A new method using alternating penalty trilinear decomposition algorithm coupled with excitation-emission matrix fluorometry has been developed for simultaneous resolution and determination of tyrosine, phenylalanine and tryptophan. Their correlation coefficients were 0.9987, 0.9995 and 0.9993 respectively. The contents of tyrosine, phenylalanine and tryptophan in Hibiscus syriacus L. leaves were also be determined by this method after being extracted by ultrasonic. The coefficients of variation and the recoveries of the three amino acids were 0.84%, 0.36%, 1.59% and 101.0%-92.7%, 106.5%-93.0%, 103.0%-95.0% respectively. All these show that this is a simple, fast and cridible method.
Constructing supplying mechanism of rural public culture service is one of the hot issues in the research of public administration in recent years.Researchers have studied rural public cultural services from different fields and perspectives in the domestic academic circles in the latest eight years.They put forward four kinds of supplying mechanisms,that is,government-leading mechanism,market mechanism,social mechanism and cooperative mechanism,and further discussed functions,operation logic and predicament of each mechanism.There are two shortcomings in the current research:one is that we should strengthen the study of the applicable conditions of the different supplying mechanisms;the other is that we should pay more attention to the relationship between rural regional differences and the choice of supply mechanism.
The effect of sulfur and calcium impurities on coke reaction was investigated by simulating petroleum coke with low-impurity pitch coke and via impurity doping. Its mechanism has often been discussed via X-ray powder diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and energy-dispersive spectrometry. The results show that sulfur has a strong catalytic effect on both the reactivity of coke in air and CO2 in the case with no other impurity interference. Its catalysis is probably realized by triggering a reaction system. However, during the carbon–air and carbon–CO2 reactions, an obvious mutual inhibition between the catalytic impurities of sulfur and those of calcium occurred when calcium was added. Inert CaSO4 and weak catalytic CaS are likely to be the key to producing this mutual inhibition.
Patients with bilateral vestibular disease (BVD) often present a severe balance disability and treatment of BVD disease is complex and time-consuming. Patients can be treated with balance retraining exercises but the improvement is not likely to be full recovery. Based on brain plasticity and sensory substitution, this paper proposed noninvasive vibrotactile stimulator prosthesis to help BVD patients to get their bodies' movement information which can be used to keep balance. We designed a vestibular sensory substitution system, called vibrotactile balance belt, which feed the patients with balance information an array of vibrotactile stimulators. With proper physical training and exercises, patients can regain or enhance their balance ability with the help of vibrotactile stimulators. In this paper, we designed a prototype system, which used acceleration sensor, gyro sensor and magnetic field sensor to detect body's linear and rotational motion. Multiple vibrotactile stimulator encodings were considered. And we also discussed the optimal stimulus encoding and the stimulus position to avoid the problem of reduced sensitivity effect while the stimulatory signals frequently generated.
High-purity trichlorosilane (SiHCl 3 ) is a key raw material for electronic grade polysilicon and semiconductor chips. The byproduct and main impurity of SiHCl 3 , methyl dichlorosilane (CH 3 SiHCl 2 ), will increase the density of crystal defects and lead to a higher leakage current for the final products. However, CH 3 SiHCl 2 has a similar boiling point and needs complex several-stages distillation to separate. Hence, a novel photocatalytic chlorination combined with simplified distillation to produce electronic grade high-purity (SiHCl 3 > 99.998%) SiHCl 3 was achieved via microchannel reactor experiments. Photocatalytic chlorination via heart-shaped microchannel reactors was proposed to significantly reduce distillation times. The optimal conditions of photocatalytic chlorination reaction were determined: 365 nm of ultraviolet (UV) wavelength, 323 K of the reaction temperature, 15W of the light intensity, 20 s of the reaction time, and mol ratio of Cl 2 : CH 3 SiHCl 2 is 5. Multiphase-flow microreactor simulation indicated that each chamber of the reactor has a high-level impact and turbulence phenomenon, and the mixing performance is excellent. Reactive force field (ReaxFF) molecular dynamic (MD) simulation and density-functional theory (DFT) calculation determined that compared with SiHCl 3 , Cl· reacts extremely inclined to CH 3 SiHCl 2 , especially at low temperatures. And the reaction mechanism is mainly by Cl· replacing H attached to Si in CH 3 SiHCl 2 . This feasible approach has the advantages of a purer product, simpler process, energy-saving, and economy, and is worthy of promotion.
Bench-scale enhanced coagulation was conducted to treat source water sample from the Pearl River with particular interests in distribution of micro-particles ranging between one and forty micro-meter. Special equipment was used to count the particulates number and mixing pattern on the coagulation result was investigated.
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