检索结果-南通市图书馆

Structures and luminescence properties of Yb^(3+) in the double perovskites Ba_2 YB'O_6 (B'=Ta^(5+),Nb^(5+) phosphors

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2011年第1期20卷 493-500页

作者：周文龙张庆礼高进云刘文鹏丁丽华殷绍唐 Anhui provincial Key Laboratory of Photonic Devices and Materials Anhui Institute of Optics and Fine Mechanics Chinese Academy of Sciences Graduate School of the Chinese academy of sciences

The Yb3＋ doped Ba2YB＇O6 （B＇= Ta5＋, Nb5＋） were prepared by high temperature solid-state reaction method, their structures were determined by x-ray diffraction and refined by Rietveld method. The diffuse reflection absorption, excitation and emission spectra of yb3＋：Ba2YB＇O6 （B＇= Ta5＋, Nb5＋） were measured at room temperature. Under the excitation of ultraviolet light, these phosphors exhibit broad charge transfer band emissions of TaO6 or NbO6 centre with large Stokes shift. The Yb3＋ doped into these hosts are situated at y3＋ sites of cubic symmetry （Oh）. The experimental energy levels of Yb3＋ in Ba2YTaO6 and Ba2YNbO6 were determined by photoluminescence and diffuse reflection absorption spectra. Their wavefunctions and theoretical energy levels were obtained by diagonalising the Hamiltonian matrix. The experimental energy levels were fitted by Levenberg-Marquardt iteration algorithm to determine crystal field parameters. Then, the magnetic-pole transition line strengths of yb3＋：Ba2YB＇O6 （B＇=Ta5＋, Nb5＋） from （2F5/2）Г8-to the low-energy states were calculated.

关键词： luminescence properties Yb3+ Ba2YTaO6 Ba2YNbO6

TaSnRK2.4 is a vital regulator in control of thousand-kernel weight and response to abiotic stress in wheat

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2021年第1期20卷 46-54页

作者： MIAO Li-li LI Yu-ying ZHANG Hong-juan ZHANG Hong-ji LIU Xiu-lin WANG Jing-yi CHANG Xiao-ping MAO Xin-guo JING Rui-lian heilongjiang academy of Agricultural sciences Postdoctoral Programme Harbin 150086P.R.China Institute of Crop Resources Heilongjiang Academy of Agricultural SciencesHarbin 150086P.R.China Institute of Crop sciences Chinese Academy of Agricultural SciencesBeijing 100081P.R.China Institute of Soybean Heilongjiang Academy of Agricultural SciencesHarbin 150086P.R.China

Sucrose non-fermenting 1-related protein kinase 2(Sn RK2) is a plant-specific serine/threonine kinase involved in response to adverse environmental stimuli. Previous studies showed that Ta Sn RK2.4 was involved in response to abiotic stresses and conferred enhanced tolerance to multiple stresses in Arabidopsis. Further experiments were performed to decipher the underlying mechanisms and discover new functions. The genomic sequences of Ta Sn RK2.4 s locating on chromosome 3 A, 3 B and 3 D were obtained. Sequencing identified one and 13 variations of Ta Sn RK2.4-3 A and Ta Sn RK2.4-3 B, respectively, but no variation was detected in Ta Sn RK2.4-3 D. The markers 2.4 AM1, 2.4 BM1 and 2.4 BM2 were developed based on three variations. Association analysis showed that both Ta Sn RK2.4-3 A and Ta Sn RK2.4-3 B were significantly associated with thousand-kernel weight(TKW), and that SNP3 A-T and SNP3 B-C were favorable alleles for higher TKW. Yeast two-hybrid and split luciferase assays showed that Ta Sn RK2.4 physically interacted with abiotic stress responsive protein Ta LTP3, suggesting that Ta Sn RK2.4 enhanced abiotic stress tolerance by activating Ta LTP3. Our studies suggested that Ta Sn RK2.4 have potential in improving TKW and response to abiotic stress.

关键词： TaSnRK2.4 association analysis TKW abiotic stress

Purification and Characterization of a Low-temperature Hydroxylamine Oxidase from Heterotrophic Nitrifier Acinetobacter sp.Y16

在线全文

学校读者我要写书评

暂无评论

Biomedical and Environmental sciences 2014年第7期27卷 515-522页

作者： ZHANG Shu Mei LI Wei Guang ZHANG Duo Ying HUANG Xiao Fei QIN Wen SHA Chang Qing Institute of Microbiology Heilongjiang Academy of Sciences School of Municipal and Environmental Engineering Harbin Institute of Technology State Key Laboratory of Urban Water Resource and Environment Harbin Institute of Technology heilongjiang academy of sciences

Objective To purify a low-temperature hydroxylamine oxidase （HAO） from a heterotrophic nitrifying bacterium Acinetobacter sp. Y26 and investigate the enzyme property. Methods A HAO was purified by an anion-exchange and gel-filtration chromatography from strain Y16. The purity and molecular mass were determined by RP-HPLC and SDS-PAGE. The HAO activity was detected by monitoring the reduction of potassium ferricyanide using hydroxylamine as substrate and ferricyanide as electron acceptor. The partial amino acid sequence was determined by mass spectrometry. Results The low-temperature HAO with a molecular mass of 61 kDa was purified from strain Y26 by an anion-exchange and gel-filtration chromatography. The enzyme exhibited an ability to oxidize hydroxylamine in wide temperature range （4-40 ℃） in vitro using hydroxylamine as substrate and ferricyanide as electron acceptor. It was stable in the temperature range of 4 to 25 ℃ and pH range of 6.0 to 8.5 with less than 30% change in its activity. The optimal temperature and pH were 15 ℃ and 7.5, respectively. Three peptides were determined by mass spectrometry which were shown to be not identical to other reported HAOs. Conclusion This is the first study to purify a low-temperature HAO from a heterotrophic nitrifier Acinetobecter sp. It differs from other reported HAOs in molecular mass and enzyme properties. The findings of the present study have suggested that the strain Y26 passes through a hydroxylamine-oxidizing process catalyzed by a low-temperature HAO for ammonium removal.

关键词： Hydroxylamine oxidase Purification Heterotrophic nitrifier Acinetobacter sp Y16

Litter decomposition and C and N dynamics as affected by N additions in a semi-arid temperate steppe, Inner Mongolia of China

在线全文

学校读者我要写书评

暂无评论

Journal of Arid Land 2014年第4期6卷 432-444页

作者： Qin PENG YuChun QI YunShe DONG YaTing HE ShengSheng XIAO XinChao LIU LiangJie SUN JunQiang JIA ShuFang GUO CongCong CAO Institute of Geographic sciences and Natural Resources Research Chinese Academy of Sciences University of Chinese academy of sciences Jiangxi provincial Research Institute for Soil and Water Conservation

Litter decomposition is the fundamental process in nutrient cycling and soil carbon（C） sequestration in terrestrial ecosystems. The global-wide increase in nitrogen（N） inputs is expected to alter litter decomposition and,ultimately, affect ecosystem C storage and nutrient status. Temperate grassland ecosystems in China are usually N-deficient and particularly sensitive to the changes in exogenous N additions. In this paper, we conducted a 1,200-day in situ experiment in a typical semi-arid temperate steppe in Inner Mongolia to investigate the litter decomposition as well as the dynamics of litter C and N concentrations under three N addition levels（low N with 50 kg N/（hm2？a）（LN）, medium N with 100 kg N/（hm2？a）（MN）, and high N with 200 kg N/（hm2？a）（HN）） and three N addition forms（ammonium-N-based with 100 kg N/（hm2？a） as ammonium sulfate（AS）, nitrate-N-based with 100 kg N/（hm2？a） as sodium nitrate（SN）, and mixed-N-based with 100 kg N/（hm2？a） as calcium ammonium nitrate（CAN）） compared to control with no N addition（CK）. The results indicated that the litter mass remaining in all N treatments exhibited a similar decomposition pattern： fast decomposition within the initial 120 days, followed by a relatively slow decomposition in the remaining observation period（120–1,200 days）. The decomposition pattern in each treatment was fitted well in two split-phase models, namely, a single exponential decay model in phase I（〈398 days） and a linear decay function in phase II（≥398 days）. The three N addition levels exerted insignificant effects on litter decomposition in the early stages（〈398 days, phase I; P〉0.05）. However, MN and HN treatments inhibited litter mass loss after 398 and 746 days, respectively（P〈0.05）. AS and SN treatments exerted similar effects on litter mass remaining during the entire decomposition period（P〉0.05）. The effects of these two N addition forms differed greatly from those of CAN after 746 and 1,053 days, respectively（P〈0.05）. During the decomposition pe

关键词： litter decomposition N deposition N level N form C sequestration semi-arid temperate grassland

Deep Convective Clouds over the Northern Pacific and Their Relationship with Oceanic Cyclones

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric sciences 2015年第6期32卷 821-830页

作者： YI Mingjian FU Yunfei LIU Peng ZHENG Zhixia University of Science and Technology of China Anhui provincial academy of Environmental sciences State Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences

Based on combined CloudSat/CALIPSO detections, the seasonal occurrence of deep convective clouds （DCCs） over the midlatitude North Pacific （NP） and cyclonic activity in winter were compared. In winter, DCCs are more frequent over the central NP, from approximately 30~N to 45~N, than over other regions. The high frequencies are roughly equal to those occurring in this region in summer. Most of these DCCs have cloud tops above a 12 km altitude, and the highest top is approximately 15 km. These wintertime marine DCCs commonly occur during surface circulation conditions of low pressure, high temperature, strong meridional wind, and high relative humidity. Further, the maximum probability of DCCs, according to the high correlation coefficient, was found in the region 10^-20~ east and 5^-10~ south of the center of the cyclones. The potential relationship between DCCs and cyclones regarding their relative locations and circulation conditions was also identified by a case study. Deep clouds were generated in the warm conveyor belt by strong updrafts from baroclinic flows. The updrafts intensified when latent heat was released during the adjustment of the cyclone circulation current. This indicates that the dynamics of cyclones are the primary energy source for DCCs over the NP in winter.

关键词： CloudSat deep convective clouds marine cyclones northern Pacific

Pollution levels and characteristics of phthalate esters in indoor air in hospitals

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental sciences 2015年第11期27卷 67-74页

作者： Xueqing Wang Min Song Min Guo Chenchen Chi Feifei Mo Xueyou Shen College of Environmental & Resource sciences Zhejiang University Research Center for Eco-Environmental sciences Chinese Academy of Sciences Chinese Research academy of Environmental sciences Zhejiang provincial Key Laboratory of Organic Pollution and Control

The concentrations of phthalate esters（PAEs） in Chinese hospitals were investigated by simultaneously determining concentrations of gas- and particle-phase PAEs. PAEs were detected in two third-class first-grade hospitals, two second-class first-grade hospitals, and a community health service center. Hospital drugstores had the highest concentration（24.19 μg/m3）, which was 1.54 times that of newly decorated houses. The second highest concentration was found in the transfusion rooms, averaging 21.89 μg/m3; this was followed by the concentrations of PAEs in the nurse＇s workstations, the wards, and the doctor＇s offices, with mean concentrations of 20.66, 20.0, and 16.92 μg/m3, respectively. The lowest concentrations were found in the hallways（16.30 μg/m3）. Of the six different kinds of PAEs found, major pollutants included diethyl phthalates, dibutyl phthalates, butylbenzyl phthalates and di（2-ethylhexyl） phthalates, comprising more than 80% of all PAEs ***, a comparison between different wards showed that PAE concentrations in the maternity wards were 1.63 times higher than in the main wards. Based on known health hazards, our results suggest that the PAEs seriously influence the health of the pregnant women and babies; therefore, it is of great importance to take the phthalate concentrations in hospitals into consideration. In addition, hospital indoor air was more seriously contaminated than the air of newly decorated houses.

关键词： Air pollution Hospital Indoor air Phthalate concentrations

Numerical Study on Microphysical Processes of Two Different Snowfall Cases in Northern China

在线全文

学校读者我要写书评

暂无评论

Acta meteorologica Sinica 2007年第4期21卷 420-437页

作者：孙晶王鹏云李想逯莹 Institute of Atmospheric Physics Chinese Academy of Sciences Chinese academy of Meteorological sciences Shuangyashan Meteorological Bureau of heilongjiang Province

In this paper, two snowfall cases under different weather conditions in northern China are simulated by using the meso scale model MM5. Two-way nesting structure of domains is designed for each case. Among the explicit schemes of MM5, the Reisner graupel scheme is selected to describe the microphysical process. The simulated snow-bands of two cases are basically consistent with observations. The simulated results of microphysical processes are mainly discussed. The hydrometeors and their sources and sinks under different weather backgrounds are described. The feedback effects of microphysical processes on the thermal and dynamic processes are also discussed. Method that outputs the accumulative sources and sinks per hour is used to analyze the distribution characteristics of hydrometeors during the strongest snowfall period. Two sensitivity tests （called heat test and drag test） are conducted to examine the effects of microphysical processes on cloud produced by the latent heat and drag force. Results have shown that the distribution of particles has a close relation with temperature. The temperature of Beijing snowfall is under 0℃ and there exist vapor and solid phase particles, while Liaoning snowfall has vapor, liquid, and solid phase particles due to the warm temperature. The distribution of these particles is not the same at different development stages. From the analyses of the characteristics of sources and sinks, it is found that snow is mainly produced by the deposition and accretion with ice. Cloud water is crucial to graupel. The melting of ice-phase particles enhances the rain production. The results of heat tests and drag tests reveal that the microphysical processes have interacted with the dynamic and thermal processes. Latent heat release of hydrometeors feeds back positively on snowfall while the drag force not. At last, comparisons of simulated results have been done between the two different kinds of snowfall cases. The microphysical processes o

关键词： snowfall mesoscale model MM5 microphysical process sources and sinks

Growth and energy budget of juvenile lenok Brachymystax lenok in relation to ration level

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Oceanology and Limnology 2015年第2期33卷 347-355页

作者：刘洋李钟杰张堂林苑晶牟振波刘家寿 State Key Laboratory of Freshwater Ecology and Biotechnology Institute of HydrobiologyChinese Academy of Sciences University of Chinese academy of sciences heilongjiang River Fisheries Research Institute Chinese Academy of Fishery Sciences

We evaluated the effect of ration level （RL） on the growth and energy budget of lenok Brachymystax lenok. Juvenile lenok （initial mean body weight 3.06±0.13 g） were fed for 21 d at five different ration levels： starvation, 2%, 3%, 4% bwd （body weight per day, based on initial mean values）, and apparent satiation. Feed consumption, apparent digestibility, and growth were directly measured. Specific growth rates in terms of wet weight, dry weight, protein, and energy increased logarithmically with an increase in ration levels. The relationship between specific growth rate in terms of wet weight （SGRw, %/d） and RL （%） was characterized by a decelerating curve： SGRw=- 1.417＋3.1661n（RL＋ 1）. The apparent digestibility coefficients of energy exhibited a decreasing pattern with increasing ration level, and there was a significant difference among different RLs. Body composition was significantly affected by ration size. The relationship between feed efficiency rate in terms of energy （FERe） and RL was： FERe=- 14.167＋23.793RL-3.367（RL）2, and the maximum FERe was observed at a 3.53% ration. The maintenance requirement for energy of juvenile lenok was 105.39 kJ BW （kg）-0.80/d, the utilization efficiency of DE for growth was 0.496. The energy budget equation at satiation was： 100IE=29.03FE＋5.78（ZE＋UE）＋39.56 HE＋25.63 RE, where IE is feed energy, FE is fecal energy, ZE＋UE is excretory energy, HE is heat production, and RE is recovered energy. Our results suggest that the most suitable feeding rate for juvenile lenok aquaculture for wet weight growth is 2.89% bwd, whereas for energy growth, the suggested rate is 3.53% bwd at this growth stage.

关键词： ration level growth energy budget Brachymystax lenok

Study on extraction of agaropectin from Gelidium amansii and its anticoagulant activity

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Oceanology and Limnology 2008年第2期26卷 186-189页

作者：綦慧敏李大新张晶晶刘力张全斌 Institute of Oceanology Chinese Academy of Sciences Shandong provincial Pharmaceutical Co.

Gelidium amansii agar was fractionated on DEAE-cellulose and four fractions were obtained sequentially. The yields of 1.0 mol/L NaCl fraction and 2.5 mol/L NaCl fraction were 2.80% and 2.03%. They are highly sulfated agar, and named as agaropectin with sulfate content being 22.8% and 32.5%, respectively. The anticoagulant experiment results show that agaropectin could effectively prolong the coagulation time in a dose-dependent manner in vitro. Agaropection could be absorbed and effectively prolong the plasma coagulation time in vivo. After intragastric administration at the doses of 100, 200, and 400 mg/kg·d in rats for 15 days, TT (thrombin time), CT (coagulation time), PT (prothrombin time), and APTT (activated partial thromboplastin time) could be effectively prolonged and the plasma Fib level could be significantly lowered.

关键词： agar Gelidium amansii agaropectin anticoagulation