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Which Cation can be Introduced into the Lattice of Layered Double Hydroxides Stably:Theoretical Investigation Based on metal-Oxygen Octahedral Coordination Units

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Which Cation can be Introduced into the Lattice of Layered D...

Kinetics of chloride ion removal from aqueous solution by calcined layered double hydroxides

中国化学会第五届全国结构化学学术会议

作者： David G.evans School of Chemistry and Chemical Engineering Key Laboratory of Mesoscopic Chemistry of MOENanjing UniversityNanjing210093P.R.China

The basic structural unit of layered double hydroxides(LDHs)layers,mO,has been investigated by density functional theory(DFT)calculations at(U)B3LYP/LANL2DZ/6-31G(d) level modeled as [m(OH)](m=metal cation,n=2,3).Geometric optimization calculation results quantitatively revealed that the construction of LDHs layers is more closely related to the distortion angle of mO(m=introduced cation)octahedral unit than the ion *** metal cations which can form the canonical basic octahedral unit with the distortion angle(θ)smaller than 1° are easily incorporated into LDHs layers to form stable structures,while those which form octahedral unit structure in heavy distortion with θ larger than 10° are difficult to be introduced into LDHs *** is in agreement with the experimental findings and appears to be a more rational criterion than the empirical rule based on ion-size for the design and preparation of LDHs materials.

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Kinetics of chloride ion removal from aqueous solution by ca...

Oxbow Lakes as Geological Archives of Historical Changes in Channel Substrate, Swan Creek, Toledo, Ohio (USA)

第九届全国化学动力学会议

作者： D．G. evans Key Laboratory of Science and Technology of Controllable Chemical Reactions Ministry of EducationBeijing University of Chemical TechnologyBeijing 100029China

＜正＞Layered double hydroxide （LDHs）, a kind of anionic clay with high anion exchange capacity, is an effective adsorbent for removal of a variety of anionic pollutants. The chemical composition of LDH can be described by the formula [m2+l-xm3+x（OH）2]x+（An-）x/n·mH2O, where m2+ and m3+ are metal cations, for example

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Open Journal of modern Hydrology 2022年第2期12卷 32-54页

作者： Jocelyn L. Hicks James E. evans Department of Geology School of Earth Environment and Society Bowling Green State University Bowling Green OH USA

Efforts to restore urban rivers require an understanding of human-influenced changes in channel substrates. This study uses three naturally-occurring oxbows in a 3.5 km reach of Swan Creek, flowing through the City of Toledo, Ohio (USA) to reconstruct historical changes in channel substrate. Human impacts in the watershed were: 1) land clearance for agriculture (peaking in 1900-1920) and for suburban housing tracts (peaking in 1945-1970), followed by 2) the post-1940 creation of more efficient urban run-off systems from streets, parking lots, housing developments, and shopping centers. Historical aerial photographs and maps from 1935, 1940, 1950, 1963, 1974, and 1994 were georeferenced using ground control points, input to ArcGIS, and have root mean square error (RmSE) ranging from 0.19 - 0.77 m (average RmSE = 0.47 ± 0.20 m) when compared to the 2006 digital ortho quarter-quadrangle (DOQQ) image used as the basis for comparison. Results showed that channel sinuosity continually increased from 1.88 (1935) to 1.99 (2006). Two oxbows probably formed in 1913, and the third formed in 1940. Sediment cores and trenches were used to recognize historical channel substrates. Age control was provided by 14C geochronology and labels on food packaging materials found in flood layers. Grain-size analysis of channel substrates shows a historical coarsening-upward trend: the largest clast size interval (f5) changes from +0.78f in pre-1935 channels, to -1.15f in pre-1940 channels, to -1.69f in the 2006 channel. These results indicate recent urban runoff created fluvial pavements and increasing channel mobility as the stream removes legacy sediment from intrabasinal sediment storage.

关键词： Oxbows Channel Substrate Legacy Sediment Anthropogenic Change Sediment Budget

THE TRANSFORmATION OF THE STATE OF NITROGEN IN DIAmOND

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Science in China,Ser.B 1985年第10期 1009-1021页

作者：亓曾笃 T.evans Shanghai Institute of Ceramics Academia Sinica University of Reading England

Synthetic type Ib diamonds have been treated in the temperature range of 1500℃—2500℃ under stabilizing pressures of 6.5 GPa and 9.5 GPa. All nitrogen aggregates found in natural type Ia diamonds have been produeed. The single substitutional nitrogen was converted into A-centres, B-centres and N3-centres. The 7,3 μm peak of the infrared absorption spectrum and the associated platelets have been farmed. The synthetic type Ib diamonds have become much harder after heat treatment at above 2000℃ under a stabilizing pressure of about 9.5 GPa. Natural type Ia diamonds have been treated up to 2700℃ under a stabilizing pressure of about 9.5 GPa. The 7.3μm, 7.8μm, 8.5μm, 9.1μm, 9.9μm absorption peaks in infrared absorption spectrum have been changed. A-centres have been converted into B-centres and broken up into single nitrogen atoms, forming N3-centres.

关键词： THE TRANSFORmATION OF THE STATE OF NITROGEN IN DIAmOND

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TPPTS柱撑水滑石的制备及表征

石油学报（石油加工） 1999年第1期15卷 71-74页

作者：卫敏何静李峰 D G evans 段雪北京化工大学应用化学系

制备了水溶性好的烯烃氢甲酰化反应催化剂的配体—间三苯基膦三磺酸钠盐（Ｐ（ｍ－Ｃ６Ｈ４ＳＯ３Ｎａ）３，ＴＰＰＴＳ），采用３１ＰＮＭＲ和ＩＲ对其进行了表征。以层柱化合物类水滑石为插层主体，ＴＰＰＴＳ为插层客体，采用离子交... 详细信息

制备了水溶性好的烯烃氢甲酰化反应催化剂的配体—间三苯基膦三磺酸钠盐（Ｐ（ｍ－Ｃ６Ｈ４ＳＯ３Ｎａ）３，ＴＰＰＴＳ），采用３１ＰＮＭＲ和ＩＲ对其进行了表征。以层柱化合物类水滑石为插层主体，ＴＰＰＴＳ为插层客体，采用离子交换法和一步合成法制备了ＴＰＰＴＳ柱撑水滑石，并采用ＩＲ和ＸＲＤ对其进行了表征。ＩＲ谱图显示出ＴＰＰＴＳ的特征吸收峰，ＸＲＤ表征ｄ００１在１．５９～１．６４ｎｍ，可见两种方法均可制备ＴＰＰＴＳ柱撑水滑石。

关键词： TPPTS 柱撑水滑石制备催化剂

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Surface Tension Profiles under Various microwave Radiation modes

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Journal of Energy and Power Engineering 2014年第3期8卷 585-588页

作者： Yusuke Asakuma Yushin Kanazawa Harisinh Parmar Vishnu. Pareek Chi m. Phan G. evans mechanical and System Engineering University of Hyogo Hyogo 671-2280 Japan Chemical Engineering Curtin University Perth WA 6845 Australia Chemical Engineering University of Newcastle Chemical Engineering Callaghan NSW 2308 Australia

Surface tension of fluids is crucial for multiphase systems and is often controlled during industrial processes by introducing surfactants. In this study, effect of various microwave radiation modes on surface tension of water was investigated as an alternative physical method to manipulate the surface tension without using chemicals. It is found that surface tension decreased quickly while temperature increased during microwave. Once the radiation was turned off, the temperature returned rapidly as expected. However, surface tension did not recover so much. The minimum surface tension after microwave radiation depended on the power. moreover, a second radiation can have additional reduction on surface tension.

关键词： microwave surface tension water memory.

Hβ负载锆催化剂的研制及其催化性能和结构性能的研究

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燃料化学学报 2002年第4期30卷 358-362页

作者：李隽春张慧 D.G. evans 段雪北京化工大学可控化学反应科学与技术基础教育部重点实验室北京100029

根据层状四水硫酸锆和Hβ沸石各自的催化性能和结构特点 ,设计并制备得到Hβ负载锆 (Zr Hβ)催化剂。以异丙苯歧化反应为目标体系 ,研究了Zr Hβ的催化性能。利用吡啶吸附程序升温脱附和低温氮吸附等方法研究了Zr Hβ和Hβ的表面酸性和... 详细信息

根据层状四水硫酸锆和Hβ沸石各自的催化性能和结构特点 ,设计并制备得到Hβ负载锆 (Zr Hβ)催化剂。以异丙苯歧化反应为目标体系 ,研究了Zr Hβ的催化性能。利用吡啶吸附程序升温脱附和低温氮吸附等方法研究了Zr Hβ和Hβ的表面酸性和孔结构 ,与反应性能进行关联。结果表明 ,Zr Hβ较Hβ弱酸强度更弱、强酸强度更强 ,导致其歧化反应活性较Hβ大大提高 ,歧化选择性较Hβ略有提高 ,但其初始歧化选择性较Hβ降低 ;Zr Hβ和Hβ的最可几孔径基本一致 ,因而Zr Hβ催化异丙苯歧化反应产物中间位对位

关键词：催化性能结构性能 Hβ负载锆催化剂异丙苯歧化吡啶吸附程序升温脱附酸性孔结构

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Avulsion Dynamics in a River with Alternating Bedrock and Alluvial Reaches, Huron River, Northern Ohio (USA)

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Open Journal of modern Hydrology 2019年第1期9卷 20-39页

作者： mark J. Potucek James E. evans Arizona Department of Water Resources Phoenix AZ USA Department of Geology Bowling Green State University Bowling Green OH USA

The Huron River consists of alternating bedrock reaches and alluvial reaches. Analysis of historical aerial photography from 1950-2015 reveals six major channel avulsion events in the 8-km study area. These avulsions occurred in the alluvial reaches but were strongly influenced by the properties of the upstream bedrock reach (“inherited characteristics”). The bedrock reaches aligned with the azimuth of joint sets in the underlying bedrock. One inherited characteristic in the alluvial reach downstream is that the avulsion channels diverged only slightly from the orientation of the upstream bedrock channel (range 2 °- 38 °, mean and standard deviation 12.1 °± 13.7 °). A second inherited characteristic is that avulsion channels were initiated from short distances downstream after exiting the upstream bedrock channel reach (range 62 - 266 m, mean and standard deviation 143.7 ± 71.0 m), which is a fraction of the meander wavelength (1.2 km). Field evidence shows that some avulsion channel sites were re-occupied episodically. In addition, two properties were necessary for channel avulsions: 1) avulsion events were triggered by channel-forming hydrologic events (5-year recurrence interval flows), but not every channel-forming hydrologic event resulted in an avulsion, and 2) channel sinuosity (P) increased to 1.72 - 1.77 prior to an avulsion then decreased to 1.65 - 1.70 following an avulsion, suggesting that P ≥ 1.72 is the “critical sinuosity” or triggering value for avulsions on the Huron River. In summary, for this river consisting of alternating bedrock and alluvial reaches, the bedrock reaches impose certain parameters on downstream alluvial reaches (including sediment supply, channel direction and avulsion channel position downstream after exiting a bedrock reach) while adjustments in sinuosity and sediment storage occur in the alluvial reaches.

关键词： Avulsion Bedrock Channels Alluvial Channels Cut-Offs Historical Changes Fluvial Sediment Budgets

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