German engineer Heinrich Hildebrand came to China as a spy in 1891,serving at the German Embassy in Beijing and collecting Chinese railway information.In 1892,he began to work for Zhang Zhidong and participated in the...German engineer Heinrich Hildebrand came to China as a spy in 1891,serving at the German Embassy in Beijing and collecting Chinese railway information.In 1892,he began to work for Zhang Zhidong and participated in the construction of the Daye railway and Hanyang Iron Works,among other projects.Recommended by Zhang Zhidong,he was appointed as counselor of the China Railway Company by Sheng Xuanhuai.After Germany took Jiaozhou Bay in 1897,Hildebrand presided over the survey and construction of the Shandong Railway.He served as its General Director and chief engineer for ten years,which was the most important period of his career.As his identity switched from German spy in Zhang Zhidong’s staff to General Director of the Shandong Railway,his colonialist mentality gradually came to the fore,and he took a tough stance when dealing with Chinese officials and workers.He was highly appreciated by Zhang Zhidong and strongly opposed by Yuan Shikai.Western engineers in early modern China played a dual role in the course of China’s modernization.On the one hand,they promoted the cause of China’s modernization as professionals,and on the other hand,they often became spokesmen for and active agents of imperialism.展开更多
In this work, some chemometrics methods are applied for the modeling and prediction of the Hildebrand solubility parameter of some polymers. A genetic algorithm （GA） method is designed for the selection of variables...In this work, some chemometrics methods are applied for the modeling and prediction of the Hildebrand solubility parameter of some polymers. A genetic algorithm （GA） method is designed for the selection of variables to construct two models using the multiple linear regression （MLR） and least square-support vector machine （LS-SVM） methods in order to predict the Hildebrand solubility parameter. The MLR method is used to build a linear relationship between the molecular descriptors and the Hildebrand solubility parameter for these compounds. Then the LS-SVM method is utilized to construct the non-linear quantitative structure-activity relationship （QSAR） models. The results obtained using the LS-SVM method are then compared with those obtained for the MLR method; it was revealed that the LS-SVM model was much better than the MLR one. The root-mean-square errors of the training set and the test set for the LS-SVM model were 0.2912 and 0.2427, and the correlation coefficients were 0.9662 and 0.9518, respectively. This paper provides a new and effective method for predicting the Hildebrand solubility parameter for some polymers, and also reveals that the LS-SVM method can be used as a powerful chemometrics tool for the quantitative structure-property relationship （QSPR） studies.展开更多
Extraction of sulphonated dyes through supramolecular interaction with calix[4]arene derivatives is being presented here. The selectivity of calixarene derivatives namely piperidine derivative of calix[4]arene (calix-...Extraction of sulphonated dyes through supramolecular interaction with calix[4]arene derivatives is being presented here. The selectivity of calixarene derivatives namely piperidine derivative of calix[4]arene (calix-1), 1-methyl piperazine derivative of calix[4]arene (calix-2), and di-methyl amine derivative of calix[4]arene (calix-3) were evaluated initially against reactive red 2 (RR-2), acid black (AB), reactive blue 19 (B-19) and synthetic dye (D-2) by liquid-liquid extraction experiment. The results showed that the above three calixarenes possess excellent complexation abilities toward the selected dyes. The stoichiometric ratio for the calixarene derivatives and dyes was estimated through Job’s plot, whereas Hildebrand-Benesi equation was used to calculate formation constant (K<sub>s</sub>) and molar absorptivity (Δε) of complexes. The binding association (K<sub>a</sub>) and dissociation (K<sub>d</sub>) constants were calculated by Scatchard plot additionally to further support the complexation data obtained from Hildebrand-Benesi equation. Conversely association constants from, both Hildebrand-Benesi equation and Scatchard plot i.e. K<sub>s</sub> and K<sub>a</sub> favor strong binding interaction between calix-1: D-2, calix-2: B-19, and calix-3: AB complexes. Thus present study adeptly supports the complexation of calixarene derivatives for sulfonated dyes.展开更多
Before an excited molecule returns to the ground State, it can interact with another molecule of the same kind in the ground state to form an excimer or with the molecule of a different kind to form an exciplex. As ex...Before an excited molecule returns to the ground State, it can interact with another molecule of the same kind in the ground state to form an excimer or with the molecule of a different kind to form an exciplex. As exciplex is often present as an intermediate product in photochemical reactions and photoconductivity processes, so it has become an active field of study in physical chemistry. Weller proposed that the forma-展开更多
Polymer-solvent interaction is a fundamentally important concept routinely described by the Flory-Huggins interaction(χ),Hildebrand solubility(Δδ)and the relative energy difference(RED)determined from Hansen solubi...Polymer-solvent interaction is a fundamentally important concept routinely described by the Flory-Huggins interaction(χ),Hildebrand solubility(Δδ)and the relative energy difference(RED)determined from Hansen solubility in experimental,theoretical and simulation studies.Here we performed a machine learning study based on a comprehensive and representative dataset covering the interaction pairs from 81polymers and 1221 solvents.The regression models provide the coefficients of determination in the range of 0.86-0.94 and the classification models deliver the area under the receiver operating characteristic curve(AUCs)better than 0.93.These models were integrated into a newly developed software polySML-PSI.Important features including Log P,molar volume and dipole are identified,and their non-linear,nonmonotonic contributions to polymer-solvent interactions are presented.The widely known“like-dissolve-like”rule and two broadly used empirical equations to estimateχas a function of temperature or Hansen solubility are also evaluated,and the polymer-specified constants are presented.This study provides a quantitative reference and a tool to understand and utilize the concept of polymer-solvent interactions.展开更多
基金funded by a Knowledge Innovation Project of the Chinese Academy of Sciences,“Comparative Study of Science and Technology between China and Foreign Countries”(GZ01-07-01).
文摘German engineer Heinrich Hildebrand came to China as a spy in 1891,serving at the German Embassy in Beijing and collecting Chinese railway information.In 1892,he began to work for Zhang Zhidong and participated in the construction of the Daye railway and Hanyang Iron Works,among other projects.Recommended by Zhang Zhidong,he was appointed as counselor of the China Railway Company by Sheng Xuanhuai.After Germany took Jiaozhou Bay in 1897,Hildebrand presided over the survey and construction of the Shandong Railway.He served as its General Director and chief engineer for ten years,which was the most important period of his career.As his identity switched from German spy in Zhang Zhidong’s staff to General Director of the Shandong Railway,his colonialist mentality gradually came to the fore,and he took a tough stance when dealing with Chinese officials and workers.He was highly appreciated by Zhang Zhidong and strongly opposed by Yuan Shikai.Western engineers in early modern China played a dual role in the course of China’s modernization.On the one hand,they promoted the cause of China’s modernization as professionals,and on the other hand,they often became spokesmen for and active agents of imperialism.
文摘In this work, some chemometrics methods are applied for the modeling and prediction of the Hildebrand solubility parameter of some polymers. A genetic algorithm （GA） method is designed for the selection of variables to construct two models using the multiple linear regression （MLR） and least square-support vector machine （LS-SVM） methods in order to predict the Hildebrand solubility parameter. The MLR method is used to build a linear relationship between the molecular descriptors and the Hildebrand solubility parameter for these compounds. Then the LS-SVM method is utilized to construct the non-linear quantitative structure-activity relationship （QSAR） models. The results obtained using the LS-SVM method are then compared with those obtained for the MLR method; it was revealed that the LS-SVM model was much better than the MLR one. The root-mean-square errors of the training set and the test set for the LS-SVM model were 0.2912 and 0.2427, and the correlation coefficients were 0.9662 and 0.9518, respectively. This paper provides a new and effective method for predicting the Hildebrand solubility parameter for some polymers, and also reveals that the LS-SVM method can be used as a powerful chemometrics tool for the quantitative structure-property relationship （QSPR） studies.
文摘Extraction of sulphonated dyes through supramolecular interaction with calix[4]arene derivatives is being presented here. The selectivity of calixarene derivatives namely piperidine derivative of calix[4]arene (calix-1), 1-methyl piperazine derivative of calix[4]arene (calix-2), and di-methyl amine derivative of calix[4]arene (calix-3) were evaluated initially against reactive red 2 (RR-2), acid black (AB), reactive blue 19 (B-19) and synthetic dye (D-2) by liquid-liquid extraction experiment. The results showed that the above three calixarenes possess excellent complexation abilities toward the selected dyes. The stoichiometric ratio for the calixarene derivatives and dyes was estimated through Job’s plot, whereas Hildebrand-Benesi equation was used to calculate formation constant (K<sub>s</sub>) and molar absorptivity (Δε) of complexes. The binding association (K<sub>a</sub>) and dissociation (K<sub>d</sub>) constants were calculated by Scatchard plot additionally to further support the complexation data obtained from Hildebrand-Benesi equation. Conversely association constants from, both Hildebrand-Benesi equation and Scatchard plot i.e. K<sub>s</sub> and K<sub>a</sub> favor strong binding interaction between calix-1: D-2, calix-2: B-19, and calix-3: AB complexes. Thus present study adeptly supports the complexation of calixarene derivatives for sulfonated dyes.
文摘Before an excited molecule returns to the ground State, it can interact with another molecule of the same kind in the ground state to form an excimer or with the molecule of a different kind to form an exciplex. As exciplex is often present as an intermediate product in photochemical reactions and photoconductivity processes, so it has become an active field of study in physical chemistry. Weller proposed that the forma-
基金financially supported by the National Natural Science Foundation of China(Nos.21774128,U1832177,22173094,51988102)CAS Key Research Program of Frontier Sciences(No.QYZDY-SSW-SLH027)Network and Computing Center,Changchun Institute of Applied Chemistry for essential support。
文摘Polymer-solvent interaction is a fundamentally important concept routinely described by the Flory-Huggins interaction(χ),Hildebrand solubility(Δδ)and the relative energy difference(RED)determined from Hansen solubility in experimental,theoretical and simulation studies.Here we performed a machine learning study based on a comprehensive and representative dataset covering the interaction pairs from 81polymers and 1221 solvents.The regression models provide the coefficients of determination in the range of 0.86-0.94 and the classification models deliver the area under the receiver operating characteristic curve(AUCs)better than 0.93.These models were integrated into a newly developed software polySML-PSI.Important features including Log P,molar volume and dipole are identified,and their non-linear,nonmonotonic contributions to polymer-solvent interactions are presented.The widely known“like-dissolve-like”rule and two broadly used empirical equations to estimateχas a function of temperature or Hansen solubility are also evaluated,and the polymer-specified constants are presented.This study provides a quantitative reference and a tool to understand and utilize the concept of polymer-solvent interactions.
