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Water Absorption and Chloride Ion Penetrability of Concrete Damaged by Freeze-thawing and Loading 被引量:1
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作者 杨林 SUN Wei +2 位作者 LIU Cheng 张云升 LIANG Fei 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2017年第2期330-337,共8页
In order to investigate water and chloride ion transport in damaged concrete, three types of concrete were prepared, freeze-thawing(F-T) cycling and compressive loading were adopted to induce damage to concrete. Ult... In order to investigate water and chloride ion transport in damaged concrete, three types of concrete were prepared, freeze-thawing(F-T) cycling and compressive loading were adopted to induce damage to concrete. Ultrasonic pulse velocity technique was used for evaluating the damage degree of concrete, and the defects of damaged concrete were also detected by X-CT. Water absorption and chloride ion penetrability were used for describing the transport properties of damaged concrete. Effects of damage degree on the water absorption rate and chloride ion penetrability were investigated in detail and the relationships were also established. The results show that the water absorption of concrete makes various responses to damage degree due to the difference of concrete type and damage method. For same concrete with similar damage degree, the water absorption rate of F-T damaged concrete is usually larger than that of concrete damaged by loading. The chloride ion penetrability of damaged concrete increases linearly with increasing damage degree, which is more sensitive to damage degree if the original penetrability of sound concrete is higher. 展开更多
关键词 concrete water absorption chloride ion freeze-thawing loading durability
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Optical absorption of ion irradiated multi-walled carbon nanotube sheets in the visible to terahertz ranges 被引量:2
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作者 ISHAQ Ahmad YAN Long +2 位作者 HE Suixia ZHU Dezhang ZHOU Xingtai 《Nuclear Science and Techniques》 SCIE CAS CSCD 2009年第4期197-201,共5页
Optical absorption of Ar and H ion beam irradiated multi-walled carbon nanotube (MWCNT) sheets at various doses in the visible and terahertz spectral ranges was investigated.It was found that the optical absorption of... Optical absorption of Ar and H ion beam irradiated multi-walled carbon nanotube (MWCNT) sheets at various doses in the visible and terahertz spectral ranges was investigated.It was found that the optical absorption of MWCNT sheets in the visible range was decreased with increasing ion irradiation dose.Similar behavior was observed in terahertz range,where the optical absorption of MWCNT sheets in the range of 0 to 1.5 THz was also decreased with increasing ion irradiation dose.The optical absorption decreases in irradiated MWCNT sheets can be ascribed to the increase of defects in the irradiated MWCNTs. 展开更多
关键词 碳元素 离子照射 MWCNT 原子核物理学
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Optical absorption of Tl^+ ions in KBr_(1-x)I_x:TlI mixed crystals
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作者 Eswaran P Ravisankar R Nagarajan S 《Nuclear Science and Techniques》 SCIE CAS CSCD 2009年第4期208-218,共11页
Optical absorption spectra of the mixed crystals of KBr1-xIx:Tl+ crystals studied at room temperature are reported.The absorption spectra indicated the appearance of additional bands on the low energy side of the Char... Optical absorption spectra of the mixed crystals of KBr1-xIx:Tl+ crystals studied at room temperature are reported.The absorption spectra indicated the appearance of additional bands on the low energy side of the Characteristic A,B and C absorption bands of KBr:Tl+ single crystals with increasing iodine composition.Comparing with earlier reports,the additional bands were attributed to the complex Tl+centers in the mixed configuration surrounded by Br-and I-ions as nearest neighbors.The absorption spectra of gamma irradiated mixed crystals showed F band,which shifts towards low energy side with the composition of iodine ions in the mixed crystals. 展开更多
关键词 能级 核技术 光谱吸收 碘离子
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The characterization of low energy molecular hydrogen ion-induced defects in synthetic diamond by optical absorption
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作者 MaZhong-Quan AokiY 《Nuclear Science and Techniques》 SCIE CAS CSCD 1998年第2期102-108,共7页
The results of optical absorption analysis of the synthetic diamonds(type Ib) which were implanted with 40 keV molecular hydrogen ions at doses of 10^15-10^17H/cm^2(at 100K),showed that the increase of optical density... The results of optical absorption analysis of the synthetic diamonds(type Ib) which were implanted with 40 keV molecular hydrogen ions at doses of 10^15-10^17H/cm^2(at 100K),showed that the increase of optical density(OD) of modified layer(-140nm) in UV-VIS region was dependent upon the damage level caused by ion implantation process.The range of relative optical band gap(Er.opt) around 2.0eV suggested that an amorphous carbon network structure like a-C film,which probably contains some localized subtetrabedral-coordinated clusters embedded in the fourflod(sp^3) sites.was tentatively found in this layer,basing on the optical gap of carbon materials.The evolution of Er,opt with ion fluence indicated that no more hydrogenated carbon compositions were produced in as -implanted samples,while the increase of Er,opt with annealing temperature was very similar to that of hydrogen content dependence of Eopt in hydrogenately amorphous carbon(a-C:H):In addition the optical inhomogeneity of type Ib diamond has been revealed by a 2-dimension topograph in transmission mode at λ=430nm。 展开更多
关键词 金刚石 光吸收 氢离子移植
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Simulation of Intermediate State Absorption Enhancement in Rare-Earth Ions by Polarization Modulated Femtosecond Laser Field
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作者 Wen-Jing Cheng Shi-Hua Zhao 《Chinese Physics Letters》 SCIE CAS CSCD 2018年第11期23-27,共5页
We extend the third perturbation theory to study the polarization control behavior of the intermediate state absorption in Nd^(3+)ions. The results show that coherent interference can occur between the single-photo... We extend the third perturbation theory to study the polarization control behavior of the intermediate state absorption in Nd^(3+)ions. The results show that coherent interference can occur between the single-photon and three-photon excitation pathways, and depends on the central frequency of the femtosecond laser field. Moreover,single-photon and three-photon absorptions have different polarization control efficiencies, and the relative weight of three-photon absorption in the whole excitation processes can increase with increasing the laser intensity.Therefore, the enhancement or suppression of the intermediate state absorption can be realized and manipulated by properly designing the intensity and central frequency of the polarization modulated femtosecond laser field.This research can not only enrich theoretical research methods for the up-conversion luminescence manipulation of rare-earth ions, but also can provide a clear physical picture for understanding and controlling multi-photon absorption in a multiple energy level system. 展开更多
关键词 ab Simulation of Intermediate State absorption Enhancement in Rare-Earth ions by Polarization Modulated Femtosecond Laser Field
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Simulating resonance-mediated two-photon absorption enhancement in rare-earth ions by a rectangle phase modulation
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作者 齐大龙 郑烨 +6 位作者 程文静 姚云华 邓联忠 冯东海 贾天卿 孙真荣 张诗按 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第1期329-334,共6页
Improving the up-conversion luminescence efficiency crucial in several related application areas. In this work, of rare-earth ions via the multi-photon absorption process is we theoretically propose a feasible scheme ... Improving the up-conversion luminescence efficiency crucial in several related application areas. In this work, of rare-earth ions via the multi-photon absorption process is we theoretically propose a feasible scheme to enhance the resonance-mediated two-photon absorption in Er3+ ions by shaping the femtosecond laser field with a rectangle phase modulation. Our theoretical results show that the resonance-mediated two-photon absorption can be decomposed into the on-resonant and near-resonant parts, and the on-resonant part mainly comes from the contribution of laser central frequency components, while the near-resonant part mainly results from the excitation of low and high laser frequency components. So, the rectangle phase modulation can induce a constructive interference between the two parts by properly designing the modulation depth and width, and finally realizes the resonance-mediated two-photon absorption enhancement. More- over, our results also show that the enhancement efficiency of resonance-mediated two-photon absorption depends on the laser pulse width (or laser spectral bandwidth), final state transition frequency, and intermediate and final state absorption bandwidths. The enhancement efficiency modulation can be attributed to the relative weight manipulation of on-resonant and near-resonant two-photon absorption in the whole excitation process. This study presents a clear physical insight for the quantum control of resonance-mediated two-photon absorption in the rare-earth ions, and there will be an important significance for improving the up-conversion luminescence efficiency of rare-earth ions. 展开更多
关键词 coherent quantum control femtosecond pulse shaping two-photon absorption rare-earth ions
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Isomerism and coordination mode effects on two-photon absorption of tris(picolyl)amine-based fluorescent probes for zinc ions
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作者 Ke Zhao Jun Song +2 位作者 Mei-Yu Zhu Han Zhang Chuan-Kui Wang 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第10期293-299,共7页
One-photon absorption and two-photon absorption(TPA) properties of three tris(picolyl)amine-based zinc ion sensors are investigated by employing the density functional response theory in combination with the polar... One-photon absorption and two-photon absorption(TPA) properties of three tris(picolyl)amine-based zinc ion sensors are investigated by employing the density functional response theory in combination with the polarizable continuum model.The different isomer and coordination geometry of each probe are taken into account. Special emphasis is placed on the effects of isomerism and the coordination mode on the optical properties. The intra-molecular charge transfer(ICT)properties are specified by natural bond orbital charge analysis. It is shown that the isomerism has non-negligible effects on TPA properties of free ligands. It is found that both the TPA wavelength and the cross section are highly dependent on the coordination mode. When the zinc ion connects with the picolyl unit in the middle of a ligand, the zinc complex has a large TPA intensity in a long wavelength range due to the increased ICT mechanism. 展开更多
关键词 two-photon absorption ISOMERISM coordination mode zinc ion
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Determination of Absorption Cross Section of J/ψ in Relativistic Heavy Ion Collisions
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作者 Chao Wei-qin Liu Bo (Institute of High Energy Physics,Chinese Academy of Sciences,P.O.Box 918(4),Beijing 100039) 《Chinese journal of nuclear physics》 1994年第4期283-290,共8页
The absorption cross section σ<sub>abs</sub> of J/ψ produced in relativistic heavy ioncollisions is deduced based on the analysis of the absorption length through which theproduced J/ψ passes in the col... The absorption cross section σ<sub>abs</sub> of J/ψ produced in relativistic heavy ioncollisions is deduced based on the analysis of the absorption length through which theproduced J/ψ passes in the colliding nuclei.The obtained σ<sub>abs</sub> in A-A collisions is con-siderably higher than that in h-A processes.The reason for this different result is dis-cussed in terms of an analysis of the p<sub>T</sub>-dependence of the produced J/ψ. 展开更多
关键词 absorption cross section RELATIVISTIC HEAVY ion COLLISion J/Ψ SUPPRESSion
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The microwave absorption of ceramic-cup microwave ion source
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作者 LIU Lin-Mao, JING Shi-Wei, LI Wen-Sheng, GU Li (Physics Department, foe Northeast Normal University, Changchun 130024) 《Nuclear Science and Techniques》 SCIE CAS CSCD 2000年第3期155-161,共7页
An experiment system of ceramic-cup microwave ion source has been built here. Its microwave absorption efficiency as a function of the magnetic field and the pressure is presented. When the microwave incident power is... An experiment system of ceramic-cup microwave ion source has been built here. Its microwave absorption efficiency as a function of the magnetic field and the pressure is presented. When the microwave incident power is 300-500W the microwave absorption efficiencies are more than 90% if the system is optimized and the magnetic field at the microwave window is 0.095T. 展开更多
关键词 微波离子源 中子管 陶瓷材料 微波吸收效率 电子回旋加速器
全文增补中
Metal ion–binding properties of the L-aspartic acid and tartaric acid, a coparative investigation. How can be increased the dosage of mineral absorption in the body
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作者 Seyed Ali Akbar Sajadi 《Advances in Bioscience and Biotechnology》 2010年第4期354-360,共7页
A comparative research has been developed for acidity and stability constants of M(TTA)1 and M(Asp)2 complexes which have been determined by potentiometric pH titration. Depending on metal ion–binding properties, vit... A comparative research has been developed for acidity and stability constants of M(TTA)1 and M(Asp)2 complexes which have been determined by potentiometric pH titration. Depending on metal ion–binding properties, vital differences in building complex were observed. The present study shows that in M(TTA) complexes, metal ions are coordinated to the carboxyl groups, but in M(Asp) some metal ions are able to build macrochelate over amine group. Hence, the following intermolecular and as a result independent concentration equilibrium between an open–isomer M(Asp)op and a closed–isomer M(Asp)cl, has to be considered cl op. The amounts are reported. The results mentioned above demonstrate that for some M(Asp) complexes the stability constants is also largely determined by the affinity of metal ions for amine group. This leads to a kind of selectivity of metal ions and transfer them via building complexes with the aspartate. The result of this effect is a higher dosage-absorption of minerals in body. Based on the sort of metal ions, the drug-therapy can be different. For heavy metal ions this building complex helps the absorption and filtration of the blood plasma, and consequently the excursion of heavy metal ions takes place. This is an important method in microdialysis. Other metal ions such as the complexes can be considered as mineral carriers. These complexes in certain conditions (PH–range) can release the minerals in body. 展开更多
关键词 Tartaric Acid DIVALENT Metal ions POTENTIOMETRIC TITRATion ACIDITY and Stability CONSTANTS Mineral absorption Minerals in Body
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Impact of Salt Stress on Growth and Ion Uptake of Different Parts of Oil Sunflower Seedlings 被引量:7
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作者 杨晓翠 李文建 +1 位作者 曲颖 张天虎 《Agricultural Science & Technology》 CAS 2011年第3期354-358,共5页
[Objective] The purpose was to discuss the effects of different NaCl concentrations on fresh weight and dry weight,ion absorption and distribution in oil sunflower seedlings. [Method] Under the simulated salt environm... [Objective] The purpose was to discuss the effects of different NaCl concentrations on fresh weight and dry weight,ion absorption and distribution in oil sunflower seedlings. [Method] Under the simulated salt environment by using NaCl solutions at different concentrations,the dry weight,fresh weight and ion content of oil sunflower seedlings were determined. [Result] With the increase of NaCl concentration,the growth rate of oil sunflower seedling was inhibited. In addition,its fresh weight and dry weight also decreased; the fresh weight of leaf decreased most significantly by 60%,and that of cotyledon decreased most slightly by 13% at 200 mmol/L NaCl concentration. The dry weight of root,stem,leaf and cotyledon decreased by 35%,39%,55% and 8% respectively,showing a similar decreasing trend with fresh weight. Under NaCl stress,Na+ content in root and stem of oil sunflower seedling increased while K+ decreased. Na+ content was mainly concentrated in roots and stems much more than in leaves; K+ content in roots decreased most significantly by 21% compared with control,and it was relatively high in leaf. Ca2+ and Mg2+ content was decreased slightly in roots and stems; Ca2+ content in leaves and cotyledons was stable; Mg2+ content was slightly increased. [Conclusion] Oil sunflower maintained high mineral ion absorptionunder salt stress,that maybe the part reason for high salt tolerance of oil sunflower seedlings. 展开更多
关键词 Oil sunflower seedlings NACL ion absorption
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Optical and structural properties of Ge-ion-implanted fused silica after annealing in different ambient conditions 被引量:1
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作者 向霞 陈猛 +3 位作者 陈美艳 祖小涛 朱莎 王鲁闽 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第1期551-556,共6页
Ge^+ ions are implanted into fused silica glass at room temperature and a fluence of 1 × 10^17 cm^-2. The as-implanted samples are annealed in O2, N2 and Ar atmospheres separately. Ge^0, GeO and GeO2 coexist in ... Ge^+ ions are implanted into fused silica glass at room temperature and a fluence of 1 × 10^17 cm^-2. The as-implanted samples are annealed in O2, N2 and Ar atmospheres separately. Ge^0, GeO and GeO2 coexist in the as-implanted and annealed samples. Annealing in different atmospheres at 600℃ leads each composite to change its content. After annealing at 1000℃, there remains some amount of Ge^0 in the substrates. However, the content of Ge decreases due to out-diffusion. After annealing in N2, Si N composite is formed. The absorption peak of GeO appears at 240 nm after annealing in O2 atmosphere, and a new absorption peak occurs at 418 nm after annealing in N2 atmosphere, which is attributed to the Si N composite. There is no absorption peak appearing after annealing in Ar atmosphere. Transmission electron microscopic images confirm the formation of Ge nanoparticles in the as-implanted sample and GeO2 nanoparticles in the annealed sample. In the present study, the GeO content and the GeO2 content depend on annealing temperature and atmosphere. Three photolumineseence emission band peaks at 290, 385 and 415 nm appear after ion implantation and they become strong with the increase of annealing temperature below 700℃ and their photoluminescences recover to the values of as-grown samples after annealing at 700℃. Optical absorption and photoluminescence depend on the annealing temperature and atmosphere. 展开更多
关键词 NANOPARTICLES optical absorption PHOTOLUMINESCENCE ion implantation
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Comparison of different plasma chambers in microwave ion source for the intense neutron tube 被引量:1
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作者 JING Shi-Wei, LIU Lin-Mao (Physics Department, Northeast Normal University, Changchun 130024) 《Nuclear Science and Techniques》 SCIE CAS CSCD 2003年第1期83-85,共3页
The microwave absorption efficiency, which is relevant to magnet field and its distribution, is a major parameter of the microwave ion source (MWIS) for the intense neutron tube. Based on previous work, the relations ... The microwave absorption efficiency, which is relevant to magnet field and its distribution, is a major parameter of the microwave ion source (MWIS) for the intense neutron tube. Based on previous work, the relations between microwave absorption efficiency and plasma chamber structure and thickness of the microwave introduction window are studied. The microwave absorption efficiency reaches to 100% when plasma chamber is 100mm long and the window thickness is 30mm. The microwave absorption efficiency as a function of pressure is also presented. 展开更多
关键词 等离子体 微波离子谱 微波吸收功率 MWIS 高密度中子管
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Er^(3+) ion concentration effect on transient and steady-state behavior in Er^(3+):YAG crystal 被引量:1
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作者 Asadpour Seyyed Hossein Rahimpour Soleimani H 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第10期248-253,共6页
The effect of Er3+ ion concentration on transient and steady-state behavior in 45-nm Er3+ :YAG crystal is investigated. It is shown that by changing the signal field, the coherent field and the concentration of Er3... The effect of Er3+ ion concentration on transient and steady-state behavior in 45-nm Er3+ :YAG crystal is investigated. It is shown that by changing the signal field, the coherent field and the concentration of Er3+ ions in the crystal, the absorption, dispersion, and group index of the weak probe field can be adjusted. Also, it is found that the probe absorption occurs in the presence of population inversion and probe amplification is obtained in the absence of population inversion. 展开更多
关键词 Er3+ ion concentration absorption DISPERSion group index
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Spectra of sodium aluminate solutions 被引量:3
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作者 马淑花 郑诗礼 +1 位作者 徐红彬 张懿 《中国有色金属学会会刊:英文版》 EI CSCD 2007年第4期853-857,共5页
The UV spectra of sodium aluminate solutions were obtained in the sodium oxide concentration range from 59 to 409 g/L and the caustic ratio range from 1.5 to 4.0 to reveal the structure characteristics of them. It is ... The UV spectra of sodium aluminate solutions were obtained in the sodium oxide concentration range from 59 to 409 g/L and the caustic ratio range from 1.5 to 4.0 to reveal the structure characteristics of them. It is found that a new peak appears at about 370 nm besides peaks at about 220 and 266 nm in all solutions. The new peak is strongly favored by high hydroxide concentration and high caustic ratio. And it only appears when the solutions are prepared by dissolving sodium hydroxide and aluminum hydroxide. In addition, the IR and Raman spectra of sodium aluminate solutions with high alkali concentration and high caustic ratio were measured, and the UV spectra of aqueous solutions of Al( H2O )36+and AlF 36?were measured as well. According to the crystal field theory in coordination chemistry as well as the above spectra characteristics, this new peak at about 370 nm is determined as the evidence of a new species of aluminate ion with a coordination number of 6. 展开更多
关键词 铝酸钠溶液 紫外光谱 红外吸收光谱 喇曼光谱 铝酸盐离子
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Cluster-assisted generation of multi-charged ions in nanosecond laser ionization of pulsed hydrogen sulfide beam at 1064 and 532 nm 被引量:1
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作者 牛冬梅 李海洋 +3 位作者 罗晓琳 梁峰 程爽 李安林 《Chinese Physics B》 SCIE EI CAS CSCD 2006年第7期1511-1516,共6页
The multi-charged sulfur ions of Sq^+ (q ≤ 6) have been generated when hydrogen sulfide cluster beams are irradiated by a nanosecond laser of 1064 and 532 nm with an intensity of 10^10- 10^12W.cm^-2. S^6+ is the ... The multi-charged sulfur ions of Sq^+ (q ≤ 6) have been generated when hydrogen sulfide cluster beams are irradiated by a nanosecond laser of 1064 and 532 nm with an intensity of 10^10- 10^12W.cm^-2. S^6+ is the dominant multicharged species at 1064 nm, while S^4+, S^3+ and S^2+ ions are the main multi-charged species at 532 nm. A three-step model (i.e., multiphoton ionization triggering, inverse bremsstrahlung heating, electron collision ionizing) is proposed to explain the generation of these multi-charged ions at the laser intensity stated above. The high ionization level of the clusters and the increasing charge state of the ion products with increasing laser wavelength are supposed mainly due to the rate-limiting step, i.e., electron heating by absorption energy from the laser field via inverse bremsstrahlung, which is proportional to λ2,λA being the laser wavelength. 展开更多
关键词 CLUSTER multi-charged ion inverse bremsstrahlung absorption electron impact ionization
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Thermal Analysis and Immobilisation of Spent Ion Exchange Resin in Borosilicate Glass 被引量:3
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作者 Nasir Hamodi Kassandra Papadopoulou +1 位作者 Tristan Lowe Timothy Abram 《New Journal of Glass and Ceramics》 2012年第3期111-120,共10页
The underground disposal of waste arising from the nuclear industry needs constant evaluation in order to improve upon it through minimizing the volume and cost by reducing the amount of glass used without compromisin... The underground disposal of waste arising from the nuclear industry needs constant evaluation in order to improve upon it through minimizing the volume and cost by reducing the amount of glass used without compromising the safety of any leakage from the radioactive waste form. The immobilization of the spent resin (NRW-40) in borosilicate glass was investigated to meet the acceptance criteria for disposal of nuclear waste. The organic mixed bed resin in granular form was used as a waste target. The analysis of surrogate resin doped with radioactive and non-radioactive cesium (Cs) and cobalt (Co) was carried out to investigate their thermal and chemical properties and their compatibility with an alkaline borosilicate glass. The thermal analysis indicates that the structural damage caused by 1 mSv gamma radiation to the radioactive resin has altered its properties in comparison with the non-radioactive resin, same amount of cesium (8.88 wt%) and cobalt (1.88 wt%) were used in both resins. The immobilization of residue shows that the excess sulfur in the residue caused phase crystallization in the final glass matrix. It was found that the volatilization of Cs-137 and Co-60 from the successful radioactive resin-glass matrix (HG-3-IER-500) were more than that in the non-radioactive resin-glass matrix (HG-3-IEX-500). The study demonstrates comprehensive experimental and analytical works and shows that it is possible to minimise the volume of the waste while keeping the required safety levels, however further research needs to be carried out in this area. 展开更多
关键词 absorption Processes BOROSILICATE Glass IMMOBILIZATion ion EXCHANGE RESIN Radiation Damage
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An Amidoximated-UHMEPE Fiber for Selective and High Efficient Removal of Uranyl and Thorium from Acid Aqueous Solution 被引量:1
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作者 Chan Jin Jiangtao Hu +6 位作者 Jianqiang Wang Chunyun Xie Yajun Tong Linjuan Zhang Jing Zhou Xiaojing Guo Guozhong Wu 《Advances in Chemical Engineering and Science》 2017年第1期45-59,共15页
High efficient removal and recovery of uranium and thorium from nuclear waste solution are essential for environmental preservation and fuel recycle. A new polymer fiber adsorbent (UHMEPE-g-PAO fiber), prepared by ami... High efficient removal and recovery of uranium and thorium from nuclear waste solution are essential for environmental preservation and fuel recycle. A new polymer fiber adsorbent (UHMEPE-g-PAO fiber), prepared by amidoximation of grafted polyacrylonitrile onto Ultra High Molecular Weight Polyethylene (UHMWPE) fiber, was used to remove the uranyl and thorium ions from acid aqueous solutions and its performance was carefully investigated. It was found that uranyl ion can penetrate the fiber through the connected pore structures, forming (UO2) (R-C(NH2)-NO)2 chelates with the amidoxime groups within the fiber. Two amidoxime groups (U-N and U-Oeq) and two water molecules (U-Oeq2) are bound to uranyl ion in the fiber. On the contrary, thorium ions are adsorbed mainly on the fiber surface in the form of Th(OH)4 precipitate that blocks the entrance of Th4+ ion into fiber pores. The maximum included other two capacities of uranyl and thorium ions were estimated to be 262.01 mg/g and 160 mg/g at room temperature with pH 3.0, respectively. The results also indicate that the UHMWPE-g-PAO fiber has higher adsorption selectivity for uranyl ion than thorium ion. Uranium and thorium oxide particles were obtained as the ultimate product after sintering of the fiber adsorbent. This novel and environmentally friendly adsorption process is feasible to extract uranium or thorium from acidic aqueous solution. 展开更多
关键词 UHMWPE FIBER Uranium ionS THORIUM ionS SELECTIVE absorption Mechanism XAFS SR-FTIR
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Responsive mechanism and molecular design of di-2-picolylamine-based two-photon fluorescent probes for zinc ions
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作者 朱美玉 赵珂 +1 位作者 宋军 王传奎 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第2期327-333,共7页
The properties of one-photon absorption(OPA), emission and two-photon absorption(TPA) of a di-2-picolylaminebased zinc ion sensor are investigated by employing the density functional theory in combination with res... The properties of one-photon absorption(OPA), emission and two-photon absorption(TPA) of a di-2-picolylaminebased zinc ion sensor are investigated by employing the density functional theory in combination with response functions.The responsive mechanism is explored. It is found that the calculated OPA and TPA properties are quite consistent with experimental data. Because the intra-molecular charge transfer(ICT) increases upon zinc ion binding, the TPA intensity is enhanced dramatically. According to the model sensor, we design a series of zinc ion probes which differ by conjugation center, acceptor and donor moieties. The properties of OPA, emission and TPA of the designed molecules are calculated at the same computational level. Our results demonstrate that the OPA and emission wavelengths of the designed probes have large red-shifts after zinc ions have been bound. Comparing with the model sensor, the TPA intensities of the designed probes are enhanced significantly and the absorption positions are red-shifted to longer wavelength range. Furthermore, the TPA intensity can be improved greatly upon zinc ion binding due to the increased ICT mechanism. These compounds are potential excellent candidates for two-photon fluorescent zinc ion probes. 展开更多
关键词 two-photon absorption fluorescent probe zinc ion intra-molecular charge transfer
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Comparison of Three Methods for Determination of Ammonia Nitrogen in Surface Water
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作者 Zuo Jia Dai Shuhao +2 位作者 Wei Baomei Qiu Lan Tu Xiaobin 《Meteorological and Environmental Research》 CAS 2019年第3期90-91,97,共3页
Nessler's reagent spectrophotometry,gas phase molecular absorption spectrometry and ion chromatography were respectively used to determine ammonia nitrogen in surface water.The detection limit,precision,accuracy a... Nessler's reagent spectrophotometry,gas phase molecular absorption spectrometry and ion chromatography were respectively used to determine ammonia nitrogen in surface water.The detection limit,precision,accuracy and recovery rate of the three methods were compared,and the determination results of the actual water samples were analyzed by t test.The results showed that the three methods all could meet the requirement of the laboratory quality control,and there was no significant difference in the determination results.Compared with Nessler's reagent spectrophotometry,the operation of gas phase molecular absorption spectrometry and ion chromatography operation was more convenient and fast and has no pollution,which can be used for the determination of ammonia nitrogen content in a large quantity of surface water samples. 展开更多
关键词 Gas phase molecular absorption SPECTROMETRY ion CHROMATOGRAPHY Nessler's REAGENT SPECTROPHOTOMETRY t test Surface water
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