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内蒙百万肥尾羊出口中东
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作者 王卫国 《外向经济》 1996年第11期8-8,共1页
内蒙古乌珠穆肥尾羊打入中东,出口数量成倍增长。截止目前,活羊已累计出口100万头(只),创汇5000多万美元。
关键词 肥尾羊 活羊 出口数量 蒙古羊 上颗粒 人工选择 粗毛 锡林郭勒盟 成集 饲料加工厂
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小孩不宜多吃爆米花
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《医学文选》 1997年第Z1期70-71,共2页
爆米花酥脆、香甜,是孩子们喜欢吃的零食。但吃多了对人体有害。爆米花机罐是铁做的,因为罐内有一层铅或铅锡合金,当罐体加热,罐内温度升高时,就有大量的铅蒸气和铅烟喷出并随温度的升高而增多,且弥漫均匀地拌在米粒之中。
关键词 爆米花机 铅锡合金 罐内温度 生长发育迟缓 铅蒸气 上颗粒 精神抑郁 铅含量 关节酸痛 消化系
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Facile synthesis of UCNPs/Zn_xCd_(1-x)S nanocomposites excited by near-infrared light for photochemical reduction and removal of Cr(Ⅵ) 被引量:7
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作者 Mengli Zhao Wanni Wang +5 位作者 Chenxi Huang Wang Dong Yang Wang Sheng Cheng Huiqing Wang Haisheng Qian 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2018年第7期1240-1248,共9页
Photocatalysis driven by near-infrared(NIR)light is of scientific and technological interest for ex-ploiting solar energy.In this study,we demonstrate a facile hydrothermal process to synthesize core-shell nanoparti... Photocatalysis driven by near-infrared(NIR)light is of scientific and technological interest for ex-ploiting solar energy.In this study,we demonstrate a facile hydrothermal process to synthesize core-shell nanoparticles combining upconversion nanoparticles(UCNPs)and alloyed ZnxCwhich can be excited using NIR or visible light.Morphologies,phase,and chemical composition have been investigated using field-emission scanning electron microscopy,transmission electron mi-croscopy,X-ray diffraction analysis,and atomic absorption spectroscopy.Moreover,we found that amorphous TiO2 layers existing in the final samples play an important role in formation ofyolk-shell nanoparticles,which bind the as-prepared ZnxCnanoparticlescan be tuna-ble by adjusting the amount of the Cd and Zn source compounds.The photochemical reduction of Cr(Ⅵ)in water has been performed to study the photocatalytic performance under irradiation by NIR light or a simulated solar light,showing efficient photoreduction and Cr(Ⅵ)removal over the/TiO2 yolk-shell nanoparticles.The as-prepared UCNPs@ZnxC/TiO2 nanoparticles show excellent production of hydroxyl radicals,which are responsible for the photochemical reduction of Cr(Ⅵ)to Cr(Ⅲ).This study will provide an alternative strategy for en-vironmental wastewater treatment,making full use of solar energy. 展开更多
关键词 Upconversion nanoparticle ZnxCd1-xS alloyed semiconductor Yolk-shell PHOTOCATALYSIS Hydrothermal synthesis
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TiO_2 composite nanotubes embedded with CdS and upconversion nanoparticles for near infrared light driven photocatalysis 被引量:6
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作者 Wanni Wang Fu Zhang +4 位作者 Chuanling Zhang Yang Wang Wei Tao Sheng Cheng Haisheng Qian 《Chinese Journal of Catalysis》 CSCD 北大核心 2017年第11期1851-1859,共9页
We report a colloidal process to coat a layer of TiO2onto SiO2composite nanofibers containing embedded CdS and upconversion nanoparticles(UCNPs).The SiO2composite nanofibers were fabricated by electrospinning.To impro... We report a colloidal process to coat a layer of TiO2onto SiO2composite nanofibers containing embedded CdS and upconversion nanoparticles(UCNPs).The SiO2composite nanofibers were fabricated by electrospinning.To improve the energy transfer efficiency,UCNPs and CdS nanoparticles were bound in close proximity to each other within the SiO2matrix.β‐NaYF4:Yb(30%),Tm(0.5%)@NaYF4:Yb(20%),Er(2%)core–shell nanoparticles were used as nanotransducers for near infrared light.These nanoparticles exhibited enhanced upconversion fluorescence compared withβ‐NaYF4:Yb(30%),Tm(0.5%)orβ–NaYF4:Yb(30%),Tm(0.5%)@NaYF4nanoparticles.The morphologies,size and chemical compositions have been extensively investigated using field emission scanning electron microscopy(FESEM),transmission electron microscopy(TEM),X‐ray diffraction(XRD)and X‐ray photoelectron spectra(XPS),respectively.The TEM images showed that the TiO2composite nanotubes were embedded with a large amount of UCNPs and CdS nanoparticles.The composite TiO2nanotubes degraded more than90%of rhodamine B(RhB)dye during20min of irradiation by simulated solar light.In particular,more than50%of RhB was decomposed in70min,under irradiation of near infrared light(NIR).This high degradation was attributed to the full spectrum absorption of solar light,and the enhanced transfer efficiency for near infrared light.The as‐prepared nanostructures can harness solar energy,and provide an alternative to overcome energy shortages and environmental protection. 展开更多
关键词 TiO2 nanotubes Upconversion nanoparticles Energy transfer PHOTOCATALYSIS Nanotransducer
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Theoretical Approach to Concentration Distribution and Adhesion Efficiency of Fine Particles Around a Rising Bubble in Slurry Systems 被引量:1
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作者 蔡旺锋 许春建 周明 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2002年第5期550-557,共8页
Quantitative prediction of distribution function and adhesionefficiency of particles around a rising bubble in slurry systems ispresented in this work. By solving the convection-diffusion equation(Fokker-Planck equati... Quantitative prediction of distribution function and adhesionefficiency of particles around a rising bubble in slurry systems ispresented in this work. By solving the convection-diffusion equation(Fokker-Planck equation), the influence of Brownian diffusivity offine particles on concentration distribution and adhesion efficiencyis demonstrated with the hydrodynamic force and van der Waalsattractive potential between particles and bubble considered. It isfound that two kinds of mechanism dominate the adhesion process ofparticles on bubble according to different Peclet number or size ofparticles and bubble, as well as other properties of the slurrysystems. In addition, the viscosity ratio of bubble to the suspendingfluid was found to have obvious influence on particle adhesion. 展开更多
关键词 adhesion efficiency Brownian diffusivity distribution function Fokker-Planck equation
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Neurobiology of mammalian olfactory learning that occurs during sensitive periods
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作者 Hideto KABA 《Current Zoology》 SCIE CAS CSCD 北大核心 2010年第6期819-833,共15页
This review examines the organizational principles underlying olfactory learning in three specialized contexts that occur during sensitive periods of enhanced neural plasticity and emphasizes some of their common feat... This review examines the organizational principles underlying olfactory learning in three specialized contexts that occur during sensitive periods of enhanced neural plasticity and emphasizes some of their common features. All three forms of olfactory learning are associated with neural changes in the olfactory bulb (OB) at the first stage of sensory processing. These changes require the association of the olfactory and somatosensory signals in the OB. They all depend on somatosensory stimulation-induced release of noradrenaline that induces structural and functional changes at mitral-granule cell reciprocal synapses in the OB, resulting in increases in inhibitory transmission. In the accessory olfactory bulb, this represents the enhanced self-inhibition of mitral cells, which selectively disrupts the transmission of the mating male's pregnancy-blocking signal at this level. In contrast, an extensive network of secondary dendrites of mitral cells in the main olfactory bulb probably results in a sharpening of the odor-induced pattern of activity, due to increases in lateral inhibition, leading to offspring recognition in sheep and neonatal learning in rats and rabbits. These findings show that inhibitory intemeurons play a critical role in olfactory learning. Further work on how these neurons shape olfactory circuit function could provide important clues to understand memory functions of interneurons in other systems. Moreover, recent research has suggested that three forms of olfactory learning are controlled by synergistic, redundant, and distributed neural mechanisms. This has general implications regarding the mechanisms that may contribute to the robustness of memories [Current Zoology 56 (6): 819-833, 2010]. 展开更多
关键词 Mate recognition memory Maternal recognition Olfactory bulb Olfactory learning Sensitive period
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The association between IgG1,IgG2 subclasses toward human papillomavirus 16-like particles in the serum and cervical intraepithelial neoplasia
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作者 Ling Han Bingyi Zhang +3 位作者 Hairong Li Manzhen Zuo Yuezhen Xue Jun Zhang 《The Chinese-German Journal of Clinical Oncology》 CAS 2010年第5期278-282,共5页
Objective:The paper aimed to study the relationship between the expressions of immunoglobulin G(IgG) subclasses toward human papillomavirus 16-like particles(HPV16VLPs) in the serum of patients and different grades of... Objective:The paper aimed to study the relationship between the expressions of immunoglobulin G(IgG) subclasses toward human papillomavirus 16-like particles(HPV16VLPs) in the serum of patients and different grades of cervical lesions.Methods:The expressions of IgG subclasses in 32 cases of human papillomavirus(HPV) infection,30 cervical intraepithelial neoplasia(CIN I),43 CIN Ⅱ-Ⅲ,and 24 hysteromyoma and chronic cervicitis were examined by ELISA.Results:The absorbance values of HPV16VLPs-IgG,IgG1 increased with the grade of CIN(P < 0.05).The IgG2 dominance(IgG2/IgG1 ratio > 1) from control group was 100%,87.50% for HPV infection group,75% for CIN I group,compared with that from CIN Ⅱ-Ⅲ patients(9.52%)(P < 0.05).The positive rates and absorbance values of HPV16VLPs-IgG,IgG1 and IgG2 from HPV16-DNA positive group were significantly higher than those from non-HPV16-DNA positive group(P < 0.05).There was a moderate correlation between the HPV16-DNA testing and detection of HPV16VLPs-IgG(r = 0.531,P < 0.05).Conclusion:An increase of the expressions of HPV16VLPs-IgG and its subclasses in the serum of the patients with cervical precancerous lesions,especially those with CIN II-III,might be associated with duration of HPV infection and severity of cervical lesions.An increase of the IgG2 dominance(IgG2/IgG1 > 1) in serum from low grade cervical lesions group and normal control group,might indicate the clearance of HPV infection and the regression of cervical lesions. 展开更多
关键词 cervical intraepithelial neoplasia(CIN) IgG1 and IgG2 subclasses ELISA
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话说蝗虫
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作者 刁永泉 《诗刊》 北大核心 1999年第1期61-61,共1页
关键词 蝗虫 庄稼 象形文字 上颗粒 繁殖 装饰 歉收 蝴蝶 蜻蜓 黄熟
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魔兽也有蔫了的时候
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《NBA特刊》 2012年第12期104-104,共1页
11月22日,湖人客场97-113负于国王,"魔兽"霍华德被彻底打蔫了,上半场只得2分,全场得7分9个篮板,完全没有展现出联盟顶级中锋应有的水准。霍华德在第一节进攻端上颗粒无收,直到上半场还剩1分半钟时才接保罗-加索尔匪夷所思的... 11月22日,湖人客场97-113负于国王,"魔兽"霍华德被彻底打蔫了,上半场只得2分,全场得7分9个篮板,完全没有展现出联盟顶级中锋应有的水准。霍华德在第一节进攻端上颗粒无收,直到上半场还剩1分半钟时才接保罗-加索尔匪夷所思的妙传完成空接灌篮,事实上后者在这次进攻上中完全可以独立完成。 展开更多
关键词 进攻 下肢力量 联盟 比赛 球员 独立完成 缺陷 完全 位置 上颗粒
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Unexpected luminescence enhancement of upconverting nanocrystals by cation exchange with well retained small particle size 被引量:10
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作者 Mingliang Deng LeyuWang 《Nano Research》 SCIE EI CAS CSCD 2014年第5期782-793,共12页
Highly luminescent upconversion nanoparticles (UCNPs) with small sizes are highly desirable for bioapplications. A facile in situ cation exchange strategy has been developed to greatly enhance the UC luminescence of... Highly luminescent upconversion nanoparticles (UCNPs) with small sizes are highly desirable for bioapplications. A facile in situ cation exchange strategy has been developed to greatly enhance the UC luminescence of hexagonal phase NaYF4 NPs while maintaining their small particle size and shape. Via a cation exchange treatment by hot-injecting Gd3+ precursors into the as-prepared NPs solution without pre-separation, the naked-eye visible UC emission of the NPs was enhanced about 29 times under 980 nm near infrared (NIR) excitation with unchanged particle size. The cation exchange process was further demonstrated for the case of NaYF4 nanorods (NRs). After the cation exchange, the nanorod was broken into two NPs with stronger emission. The cation exchanged hydrophobic UCNPs were further encapSulated with poly(amino acid) and successfully applied for targeted cancer cell UC luminescence imaging. 展开更多
关键词 cation replacement upconversionluminescence cell imaging luminescence enhancement
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A novel strategy for improving upconversion luminescence of NaYF4:Yb, Er nanocrystals by coupling with hybrids of silver plasmon nanostructures and poly(methyl methacrylate) photonic crystals 被引量:8
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作者 Wen Xu Yongsheng Zhu +5 位作者 Xu Chen Jing Wang Li Tao Sai Xu Tong Liu Hongwei Song 《Nano Research》 SCIE EI CAS CSCD 2013年第11期795-807,共13页
The coupling of upconversion nanophosphors (UCNPs) with the surface plasmonic resonance (SPR) of noble metals is a promising way to improve luminescent efficiency of UCNPs; however, it is still a challenge to achi... The coupling of upconversion nanophosphors (UCNPs) with the surface plasmonic resonance (SPR) of noble metals is a promising way to improve luminescent efficiency of UCNPs; however, it is still a challenge to achieve stable, reproducible and effective upconversion luminescence (UCL) enhancement through such coupling. In this work, we present a novel strategy to improve UCL of NaYF4:ybB,Er3. UCNPs, by combining the near-field coupling of SPR of silver and the far-field coupling of poly(methyl methacrylate) (PMMA) opal photonic crystals (OPCs) with the UCNPs. In order to control the effective interaction distance between the UCNPs and the SPR, a porous silver film consisting of randomly distributed silver nanoparticles (NPs) (〉 100 nm) was prepared which demonstrated strong SPR over a broad wavelength range, and its coupling to the UCNPs was found to be much stronger than that of a dense film. In the far-field coupling of OPCs, the photonic stop band (PSB) of the PMMA OPCs was tuned to 980 nm, matching exactly the excitation light. By modulating the particle size of the UCNPs, and the direction and excitation power of the incident light, a maximum enhancement of 60-fold was observed, which is an important advance for metaMnduced UCL enhancement systems. 展开更多
关键词 upconverslon porous Ag film near-field coupling opal photonic crystals(OPCs) far-field coupling
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