Tetrabutylammonium fluoride （TBAF） effectively facilitated a denitrative substitution reaction of electron-deficient nitroarenes with phenylthiotrimethylsilane （PhSTMS） under mild and base-free neutral conditions ...Tetrabutylammonium fluoride （TBAF） effectively facilitated a denitrative substitution reaction of electron-deficient nitroarenes with phenylthiotrimethylsilane （PhSTMS） under mild and base-free neutral conditions at room temperature, providing a practical and efficient synthesis of useful unsymmetrical diaryl thioethers. Nitroarenes bearing ortho- and para-positioned electron-withdrawing groups are the most reactive substrates, indicating that this reaction most possibly proceeded via the nucleophilic aromatic substitution （SNAr） mechanism.展开更多
2.25Cr–1Mo–0.25V base metal(BM)and welded metal(WM)with different temper embrittlement states were obtained by isothermal temper embrittlement test.The ductile–brittle transition temperature and the carbide size of...2.25Cr–1Mo–0.25V base metal(BM)and welded metal(WM)with different temper embrittlement states were obtained by isothermal temper embrittlement test.The ductile–brittle transition temperature and the carbide size of temper embrittled 2.25Cr–1Mo–0.25V BM and WM increased with the isothermal tempering time.The increase in temper embrittlement time leads to a decrease in yield strength(YS)and ultimate tensile strength(UTS).Hydrogen embrittlement(HE)can decrease the ductility and increase YS and UTS of the material.The hydrogen embrittlement sensitivity and microstructure analysis both show a combined effect of HE and temper embrittlement.The deeper the temper embrittlement,the more sensitive the material to HE.When the hydrogen content in the material is low,the WM is less susceptible to HE due to its welding defects.展开更多
基金Supported by National Basic Research Program of China grant(to Zhu B),No.2011CB505201National Natural Science Foundation of China No.81130063 and No.81173345(to Zhu B and Gao X)
文摘AIM: To investigate the effect and mechanism of acupuncture at heterotopic acupoints on jejunal motility, particularly in pathological conditions.
基金the National Natural Science Foundation of China(No.20902070)Natural Science Foundation of Zhejiang Province(No.Y4100579)Qianjiang Talents Program of Zhejiang Province(No.QJD0902004) for financial supports
文摘Tetrabutylammonium fluoride （TBAF） effectively facilitated a denitrative substitution reaction of electron-deficient nitroarenes with phenylthiotrimethylsilane （PhSTMS） under mild and base-free neutral conditions at room temperature, providing a practical and efficient synthesis of useful unsymmetrical diaryl thioethers. Nitroarenes bearing ortho- and para-positioned electron-withdrawing groups are the most reactive substrates, indicating that this reaction most possibly proceeded via the nucleophilic aromatic substitution （SNAr） mechanism.
基金the financial supports of National Key R&D Program of China(No.2018YFC0808800).
文摘2.25Cr–1Mo–0.25V base metal(BM)and welded metal(WM)with different temper embrittlement states were obtained by isothermal temper embrittlement test.The ductile–brittle transition temperature and the carbide size of temper embrittled 2.25Cr–1Mo–0.25V BM and WM increased with the isothermal tempering time.The increase in temper embrittlement time leads to a decrease in yield strength(YS)and ultimate tensile strength(UTS).Hydrogen embrittlement(HE)can decrease the ductility and increase YS and UTS of the material.The hydrogen embrittlement sensitivity and microstructure analysis both show a combined effect of HE and temper embrittlement.The deeper the temper embrittlement,the more sensitive the material to HE.When the hydrogen content in the material is low,the WM is less susceptible to HE due to its welding defects.
