The layered film-substrate structure is widely used in many fields such as microelectronic devices,but the ultrasonic measurement of film material parameters,especially the characterization of shear wave velocity,is a...The layered film-substrate structure is widely used in many fields such as microelectronic devices,but the ultrasonic measurement of film material parameters,especially the characterization of shear wave velocity,is a difficult problem.In this paper,the dispersion characteristics of Scholte wave at the liquid-solid interface and the acoustic pressure response generated by a pulse excitation are theoretically analyzed.The results show that the Scholte wave dispersion at the liquid-solid interface is closely related to the velocity distribution of the layered film-substrate structure.The thickness and shear wave velocity of each layer of the thin film material have a significant effect on the interface wave dispersion characteristics.Based on the dispersion properties of Scholte interface waves,a multi-parameter inversion characterization method for multilayer films is proposed.Firstly,the film parameter inversion is carried out for the theoretical signal,which verifies the feasibility of the method.Subsequent experiments on the excitation and acquisition of liquid-solid interface waves are carried out on different types of multilayer film material samples,and the film parameter inversion results of the experimental signals further verify the feasibility and effectiveness of the method.展开更多
In this paper, the activities of electrophilic sites on benzene ring of 4-substituted anilines and their acyl compounds were studied with the quantitative indicator of multiphilicity descriptor. Four substituents were...In this paper, the activities of electrophilic sites on benzene ring of 4-substituted anilines and their acyl compounds were studied with the quantitative indicator of multiphilicity descriptor. Four substituents were synthe- sized with microwave irradiation in good yields to verify the quantitative analysis data. Friedel-Crafts acylation was carried out by the microwave method for the first time.展开更多
Hyperglycemia is frequently accompanying with hyperlipidemia. To explore the potent drugs with dual-activity and dual-site effects that could reduce blood glucose and blood lipid at the same time, fibrate group with l...Hyperglycemia is frequently accompanying with hyperlipidemia. To explore the potent drugs with dual-activity and dual-site effects that could reduce blood glucose and blood lipid at the same time, fibrate group with lipid-lowering effect on the 9th position of berberine（BBR） was introduced using the drug design combination principle and the multi-target collaborative treatment method, Moreover, the molecular structure of BBR was modified, and six 9-substituted derivatives of BBR were designed and synthesized, among which, five compotmds have never been reported before. In addition, the molecular structttres of these derivatives were identified using liquid chromato- graphy-mass spectrometry（LC-MS）, IH nuclear n^tgnetic resonance（1H NMR） and 13C NMR, respectively. Fu^her- more, the microwave irradiation experimental technique was applied in the synthesis reaction using the novel micro- wave synthesizer, which accelerated the reaction rate, enhanced the reaction yield, reduced the reaction by-products, and simplified the post-processing steps. In the meantime, the 9-position regioselective demethylation of BBR was explored through quantum chemical calculation during the synthesis of berberrubine. The computations were consistent with the experimental results, which contributed to deducing the mechanism of its selective methylation.展开更多
Chemical reaction possibility was described quantitatively for the case of nitrotriazolam preparation with 2-clonazepam by using the data of two quantum chemical reactivity indices: net electrophilicity index and Wibe...Chemical reaction possibility was described quantitatively for the case of nitrotriazolam preparation with 2-clonazepam by using the data of two quantum chemical reactivity indices: net electrophilicity index and Wiberg bond order. Furthennore, relevant reaction mechanism was derived from tlie aspect of quantum chemistry. The results show that the indices used can quantitatively explain the chemical reactivity and reaction mechanism of the nitrotriazolam preparation. To validate the universal applicability of the proposed approach, the authors continued to use the quantum chemical reactivity indices to describe some classic chemical reactions, expecting to predict major issues related to physical organic chemistry, such as new chemical reactions and their mechanisms.展开更多
Applying the Fourier transform to the wave equations of elastic medium at its surface a laser pulse line source is acted, the integral representations of solutions are obtained. Displacement waveforms are calculated n...Applying the Fourier transform to the wave equations of elastic medium at its surface a laser pulse line source is acted, the integral representations of solutions are obtained. Displacement waveforms are calculated numerically by using double FFT. The calculated results include the displacements of the elastic half space of Aluminum medium, and epicenter and off-epicenter of an Aluminum plate. The two exciting sources of thermoelastic and ablating generation are considered respectively. The experiment was made on the Aluminum medium with a Nd:YAG laser and the normal displacement signals are detected by a laser interferometer. The numerical results are quite in agreement with experiments.展开更多
基金supported by the National Natural Science Foundation of China(11774264)。
文摘The layered film-substrate structure is widely used in many fields such as microelectronic devices,but the ultrasonic measurement of film material parameters,especially the characterization of shear wave velocity,is a difficult problem.In this paper,the dispersion characteristics of Scholte wave at the liquid-solid interface and the acoustic pressure response generated by a pulse excitation are theoretically analyzed.The results show that the Scholte wave dispersion at the liquid-solid interface is closely related to the velocity distribution of the layered film-substrate structure.The thickness and shear wave velocity of each layer of the thin film material have a significant effect on the interface wave dispersion characteristics.Based on the dispersion properties of Scholte interface waves,a multi-parameter inversion characterization method for multilayer films is proposed.Firstly,the film parameter inversion is carried out for the theoretical signal,which verifies the feasibility of the method.Subsequent experiments on the excitation and acquisition of liquid-solid interface waves are carried out on different types of multilayer film material samples,and the film parameter inversion results of the experimental signals further verify the feasibility and effectiveness of the method.
文摘In this paper, the activities of electrophilic sites on benzene ring of 4-substituted anilines and their acyl compounds were studied with the quantitative indicator of multiphilicity descriptor. Four substituents were synthe- sized with microwave irradiation in good yields to verify the quantitative analysis data. Friedel-Crafts acylation was carried out by the microwave method for the first time.
文摘Hyperglycemia is frequently accompanying with hyperlipidemia. To explore the potent drugs with dual-activity and dual-site effects that could reduce blood glucose and blood lipid at the same time, fibrate group with lipid-lowering effect on the 9th position of berberine（BBR） was introduced using the drug design combination principle and the multi-target collaborative treatment method, Moreover, the molecular structure of BBR was modified, and six 9-substituted derivatives of BBR were designed and synthesized, among which, five compotmds have never been reported before. In addition, the molecular structttres of these derivatives were identified using liquid chromato- graphy-mass spectrometry（LC-MS）, IH nuclear n^tgnetic resonance（1H NMR） and 13C NMR, respectively. Fu^her- more, the microwave irradiation experimental technique was applied in the synthesis reaction using the novel micro- wave synthesizer, which accelerated the reaction rate, enhanced the reaction yield, reduced the reaction by-products, and simplified the post-processing steps. In the meantime, the 9-position regioselective demethylation of BBR was explored through quantum chemical calculation during the synthesis of berberrubine. The computations were consistent with the experimental results, which contributed to deducing the mechanism of its selective methylation.
文摘Chemical reaction possibility was described quantitatively for the case of nitrotriazolam preparation with 2-clonazepam by using the data of two quantum chemical reactivity indices: net electrophilicity index and Wiberg bond order. Furthennore, relevant reaction mechanism was derived from tlie aspect of quantum chemistry. The results show that the indices used can quantitatively explain the chemical reactivity and reaction mechanism of the nitrotriazolam preparation. To validate the universal applicability of the proposed approach, the authors continued to use the quantum chemical reactivity indices to describe some classic chemical reactions, expecting to predict major issues related to physical organic chemistry, such as new chemical reactions and their mechanisms.
基金This work is supported by the National Natural Science Foundation of ChinaState key Lab.of Information Function Material of
文摘Applying the Fourier transform to the wave equations of elastic medium at its surface a laser pulse line source is acted, the integral representations of solutions are obtained. Displacement waveforms are calculated numerically by using double FFT. The calculated results include the displacements of the elastic half space of Aluminum medium, and epicenter and off-epicenter of an Aluminum plate. The two exciting sources of thermoelastic and ablating generation are considered respectively. The experiment was made on the Aluminum medium with a Nd:YAG laser and the normal displacement signals are detected by a laser interferometer. The numerical results are quite in agreement with experiments.
