spectral to contrast the spectral filtering effect, after analysizing the quantitative model results of linalool and linalyl acetate, the root mean square error prediction(RMSEP) of orthogonal signal transformation (OSC) was 0.226, 0.558, spectrally, it was the optimum pretreatment method. In addition, forward interval partial least squares (FiPLS) method was used to exclude the wavelength points which has nothing to do with determination composition or present nonlinear correlation, finally 8 spectral intervals totally 160 wavelength points were obtained as the dataset. Combining the data sets which have optimized by OSC-FiPLS with partial least squares(PLS) to establish a rapid quantitative analysis model for determining the content of linalool and linalyl acetate in Xinjiang lavender essential oil, numbers of hidden variables of two components were 8 in the model. The performance of the model was evaluated according to root mean square error of cross-validation (RMSECV) 9 root mean square error of prediction (RMSEP). In the model, RESECV of linalool and linalyl acetate were 0.170 and 0.416, respectively; RMSEP were 0.188 and 0.364. The results indicated that raw data was pretreated by OSC and FiPLS, the NIR-PLS quantitative analysis model with good robustness, high measurement precision; it could quickly determine the content of linalool and linalyl acetate in lavender essential oil. In addition, the model has a favorable prediction ability. The study also provide a new effective method which could rapid quantitative analysis the major components of Xinjiang lavender essential oil.     

Thermal properties of chlorosulfonated polyethylene via gas–solid phase method

The thermal properties of chlorosulfonated polyethylene (CSM), which was prepared via gas–solid phase method, were studied in this article. The thermal curves were completely tested by differential thermal analysis, thermogravimetry, and differential thermogravimetry. The results showed that CSM 3550 and CSM 3570 prepared by gas–solid phase method had more excellent thermal properties (high initial/final temperature of degradation) than those via solution method, due to the uniform chlorine distribution of them in macromolecular chain. The differential scanning calorimetry curves showed that the transitions of CSM 3550 and CSM 3570 from glassy to the elastic state were also higher than those via solution method. Particularly, CSM 3570 was amorphous and no clear melting peak was observed during the melting process.     

Improved Crystallinity of Poly(3-hexylthiophene-2,5-diyl):[6,6]-Phenyl-C61 Butyric Acid Methyl Ester Film by Pulsed Electrospray Deposition

We investigated crystallinity parameters and ordering domains of poly(3-hexylthiophene-2,5-diyl) blended in [6,6]-phenyl-C₆₁-butyric acid methyl ester films, which were fabricated by pulsed electrospray deposition methods. The crystallinity parameter and the ordering domain were estimated from Raman and optical absorption spectra, respectively. As a result, they were improved with decreasing the off time of pulse voltage, corresponding to the slow evaporation speed of solvent. In addition, both the space-charge limited current mobility and the photoconversion efficiency showed same trend. A highest photoconversion efficiency of 1.11 % was achieved without the thermal annealing process after depositing the active layer.     

Design of a quad-stable piezoelectric energy harvester capable of programming the coordinates of equilibrium points

In this study, a novel quad-stable energy harvester (QEH) is developed, in which its coordinates of equilibrium points can be user-defined like programming. This programmable feature distinguishes the proposed QEH from all reported magnet-type or buckling-type vibration energy harvesters. It has the advantage that it is easy to develop a high-performance QEH by appropriately programming these coordinate points and customizing a personalized QEH for different vibration environments. The dynamic model is established by the Ritz method and the Lagrange equation. The analytical steady periodic response is obtained by the average method. When the excitation acceleration is 2 m/s², the peak power is 575 μW at 8.5 Hz. Also, the influence of the coordinate arrangement of the equilibrium points on the energy harvesting performance is studied. A formula that can quickly determine the equilibrium point coordinates is given, and the QEH designed according to this formula has superior performance. At last, the performance of the designed QEH is compared with other reported vibration energy harvesters. It shows that the QEH has a high average output power (287 μW), high normalized power density (59.8 μW/cm³/g²), and wide operating frequency range (8.4 Hz) among these harvesters.

     

Magnetron sputtering deposition of silicon nitride on polyimide separator for high-temperature lithium-ion batteries

To date,lithium-ion batteries are becoming increasingly significant in the application of portable devices and electrical vehicles,and revolutionary progress in theoretical research and industrial application has been achieved.However,the commercial polyolefin separators with unsatisfying electrolytes affinity and poor thermal stability have extremely restricted the further application of lithium-ion batteries,especially in the high-temperature fields.In this work,magnetron sputtering deposition technique is employed to modify the commercial polyimide separator by coating silicon nitride on both sides.Magnetron sputtering deposition modified polyimide(MSD-PI)composite separator shows high thermal stability and ionic conductivity.More importantly,compared with the cells using Celgard separator,the cells with MSD-PI separator exhibit superior electrochemical performance,especially long-term cycle performance under high temperature environment,owing to the high thermal conductivity of surface Si3 N4 particles.Hence,lithium-ion batteries with MSD-PI separator are capable of improving thermal safety and capacity retention,which demonstrates that magnetron sputtering deposition technique could be regarded as a promising strategy to develop advanced organic/inorganic composite separators for high-temperature lithium-ion batteries.     

Tributylstibine-mediated olefination of carbonyl compounds with bromomalonic ester and with dibromomalonic ester—A possible pathway through a stibonium ylide via halophilic initiation by tertiary stibines

Tributylstibine can mediate the olefination of carbonyl compounds with bromomalonic ester and with dibromomalonic ester. An initial halophilic attack of tributylstibine on the bromine of bromomalonic or dibromomalonic ester forming an ion pair of bromotributylstibonium cation and malonic (A) or bromomalonic ester carbanion (B) , respectively, is proposed. These ion pairs react with carbonyl compounds to achieve subsequent olefination. Alternatively, 2 equiv of A collapse, with elimination of malonic ester, to form stiborane D , and the ion pair B reacts with another equivalent of tributylstibine to form stiborane D. This last undergoes a Wittig-type reaction with carbonyl compound to achieve olefination.     

Modelling and dynamic analysis of spline-connected multi-span rotor system

Meccanica - Self-excited oscillation induced by the internal frictions of spline joints is a major cause of rotor system instability. In this study, the dynamic equations of spline-connected...     

Quantum Thermalization and Vanishing Thermal Entanglement in the Open Jaynes–Cummings Model

The quantum thermalization of the Jaynes–Cummings (JC) model in both equilibrium and non-equilibrium open-system cases is studied, in which the two subsystems, a two-level system and a single-mode bosonic field, are in contact with either two individual heat baths or a common heat bath. It is found that in the individual heat-bath case, the JC model can only be thermalized when either the two heat baths have the same temperature or the coupling of the JC system to one of the two baths is turned off. In the common heat-bath case, the JC system can be thermalized irrespective of the bath temperature and the system–bath coupling strengths. The thermal entanglement in this system is also studied. A counterintuitive phenomenon of vanishing thermal entanglement in the JC system is found and proved.