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| 1 | Magnetic and microwave absorption properties of Ni_(1-x)Zn_xFe_2O_4 nanocrystalline synthesized by sol-gel method显示文摘Ni1-xZnxFe2O4(0≤x≤1,in steps of 0.1) nanocrystallines were synthesized by sol-gel route.The doping effects of zinc on structural,magnetic and microwave absorption properties were investigated in detail.X-ray diffraction(XRD) results show that all the samples are single-phase spinel structure.The magnetic and microwave absorption properties are strongly dependent on the zinc content,which can be understood in terms of the cations redistribution in spinel tetrahedral and octahedral sites with the increase of zinc content.The magnetic measurement shows the antiferromagnetic nature of the samples for x=0.9 and x=1.0.The saturation magnetization reaches the maximum of 3.35μB/f.u.at x=0.5.The optimal reflection loss(RL) of-29.6 dB is found at 6.5 GHz for an absorber thickness of 5 mm.The RL values exceeding 10 dB are obtained for the absorber in the range of 3.9-8.9 GHz.These Ni1-xZnxFe2O4 nanocrystallines may be attractive candidates for electromagnetic wave absorption materials. | ZHANG Min LIU QiangChun ZI ZhenFa DAI YuQiang ZHU XueBin SUN YuPing DAI JianMing | 2013 | Science China(Technological Sciences)2013，56，1： | 4 |
| 2 | Complex sources of air-soil-water pollution processes in the Miyun reservoir region显示文摘The comprehensive impact of atmospheric dry deposition and wet deposition and the pollution sources of farmlands, mining areas, and towns along the Baihe River on the water quality of Miyun reservoir is investigated from the angle of the complex sources of air-soil-water pollution processes, in the context of the 1990-2001 precipitation chemical data at Shangdianzi station--a WMO regional background air pollution monitoring station 15 km far from the Miyun reservoir, in conjunction with the atmospheric dry deposition and wet deposition data of the 2002-2003 Beijing City Air Pollution Observation Field Experiment (BECAPEX). Analysis results suggest that the major ions in precipitation in the Miyun reservoir region in this period were SO, NO, NH and Ca2+; wet acid deposition quantity of Miyun reservoir in the summer half year (April to September) was greater than the quantity in the winter half year (October to March), and the annual wet acid deposition in the reservoir exhibited a rising trend with the mean 1038.45 t, the maximum 1766.31 t occurred in 1996, and the minimum 604.02 t in 1994; the long-term averaged pH of atmospheric precipitation in the Miyun reservoir region was 5.20, i.e. weakly acidic, and the interannual variation of pH values displayed a falling trend. pH values of water body at various depths in the Miyun reservoir were all greater than 7.0, but they exhibited vertical and horizontal nonhomogeneity, and at the same region pH decreased vertically with depth; the 2002 and 2003 annual dustfalls in the Miyun reservoir were 13513.08 t and 3577.64 t, respectively, and the spring dustfall was the number one in a year, accounting for the 61.91% and 44.56% of the annual totals of 2002 and 2003, respectively. Because the atmospheric dry deposition and wet depositions contain multiple types heavy metal elements and harmful elements, they to some extent exacerbated the eutrophication, acidification and potential heavy metal pollution of the reservoir water. The above comprehensive analysis results reveal the complex source characters of the air-soil-water pollution process and the multi-sphere interaction effect. Besides, summer (rainy season) is a season when local soil pollutants enter the water system of reservoir after being washed out by torrential rain or heavy precipitation, which starts the air-soil- water chaining pollution processes, and results in the water pollution of rivers and reservoirs. It is found from the statistical analysis in this paper that the water pollution of Miyun reservoir was correlated with the rain wash-out and confluent flow in the peripheral and upstream local region of the reservoir, and the pollutant concentration of the reservoir water was significantly correlated with the upstream local region precipitation. Those correlation characters reveal the effect of the air-soil-water multi-spheric interaction of reservoir water pollution process. This paper presents the point of view of the complex source analysis of reservoir water pollution and a technical approach for tracing the spatial distribution of the upstream pollution source of the water systems of reservoir. | YANG Dongzhen, XU Xiangde, LIU Xiaoduan, XU Qing, DING Guoan, CHENG Xinghong, CHEN Huailiang, ZHOU Huaigang, WANG Zhenfa, WANG Wenyan Key Laboratory of Atmospheric Chemistry, Center for Atmosphere Watch and Services, Chinese Academy of Meteorological Sciences, CMA, Beijing 100081, China Key Laboratory of Meteorological Disasters, CAMS, Beijing 100081, China National Center for Geological Testing, Beijing 100037, China Meteorological Bureau of Henan Province, Zhenzhou 450000, China Shangdianzi Background Atmospheric Pollution Observation Station, Miyun County, Beijing 101507, China | 2005 | Science China Earth Sciences2005，48，z2： | 4 |
| 3 | Y_(2)O_(3)modification on nickel-rich LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)with improved electrochemical performance in lithium-ion batteries显示文摘Doping and coating are frequently employed for the improvement of the properties of Ni-rich NCM materials.In this work,we prepared stable LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)materials modified withY_(2)O_(3)via a wet chemical method.In order to investigate the action mechanism ofY_(2)O_(3)on NCM811,we analyzed the micro structures using X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM),and transmission electron microscopy(TEM).Also,to study the electrochemical performances,we conducted a charge/discharge test and cyclic voltammetry.Our results show thatY_(2)O_(3)modified NCM811 materials have good thermal stability,and proper content ofY_(2)O_(3)can effectively prevent the materials from damaging and significantly improve the electrochemical properties of the materials.Particularly,1%Y2 O3 modified NCM811 material show much better cycling performance than other samples.During cycling at 1.0 C the 1%Y2 O3 modified NCM811 shows capacity retention of 90.1%after 100 cycles,which is higher than 69.4%for pristine NMC811.We examined the microstructures of the materials before and after circulation.Using the SEM results,we conclude that structural changes are among the key factors that lead to the degradation of the electrochemical properties of materials. | Rui He Xue Bai Aijia Wei Lihui Zhang Peng Liu Zhenfa Liu | 2022 | Journal of Rare Earths2022，40，2： | 2 |
| 4 | Ni_(2)P/MoS_(2) interfacial structures loading on N-doped carbon matrix for highly efficient hydrogen evolution显示文摘Electrochemical catalysts for the hydrogen evolution reaction(HER) have attracted increasing attentions. Noble metal-free cocatalysts play a vital role in HER applications. Herein, a novel strategy to prepare a Ni_(2)P/MoS_(2) cocatalyst through a simple hydrothermal-phosphorization method was reported, and the prepared cocatalyst was then loaded on an N-doped carbon substrate with excellent conductive performance. The large surface area of the carbon substrate provided many active sites, and the interface between Ni_(2)P and MoS_(2) improved the catalytic performance for the HER. Compared with pure Ni_(2)P catalyst and MoS_(2) catalyst, the prepared Ni_(2)P/MoS_(2) cocatalyst exhibited enhanced catalytic performance. In addition, the results indicate that the prepared cocatalyst has a wide p H range and low onset potential values of 280, 350 and40 m V in acidic, phosphate-buffered saline and alkaline solutions, respectively, and the corresponding Tafel slopes are 75, 121 and 95 mV dec^(-1),respectively. Density functional theory(DFT) was adopted to calculate the hydrogen adsorption free energy(ΔG_(H)^(*)). The results showed that the interface between Ni_(2)P and MoS_(2) reduced ΔG_H^(*), which was beneficial to the adsorption of hydrogen. Present preparation of cocatalysts with unique interfaces provides a new strategy for improving the catalytic performance of HER. | Yuelong Xu Ran Wang Zhan Liu Lili Gao Tifeng Jiao Zhenfa Liu | 2022 | Green Energy & Environment2022，7，4： | 0 |
| 5 | A metabolome atlas of mouse brain on the global metabolic signature dynamics following short-term fasting显示文摘Calorie restriction(CR)or a fasting regimen is considered one of the most potent non-pharmacological interventions to prevent chronic metabolic disorders,ameliorate autoimmune diseases,and attenuate aging.Despite efforts,the mechanisms by which CR improves health,particularly brain health,are still not fully understood.Metabolic homeostasis is vital for brain function,and a detailed metabolome atlas of the brain is essential for understanding the networks connecting different brain regions. | Yaping Shao Zhenfa Fu Yanfeng Wang Zhaofei Yang Yushan Lin Song Li Cheng Cheng Min Wei Zheyi Liu Guowang Xu Weidong Le | 2023 | Signal Transduction and Targeted Therapy2023，8，10： | 0 |
| 6 | Synergistic scale inhibition of polyaspartic acid composite with magnetic field显示文摘Polyaspartic acid(PASP)composite,a scale inhibitor,was prepared from PASP,itaconic acid—acrylic acid—acrylic ester(IA-AA-AE)terpolymer and 2-phosphonobutane-1,2,4-tricarboxylic acid(PBTCA).The scale inhibition of PASP composite and the effect of its synergism with a magnetic field on scale inhibition were investigated.Calcium carbonate crystals in scale samples were characterized by means of SEM and XRD.The static and dynamic experiments show that the chelating function of PASP composite for Ca2+can be enhanced by synergism with a magnetic field.Under Ca2+650 mg/L,HCO3-1,300 mg/L and PASPcomposite 4 mg/L,the scale inhibition rate of PASP composite in magnetic water can increase by 10%in static state and by 20%in dynamic experiments.Scanning electron microscope(SEM)and X-ray diffraction(XRD)results show that calcite and aragonite can be completely transformed into vaterite by using PASP composite. | LIU Zhenfa WANG Yanji GAO Yuhua ZHANG Lihui | 2007 | Frontiers of Chemical Science and Engineering2007，1，3： | 0 |
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