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The mRNA Expression and Methylation Status in Imprinting Control Region of H19 Gene Between Cattle-Yak and Their Parents

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Journal of Integrative Agriculture 2012年第10期11卷 1691-1699页

作者： LI Ming-gui LIU Zhen-shan PAN Zeng-xiang LUO Hua XIE Zhuang LI Qi-fa College of Animal Science and Technology Nanjing Agricultural University

The H19 gene, which is imprinted with preferential expression from the maternal allele, was one of the first identified imprinting genes in mammals. Recent studies revealed that correct imprinting of the H19 gene plays a vital role in human spermatogenesis. To investigate whether imprinting defects were associated with the hybrid sterility of male cattle-yak, the methylation patterns of the H19 imprinting control region （ICR） and H19 mRNA expression in the testes of cattle-yak, yak, and cattle were examined. The results showed that the 3rd CCCTC-binding factor （CTCF） site of the H19 ICR was significantly hypomethylated in the testes of cattle-yak compared with yak or cattle. As expected, H19 was expressed at a significantly higher level in cattle-yak than in yak or cattle. These results suggest that imprinting defects of the CTCF- binding site in the HI9 ICR were possibly associated with disturbed spermatogenesis of male cattle-yak. Thus, we propose that disorders in H19 imprinting, resulting in an increased H19 mRNA expression, might contribute to the sterility of F1 male hybrids between cattle and yak.

关键词： cattle-yak male sterility H19 ICR CTCF-binding site mRNA expression DNA methylation

Numerical investigation for anisotropy of compressive strength of rock mass with multiple natural joints

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Journal of Coal Science & Engineering(China) 2010年第3期16卷 246-248页

作者： HAN Feng-shan tang Chun-an Research Center for Numerical Tests on Material failure Dalian University Dalian 116622 China College of Civil and Hydraulic Engineering Dalian University of Technology Dalian 116024 China

Based on Rock failure Process Analysis model RFPA2D, the evolutionary proc- esses of failure process of rock mass with multiple natural joints were simulated. Numeri- cal simulations show that anisotropy of compressive strength of jointed rock mass varies with the number of natural joints and inclination of natural joints. As the number of natural joints in rock mass increases, the anisotropy becomes less and less. It is justifiable to treat approximately rock mass containing six or more natural joints instead of four or more joints that was described in literature of Hoek and Brown as isotropy.

关键词： anisotropy compressive strength rock mass multiple natural joints

Reflection and refraction of elastic wave at VTI-TTI media interface

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Frontiers of physics 2020年第2期15卷 39-55页

作者： Lin fa Jiaojiao tang Qi Zhang Minjin Zhang Yandong Zhang Meng Liang Meishan Zhao School of Electronic Engineering Xi'an University of Posts and TelecommunicationsXi’an 710121China James Franck Institute and Department of Chemistry The University of ChicagoChicagoIL 60637USA

We explore the physical phenomenon of acoustic waves induced at the interface between two different anisotropic rock ***,one medium is a transversely isotropic medium with a vertical axis of symmetry(VTI medium)and the other one is a transversely isotropic medium with a tilt axis of symmetry(TTI medium).By solving the Kelvin-Christoffel equation,an eighth-order polynomial is established for reflection and refraction angles,which is confirmed from SnelFs *** types of analytical expressions of the polarization coefficients of the induced waves are obtained corresponding to different incident angle *** effective algorithm has been developed for numerical analysis of the polarization *** characteristic anisotropic parameters reported in the literature,the influencing factors on reflection and refraction coefficients are analyzed,e.g.,the anisotropy,the tilt-angle of rock-layer,and the *** calculated reflection and refraction coefficients have been rechecked for energy conservation.

关键词： VTI-TTI interface reflection refraction rock anisotropy tilt-angle

Morphology and photocatalytic performance of nano-sized TiO_2 prepared by simple hydrothermal method with different pH values

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Rare Metals 2018年第9期37卷 750-758页

作者： Hao Xu Shi-Qi Liu shan Zhou tang-Zhi-Jiu Yuan Xiang Wang Xia tang Jian Yin Hui-Jin Tao School of Material Science and Engineering Central South University State Key Laboratory for Powder Metallurgy Central South University Key Lab of Nonferrous Materials Science and Engineering Ministry of EducationCentral South University

pH value is a key factor in the preparation of nano-sized TiO2 with hydrothermal method. Using Ti（SO4）2 as the titanium source, H2O2 as the complexing agent, NaOH and HCl as the pH value regulator, nano- sized TiO2 powder with various morphologies and sizes was synthesized. Changes in morphology, size and phase type with pH values of samples were characterized by X-ray diffraction （XRD） and transmission electron micro- scopy （TEM） measurements. Results show that under the present preparation conditions, TiO2 powder is an anatase phase with pH value less than 11, but is more likely to be a brookite phase with pH value more than 11. With the increase in pH value from 1 to 11 in hydrothermal envi- ronment, nano-sized anatase TiO2 gradually grows up in all directions. {001 }, { 101 } and { 100} groups of crystal plane are the exposed crystal planes of nano-sized anatase TiO2 for the （004）, （101） and （200） facets found in high-reso- lution TEM image. The photocatalytic performance of nano-sized TiO2 with different morphologies was com- pared by measuring their photocatalytic degradation rates for methylene blue under ultraviolet light. Results show that anatase TiO2 prepared under the alkalescenthydrothermal environment （pH = 9, 11） has a better pho- tocatalytic degrading performance. Different sizes and phases of nanoscaled TiO2 powders with different photo- catalytic performances can be prepared by the control of pH value of hydrothermal solutions.

关键词： Hydrothermal method pH value Anatase Brookite Nano-sized crystal morphology

A facile solution processed ZnO@ZnS core–shell nanorods arrays for high-efficiency perovskite solar cells with boosted stability

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Journal of Energy Chemistry 2021年第10期30卷 553-560,I0014页

作者： Kun Chen Weijian tang Yu Chen Ruihan Yuan Yinhua Lv Wenjuan shan Wen-Hua Zhang Sichuan Research Center of New Materials Institute of Chemical MaterialsChina Academy of Engineering Physics596 Yinhe RoadChengdu 610200SichuanChina Tongwei Solar(Chengdu)Co. LTD888 Linjiaci RoadChengdu 610200SichuanChina Institute of Chemistry for Functionalized Materials College of Chemistry and Chemical EngineeringLiaoning Normal UniversityDalian 116029LiaoningChina

Zinc Oxide(ZnO)has been extensively applied as electron transport material(ETM)in perovskite solar cells(PSCs)since the emergence of ***,some chemisorbed oxygen species on the surface of ZnO can cause the degradation of CH3NH3+(MA^(+))based *** avoid the destructive effect of ZnO,a facile solution strategy was proposed to produce a ZnS shell around the ZnO nanorods arrays(ZnO-NRs),***@ZnS core-shell nanorods(ZnO-NRs@ZnS).The ZnO-NRs@ZnS cascade structure can not only facilitate carrier transport,but also enhance the stability of ZnO based PSCs.A power conversion efficiency(PCE)of 20.6%was finally yielded,which is the-state-of-the-art efficiency for PSCs with one-dimensional(1 D)ZnO electron transport materials(ETMs).Moreover,over 90%of the initial efficiency was retained for the unencapsulated device with ZnO-NRs@ZnS ETMs at 85℃for 500 h,demonstrating excellent *** work provides a simple and efficient avenue to simultaneously enhance the photovoltaic(PV)performance and stability of 1 D ZnO nanostructure-based PSCs.

关键词： Zinc Oxide nanorods arrays Core-cell structure Electron transport material Perovskite solar cells Stability

Synthesis of Polyethylenes with In-Chain Isolated Carbonyls from CO_(2)and Ethylene via a Tandem Photoreduction/Polymerization Protocol

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CCS Chemistry 2024年第6期6卷 1591-1599页

作者： Fulin Zhou Haojie Dai shan tang Yongfeng Zhou Frontiers Science Center for Transformative Molecules Shanghai Key Laboratory for Molecular Engineering of Chiral DrugsSchool of Chemistry and Chemical EngineeringShanghai Jiao Tong UniversityShanghai 200240

Aiming at accessing polyethylene-bearing in-chain degradable functionality,copolymerization of carbon dioxide(CO_(2))with ethylene has long been recognized as a significant but highly challenging ***,most trials have resulted in ethylene homopolymerization because of the endothermic property and high energy barriers of CO_(2)insertion during polymer chain *** we report an unprecedented tandem reaction protocol for the synthesis of polyethylenes with in-chain carbonyls from CO_(2)and ethylene by the combination of photocatalytic CO_(2)reduction and palladium-catalyzed coordination/insertion *** protocol provides an easy way to adjust the carbonyl content(from 0.13 to 12 mol%)and insertion selectivity(up to 99%isolated carbonyls)of the polyethylene copolymers,which enables the polymers tomaintain the main properties of highdensity polyethylene and simultaneously endows them with good *** addition,besides apolar polyethylene copolymers,polar-functionalized polyethylenes with in-chain isolated carbonyls can also be synthesized from CO_(2),ethylene and a polar monomer using the same *** believe our present work sheds new light on the synthesis of degradable polyethylenes by employing CO_(2)as a green carbonyl source.

关键词： carbon dioxide coordination polymerization polyethylene photoreduction photodegradation

Carbon hollow spheres as cocatalyst of Cu-doped TiO_(2)nanoparticles for improved photocatalytic H_(2)generation

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Rare Metals 2022年第6期41卷 2063-2073页

作者： Li-Juan Sun Hai-Wei Su Di-fa Xu Le-Le Wang Hua tang Qin-Qin Liu School of Materials Science and Engineering Jiangsu UniversityZhenjiang 212013China Hunan Key Laboratory of Applied Environmental Photocatalysis Changsha UniversityChangsha 410022China State Key Laboratory of Photocatalysis on Energy and Environment College of ChemistryFuzhou UniversityFuzhou 350108China School of Environmental Science and Engineering Qingdao UniversityQingdao 266071China

The reasonable employment of cocatalyst in photocatalysis can effectively promote the photocatalytic H_(2)production *** this study,carbon hollow spheres(C),as a good conductive nonmetallic material,have been utilized as a novel cocatalyst and a matrix for loading the Cu-doped-TiO_(2)nanoparticles by a successive hydrother-mal method and metal molten salt *** Cu-doped-TiO_(2)nanoparticles were tightly anchored on the surface of carbon hollow sphere to form a zero-dimensional/three dimensional(0D/3D)Cu-doped-TiO2/C *** optimal Cu-doped-TiO_(2)/C heterojunction demon-strated greatly enhanced photocatalytic H_(2) generation activity(14.4 mmol·g^(-1)·h^(-1))compared with TiO_(2)(0.33 mmol·g^(-1)·h^(-1))and TiO_(2)/C(0.7 mmol·g^(-1)·h^(-1)).The performance improvement was mainly due to the syner-gistic effect of carbon hollow sphere cocatalyst and Cu-doping,the Cu-doping in TiO_(2)nanoparticles can minimize charge recombination and enhance the available photoex-cited electrons,while the 3D carbon hollow spheres can act as electron traps to accelerate the charge separation and offer abundant active sites for solar water splitting reaction.

关键词： Cartbon hollow sphere Cu-doped TiO_(2) Photocatalytic H_(2)generation

Spatiotemporal variation in forest fire danger from 1996 to 2010 in Jilin Province,China

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Journal of Forestry Research 2017年第5期28卷 983-996页

作者： Yanlong shan Yonghe Wang Mike Flannigan Shuyuan tang Pingyan Sun Fengguo Du Provincial Key Laboratory of Forestry and Ecological Environment Forestry CollegeBeihua University Northern Forestry Centre Canadian Forest ServiceNatural Resources Canada The Department of Renewable Resources The University of Alberta Forestry College Beihua University Forestry Department of Jilin Province

We evaluated the spatial and temporal patterns of forest fires in two fire seasons (March to June and September to November) from 1996 to 2010 in Jilin Province, China, using the Canadian Forest Fire Weather Index System. Fire data were obtained from the Provincial Fire Agency, and historical climate records of daily weather observations were collected from 36 weather stations in Jilin and its neighboring provinces. A linear regression model was used to analyze linear trends between climate and fire weather indices with time treated as an independent variable. Correlation analysis was used to detect correlations between fire frequency, areas burned, and fire weather indices. A thin-plate smooth spline model was used to interpolate the point data of 36 weather stations to generate a surface covering the whole province. Our analyses indicated fire frequency and areas burned were significantly correlated with fire weather indices. Overall, the Canadian Forest Fire Weather Index System appeared to be work well for determining the fire danger rating in Jilin Province. Also, our analyses indicated that in the forthcoming decades, the overall fire danger in March and April should decrease across the province, but the chance of a large fire in these months would increase. The fire danger in the fall fire season would increase in the future, and the chance of large fire would also increase. Historically, because most fires have occurred in the spring in Jilin Province, such a shift in the future fire danger between the two fire seasons would be beneficial for the province's fire management.

关键词： Canadian Forest Fire Weather Index System Correlation analysis Human-caused fires Linear regression Thin-plate smooth spline model

Electrical conductivity optimization of the Na3AlF6–Al2O3–Sm2O3 molten salts system for Al–Sm intermediate binary alloy production

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International Journal of Minerals,Metallurgy and Materials 2017年第9期24卷 1034-1042页

作者： Chun-fa Liao Yun-fen Jiao Xu Wang Bo-qing Cai Qiang-chao Sun Hao tang Institute of Metallurgical and Chemical Engineering Jiangxi University of Science and Technology

Metal Sm has been widely used in making Al–Sm magnet alloy materials. Conventional distillation technology to produce Sm has the disadvantages of low productivity, high costs, and pollution generation. The objective of this study was to develop a molten salt electrolyte system to produce Al–Sm alloy directly, with focus on the electrical conductivity and optimal operating conditions to minimize the energy consumption. The continuously varying cell constant(CVCC) technique was used to measure the conductivity for the Na3AlF6–AlF3–LiF–MgF2–Al2O3–Sm2O3electrolysis medium in the temperature range from 905 to 1055°C. The temperature(t) and the addition of Al2O3(W(Al2O3)), Sm2O3(W(Sm2O3)), and a combination of Al2O3and Sm2O3into the basic fluoride system were examined with respect to their effects on the conductivity(κ) and activation energy. The experimental results showed that the molten electrolyte conductivity increases with increasing temperature(t) and decreases with the addition of Al2O3or Sm2O3or both. We concluded that the optimal operation conditions for Al–Sm intermediate alloy production in the Na3AlF6–AlF3–LiF–MgF2–Al2O3–Sm2O3system are W(Al2O3) + W(Sm2O3) = 3wt%, W(Al2O3):W(Sm2O3) = 7:3, and a temperature of 965 to 995°C, which results in satisfactory conductivity, low fluoride evaporation losses, and low energy consumption.

关键词： aluminium oxide samarium oxide molten salt electrical conductivity regression analysis Al–Sm intermediate alloy