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1.
In view of water pollutants becoming more complex, both anionic and cationic pollutants need to be removed. The multi‐pollutants simultaneous removal is paid more and more attention. Hence, development composite materials for treatment complex wastewater are the aim of this study. In this research, iron–nickel nanoparticles deposited onto aluminum oxide (α‐Al2O3) and carbon nanotubes (CNTs) to form nanocomposite materials Fe–Ni/Al2O3 and Fe–Ni/CNTs, respectively, were used as adsorbents. The adsorption capacities of Fe–Ni/Al2O3 and Fe–Ni/CNTs for AO7, HSeO, and Pb2+ were observed to be 5.46, 8.28, 27.02, and 25.6 mg/g, 15.29 and 17.12 mg/g, separately. The composite materials with negative charges were superior in adsorption of anionic pollutants. Using orthogonal experimental design and analysis of variance to co‐treat dye AO7, HSeO and Pb2+ in aqueous solutions, seven testing factors were included: (1) adsorbent types, (2) amount of iron, (3) solution pHs, (4) AO7 concentrations, (5) Pb2+ concentrations, (6) HSeO concentrations and (7) reaction time. The experimental results showed that the removal of complex pollutants AO7, HSeO, and Pb2+ on Fe–Ni/CNTs could reach up to 90% in the optimal treatment conditions. When using Fe–Ni/CNTs as the adsorbent, the sorption isothermals were well fitted in the Freundlich isotherm, and R2 could reach up to 0.98. 相似文献
2.
Partition coefficients (D) for Nb and Ta between rutile and haplogranite melts in the K2O-Al2O3-SiO2 system have been measured as functions of the K2O/Al2O3 ratio, the concentrations of Nb2O5 and Ta2O5, the temperature, in air and at 1 atmosphere pressure. The Ds increase in value as the K* [K2O/(K2O + Al2O3)] molar ratio continuously decreases from highly peralkaline [K* ∼ 0.9] to highly peraluminous [K* ∼ 0.35] melts. The D values increase more dramatically with a unit decrease in K* in peraluminous melts than in peralkaline melts. This compositional dependence of Ds can be explained by the high activity
of NbAlO4 species in peraluminous melts and the high activity of KONb species (or low activity of NbAlO4 species) in peralkaline melts. A coupled substitution, Al+3 + Nb+5 (or Ta+5) = 2Ti+4, accounts for the Ds of Nb (Ta) being much greater in peraluminous melts than in peralkaline melts because this substitution
allows Nb (Ta) to enter into the rutile structure more easily. The Ds of Ta between rutile and melt are greater than those
of Nb at comparable concentrations because the molecular electronic polarizability of Ta is weaker than that of Nb. The Nb+5 with a large polarizing power forms a stronger covalent bond with oxygen than Ta+5 with a small polarizing power. The formation of the strong bond, Nb-O, distorts the rutile structure more severely than the
weak bond, Ta-O; therefore, it is easier for Ta to partition into rutile than for Nb. These results imply that the utilization
of the Nb/Ta ratio in liquid as a petrogenetic indicator in granitic melts must be done with caution if rutile (or other TiO2-rich phases) is a liquidus phase. The crystallization of rutile will increase the Nb/Ta ratio of the residual liquid because
the Ds of Ta between rutile and melts are greater than those of Nb.
Received: 28 December 1998 / Accepted 27 September 1999 相似文献
3.
Jiann-Tsorng Horng 《Astrophysics and Space Science》1975,34(2):L1-L5
Cyclotron waves in the solar wind near 1 AU with frequencies well below the electron cyclotron frequency and wavelengths much larger than the electron cyclotron radius but less than the proton cyclotron radius are considered. The cyclotron radii are defined from parallel thermal velocity of electron component and proton component with respect to the interplanetary magnetic field. No LH cyclotron waves are found to propagate for
p
< 0, where
p
1 –T
p/T
p is the temperature anisotropy of the proton component with respect to the interplanetary magnetic field. The damping or growth of RH cyclotron waves is found to depend on the frequency range and the temperature anisotropy of the proton component. The RH cyclotron waves are damped in the frequency range
r
|
p
|
p
for
p
< 0, where
p
is the proton cyclotron frequency. RH cyclotron instabilities occur in the frequency range |
p
|
p
>
r
> |
p
|
p
/(1–
r
) for
p
< 0. The marginal state is at
r
=|
p
|
p
.Abstract presented at theInternational Symposium on Solar-Terrestrial, São Paulo, Brazil, 17–22 June, 1974 相似文献
4.
This study develops a novel approach for modelling and examining the impacts of time–space land‐use changes on hydrological components. The approach uses an empirical land‐use change allocation model (CLUE‐s) and a distributed hydrological model (DHSVM) to examine various land‐use change scenarios in the Wu‐Tu watershed in northern Taiwan. The study also uses a generalized likelihood uncertainty estimation approach to quantify the parameter uncertainty of the distributed hydrological model. The results indicate that various land‐use policies—such as no change, dynamic change and simultaneous change—have different levels of impact on simulating the spatial distributions of hydrological components in the watershed study. Peak flow rates under simultaneous and dynamic land‐use changes are 5·71% and 2·77%, respectively, greater than the rate under the no land‐use change scenario. Using dynamic land‐use changes to assess the effect of land‐use changes on hydrological components is more practical and feasible than using simultaneous land‐use change and no land‐use change scenarios. Furthermore, land‐use change is a spatial dynamic process that can lead to significant changes in the distributions of ground water and soil moisture. The spatial distributions of land‐use changes influence hydrological processes, such as the ground water level of whole areas, particularly in the downstream watershed. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
5.
Che-Chuan Lin Andrew Tien-Shun Lin Char-Shine Liu Chorng-Shern Horng Guan-Yu Chen Yunshuen Wang 《Marine Geophysical Researches》2014,35(1):21-35
We utilized reflection seismic and bathymetric data to infer the canyon-infilling, fold uplift, and gas hydrate occurrences beneath the frontal fold at the toe of the accretionary wedge, offshore SW Taiwan. The lateral migrating paleo-Penghu canyons has cut across the frontal fold with six distinct canyon/channel incisions marked by channel infills. The longitudinal bathymetric profile along the modern canyon course shows a knickpoint of ~300 m relief at this frontal fold, indicating that the rate of fold uplift is greater than that of canyon incision. The age for the initial thrusting of this fontal fold is around 240 kyr ago, as estimated by using the maximum thickness of growth strata of this fold divided by the sedimentation rate obtained from a nearby giant piston core. Bottom simulating reflector (BSR) on seismic sections indicates the base of gas hydrate stability zone. Beneath the frontal fold, there is a widespread occurrence of BSRs, suggesting the highly probable existence of substantial quantities of gas hydrates. A seismic flat spot and a few push-down reflectors below BSR are found lying beneath the anticlinal axis with bathymetric four-way dip closure. The flat spot, cutting across a series of dipping reflections beneath BSR, may indicate the contact between free gas and its underlying formation water. The push-down reflectors beneath BSRs are interpreted to result from abundant free gas hosted beneath the gas hydrate stability zone. The multiple paleo-canyon infills seen along and beneath the frontal fold and above BSRs may provide thick porous sands to host gas hydrates in the frontal fold. 相似文献
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在传统上,浮游有孔虫Ｇｌｏｂｏｒｏｔａｌｉａｔｒｕｎｃａｔｕｌｉｎｏｉｄｅｓ的初现面一直被用来作为划定海相地层更新统下界的可靠依据。然而,此一初现面（２．０ＭａＢ．Ｐ．）所界定的更新统下界与超微化石Ｇａｐｈｙｒｏｃｏｐｓａｏｃｅａｎｉｃａｓ．ｌ．初现面（１．６７～１．７ＭａＢ．Ｐ．）所界定的并不一致。这一现象对大陆边缘的沉积地层尤为显著。其主要原因是,大陆边缘的高沉积速率会导致两个基面有很的层位间距。本研究证明台湾西南部二仁溪剖面之浮游有孔虫Ｐｕｌｌｅｎｉａｔｉｎａ最后一次的旋向变化（由左至右）,几乎与超微化石Ｇ．ｏｃｅａｎｉｃａｓ．ｌ．的初现面同一时间。因此,就浮游有孔虫生物地层的观点看,此一族向变化是辨识更新统下界的一个非常有用的基面。 相似文献
10.
Hybrid experimental performance of a full‐scale two‐story buckling‐restrained braced RC frame 
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下载免费PDF全文 An‐Chien Wu Keh‐Chyuan Tsai Hsun‐Horng Yang Jie‐Luen Huang Chao‐Hsien Li Kung‐Juin Wang Hsen‐Han Khoo 《地震工程与结构动力学》2017,46(8):1223-1244
This paper proposes a novel implementation of buckling‐restrained braces (BRB) in new reinforced concrete (RC) frame construction. Seismic design and analysis methods for using a proposed steel cast‐in anchor bracket (CAB) to transfer normal and shear forces between the BRB and RC members are investigated. A full‐scale two‐story RC frame with BRBs (BRB‐RCF) is tested using hybrid and cyclic loading test procedures. The BRBs were arranged in a zigzag configuration and designed to resist 70% of the story shear. The gusset design incorporates the BRB axial and RCF actions, while the beam and column members comply with ACI 318‐14 seismic design provisions. Test results confirm that the BRBs enhanced the RCF stiffness, strength, and ductility. The hysteresis energy dissipation ratios in the four hybrid tests range from 60% to 94% in the two stories, indicating that BRBs can effectively dissipate seismic input energy. When the inter‐story drift ratio for both stories reached 3.5% in the cyclic loading test, the overall lateral force versus deformation response was still very stable. No failure of the proposed steel CABs and RC discontinuity regions was observed. This study demonstrates that the proposed design and construction methods for the CABs are effective and practical for real applications. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献