The mitochondrial genome is a prominent research topic due to its indispensable role in organisms and its application in many research disciplines.However,few studies have investigated intraspecies mitogenomic variati...The mitochondrial genome is a prominent research topic due to its indispensable role in organisms and its application in many research disciplines.However,few studies have investigated intraspecies mitogenomic variation.In this study,69 mitogenomes of the Black-throated Tit(Aegithalos concinnus)were assembled and annotated from a large number of short reads generated using high-throughput sequencing technology.Comparative analyses revealed that mitogenomic characteristics such as length,gene and nucleotide composition,codon usage,and duplicated control regions were relatively conserved despite substantial intraspecies morphological changes.Yet,all the individuals from the subspecies A.c.iredalei had one more nucleotide in the 12S rRNA than the other studied subspecies.Phylogenetic analyses showed five distinct lineages based on the complete mitogenomes and the 13 combined protein-coding genes,whereas only four lineages were observed when using the duplicate control regions.Most interestingly,each lineage had both copies of the control regions of the comprising individuals,indicating that the paralogous control regions were more similar than the orthologous sequences from the distinct lineages.This suggested the control regions had undergone concerted evolution.The Black-throated Tit has complex evolutionary history and needs further investigating the taxonomic status of these lineages,as well as the underlying evolutionary processes.Our findings call for more research on intraspecies mitogenomic variation.展开更多
Solid-state batteries have received increasing attention in scientific and industrial communities,which benefits from the intrinsically safe solid electrolytes(SEs).Although much effort has been devoted to designing S...Solid-state batteries have received increasing attention in scientific and industrial communities,which benefits from the intrinsically safe solid electrolytes(SEs).Although much effort has been devoted to designing SEs with high ionic conductivities,it is extremely difficult to fully understand the ionic diffusion mechanisms in SEs through conventional experimental and theoretical methods.Herein,the temperature-dependent concerted diffusion mechanism of ions in SEs is explored through machinelearning molecular dynamics,taking Li_(10)GeP_(2)S_(12) as a prototype.Weaker diffusion anisotropy,more disordered Li distributions,and shorter residence time are observed at a higher temperature.Arrhenius-type temperature dependence is maintained within a wide temperature range,which is attributed to the linear temperature dependence of jump frequencies of various concerted diffusion modes.These results provide a theoretical framework to understand the ionic diffusion mechanisms in SEs and deepen the understanding of the chemical origin of temperature-dependent concerted diffusions in SEs.展开更多
A novel soluble regular ladder poly（benzoyl-3-aminopropyl） silsesquioxane （LPBAS） was facilely prepared under effective assistance of concerted H-bonding self-assembly of amido groups of side chains and silanol gr...A novel soluble regular ladder poly（benzoyl-3-aminopropyl） silsesquioxane （LPBAS） was facilely prepared under effective assistance of concerted H-bonding self-assembly of amido groups of side chains and silanol groups, respectively, of a new template monomer [1,3-bis（benzoyl-3-aminopropyl）-1,1,3,3-tetraethoxydisiloxane] （M）. The ordered ladder structure of LPBAS is manifested in： （1） the presence of two Bragg peaks representing the ladder width （d） and ladder thickness （t） in X-ray diffraction （XRD） pattern; （2） narrow base-line width （w = 6） of resonance absorption for -CH2SiO3/2 moiety in 29Si-NMR and （3） high glass transition temperature Tg = 1 12℃ in differential scanning calorimetry （DSC） analysis.展开更多
The rearrangement of α-substituted phenyl-α, α′-dimethoxypropanones (R1) was recently proved to he an [1, 3] siqmatropic migration of methoxy group by study of LFER, solvent effect, crossover experiment, and by ot...The rearrangement of α-substituted phenyl-α, α′-dimethoxypropanones (R1) was recently proved to he an [1, 3] siqmatropic migration of methoxy group by study of LFER, solvent effect, crossover experiment, and by other means. The rearrangement catalysed by trace of totuenesulfonic acid gave a negligible value of the Hammett reaction constant. Further experimental results show that the electronic effect of substituent on the aromatic ring for the rearrangement in neutral medium is much greater (Table 1). We propose sigmatropic migration展开更多
Distinguished vips,Ladies and gentlemen,Dear friends,Good afternoon.Let me begin by extending my warmest welcome to all of you to this thematic session on peopleto-people connectivity on behalf of the International ...Distinguished vips,Ladies and gentlemen,Dear friends,Good afternoon.Let me begin by extending my warmest welcome to all of you to this thematic session on peopleto-people connectivity on behalf of the International Department of the CPC Central Committee,the organizer of this event.Thanks to the concerted efforts展开更多
THRONGS of people were overwhelmed by tears and cheers on December 12, 2015 as French Foreign Minister Laurent Fabius, president of the Paris climate change conference, struck a green gavel. It signaled the conclusion...THRONGS of people were overwhelmed by tears and cheers on December 12, 2015 as French Foreign Minister Laurent Fabius, president of the Paris climate change conference, struck a green gavel. It signaled the conclusion of a marathon 13- day negotiation between delegates representing nearly 200 different countries and regions, who had gathered in Paris. The representatives at the 2015 United Nations Climate Change Conference made a deal that will go down in history as a rare moment of worldwide cooperation in the face of a monumental challenge, But as fellow negotiators hugged each other in celebration, grave concerns lurked in the recesses of their minds - this was just the beginning of a war against climate change that is expected to last for generations.展开更多
To develop efficient sensitizers for dye-sensitized solar cells(DSSCs),we recently reported doubly concerted companion(DCC)dye XW83 with a wrapped porphyrin sub-dye unit linked to an organic sub-dye unit through a fle...To develop efficient sensitizers for dye-sensitized solar cells(DSSCs),we recently reported doubly concerted companion(DCC)dye XW83 with a wrapped porphyrin sub-dye unit linked to an organic sub-dye unit through a flexible chain,which exhibits panchromatic absorption and excellent anti-aggregation ability.To further improve the absorption,we herein report XW87 and XW88 by inserting an ethynyl group into the organic sub-dye unit of XW83 near the donor and acceptor,respectively.For the corresponding organic dyes Z3 and Z4,the introduced ethynyl group improves their absorption,but induces aggravated charge recombination,leading to lowered power conversion efficiencies(PCEs).Similar to the organic dyes,the introduced ethynyl group improves the absorption of DCC dyes XW87 and XW88 as well.In addition,the ethynyl group near the acceptor of the organic sub-dye unit can be well protected by the long wrapping chains from the porphyrin unit.As a result,XW88 affords the highest JSC(21.84 mA/cm^(2)),V_(OC)(782 mV)and PCE(12.2%)among the DCC dyes.These results provide an effective method for developing efficient DSSC dyes by inserting an ethynyl group at a suitable position of a DCC dye.展开更多
We construct a connected network between China and the economies that are financially linked to it,based on the network topology of variance decompositions,and measure the cross-border contagion of financial risks amo...We construct a connected network between China and the economies that are financially linked to it,based on the network topology of variance decompositions,and measure the cross-border contagion of financial risks among these economies.We then examine whether the concerted use of macroprudential policies mitigates the cross-border contagion of financial risks.The empirical results show that the tightening of macroprudential policies,especially counter-cyclical capital buffers and limits on credit growth,in economies with net spillover risk(e.g.the US and China).can reduce the cross-border spillover of domestic financial risks to other economies.The concerted use of macroprudential policies can contribute to global financial stability.However,the tightening of"capital"macroprudential policy tools will increase domestic cross-border absorption of financial risks.Hence,macroprudential regulation of cross-border capital flows must be strengthened.展开更多
Constructing step-scheme(S-scheme)heterojunctions has become a popular strategy for efficient pho-tocatalytic H_(2)O_(2) generation.Herein,we in situ grew BiOBr nanosheets(NSs)on a Schiff-base covalent organic framewo...Constructing step-scheme(S-scheme)heterojunctions has become a popular strategy for efficient pho-tocatalytic H_(2)O_(2) generation.Herein,we in situ grew BiOBr nanosheets(NSs)on a Schiff-base covalent organic framework(COF)with largeπ-conjugated structures to prepare S-scheme BiOBr/COF photocat-alysts for H_(2)O_(2) synthesis.The highest photocatalytic H_(2)O_(2) production performance of the composite sample constituting the S-scheme heterojunction is 3749μmol g−1 h−1,which was 1.85 and 27 times the rates of COF and BiOBr,respectively.The construction of S-scheme heterojunction contributed to ef-ficient carrier transfer and separation in space and enhanced redox power.Moreover,the lying-down O_(2)-adsorption configuration on the COF surface favors the concerted two-electron O_(2) reduction process,which greatly reduced the reduction potential requirement for O_(2)-to-H_(2)O_(2) conversion.The synergy be-tween the S-scheme heterojunction and the unique O_(2)-COF interaction boosted photocatalytic H_(2)O_(2) pro-duction activity.展开更多
The neutral theory raised by Motoo Kimura in 1968 asserts that 'the great majority of evolutionary changes at the molecular level, as revealed by comparative studies of protein and DNA sequences. are caused not by...The neutral theory raised by Motoo Kimura in 1968 asserts that 'the great majority of evolutionary changes at the molecular level, as revealed by comparative studies of protein and DNA sequences. are caused not by Darwinian selection but by random drift of selectively neutral or nearly neutral mutants'.展开更多
To develop efficient concerted companion(CC)dyes for fabricating high-performance DSSCs,three organic dyes XL1-XL3 have been designed by varying the position and number of theβ-hexylthiophene(HT)bridges,and these org...To develop efficient concerted companion(CC)dyes for fabricating high-performance DSSCs,three organic dyes XL1-XL3 have been designed by varying the position and number of theβ-hexylthiophene(HT)bridges,and these organic dye units are covalently linked with our previously reported porphyrin dye XW10 to construct the corresponding CC dyes XW74-XW76.Among the organic dyes,XL3 contains twoβ-hexylthiophene units at both the donor and acceptor parts and thus possesses stronger light-harvesting capability in the green light region.Because of the most complementary absorption between XL3 and XW10 as well as the excellent photovoltaic behavior of the individual XL3 dye,the corresponding CC dye XW76 affords the best PCE(10.78%)among all the CC dyes.Upon coadsorption with CDCA,XW76 affords a highest PCE of 11.35%,which outperforms the previous cosensitization system of XW10+WS-5.This work provides an approach for developing efficient DSSCs based on CC dyes composed of an organic dye unit with suitableπspacers inserted at appropriate positions.展开更多
Cytokines mediate their pleiotropic actions by binding to and activating theircell-surface receptors.So far,people have learned much about their biological characteristics,biochemical profile,and the interaction or mo...Cytokines mediate their pleiotropic actions by binding to and activating theircell-surface receptors.So far,people have learned much about their biological characteristics,biochemical profile,and the interaction or modulation between cytokines and theirreceptors as well.However,people have no idea about what relationship of cytokines withtheir receptors in phylogeny exists.展开更多
Distinguished vips,Ladies and gentlemen,Friends,Good morning. I am delighted to join you at the first Wanshou Dialogue on Global Security and share with you our view on the security situation both internationally an...Distinguished vips,Ladies and gentlemen,Friends,Good morning. I am delighted to join you at the first Wanshou Dialogue on Global Security and share with you our view on the security situation both internationally and in the Asia-Pacific region.Our world is undergoing profound changes unseen in a century. The trends of global multi-polarity, economic globalization,IT application.展开更多
To win the decisive battle and overcome poverty,we must tackle the key deep poverty-stricken areas.How difficult are the deep poverty-stricken areas nowadays?How effective are these areas in overcoming poverty?Report...To win the decisive battle and overcome poverty,we must tackle the key deep poverty-stricken areas.How difficult are the deep poverty-stricken areas nowadays?How effective are these areas in overcoming poverty?Reporters’survey found that in every battlefield to overcome poverty,and on every road to prosperity,concerted efforts from many sides are inseparable-the government’s efforts.展开更多
主要介绍了BIM(Building Information Modeling)技术以及装配式建筑,并结合实际装配式建筑案例工程在BIM技术的运用中产生的价值开展研究。研究结果表明:BIM技术在装配式建筑中应用与构件生产和安装十分适用,不仅能够精准定义其尺寸,还...主要介绍了BIM(Building Information Modeling)技术以及装配式建筑,并结合实际装配式建筑案例工程在BIM技术的运用中产生的价值开展研究。研究结果表明:BIM技术在装配式建筑中应用与构件生产和安装十分适用,不仅能够精准定义其尺寸,还可以为预留的空洞和开槽等相关精细作业提前做好设计工作。BIM技术的应用对于减少传统施工中的不可预见问题,故可以提高工作效率。通过可视化的三维模型与进度和成本的关联,模拟建造过程可以直接反应建造情况,从设计、生产到施工密切配合,其协同性为合理施工提供了保障和支持。展开更多
N-Alkylhydroxylamines have been shown to undergo a stereospecific cis addition to 1-phenyl-2 -nitropropene compounds, whereas the corresponding O-alkylhydroxylamines give no diastereoselectivity. The concerted additio...N-Alkylhydroxylamines have been shown to undergo a stereospecific cis addition to 1-phenyl-2 -nitropropene compounds, whereas the corresponding O-alkylhydroxylamines give no diastereoselectivity. The concerted addition mechanism was provided to explain the difference.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant No.32060310)a grant from the Department of Education of Guangxi.
文摘The mitochondrial genome is a prominent research topic due to its indispensable role in organisms and its application in many research disciplines.However,few studies have investigated intraspecies mitogenomic variation.In this study,69 mitogenomes of the Black-throated Tit(Aegithalos concinnus)were assembled and annotated from a large number of short reads generated using high-throughput sequencing technology.Comparative analyses revealed that mitogenomic characteristics such as length,gene and nucleotide composition,codon usage,and duplicated control regions were relatively conserved despite substantial intraspecies morphological changes.Yet,all the individuals from the subspecies A.c.iredalei had one more nucleotide in the 12S rRNA than the other studied subspecies.Phylogenetic analyses showed five distinct lineages based on the complete mitogenomes and the 13 combined protein-coding genes,whereas only four lineages were observed when using the duplicate control regions.Most interestingly,each lineage had both copies of the control regions of the comprising individuals,indicating that the paralogous control regions were more similar than the orthologous sequences from the distinct lineages.This suggested the control regions had undergone concerted evolution.The Black-throated Tit has complex evolutionary history and needs further investigating the taxonomic status of these lineages,as well as the underlying evolutionary processes.Our findings call for more research on intraspecies mitogenomic variation.
基金supported by the National Key Research and Development Program(2021YFB2500210)the Beijing Municipal Natural Science Foundation(Z20J00043)+4 种基金the National Natural Science Foundation of China(22109086 and 21825501)the China Postdoctoral Science Foundation(2021TQ0161 and 2021 M691709)the Guoqiang Institute at Tsinghua University(2020GQG1006)the support from the Shuimu Tsinghua Scholar Program of Tsinghua Universitythe support from the Tsinghua National Laboratory for Information Science and Technology for theoretical simulations。
文摘Solid-state batteries have received increasing attention in scientific and industrial communities,which benefits from the intrinsically safe solid electrolytes(SEs).Although much effort has been devoted to designing SEs with high ionic conductivities,it is extremely difficult to fully understand the ionic diffusion mechanisms in SEs through conventional experimental and theoretical methods.Herein,the temperature-dependent concerted diffusion mechanism of ions in SEs is explored through machinelearning molecular dynamics,taking Li_(10)GeP_(2)S_(12) as a prototype.Weaker diffusion anisotropy,more disordered Li distributions,and shorter residence time are observed at a higher temperature.Arrhenius-type temperature dependence is maintained within a wide temperature range,which is attributed to the linear temperature dependence of jump frequencies of various concerted diffusion modes.These results provide a theoretical framework to understand the ionic diffusion mechanisms in SEs and deepen the understanding of the chemical origin of temperature-dependent concerted diffusions in SEs.
基金This work was financially supported by NSFC (Nos. 50073028, 29974036 and 20174047).
文摘A novel soluble regular ladder poly（benzoyl-3-aminopropyl） silsesquioxane （LPBAS） was facilely prepared under effective assistance of concerted H-bonding self-assembly of amido groups of side chains and silanol groups, respectively, of a new template monomer [1,3-bis（benzoyl-3-aminopropyl）-1,1,3,3-tetraethoxydisiloxane] （M）. The ordered ladder structure of LPBAS is manifested in： （1） the presence of two Bragg peaks representing the ladder width （d） and ladder thickness （t） in X-ray diffraction （XRD） pattern; （2） narrow base-line width （w = 6） of resonance absorption for -CH2SiO3/2 moiety in 29Si-NMR and （3） high glass transition temperature Tg = 1 12℃ in differential scanning calorimetry （DSC） analysis.
文摘The rearrangement of α-substituted phenyl-α, α′-dimethoxypropanones (R1) was recently proved to he an [1, 3] siqmatropic migration of methoxy group by study of LFER, solvent effect, crossover experiment, and by other means. The rearrangement catalysed by trace of totuenesulfonic acid gave a negligible value of the Hammett reaction constant. Further experimental results show that the electronic effect of substituent on the aromatic ring for the rearrangement in neutral medium is much greater (Table 1). We propose sigmatropic migration
文摘Distinguished vips,Ladies and gentlemen,Dear friends,Good afternoon.Let me begin by extending my warmest welcome to all of you to this thematic session on peopleto-people connectivity on behalf of the International Department of the CPC Central Committee,the organizer of this event.Thanks to the concerted efforts
文摘THRONGS of people were overwhelmed by tears and cheers on December 12, 2015 as French Foreign Minister Laurent Fabius, president of the Paris climate change conference, struck a green gavel. It signaled the conclusion of a marathon 13- day negotiation between delegates representing nearly 200 different countries and regions, who had gathered in Paris. The representatives at the 2015 United Nations Climate Change Conference made a deal that will go down in history as a rare moment of worldwide cooperation in the face of a monumental challenge, But as fellow negotiators hugged each other in celebration, grave concerns lurked in the recesses of their minds - this was just the beginning of a war against climate change that is expected to last for generations.
基金financially supported by the National Natural Science Foundation of China(Nos.22131005,22201074,22075077 and 21971063)the Fundamental Research Funds for the Central Universities,Program of Shanghai Academic Research Leader(No.20XD1401400)+1 种基金Shanghai Rising-Star Program(No.23QA1402100)Natural Science Foundation of Shanghai(Nos.23ZR1415600,22ZR1416100).
文摘To develop efficient sensitizers for dye-sensitized solar cells(DSSCs),we recently reported doubly concerted companion(DCC)dye XW83 with a wrapped porphyrin sub-dye unit linked to an organic sub-dye unit through a flexible chain,which exhibits panchromatic absorption and excellent anti-aggregation ability.To further improve the absorption,we herein report XW87 and XW88 by inserting an ethynyl group into the organic sub-dye unit of XW83 near the donor and acceptor,respectively.For the corresponding organic dyes Z3 and Z4,the introduced ethynyl group improves their absorption,but induces aggravated charge recombination,leading to lowered power conversion efficiencies(PCEs).Similar to the organic dyes,the introduced ethynyl group improves the absorption of DCC dyes XW87 and XW88 as well.In addition,the ethynyl group near the acceptor of the organic sub-dye unit can be well protected by the long wrapping chains from the porphyrin unit.As a result,XW88 affords the highest JSC(21.84 mA/cm^(2)),V_(OC)(782 mV)and PCE(12.2%)among the DCC dyes.These results provide an effective method for developing efficient DSSC dyes by inserting an ethynyl group at a suitable position of a DCC dye.
基金the Humanities and Social Science Fund Project of Ministry of Education of China(No.20YJA790003)the Natural Science Foundation of Shandong Province(No.ZR2020MG039)the Future Plan for Young Scholars of Shandong University(No.2016WLJH05).
文摘We construct a connected network between China and the economies that are financially linked to it,based on the network topology of variance decompositions,and measure the cross-border contagion of financial risks among these economies.We then examine whether the concerted use of macroprudential policies mitigates the cross-border contagion of financial risks.The empirical results show that the tightening of macroprudential policies,especially counter-cyclical capital buffers and limits on credit growth,in economies with net spillover risk(e.g.the US and China).can reduce the cross-border spillover of domestic financial risks to other economies.The concerted use of macroprudential policies can contribute to global financial stability.However,the tightening of"capital"macroprudential policy tools will increase domestic cross-border absorption of financial risks.Hence,macroprudential regulation of cross-border capital flows must be strengthened.
基金This work was supported by the National Natural Science Foundation of China(Nos.22278324,51932007,22238009,U1905215,52073223,52073034,and 22208332)the Postdoctoral Science Foundation of China(No.2022M712946)the Natural Science Foundation of Hubei Province of China(No.2022CFA001).
文摘Constructing step-scheme(S-scheme)heterojunctions has become a popular strategy for efficient pho-tocatalytic H_(2)O_(2) generation.Herein,we in situ grew BiOBr nanosheets(NSs)on a Schiff-base covalent organic framework(COF)with largeπ-conjugated structures to prepare S-scheme BiOBr/COF photocat-alysts for H_(2)O_(2) synthesis.The highest photocatalytic H_(2)O_(2) production performance of the composite sample constituting the S-scheme heterojunction is 3749μmol g−1 h−1,which was 1.85 and 27 times the rates of COF and BiOBr,respectively.The construction of S-scheme heterojunction contributed to ef-ficient carrier transfer and separation in space and enhanced redox power.Moreover,the lying-down O_(2)-adsorption configuration on the COF surface favors the concerted two-electron O_(2) reduction process,which greatly reduced the reduction potential requirement for O_(2)-to-H_(2)O_(2) conversion.The synergy be-tween the S-scheme heterojunction and the unique O_(2)-COF interaction boosted photocatalytic H_(2)O_(2) pro-duction activity.
基金Project supported by the National Natural Science Foundation of China.
文摘The neutral theory raised by Motoo Kimura in 1968 asserts that 'the great majority of evolutionary changes at the molecular level, as revealed by comparative studies of protein and DNA sequences. are caused not by Darwinian selection but by random drift of selectively neutral or nearly neutral mutants'.
基金financially supported by the National Natural Science Foundation of China (Nos. 22131005, 21772041, 21971063 and 22075077)the Program of Shanghai Academic Research Leader (No. 20XD1401400)+1 种基金the Natural Science Foundation of Shanghai (No. 20ZR1414100)the Fundamental Research Funds for the Central Universities (No. 222201717003)
文摘To develop efficient concerted companion(CC)dyes for fabricating high-performance DSSCs,three organic dyes XL1-XL3 have been designed by varying the position and number of theβ-hexylthiophene(HT)bridges,and these organic dye units are covalently linked with our previously reported porphyrin dye XW10 to construct the corresponding CC dyes XW74-XW76.Among the organic dyes,XL3 contains twoβ-hexylthiophene units at both the donor and acceptor parts and thus possesses stronger light-harvesting capability in the green light region.Because of the most complementary absorption between XL3 and XW10 as well as the excellent photovoltaic behavior of the individual XL3 dye,the corresponding CC dye XW76 affords the best PCE(10.78%)among all the CC dyes.Upon coadsorption with CDCA,XW76 affords a highest PCE of 11.35%,which outperforms the previous cosensitization system of XW10+WS-5.This work provides an approach for developing efficient DSSCs based on CC dyes composed of an organic dye unit with suitableπspacers inserted at appropriate positions.
基金Project supported by the National Natural Science Foundation of China.
文摘Cytokines mediate their pleiotropic actions by binding to and activating theircell-surface receptors.So far,people have learned much about their biological characteristics,biochemical profile,and the interaction or modulation between cytokines and theirreceptors as well.However,people have no idea about what relationship of cytokines withtheir receptors in phylogeny exists.
文摘Distinguished vips,Ladies and gentlemen,Friends,Good morning. I am delighted to join you at the first Wanshou Dialogue on Global Security and share with you our view on the security situation both internationally and in the Asia-Pacific region.Our world is undergoing profound changes unseen in a century. The trends of global multi-polarity, economic globalization,IT application.
文摘To win the decisive battle and overcome poverty,we must tackle the key deep poverty-stricken areas.How difficult are the deep poverty-stricken areas nowadays?How effective are these areas in overcoming poverty?Reporters’survey found that in every battlefield to overcome poverty,and on every road to prosperity,concerted efforts from many sides are inseparable-the government’s efforts.
文摘主要介绍了BIM(Building Information Modeling)技术以及装配式建筑,并结合实际装配式建筑案例工程在BIM技术的运用中产生的价值开展研究。研究结果表明:BIM技术在装配式建筑中应用与构件生产和安装十分适用,不仅能够精准定义其尺寸,还可以为预留的空洞和开槽等相关精细作业提前做好设计工作。BIM技术的应用对于减少传统施工中的不可预见问题,故可以提高工作效率。通过可视化的三维模型与进度和成本的关联,模拟建造过程可以直接反应建造情况,从设计、生产到施工密切配合,其协同性为合理施工提供了保障和支持。
文摘N-Alkylhydroxylamines have been shown to undergo a stereospecific cis addition to 1-phenyl-2 -nitropropene compounds, whereas the corresponding O-alkylhydroxylamines give no diastereoselectivity. The concerted addition mechanism was provided to explain the difference.
