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| 1 | In situ investigation of SiC powder's microwave sintering by SR-CT technique显示文摘Microwave sintering is being developed as a novel technique for the preparation of dense structural ceramics,but the mature theory has not been established due to the technical difficulties.The synchrotron radiation X-ray computed tomography(SR-CT) technique was introduced for the first time into the study of microwave sintering to in-situ observe the microstructure evolution of silicon carbide(SiC) material in this paper.By applying the SR-CT technique,the reconstructed 2D and 3D images of the specimen were obtained and the double logarithm curve of mean neck size and time(Ln(x)-Ln(t)) were obtained from these reconstructed images.Various sintering phenomena including sintering neck growth during microwave treatment were observed from the reconstructed images.Furthermore,the differences in microstructure evolution and sintering kinetics between microwave and conventional sintering were analyzed based on the reconstructed images and the Ln(x)-Ln(t) curve.1) The sharp surface of grains near the contact region distinctly grew blunt and the sintering neck growth between these grains were obviously observed at the early stage.Besides,the larger particles grew faster than smaller ones.The main reason for these phenomena may be the micro-focusing effect of electric fields.2) During each of the three sintering stages,the sintering kinetics curve of double logarithm relationship between mean neck size and time shows a good linear relationship,but at the middle stage the slope of the curve increases dramatically,which is quite larger than conventional sintering.The preliminary interpretation for these extraordinary phenomena has been discussed in details. | LI YongCun XU Feng HU XiaoFang QU HongYan MIAO Hong ZHANG Zhong XIAO TiQiao | 2011 | Science China(Technological Sciences)2011，54，6： | 4 |
| 2 | Mudcake effects on wellbore stress and fracture initiation pressure and implications for wellbore strengthening显示文摘Although a large volume of mudcake filtration test data is available in the literature, effects of mudcake on wellbore strengthening cannot be quantified without incorporating the data into a stress-analysis model. Traditional models for determining fracture initiation pressure(FIP) either consider a wellbore with an impermeable mudcake or with no mudcake at all. An analytical model considering permeable mudcake is proposed in this paper. The model can predict pore pressure and stress profiles around the wellbore, and consequently the FIP, for different mudcake thickness, permeability, and strength. Numerical examples are provided to illustrate the effects of these mudcake parameters. The results show that a low-permeability mudcake enhances FIP, mainly through restricting fluid seepage and pore pressure increase in the nearwellbore region, rather than by mudcake strength. Fluid loss pressure(FLP) should be distinguished from FIP when a mudcake is present on the wellbore wall. Fracture may occur behind the mudcake at FIP without mudcake rupture. The small effect of mudcake strength on FIP does not mean its effect on FLP is small too. Mudcake strength may play an important role in maintaining integrity of the wellbore once a fracture has initiated behind the mudcake. | Yongcun Feng Xiaorong Li K.E.Gray | 2018 | Petroleum Science2018，15，2： | 3 |
| 3 | siRNA of ADAM17 gene induces apoptosis,proliferation inhibition and enhances the effects of genistein on HepG2 cells显示文摘Objective:To investigate the effects of siRNA of ADAM17 gene and genistein on apoptosis and the inhibition of proliferation in HepG2 cells in an attempt to seek an effective therapy for hepatocellular carinoma. Methods:Cells were divided into control groups and experimental groups and siRNA was used to silence the ADAM17 gene, alone and in combination with genistein. Cells were harvested at several time periods and assessed for proliferation and apoptosis. Proliferation was assayed by MTT at 24, 48, 72 and 96 hours following treatment and apoptosis was assessed by flow cytometric analysis at 48 hours. Results:In siRNA groups, proliferation of cells was significantly inhibited compared to the control groups at 24, 48 and 72 hours(P < 0.05), and apoptosis was significantly increased at 48 hours(P < 0.01); In genistein groups, proliferation was inhibited at 24, 48, 72 and 96 hours, and the apoptosis ratio was significantly increased at 48 hours(P < 0.01); while in the groups that received the combination of siRNA transfection and genistein treatment, there was a further significant decrease of proliferation and increase in apoptosis compared with either treatment alone. Conclusion:The ADAM17 gene could be an effective target, and genistein could be a useful agent, in the treatment of hepatocellular carcinoma. siRNA of ADAM17 gene and genistein both inhibited HepG2 cells proliferation and promoted apoptosis, and further, the combination of these treatments had a greater effect than either treatment alone. | Yongcun Liu Zuoren Wang Yuqiang Ji Feng Li | 2009 | Journal of Nanjing Medical University2009，23，2： | 2 |
| 4 | Temporal and spatial variability of soil organic matter and total nitrogen in an agricultural ecosystem as affected by farming practices显示文摘 | Biao Huang Weixia Sun Yongcun Zhao Jing Zhu Rongqing Yang Zhong Zou Feng Ding Jianping Su | 2007 | Geoderma2007，，3： | 2 |
| 5 | Temporal and spatial variability of soil organic matter and total nitrogen in an agricultural ecosystem as affected by farming practices显示文摘 | Biao Huang Weixia Sun Yongcun Zhao Jing Zhu Rongqing Yang Zhong Zou Feng Ding Jianping Su | 2007 | Geoderma2007，，3： | 1 |
| 6 | Temporal and spatial variability of soil organic matter and total nitrogen in an agricultural ecosystem as affected by farming practices 显示文摘 | Huang Biao Sun Weixia Zhao Yongcun Zhu Jing Yang Rongqing Zou Zhong Ding Feng Su Jianping | 2007 | Geoderma2007，139，： | 1 |
| 7 | In situ SR-CT Experimental Study on the Directional Sintering of High-Temperature Superconductor YBCO Materials in the Microwave Fields显示文摘YBa_(2)Cu_(3)O_(7-x)(YBCO)is a kind of high-temperature superconducting material that has important application in information,energy,medical treatment,etc.,and the superconducting properties of YBCO are closely related to its internal microstructure.In this study,the microwave heating method was adopted to prepare the YBCO materials.The internal 3 D online evolution observation based on the synchrotron radiation computed tomography technology shows that there was directional grain growth phenomenon of YBCO during microwave sintering process.In local regions with special microstructure,these particles grew to the same point.Here,the theoretical models of single and multiple particles in the microwave electromagnetic fields were established.Based on these theoretical models and finite element analysis,it shows that the YBCO particles can modulate the distribution of electromagnetic fields,resulting in the significantly higher electric field intensity at the particle junctions than other regions.Moreover,there were very high electric field intensity and temperature gradients in the directions of particle growth.These factors were crucial in directional sintering.These results will provide theoretical basis and technical guidance for the controllable preparation and performance optimization of the internal microstructure of superconducting materials in the preparation process. | Liangyuan Wang Lei Shen Yongcun Li Yuanjie Wang Yu Xiao Xingyi Zhang Feng Xu Xiaofang Hu | 2022 | Acta Metallurgica Sinica(English Letters)2022，35，1： | 0 |
| 8 | Fracture development during disposal of hazardous drilling cuttings by deep underground injection: A review显示文摘Drilling fluids with complicated compositions are becoming more common as the oil and gas industry develops. The production of hazardous cuttings is increasing, which not only stifles the oil and gas industry’s development but also poses a severe environmental threat. Deep underground re-injection is a cost-effective and efficient method for dealing with hazardous cuttings. Numerous experiments and numerical studies on cuttings re-injection have been conducted in the past thirty years. However, there is still a divergence of views on the fracture development in the process of cuttings re-injection. A comprehensive review of existing studies is necessary to help researchers advance this technology. This paper provides a review of the fundamental studies on fracture behaviors during the deep underground re-injection of drilling cuttings. The limitations of the existing studies are also discussed to inspire new research endeavors. | Shuai Zhang Yongcun Feng Bin Li Jingen Deng Tie Geng Jincai Zhang | 2022 | Journal of Rock Mechanics and Geotechnical Engineering2022，14，5： | 0 |
| 9 | S/N-co-doped graphite nanosheets exfoliated via three-roll milling for high-performance sodium/potassium ion batteries显示文摘Due to its larger ionic radius,further studies are needed before graphite can be used as an anode for sodium/potassium-ion batteries(SIBs/KIBs).It is believed that doping and increasing the layer spacing can improve the Na+/K+storage.Herein,S/N co-doped graphite nanosheets(GNS)with an enlarged interlayer spacing of 0.39 nm were prepared via exfoliation with three-roll milling(TRM)combined with thiourea heated at different temperatures.This method generates abundant defects and active sites for GNS,as well as facilitates rapid access and transport of electrolytes and electrons/ions.The electrochemical results show that the S/N-doped GNS exfoliated 15 times and heated at 600°C(SNGNS15-600)with thiourea as the electrode delivers a discharge capacity of 94 mAh g–1 over 6000 cycles at 10 A g–1 with an enhanced rate capability and stable performance for application in SIBs.Calculations using density functional theory show that the increased interlayer spacing by TRM and S,N co-doping enhances the adsorption energies of Na+on graphite,thus improving the Na+storage.As the anode for KIBs,the SNGNS15-600 electrode has a capacity of 142 mAh g–1 after 5000 cycles at 0.5 A g–1.This study provides an essential theoretical basis for the effective exfoliation of layered graphite-based materials and their applications in energy storage. | Xin Wang Zhicong Luo Juntong Huang Zhi Chen Tong Xiang Zhijun Feng Jing Wang Sinong Wang Yongcun Ma Huiyong Yang Xibao Li | 2023 | Journal of Materials Science & Technology2023，，16： | 0 |
| 10 | Spatio-temporal Changes and Associated Uncertainties of CENTURYmodelled SOC for Chinese Upland Soils, 1980-2010显示文摘Detailed information on the spatio-temporal changes of cropland soil organic carbon(SOC) can significantly contribute to the improvement of soil fertility and mitigate climate change. Nonetheless, information and knowledge on the national scale spatio-temporal changes and the corresponding uncertainties of SOC in Chinese upland soils remain limited. The CENTURY model was used to estimate the SOC storages and their changes in Chinese uplands from 1980 to 2010. With the Monte Carlo method, the uncertainties of CENTURY-modelled SOC dynamics associated with the spatial heterogeneous model inputs were quantified. Results revealed that the SOC storage in Chinese uplands increased from 3.03(1.59 to 4.78) Pg C in 1980 to 3.40(2.39 to 4.62) Pg C in 2010. Increment of SOC storage during this period was 370 Tg C, with an uncertainty interval of –440 to 1110 Tg C. The regional disparities of SOC changes reached a significant level, with considerable SOC accumulation in the Huang-Huai-Hai Plain of China and SOC loss in the northeastern China. The SOC lost from Meadow soils, Black soils and Chernozems was most severe, whilst SOC accumulation in Fluvo-aquic soils, Cinnamon soils and Purplish soils was most significant. In modelling large-scale SOC dynamics, the initial soil properties were major sources of uncertainty. Hence, more detailed information concerning the soil properties must be collected. The SOC stock of Chinese uplands in 2010 was still relatively low, manifesting that recommended agricultural management practices in conjunction with effectively economic and policy incentives to farmers for soil fertility improvement were indispensable for future carbon sequestration in these regions. | LIU Xiaoyu ZHAO Yongcun SHI Xuezheng WANG Shihang FENG Xiang YAN Fang | 2021 | Chinese Geographical Science2021，31，1： | 0 |
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