Proton-exchange membrane water electrolysis(PEM WE)is a particularly promising technology for renewable hydrogen produc-tion.However,the excessive passivation of the gas diffusion layer(GDL)will seriously affect the h...Proton-exchange membrane water electrolysis(PEM WE)is a particularly promising technology for renewable hydrogen produc-tion.However,the excessive passivation of the gas diffusion layer(GDL)will seriously affect the high surface-contact resistance and result in energy losses.Thus,a mechanism for improving the conductivity and interface stability of the GDL is an urgent issue.In this work,we have prepared a hydrophilic and corrosion resistant conductive composite protective coating.The polydopamine(PDA)film on the Ti surface,which was obtained via the solution oxidation method,ensured that neither micropores nor pinholes existed in the final hybrid coatings.In-situ reduced gold nanoparticles(AuNPs)improved the conductivity to achieve the desired interfacial contact resistance and further enhanced the corrosion resistance.The surface composition of the treated samples was investigated using scanning electron microscopy(SEM),transmis-sion electron microscopy(TEM),X-ray diffraction(XRD),and Fourier transform infrared spectroscopy(FTIR).The results indicated that the optimized reaction conditions included a pH value of 3 of HAuCl_(4) solution with PDA deposition(48 h)on papers and revealed the lowest con-tact resistance(0.5 mΩ·cm^(2))and corrosion resistance(0.001μA·cm^(−2))in a 0.5 M H_(2)SO_(4)+2 ppm F−solution(1.7 V vs.RHE)among all the modified specimens,where RHE represents reversible hydrogen electrode.These findings indicated that the Au-PDA coating is very appropriate for the modification of Ti GDLs in PEM WE systems.展开更多
Eastern Han Dynasty(25 AD-220 AD)Height:46.2 cm,length:36.4 cm.Silver-inlaid bronze.The bronze lamp is in the shape of an ox with its head down and tail up,and with a lamp holder standing on its back.On the top of the...Eastern Han Dynasty(25 AD-220 AD)Height:46.2 cm,length:36.4 cm.Silver-inlaid bronze.The bronze lamp is in the shape of an ox with its head down and tail up,and with a lamp holder standing on its back.On the top of the lamp holder,there is a round bronze dish,and on the dish,there are two vertical arc-shaped lampshades which are rotatable and can be used to adjust the lighting direction.On the vertical lampshades,there is a bowl-shaped cover,and on the top of the cover.展开更多
Bone-inlaid wooden art is a very old artistic form that has a strong artistic appeal and local flavor. It can be traced back to the Longshan Culture in the late Neolithic Age, and becomes mature in the late Qing Dynas...Bone-inlaid wooden art is a very old artistic form that has a strong artistic appeal and local flavor. It can be traced back to the Longshan Culture in the late Neolithic Age, and becomes mature in the late Qing Dynasty. As time lapses, however, bone-inlaid wooden art is gradually out of sight. It was not until June 2008 when Ningbo bone-inlaid wooden art was included in the "second batch of national intangible cultural heritage protection list" that it once again caused social concern. Ningbo bone-inlaid wooden art has a long history, and its craftsmanship is complex. Many bone-inlaid wooden works in Ningbo have been damaged more or less. Therefore, workers in the field of heritage protection should undertake a more systematic protection and repair work based on scientific research, making contributions to the heritage and development of intangible cultural heritage.展开更多
The late Warring States Period (475 B.C-221 B.C)Caliber diameter:18.2 cm Bronze with inlaid silver The surfaces of the utensil body and the lid are decorated with cloud patterns by using the inlaid gold or silver fila...The late Warring States Period (475 B.C-221 B.C)Caliber diameter:18.2 cm Bronze with inlaid silver The surfaces of the utensil body and the lid are decorated with cloud patterns by using the inlaid gold or silver filaments and flakes. The decorative patterns are very slim and extremely exquisite.展开更多
【目的】研究兰州市黄壤土条件下不同滴灌方式对设施黄瓜生长发育及产量的影响。【方法】分别运用滴箭式膜下滴灌、内镶贴片式膜下滴灌、垄膜沟灌及水肥耦合处理方式对设施黄瓜理化性状、产量和品质的影响,采用三因素三水平正交试验,利...【目的】研究兰州市黄壤土条件下不同滴灌方式对设施黄瓜生长发育及产量的影响。【方法】分别运用滴箭式膜下滴灌、内镶贴片式膜下滴灌、垄膜沟灌及水肥耦合处理方式对设施黄瓜理化性状、产量和品质的影响,采用三因素三水平正交试验,利用方差和回归分析得出三因素影响的最优组合方案。【结果】三因素对植株理化性状的影响不大,但对其果实的理化性状、产量、品质和水分利用率极显著,影响顺序为滴灌模式>灌水量>施肥量。三因素最优组合为滴箭式膜下滴灌:灌水量66.13 m 3/hm^(2),施肥量为25.2 kg/hm^(2),日光温室黄瓜的最高产量为256942.52 kg/hm^(2)。【结论】滴箭式膜下滴灌和内镶贴片式膜下滴灌均能在不影响设施黄瓜产量和品质的前提下,节水节肥节本,其中以滴箭式膜下滴灌效果最佳。展开更多
Gold and silver inlaying is a metal processing technique popular during the Spring and Autumn Period (770-476 B. C.) and the Warring States Period (475-221 B. C.). Patterns on the surface of the bronze figure are chis...Gold and silver inlaying is a metal processing technique popular during the Spring and Autumn Period (770-476 B. C.) and the Warring States Period (475-221 B. C.). Patterns on the surface of the bronze figure are chiselled out and gold and silver threads (which can be as thin as hair) are inlaid. Finally the whole figure is filed and polished resulting in a splendid artistic work highlighting the different colours of the three different kinds of metal. The artifact shown here was unearthed from Ningxia'...展开更多
基金supported by the National Key Research and Development Program of China(No.2018 YFB1502403)。
文摘Proton-exchange membrane water electrolysis(PEM WE)is a particularly promising technology for renewable hydrogen produc-tion.However,the excessive passivation of the gas diffusion layer(GDL)will seriously affect the high surface-contact resistance and result in energy losses.Thus,a mechanism for improving the conductivity and interface stability of the GDL is an urgent issue.In this work,we have prepared a hydrophilic and corrosion resistant conductive composite protective coating.The polydopamine(PDA)film on the Ti surface,which was obtained via the solution oxidation method,ensured that neither micropores nor pinholes existed in the final hybrid coatings.In-situ reduced gold nanoparticles(AuNPs)improved the conductivity to achieve the desired interfacial contact resistance and further enhanced the corrosion resistance.The surface composition of the treated samples was investigated using scanning electron microscopy(SEM),transmis-sion electron microscopy(TEM),X-ray diffraction(XRD),and Fourier transform infrared spectroscopy(FTIR).The results indicated that the optimized reaction conditions included a pH value of 3 of HAuCl_(4) solution with PDA deposition(48 h)on papers and revealed the lowest con-tact resistance(0.5 mΩ·cm^(2))and corrosion resistance(0.001μA·cm^(−2))in a 0.5 M H_(2)SO_(4)+2 ppm F−solution(1.7 V vs.RHE)among all the modified specimens,where RHE represents reversible hydrogen electrode.These findings indicated that the Au-PDA coating is very appropriate for the modification of Ti GDLs in PEM WE systems.
文摘Eastern Han Dynasty(25 AD-220 AD)Height:46.2 cm,length:36.4 cm.Silver-inlaid bronze.The bronze lamp is in the shape of an ox with its head down and tail up,and with a lamp holder standing on its back.On the top of the lamp holder,there is a round bronze dish,and on the dish,there are two vertical arc-shaped lampshades which are rotatable and can be used to adjust the lighting direction.On the vertical lampshades,there is a bowl-shaped cover,and on the top of the cover.
基金Sponsored by Zhejiang Provincial Heritage Protection Technology Project(2017020)
文摘Bone-inlaid wooden art is a very old artistic form that has a strong artistic appeal and local flavor. It can be traced back to the Longshan Culture in the late Neolithic Age, and becomes mature in the late Qing Dynasty. As time lapses, however, bone-inlaid wooden art is gradually out of sight. It was not until June 2008 when Ningbo bone-inlaid wooden art was included in the "second batch of national intangible cultural heritage protection list" that it once again caused social concern. Ningbo bone-inlaid wooden art has a long history, and its craftsmanship is complex. Many bone-inlaid wooden works in Ningbo have been damaged more or less. Therefore, workers in the field of heritage protection should undertake a more systematic protection and repair work based on scientific research, making contributions to the heritage and development of intangible cultural heritage.
文摘The late Warring States Period (475 B.C-221 B.C)Caliber diameter:18.2 cm Bronze with inlaid silver The surfaces of the utensil body and the lid are decorated with cloud patterns by using the inlaid gold or silver filaments and flakes. The decorative patterns are very slim and extremely exquisite.
文摘【目的】研究兰州市黄壤土条件下不同滴灌方式对设施黄瓜生长发育及产量的影响。【方法】分别运用滴箭式膜下滴灌、内镶贴片式膜下滴灌、垄膜沟灌及水肥耦合处理方式对设施黄瓜理化性状、产量和品质的影响,采用三因素三水平正交试验,利用方差和回归分析得出三因素影响的最优组合方案。【结果】三因素对植株理化性状的影响不大,但对其果实的理化性状、产量、品质和水分利用率极显著,影响顺序为滴灌模式>灌水量>施肥量。三因素最优组合为滴箭式膜下滴灌:灌水量66.13 m 3/hm^(2),施肥量为25.2 kg/hm^(2),日光温室黄瓜的最高产量为256942.52 kg/hm^(2)。【结论】滴箭式膜下滴灌和内镶贴片式膜下滴灌均能在不影响设施黄瓜产量和品质的前提下,节水节肥节本,其中以滴箭式膜下滴灌效果最佳。
文摘Gold and silver inlaying is a metal processing technique popular during the Spring and Autumn Period (770-476 B. C.) and the Warring States Period (475-221 B. C.). Patterns on the surface of the bronze figure are chiselled out and gold and silver threads (which can be as thin as hair) are inlaid. Finally the whole figure is filed and polished resulting in a splendid artistic work highlighting the different colours of the three different kinds of metal. The artifact shown here was unearthed from Ningxia'...
