A[3+4]annulation of α-substituted allenes and Schiff bases is reported.This methodology serves as a conduit for the construction of a series of biologically important benzazepine derivatives in good to excellent yiel...A[3+4]annulation of α-substituted allenes and Schiff bases is reported.This methodology serves as a conduit for the construction of a series of biologically important benzazepine derivatives in good to excellent yields under mild conditions by an unprecedented mode involving β’-carbon of α-substituted allenes and the proposed mechanism is supported by capturing the intermediate.Moreover,this class of benzazepine derivatives exhibited potential ability of cytotoxicity toward cancer cells.展开更多
Improving the accuracy of the evaluation of the performance of wind farms in large wind power bases located in complex terrain under the actual atmosphere is crucial to the sustainable development of wind power.To thi...Improving the accuracy of the evaluation of the performance of wind farms in large wind power bases located in complex terrain under the actual atmosphere is crucial to the sustainable development of wind power.To this end,this study combined the Weather Research and Forecasting(WRF)model with the Wind Farm Parameterization(WFP)method to investigate the wake characteristics and operational performance of large onshore wind farms in the complex terrain of Jiuquan City,Gansu Province,China.The research results showed that after verification,the systematic error of the WRF simulations was less than 3%.The WRF model and the WFP scheme simulated a significant warming phenomenon within the wind power base area,while a cooling effect was observed outside.The analysis of the wake effects indicated that the impact of PhaseⅠconstruction on PhaseⅡconstruction of the wind power base was minimal.During the operation of the entire wind power base,the wind speed within the wind farm decreased by approximately 10%,and the influence range of the predominant wind direction extended over a hundred kilometers downwind.The research conclusions provide a powerful scientific basis for optimizing design and operation,improving efficiency,minimizing the negative impacts on adjacent wind turbines,and ensuring the sustainable development of wind energy through dynamic planning and scientific assessment.展开更多
We study the construction of mutually unbiased bases in Hilbert space for composite dimensions d which are not prime powers.We explore the results for composite dimensions which are true for prime power dimensions.We ...We study the construction of mutually unbiased bases in Hilbert space for composite dimensions d which are not prime powers.We explore the results for composite dimensions which are true for prime power dimensions.We then provide a method for selecting mutually unbiased vectors from the eigenvectors of generalized Pauli matrices to construct mutually unbiased bases.In particular,we present four mutually unbiased bases in C^(15).展开更多
The old industrial base city is in the important strategic period of old industrial bases revitalization,resource-exhausted city transformation and development,and the construction of sponge city which can absorb,pene...The old industrial base city is in the important strategic period of old industrial bases revitalization,resource-exhausted city transformation and development,and the construction of sponge city which can absorb,penetrate,conserve,and purify is imperative.Based on the experimental sponge city of Xuzhou,this paper analyzes the problems of the old industrial base city.Combined with the existing work foundation,the objectives and guiding principles of Xuzhou sponge city construction are proposed.And the four ways are implemented to improve the status quo of the old industrial base,to effectively carry out the sponge city construction characterized by the old industrial bases.展开更多
In order to implement the national aesthetic education policy,it is essential to organically integrate relevant aesthetic education resources,promote interdisciplinary education,and carry out extracurricular practical...In order to implement the national aesthetic education policy,it is essential to organically integrate relevant aesthetic education resources,promote interdisciplinary education,and carry out extracurricular practical activities centered on aesthetic education.Strengthening the foundation of aesthetic education theory,addressing practical challenges in the teaching process,and closely linking research with teaching will create a feedback loop that benefits drama education.This article provides an in-depth analysis of the construction strategies,resource advantages and disadvantages,and development of aesthetic education bases,offering countermeasures and suggestions for their construction in universities.It aims to provide a solid research foundation for the growth and development of aesthetic education bases in higher education institutions.展开更多
With the continuous expansion of medical student enrollment,the number of clinical teaching bases is gradually increasing.However,there are significant differences in clinical teaching management models and teaching l...With the continuous expansion of medical student enrollment,the number of clinical teaching bases is gradually increasing.However,there are significant differences in clinical teaching management models and teaching levels among different bases.Most clinical teaching bases have incomplete teaching management systems,inadequate teaching management institutions,insufficient teaching personnel,and inadequate implementation of teaching rules and regulations.This article combines the construction practice of three-level clinical teaching base of the General Medicine College and the First Affiliated Hospital of Xi’an Medical University.We establish a standardized management system for the three-level clinical teaching base;implement a teaching supervision system and strengthen the monitoring of teaching quality;adopt multiple evaluations to test the effectiveness of clinical teaching implementation;explore the path of homogenization construction of teaching bases in terms of unified teacher training,promoting the development of teacher teaching abilities with equal quality and excellence,and providing a reference for improving the quality of medical talent training.展开更多
To investigate the structural form of gossypol and gossypolone Schiff＇s bases, seven relevant Schiff＇s bases were synthesized and the electrospray ionization-tandem mass spectrometry （ESI-MS/MS） with low-energy co...To investigate the structural form of gossypol and gossypolone Schiff＇s bases, seven relevant Schiff＇s bases were synthesized and the electrospray ionization-tandem mass spectrometry （ESI-MS/MS） with low-energy collision-induced dissociation was used to analyze their fragmentations. A common fragmentation pathway with the loss of RNH2 from those schiff＇s bases quasi-molecular ions was observed and proposed on the basis of their MS/MS spectra data. This common pathway indicated that those Schiff＇s bases existed mainly as the enamine form not the imine form previously showed in most reports.展开更多
The economic transformation of the old industrial bases is a key research topic among geographers in China.In this paper,we propose that the concept of regional economic resilience(RER)has unique theoretical value in ...The economic transformation of the old industrial bases is a key research topic among geographers in China.In this paper,we propose that the concept of regional economic resilience(RER)has unique theoretical value in analyzing the economic transformation of the old industrial bases.We constructed an analytical framework and an index system and applied the conceptual tools to study the evolution of RER in the old industrial base of Liaoning Province in China,which is currently subjected to not only sudden shocks but‘slow burn’—longer term processes of change that may nevertheless affect the regional economy.There are four main findings:first,the evolution of RER in Liaoning can be divided into four stages from 2000 to 2015.Liaoning is currently in its conservation-release period,and the next stage will be a release-reorganization period.Second,the RER of the majority of the studied cities is lower than the average value for Liaoning,and this is mainly attributed to the relatively weak vulnerability-resistance and adaptability-transformation capacity of these cities.Third,the RER levels of the 14 cities in Liaoning differ significantly.At the first level is Shenyang and Dalian,at the second level is Dandong and Yingkou,and the third level comprises the remaining cities.Fourth,regional economic resilience is mainly determined by vulnerability-resistance,which indirectly reflects Liaoning’s lack of adaptability-transformation capacity,and the ability of the region to renew or create a new development path is weak.展开更多
Objective： A series of 2-benzylideneaminonaphthothiazoles were designed and synthesized incorporating the lipophilic naphthalene ring to render them more capable of penetrating various biomembranes. Methods： Schiff ...Objective： A series of 2-benzylideneaminonaphthothiazoles were designed and synthesized incorporating the lipophilic naphthalene ring to render them more capable of penetrating various biomembranes. Methods： Schiff bases were synthesized by the reaction of naphtha[1,2-d]thiazol-2-amine with various substituted aromatic aldehydes. 2-（2＇-Hydroxy）ben- zylideneaminonaphthothiazole was converted to its Co（Ⅱ）, Ni（Ⅱ） and Cu（Ⅱ） metal complexes upon treatment with metal salts in ethanol. All the compounds were evaluated for their antibacterial activities by paper disc diffusion method with Gram positive Staphylococcus aureus and Staphylococcus epidermidis and Gram negative Escherichia coli and Pseudomonas aeruginosa bacteria. The minimum inhibitory concentrations of all the Schiff bases and metal complexes were determined by agar streak dilution method. Results： All the compounds moderately inhibited the growth of Cram positive and Gram negative bacteria. In the present study among all Schiff bases 2-（2＇-hydroxy）benzylideneaminonaphthothiazole showed maximum inhibitory activity and among metal complexes Cu（Ⅱ） metal complex was found to be most potent. Conclusion： The results obtained validate the hypothesis that Schiff bases having substitution with halogens, hydroxyl group and nitro group at phenyl ring are required for the antibacterial activity while methoxy group at different positions in the aromatic ring has minimal role in the inhibitory activity. The results also indicated that the metal complexes are better antibacterial agents as compared to the Schiff bases.展开更多
The reaction of nitrosonium (NO+) with Schiff bases produced diazonium salts and aldehydes in good yield. The reaction is assumed to be an electrophilic reaction of nitrosonium with imines via a four-member ring inter...The reaction of nitrosonium (NO+) with Schiff bases produced diazonium salts and aldehydes in good yield. The reaction is assumed to be an electrophilic reaction of nitrosonium with imines via a four-member ring intermediate.展开更多
Interactions of the three common atmospheric bases,dimethylamine((CH3)2 NH),methylamine(CH3 NH2),ammonia(NH3),all considered to be efficient stabilizers of binary clusters in the Earth’s atmosphere,with H2 SO4,the ke...Interactions of the three common atmospheric bases,dimethylamine((CH3)2 NH),methylamine(CH3 NH2),ammonia(NH3),all considered to be efficient stabilizers of binary clusters in the Earth’s atmosphere,with H2 SO4,the key atmospheric precursor,and 14 common atmospheric organic acids(COAs)(formic,acetic,oxalic,malonic,succinic,glutaric acid,adipic,benzoic,phenylacetic,pyruvic,maleic acid,malic,tartaric and pinonic acids)have been studied using the density functional theory(DFT)and composite high-accuracy G3 MP2 method.The thermodynamic stability of mixed(COA)(H2 SO4),(COA)(B1),(COA)(B2)and(COA)(B3)dimers and(COA)(H2 SO4)(B1),(COA)(H2 SO4)(B2)and(COA)(H2 SO4)(B3)trimers,where B1,B2 and B3 refer to(CH3)2 NH,CH3 NH2 and NH3,respectively,have been investigated and their impacts on the thermodynamic stability of clusters containing H2 SO4 have been studied.Our investigation shows that interactions of H2 SO4 with GOA,(CH3)2 NH,CH3 NH2 and NH3 lead to the formation of more stable mixed dimers and trimers than(H2 SO4)2 and(H2 SO4)2(base),respectively,and emphasize the importance of common organic species for early stages of atmospheric nucleation.We also show that although amines are generally confirmed to be more active than NH3 as stabilizers of binary clusters,in some cases mixed trimers containing NH3 are more stable thermodynamically than those containing CH3 NH2.This study indicates an important role of COA,which coexist and interact with that H2 SO4 and common atmospheric bases in the Earth atmosphere,in formation of stable prenucleation clusters and suggests that the impacts of COA on new particle formation(NPF)should be studied in further details.展开更多
A series of five new Schiff bases(1–5) were synthesized by reacting 2-(trifluoromethoxy) aniline with different aromatic aldehydes. The Schiff base compounds were characterized by spectroscopic and analytical methods...A series of five new Schiff bases(1–5) were synthesized by reacting 2-(trifluoromethoxy) aniline with different aromatic aldehydes. The Schiff base compounds were characterized by spectroscopic and analytical methods. Crystal structure of one new compound was also reported. The pharmacological properties, including antibacterial(14 bacterial species), antifungal(7 strains), antimalarial, anti-trypanosomal and anti-HIV activities of the compounds, were investigated. Cytotoxicity of the tested compounds was evaluated against human cervix adernocarcinoma cells(He La). Bacterial minimum inhibitory concentration(MIC) results by broth microdilution method showed that Bacillus subtilis, Enterococcus faecalis, Staphylococcus aureus, Staphylococcus epidermidis, Proteus vulgaris, Klebsiella oxytoc and Klebsiella pneumonia were more sensitive in the presence of tested compounds with an MIC value of 15.6 μg/m L. All the tested compounds showed good to moderate activity against fungi. The sensitivity of Aspergillus fumigatus was higher than other strains with a minimum cell death concentration(MFC) of 15.6 μg/m L. Compound 1 showed greater antimalarial and anti-trypanosomal properties with very low to no cytotoxic effects against He La cells as compared with compound 5, while other compounds exhibited poor activity. Compounds 1–5 demonstrated good activity against HIV type-1. These Schiff base compounds could be used as good antimicrobial agents.展开更多
Ganoderma(lingzhi)is a famous herbal medicine and edible supplement in oriental countries for a long history.In this study,a simple micellar electrokinetic chromatography(MEKC)method was established for the analysis o...Ganoderma(lingzhi)is a famous herbal medicine and edible supplement in oriental countries for a long history.In this study,a simple micellar electrokinetic chromatography(MEKC)method was established for the analysis of nucleosides and bases,the major bioactive components in Ganoderma for the first time.By optimizing the borate concentration,the sodium dodecyl sulfate(SDS)concentration and the pH value of running buffer,10 nucleosides and bases achieved an ideal separation.In real sample analysis,the developed method was successfully used to determine the 10 target analytes in 23 batches of Ganoderma samples from different regions.Results indicated that contents of 10 investigated analytes in each sample showed obvious variation.The principal components analysis(PCA)and hierarchical cluster analysis(HCA)analysis classified the samples into three groups,and the HCA tree visualized the relationships which was mainly contributed by geographical partition.The results indicated geographical origin to be an important factor that affect the accumulation of nucleosides and bases in Ganoderma.In summary,this study provides a simple and practical strategy for quality assessment and cultivation reference of Ganoderma.展开更多
The adsorption of DNA bases on a magnetic probe composed of Fe atoms and graphene is studied by using first- principles calculations. The stability of geometry, the electronic structure and magnetic property are inves...The adsorption of DNA bases on a magnetic probe composed of Fe atoms and graphene is studied by using first- principles calculations. The stability of geometry, the electronic structure and magnetic property are investigated. The results indicate that four DNA bases, i.e., adenine, thymine, cytosine and guanine, can all be adsorbed on the probe solidly. However, the magnetic moments of the composite structure can be observed only when adenine adsorbs on the probe. In the cases of the adsorption of the other three bases, the magnetic moments of the composite structure are zero. Based on the significant change of magnetic moment of the composite structure, adenine can be distinguished conveniently from thymine, cytosine and guanine. This work may provide a new way to detect DNA bases.展开更多
On the basis of brief description of current situation of old industrial bases and primary industry of Liaoning Province, the paper introduces the general situation of agriculture-ecological zoning plan in Liaoning Pr...On the basis of brief description of current situation of old industrial bases and primary industry of Liaoning Province, the paper introduces the general situation of agriculture-ecological zoning plan in Liaoning Province. First, the ecological bases of agricultural zoning plan are introduced through various topographic and geomorphic types, regional climate differences and imbalanced distribution of natural resources; Second, in accordance with the theory of comparative advantage, distribution of production and resource economics, on the basis of comprehensive evaluation of agricultural natural resources, with the principle of fully excavating economic function of different natural resources, and in order to improve allocation efficiency of the two resources of market and government, the formation of ecological zoning plan of agriculture in Liaoning Province is analyzed; Third, according to Regional Layout Planning of Characteristic Agricultural Products of Liaoning Province (2006-2010), the paper describes basic layout of agriculture-ecological zoning plan in Liaoning Province. The policy support of agriculture-ecological zoning plan in Liaoning Province is analyzed from three aspects-support policy of functional zone major in producing grain, support policy of other characteristic agriculture-ecological zone and support measures of development of agriculture-ecological zone. The paper also analyzes experiences of agricultural development of old industrial bases in ecological zoning plan: First, agriculture-ecological zoning plan is a effective way of the revitalization of old industrial bases; Second, scientificity of plan is the basis of improving competitiveness of regional agriculture; Third, multi-input mechanism guiding by government is the key of agricultural packing effect; Fourth, integrated agricultural industrial chain is guarantee of realizing industrialization in ecological zone.展开更多
A novel method based on time-dependent stochastic orthogonal bases for stochastic response surface approximation is proposed to overcome the problem of significant errors in the utilization of the generalized polynomi...A novel method based on time-dependent stochastic orthogonal bases for stochastic response surface approximation is proposed to overcome the problem of significant errors in the utilization of the generalized polynomial chaos(GPC) method that approximates the stochastic response by orthogonal polynomials. The accuracy and effectiveness of the method are illustrated by different numerical examples including both linear and nonlinear problems. The results indicate that the proposed method modifies the stochastic bases adaptively, and has a better approximation for the probability density function in contrast to the GPC method.展开更多
Six lanthanide complexes with bis(phenylsulfinyl)ethane(bphse) and organic bases(phen: 1,10 phenanthroline and bipy: 2,2'-bipyridine) were synthesized and characterized by elemental analysis, conductance and spec...Six lanthanide complexes with bis(phenylsulfinyl)ethane(bphse) and organic bases(phen: 1,10 phenanthroline and bipy: 2,2'-bipyridine) were synthesized and characterized by elemental analysis, conductance and spectral (IR, UV Visible) data. The complexes were Ln(bphse) 2(bipy)(ClO 4) 3· n H 2O and Ln 2(bphse) 3(phen) 2(ClO 4) 6·H 2O(where Ln=Nd, Eu and Gd; n =0～2). IR spectral data confirmed that the lanthanide ions were coordinated by oxygen atoms from bphse and nitrogen atoms from phen or bipy. Exitation and emission spectra of Eu complexes were measured and discussed.展开更多
The factors affecting the developmcnt of Sinopec lubricating oil were analyzed in this paper, and an analytic hierarchy process （AHP） model for selecting lubricating-oil producing bases was developed. By using this ...The factors affecting the developmcnt of Sinopec lubricating oil were analyzed in this paper, and an analytic hierarchy process （AHP） model for selecting lubricating-oil producing bases was developed. By using this model, nine lubricating oil producing companies under Sinopec were comprehensively evaluated. The evaluation result showed that the Maoming Lubricating Oil Company （Guangdong province）, Jingmen Lubricating Oil Company （Hubei province） and Changcheng Lube Oil Company （Beijing） are top three choices, and should be developed preferentially for the development of Sinopec producing bases of lubricating oil in the future. The conclusions provide the theoretical basis for selecting lubricating oil producing bases for decision makers.展开更多
基金financially supported by the National Natural Science Foundation of China(No.21572271).
文摘A[3+4]annulation of α-substituted allenes and Schiff bases is reported.This methodology serves as a conduit for the construction of a series of biologically important benzazepine derivatives in good to excellent yields under mild conditions by an unprecedented mode involving β’-carbon of α-substituted allenes and the proposed mechanism is supported by capturing the intermediate.Moreover,this class of benzazepine derivatives exhibited potential ability of cytotoxicity toward cancer cells.
基金funded by“The Factors Affecting the Accuracy of Wind Resource Assessment and Comprehensive Post-Evaluation Techniques for Operating Wind Power Projects,”grant number YJ24.002“The Research and Application of Future Medium to Long Term Wind Resource Assessment for Wind Farms Based on Artificial Intelligence Project,”grant number 2023021。
文摘Improving the accuracy of the evaluation of the performance of wind farms in large wind power bases located in complex terrain under the actual atmosphere is crucial to the sustainable development of wind power.To this end,this study combined the Weather Research and Forecasting(WRF)model with the Wind Farm Parameterization(WFP)method to investigate the wake characteristics and operational performance of large onshore wind farms in the complex terrain of Jiuquan City,Gansu Province,China.The research results showed that after verification,the systematic error of the WRF simulations was less than 3%.The WRF model and the WFP scheme simulated a significant warming phenomenon within the wind power base area,while a cooling effect was observed outside.The analysis of the wake effects indicated that the impact of PhaseⅠconstruction on PhaseⅡconstruction of the wind power base was minimal.During the operation of the entire wind power base,the wind speed within the wind farm decreased by approximately 10%,and the influence range of the predominant wind direction extended over a hundred kilometers downwind.The research conclusions provide a powerful scientific basis for optimizing design and operation,improving efficiency,minimizing the negative impacts on adjacent wind turbines,and ensuring the sustainable development of wind energy through dynamic planning and scientific assessment.
基金Project supported by Zhoukou Normal University,ChinaHigh Level Talents Research Start Funding Project (Grant No.ZKNUC2022010)+2 种基金Key Scientific Research Project of Henan Province (Grant No.22B110022)Key Research and Development Project of Guangdong Province (Grant No.2020B0303300001)the Guangdong Basic and Applied Basic Research Foundation (Grant No.2020B1515310016)。
文摘We study the construction of mutually unbiased bases in Hilbert space for composite dimensions d which are not prime powers.We explore the results for composite dimensions which are true for prime power dimensions.We then provide a method for selecting mutually unbiased vectors from the eigenvectors of generalized Pauli matrices to construct mutually unbiased bases.In particular,we present four mutually unbiased bases in C^(15).
文摘The old industrial base city is in the important strategic period of old industrial bases revitalization,resource-exhausted city transformation and development,and the construction of sponge city which can absorb,penetrate,conserve,and purify is imperative.Based on the experimental sponge city of Xuzhou,this paper analyzes the problems of the old industrial base city.Combined with the existing work foundation,the objectives and guiding principles of Xuzhou sponge city construction are proposed.And the four ways are implemented to improve the status quo of the old industrial base,to effectively carry out the sponge city construction characterized by the old industrial bases.
文摘In order to implement the national aesthetic education policy,it is essential to organically integrate relevant aesthetic education resources,promote interdisciplinary education,and carry out extracurricular practical activities centered on aesthetic education.Strengthening the foundation of aesthetic education theory,addressing practical challenges in the teaching process,and closely linking research with teaching will create a feedback loop that benefits drama education.This article provides an in-depth analysis of the construction strategies,resource advantages and disadvantages,and development of aesthetic education bases,offering countermeasures and suggestions for their construction in universities.It aims to provide a solid research foundation for the growth and development of aesthetic education bases in higher education institutions.
基金2022 Education and Teaching Reform Research Project of Xi’an Medical University“Construction and Practice of the Teaching Quality Assurance System in the Three-Level Teaching Base of General Practice Medicine Under the Internet+Model”(Project number:2022JG-05)。
文摘With the continuous expansion of medical student enrollment,the number of clinical teaching bases is gradually increasing.However,there are significant differences in clinical teaching management models and teaching levels among different bases.Most clinical teaching bases have incomplete teaching management systems,inadequate teaching management institutions,insufficient teaching personnel,and inadequate implementation of teaching rules and regulations.This article combines the construction practice of three-level clinical teaching base of the General Medicine College and the First Affiliated Hospital of Xi’an Medical University.We establish a standardized management system for the three-level clinical teaching base;implement a teaching supervision system and strengthen the monitoring of teaching quality;adopt multiple evaluations to test the effectiveness of clinical teaching implementation;explore the path of homogenization construction of teaching bases in terms of unified teacher training,promoting the development of teacher teaching abilities with equal quality and excellence,and providing a reference for improving the quality of medical talent training.
文摘To investigate the structural form of gossypol and gossypolone Schiff＇s bases, seven relevant Schiff＇s bases were synthesized and the electrospray ionization-tandem mass spectrometry （ESI-MS/MS） with low-energy collision-induced dissociation was used to analyze their fragmentations. A common fragmentation pathway with the loss of RNH2 from those schiff＇s bases quasi-molecular ions was observed and proposed on the basis of their MS/MS spectra data. This common pathway indicated that those Schiff＇s bases existed mainly as the enamine form not the imine form previously showed in most reports.
基金Under the auspices of National Natural Science Foundation of China(No.41571152,41771179).
文摘The economic transformation of the old industrial bases is a key research topic among geographers in China.In this paper,we propose that the concept of regional economic resilience(RER)has unique theoretical value in analyzing the economic transformation of the old industrial bases.We constructed an analytical framework and an index system and applied the conceptual tools to study the evolution of RER in the old industrial base of Liaoning Province in China,which is currently subjected to not only sudden shocks but‘slow burn’—longer term processes of change that may nevertheless affect the regional economy.There are four main findings:first,the evolution of RER in Liaoning can be divided into four stages from 2000 to 2015.Liaoning is currently in its conservation-release period,and the next stage will be a release-reorganization period.Second,the RER of the majority of the studied cities is lower than the average value for Liaoning,and this is mainly attributed to the relatively weak vulnerability-resistance and adaptability-transformation capacity of these cities.Third,the RER levels of the 14 cities in Liaoning differ significantly.At the first level is Shenyang and Dalian,at the second level is Dandong and Yingkou,and the third level comprises the remaining cities.Fourth,regional economic resilience is mainly determined by vulnerability-resistance,which indirectly reflects Liaoning’s lack of adaptability-transformation capacity,and the ability of the region to renew or create a new development path is weak.
文摘Objective： A series of 2-benzylideneaminonaphthothiazoles were designed and synthesized incorporating the lipophilic naphthalene ring to render them more capable of penetrating various biomembranes. Methods： Schiff bases were synthesized by the reaction of naphtha[1,2-d]thiazol-2-amine with various substituted aromatic aldehydes. 2-（2＇-Hydroxy）ben- zylideneaminonaphthothiazole was converted to its Co（Ⅱ）, Ni（Ⅱ） and Cu（Ⅱ） metal complexes upon treatment with metal salts in ethanol. All the compounds were evaluated for their antibacterial activities by paper disc diffusion method with Gram positive Staphylococcus aureus and Staphylococcus epidermidis and Gram negative Escherichia coli and Pseudomonas aeruginosa bacteria. The minimum inhibitory concentrations of all the Schiff bases and metal complexes were determined by agar streak dilution method. Results： All the compounds moderately inhibited the growth of Cram positive and Gram negative bacteria. In the present study among all Schiff bases 2-（2＇-hydroxy）benzylideneaminonaphthothiazole showed maximum inhibitory activity and among metal complexes Cu（Ⅱ） metal complex was found to be most potent. Conclusion： The results obtained validate the hypothesis that Schiff bases having substitution with halogens, hydroxyl group and nitro group at phenyl ring are required for the antibacterial activity while methoxy group at different positions in the aromatic ring has minimal role in the inhibitory activity. The results also indicated that the metal complexes are better antibacterial agents as compared to the Schiff bases.
文摘The reaction of nitrosonium (NO+) with Schiff bases produced diazonium salts and aldehydes in good yield. The reaction is assumed to be an electrophilic reaction of nitrosonium with imines via a four-member ring intermediate.
基金supported by the Science Foundation of Chinese Research Academy of Environmental Science(No.JY41375133)the National Natural Science Foundation of China(No.41375133)+1 种基金Russian Science Foundation(No.18-71-00137)the Russian Ministry of Science and Education(Nos.1.6198.2017/6.7 and 1.7706.2017/8.9)for support
文摘Interactions of the three common atmospheric bases,dimethylamine((CH3)2 NH),methylamine(CH3 NH2),ammonia(NH3),all considered to be efficient stabilizers of binary clusters in the Earth’s atmosphere,with H2 SO4,the key atmospheric precursor,and 14 common atmospheric organic acids(COAs)(formic,acetic,oxalic,malonic,succinic,glutaric acid,adipic,benzoic,phenylacetic,pyruvic,maleic acid,malic,tartaric and pinonic acids)have been studied using the density functional theory(DFT)and composite high-accuracy G3 MP2 method.The thermodynamic stability of mixed(COA)(H2 SO4),(COA)(B1),(COA)(B2)and(COA)(B3)dimers and(COA)(H2 SO4)(B1),(COA)(H2 SO4)(B2)and(COA)(H2 SO4)(B3)trimers,where B1,B2 and B3 refer to(CH3)2 NH,CH3 NH2 and NH3,respectively,have been investigated and their impacts on the thermodynamic stability of clusters containing H2 SO4 have been studied.Our investigation shows that interactions of H2 SO4 with GOA,(CH3)2 NH,CH3 NH2 and NH3 lead to the formation of more stable mixed dimers and trimers than(H2 SO4)2 and(H2 SO4)2(base),respectively,and emphasize the importance of common organic species for early stages of atmospheric nucleation.We also show that although amines are generally confirmed to be more active than NH3 as stabilizers of binary clusters,in some cases mixed trimers containing NH3 are more stable thermodynamically than those containing CH3 NH2.This study indicates an important role of COA,which coexist and interact with that H2 SO4 and common atmospheric bases in the Earth atmosphere,in formation of stable prenucleation clusters and suggests that the impacts of COA on new particle formation(NPF)should be studied in further details.
文摘A series of five new Schiff bases(1–5) were synthesized by reacting 2-(trifluoromethoxy) aniline with different aromatic aldehydes. The Schiff base compounds were characterized by spectroscopic and analytical methods. Crystal structure of one new compound was also reported. The pharmacological properties, including antibacterial(14 bacterial species), antifungal(7 strains), antimalarial, anti-trypanosomal and anti-HIV activities of the compounds, were investigated. Cytotoxicity of the tested compounds was evaluated against human cervix adernocarcinoma cells(He La). Bacterial minimum inhibitory concentration(MIC) results by broth microdilution method showed that Bacillus subtilis, Enterococcus faecalis, Staphylococcus aureus, Staphylococcus epidermidis, Proteus vulgaris, Klebsiella oxytoc and Klebsiella pneumonia were more sensitive in the presence of tested compounds with an MIC value of 15.6 μg/m L. All the tested compounds showed good to moderate activity against fungi. The sensitivity of Aspergillus fumigatus was higher than other strains with a minimum cell death concentration(MFC) of 15.6 μg/m L. Compound 1 showed greater antimalarial and anti-trypanosomal properties with very low to no cytotoxic effects against He La cells as compared with compound 5, while other compounds exhibited poor activity. Compounds 1–5 demonstrated good activity against HIV type-1. These Schiff base compounds could be used as good antimicrobial agents.
基金financially supported by the Research Committee of the University of Macao(MYRG2018-00239-ICMS and MYRG2014-00089-ICMS-QRCM)the Macao Science and Technology Development Fund(162/2017/A3)Guangzhou International Science and Technology Cooperation Project(File no.201807010044)。
文摘Ganoderma(lingzhi)is a famous herbal medicine and edible supplement in oriental countries for a long history.In this study,a simple micellar electrokinetic chromatography(MEKC)method was established for the analysis of nucleosides and bases,the major bioactive components in Ganoderma for the first time.By optimizing the borate concentration,the sodium dodecyl sulfate(SDS)concentration and the pH value of running buffer,10 nucleosides and bases achieved an ideal separation.In real sample analysis,the developed method was successfully used to determine the 10 target analytes in 23 batches of Ganoderma samples from different regions.Results indicated that contents of 10 investigated analytes in each sample showed obvious variation.The principal components analysis(PCA)and hierarchical cluster analysis(HCA)analysis classified the samples into three groups,and the HCA tree visualized the relationships which was mainly contributed by geographical partition.The results indicated geographical origin to be an important factor that affect the accumulation of nucleosides and bases in Ganoderma.In summary,this study provides a simple and practical strategy for quality assessment and cultivation reference of Ganoderma.
基金Supported by the National Natural Science Foundation of China under Grant Nos 51301119 and 11204201the Natural Science Foundation for Young Scientists of Shanxi Province under Grant No 2013021010-1
文摘The adsorption of DNA bases on a magnetic probe composed of Fe atoms and graphene is studied by using first- principles calculations. The stability of geometry, the electronic structure and magnetic property are investigated. The results indicate that four DNA bases, i.e., adenine, thymine, cytosine and guanine, can all be adsorbed on the probe solidly. However, the magnetic moments of the composite structure can be observed only when adenine adsorbs on the probe. In the cases of the adsorption of the other three bases, the magnetic moments of the composite structure are zero. Based on the significant change of magnetic moment of the composite structure, adenine can be distinguished conveniently from thymine, cytosine and guanine. This work may provide a new way to detect DNA bases.
文摘On the basis of brief description of current situation of old industrial bases and primary industry of Liaoning Province, the paper introduces the general situation of agriculture-ecological zoning plan in Liaoning Province. First, the ecological bases of agricultural zoning plan are introduced through various topographic and geomorphic types, regional climate differences and imbalanced distribution of natural resources; Second, in accordance with the theory of comparative advantage, distribution of production and resource economics, on the basis of comprehensive evaluation of agricultural natural resources, with the principle of fully excavating economic function of different natural resources, and in order to improve allocation efficiency of the two resources of market and government, the formation of ecological zoning plan of agriculture in Liaoning Province is analyzed; Third, according to Regional Layout Planning of Characteristic Agricultural Products of Liaoning Province (2006-2010), the paper describes basic layout of agriculture-ecological zoning plan in Liaoning Province. The policy support of agriculture-ecological zoning plan in Liaoning Province is analyzed from three aspects-support policy of functional zone major in producing grain, support policy of other characteristic agriculture-ecological zone and support measures of development of agriculture-ecological zone. The paper also analyzes experiences of agricultural development of old industrial bases in ecological zoning plan: First, agriculture-ecological zoning plan is a effective way of the revitalization of old industrial bases; Second, scientificity of plan is the basis of improving competitiveness of regional agriculture; Third, multi-input mechanism guiding by government is the key of agricultural packing effect; Fourth, integrated agricultural industrial chain is guarantee of realizing industrialization in ecological zone.
基金Project supported by the National Natural Science Foundation of China(Nos.11632011,11572189,and 51421092)the China Postdoctoral Science Foundation(No.2016M601585)
文摘A novel method based on time-dependent stochastic orthogonal bases for stochastic response surface approximation is proposed to overcome the problem of significant errors in the utilization of the generalized polynomial chaos(GPC) method that approximates the stochastic response by orthogonal polynomials. The accuracy and effectiveness of the method are illustrated by different numerical examples including both linear and nonlinear problems. The results indicate that the proposed method modifies the stochastic bases adaptively, and has a better approximation for the probability density function in contrast to the GPC method.
文摘Six lanthanide complexes with bis(phenylsulfinyl)ethane(bphse) and organic bases(phen: 1,10 phenanthroline and bipy: 2,2'-bipyridine) were synthesized and characterized by elemental analysis, conductance and spectral (IR, UV Visible) data. The complexes were Ln(bphse) 2(bipy)(ClO 4) 3· n H 2O and Ln 2(bphse) 3(phen) 2(ClO 4) 6·H 2O(where Ln=Nd, Eu and Gd; n =0～2). IR spectral data confirmed that the lanthanide ions were coordinated by oxygen atoms from bphse and nitrogen atoms from phen or bipy. Exitation and emission spectra of Eu complexes were measured and discussed.
文摘The factors affecting the developmcnt of Sinopec lubricating oil were analyzed in this paper, and an analytic hierarchy process （AHP） model for selecting lubricating-oil producing bases was developed. By using this model, nine lubricating oil producing companies under Sinopec were comprehensively evaluated. The evaluation result showed that the Maoming Lubricating Oil Company （Guangdong province）, Jingmen Lubricating Oil Company （Hubei province） and Changcheng Lube Oil Company （Beijing） are top three choices, and should be developed preferentially for the development of Sinopec producing bases of lubricating oil in the future. The conclusions provide the theoretical basis for selecting lubricating oil producing bases for decision makers.
