Carbon nitride films were deposited on Si (100) substrates using plasma-enhanced chemical vapor deposition (PECVD) technique from CH4 and N2 at different applied dc bias voltage. The microstructure, composition and ch...Carbon nitride films were deposited on Si (100) substrates using plasma-enhanced chemical vapor deposition (PECVD) technique from CH4 and N2 at different applied dc bias voltage. The microstructure, composition and chemical bonding of the resulting films were characterized by Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The mechanical properties such as hardness and elastic modulus of the films were evaluated using nano-indentation. As the results, the Raman spectra, showing the G and D bands, indicate the amorphous structure of the films. XPS and FTIR measurements demonstrate the existence of various carbon-nitride bonds in the films and the hydrogenation of carbon nitride phase. The composition ratio of N to C, the nano-hardness and the elastic modulus of the carbon nitride films increase with increasing dc bias voltage and reach the maximums at a dc bias voltage of 300 V, then they decrease with further increase of the dc bias voltage. Moreover, the XRD analyses indicate that the carbon nitride film contains some polycrystalline C3N4 phase embedded in the amorphous matrix at optimized deposition condition of dc bias voltage of 300 V.展开更多
Amorphous carbon nanoparticles （a-CNPs） on a multi-walled carbon nanotube （MWCNT） film, deposited on a silicon substrate, were synthesized using an electrodeposition combination from a methanol suspension of polyd...Amorphous carbon nanoparticles （a-CNPs） on a multi-walled carbon nanotube （MWCNT） film, deposited on a silicon substrate, were synthesized using an electrodeposition combination from a methanol suspension of polydiallyldimethylammonium chloride-modified MWCNTs. A low-voltage electropho- retic deposition of the MWCNTs and a high-voltage electrochemical deposition of the a-CNPs were carried out to yield homogenously attached a-CNPs on the surfaces of the MWCNTs, and form a composite film with good adhesion to the substrate. This scalable technology can produce a large area of a-CNP/MWCNT film. And the field emission investigations show that the a-CNP/MWCNT film has turn- on electric field of 3.17 V μm- 1 （at 10 μA cm-2） and threshold field of 4.62 V μm-1 （at 1 mA cm-2）, which are lower than those of the MWCNT film. The a-CNP/MWCNT film can be deposited simply with large areas and may be a promising cathode material applied in field emission displays.展开更多
试验提出了用GC-MS检测食品中4种对羟基本甲酸酯类化合物的方法。样品经酸化后,加入乙腈提取,提取液离心,过Oasis PRIME HLB小柱后上机测定。在最佳试验条件下,4种化合物分离效果好,且在各自梯度范围内线性关系良好,相关系数R≥0.9996...试验提出了用GC-MS检测食品中4种对羟基本甲酸酯类化合物的方法。样品经酸化后,加入乙腈提取,提取液离心,过Oasis PRIME HLB小柱后上机测定。在最佳试验条件下,4种化合物分离效果好,且在各自梯度范围内线性关系良好,相关系数R≥0.9996。以空白蚝油、果汁饮料、鱼罐头样品为基体,在0.1,0.5和2.0 mg/kg三个添加水平下,平均回收率在90.1%~101.4%之间,测定值的相对标准偏差(RSD)在1.76%~6.83%之间。4种对羟基苯甲酸酯类化合物的方法检出限均为0.02 mg/kg。该方法简单高效、准确,适用于除油脂含量特别高的样品以外的大部分食品中4种对羟基苯甲酸酯含量的检测。展开更多
基金supported by the National Key Research and Development Program of China(2021YFA1200700)the National Natural Science Foundation of China(22173019,22033002 and 92056112)the Fundamental Research Funds for the Central Universities(2242022R40072)。
基金Projects(59925513 50323007) supported by the National Natural Science Foundation of China+2 种基金 project(G1999065005) supported by the National Basic Research Program of China project(2003AA305670) supported by the Hi-tech Research and Development Program of China and supported by "Top Hundred Talents Program" of Chinese Academy of Sciences
文摘Carbon nitride films were deposited on Si (100) substrates using plasma-enhanced chemical vapor deposition (PECVD) technique from CH4 and N2 at different applied dc bias voltage. The microstructure, composition and chemical bonding of the resulting films were characterized by Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The mechanical properties such as hardness and elastic modulus of the films were evaluated using nano-indentation. As the results, the Raman spectra, showing the G and D bands, indicate the amorphous structure of the films. XPS and FTIR measurements demonstrate the existence of various carbon-nitride bonds in the films and the hydrogenation of carbon nitride phase. The composition ratio of N to C, the nano-hardness and the elastic modulus of the carbon nitride films increase with increasing dc bias voltage and reach the maximums at a dc bias voltage of 300 V, then they decrease with further increase of the dc bias voltage. Moreover, the XRD analyses indicate that the carbon nitride film contains some polycrystalline C3N4 phase embedded in the amorphous matrix at optimized deposition condition of dc bias voltage of 300 V.
基金support from the Top Hundred Talents Program of Chinese Academy of Sciencesthe National Nature Science Foundation of China(No.51002161)
文摘Amorphous carbon nanoparticles （a-CNPs） on a multi-walled carbon nanotube （MWCNT） film, deposited on a silicon substrate, were synthesized using an electrodeposition combination from a methanol suspension of polydiallyldimethylammonium chloride-modified MWCNTs. A low-voltage electropho- retic deposition of the MWCNTs and a high-voltage electrochemical deposition of the a-CNPs were carried out to yield homogenously attached a-CNPs on the surfaces of the MWCNTs, and form a composite film with good adhesion to the substrate. This scalable technology can produce a large area of a-CNP/MWCNT film. And the field emission investigations show that the a-CNP/MWCNT film has turn- on electric field of 3.17 V μm- 1 （at 10 μA cm-2） and threshold field of 4.62 V μm-1 （at 1 mA cm-2）, which are lower than those of the MWCNT film. The a-CNP/MWCNT film can be deposited simply with large areas and may be a promising cathode material applied in field emission displays.
文摘试验提出了用GC-MS检测食品中4种对羟基本甲酸酯类化合物的方法。样品经酸化后,加入乙腈提取,提取液离心,过Oasis PRIME HLB小柱后上机测定。在最佳试验条件下,4种化合物分离效果好,且在各自梯度范围内线性关系良好,相关系数R≥0.9996。以空白蚝油、果汁饮料、鱼罐头样品为基体,在0.1,0.5和2.0 mg/kg三个添加水平下,平均回收率在90.1%~101.4%之间,测定值的相对标准偏差(RSD)在1.76%~6.83%之间。4种对羟基苯甲酸酯类化合物的方法检出限均为0.02 mg/kg。该方法简单高效、准确,适用于除油脂含量特别高的样品以外的大部分食品中4种对羟基苯甲酸酯含量的检测。
