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Adsorption of 2-mercaptobenzothiazole from aqueous solution by organo-bentonite

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Journal of Environmental Sciences 2013年第6期25卷 1139-1144页

作者： ping Jing Meifang Hou ping Zhao Xiaoyan Tang Hongfu Wan South ch.na Botanical Garden Chinese Academy of Sciences Graduate School of ch.nese Academy of Sciences School of Ecological Technology and Engineering Shanghai Institute of Technology Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control Guangdong Institute of Eco-environmental and Soil Sciences

The adsorption behavior of 2-mercaptobenzothiazole onto organo-bentonite was investigated. natural bentonite from Gaozhou in Guangdong Province, ch.na was collected. Organo-bentonite was prepared by intercalation of cetyltrimethyl ammonium bromide into the natural bentonite. The physicochemical properties of the prepared organo-bentonite were characterized by X-ray diffraction, n2 adsorption-desorption isotherm and Fourier transform infrared spectroscopy. The results showed that montmorillonite is the main component of the natural bentonite. The basal spacing of the natural bentonite is 1.47 nm, which increased to 1.98 nm on intercalation with cetyltrimethyl ammonium bromide. Moreover, both the surface area and pore volume increased with intercalation. Clear ch2 stretch.ng （3000-2800 cm-1） and scissoring （1480-1450 cm-1） modes of the intercalated surfactants were observed for organo- bentonite. Compared with the pseudo first-order kinetic model, the pseudo second-order kinetic model is more suitable to describe the adsorption kinetics of 2-mercaptobenzothiazole onto organo-bentonite. The adsorption capacity of 2-mercaptobenzothiazole onto organo-bentonite increased with increasing initial concentration of 2-mercaptobenzothiazole, but decreased with increasing adsorbent dosage. The adsorption isotherm of 2-mercaptobenzothiazole onto organo-bentonite fits well with the Langmuir model. The maximum adsorption capacity of organo-bentonite for 2-mercaptobenzothiazole was 33.61 mg/g, indicating that organo-bentonite is a promising adsorbent for 2-mercaptobenzothiazole.

关键词： 2-mercaptobenzothiazole bentonite intercalation adsorption

Substrate effects on spin relaxation in two-dimensional Dirac materials with strong spin-orbit coupling

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npj Computational Materials 2023年第1期9卷 1880-1889页

作者： Junqing Xu Yuan ping Department of chemistry and Biochemistry University of CaliforniaSanta CruzCA 95064USA

Understanding substrate effects on spin dynamics and relaxation is of key importance for spin-based information ***, the key factors that determine such effects, in particular for materials with strong spin-orbit coupling (SOC), have notbeen well understood. Here we performed first-principles real-time density-matrix dynamics simulations with SOC and the electron-phonon and electron-impurity scattering for spin lifetimes (τ_(s)) of supported/free-standing germanene, a prototypical strong SOC 2DDirac material. We show that the effects of different substrates on τ_(s) can surprisingly differ by two orders of magnitude. We find thatsubstrate effects on τs are closely related to substrate-induced modifications of the SOC-field anisotropy, which ch.nges the spin-flip scattering matrix elements. We propose a new electronic quantity, named spin-flip angle θ↑↓, to characterize spin relaxationthrough intervalley spin-flip scattering. We find that T_(s)^(-1) is approximately proportional to the averaged value of sin^(2)( θ↑↓/2 ) , whichserves as a guiding parameter of controlling spin relaxation.

关键词： material relaxation coupling

Parametric estimation of ultra wideband radar targets

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Journal of Systems Engineering and Electronics 2009年第3期20卷 499-503页

作者： Fan ping Jing Zhanrong School of Electronics and Information Northwestern Polytechnical Univ. Xi'an 710072 P. R. China

Based on the analysis of impulse response properties, a scattering model of ultra wideband （UWB） radar targets is developed to estimate the target parameters exactly. With this model, two algorithms of multiple signal classification （MUSIC）, and matrix pencil （MP）, are introduced to calculate the scattering center parameters of targets and their performances are compared. The simulation experiments show that there are no differences in the estimation precision of MUSIC and MP methods when the signal-to-noise ratio （SnR） is larger than 13 dB. However, the MP method has a better performance than that of MUSIC method when the SnR is smaller than 13 dB. Besides, the time consuming of MP method is less than that of MUSIC method. Therefore, the MP algorithm is preferred for the parametric estimation of UWB radar targets.

关键词： ultra wideband radar parametric estimation scattering center modeling

AtomSets as a hierarchical transfer learning framework for small and large materials datasets

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npj Computational Materials 2021年第1期7卷 1575-1583页

作者： chi ch.n Shyue ping Ong Department of nanoEngineering University of California San Diego9500 Gilman DrMail Code 0448La JollaCA 92093-0448USA

Predicting properties from a material’s composition or structure is of great interest for materials *** learning has recently garnered considerable interest in materials predictive tasks with low model errors when dealing with large materials ***,deep learning models suffer in the small data regime that is common in materials *** we develop the AtomSets framework,which utilizes universal compositional and structural descriptors extracted from pre-trained graph network deep learning models with standard multi-layer perceptrons to achieve consistently high model accuracy for both small compositional data(nd large structural data(>130,000).The AtomSets models show lower errors than the graph network models at small data limits and other non-deep-learning models at large data *** also transfer better in a simulated materials discovery process where the targeted materials have property values out of the training data *** models require minimal domain knowledge inputs and are free from feature *** presented AtomSets model framework can potentially accelerate mach.ne learning-assisted materials design and discovery with less data restriction.

关键词： Sets framework hierarchical

Solutions of the Camassa-Holm Equation near the Soliton

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Acta Mathematicae Applicatae Sinica 2023年第2期39卷 450-464页

作者： Dan-ping DInG Wei LU nonlinear Scientific Research Center School of Mathematical SciencesJiangsu UniversityZhenjiang 212013China

In this paper,solutions of the Camassa-Holm equation near the soliton Q is decomposed by pseudoconformal transformation as follows:λ^(1/2)(t)u(t,λ(t)y+x(t))=Q(y)+ε(t,y),and the estimation formula with respect toε(t,y)is obtained:|ε(t,y)|≤Ca_(3)Te^(-θ)|y|+|λ^(1/2)(t)ε0|.For the ch equation,we prove that the solution of the Cauchy problem and the soliton Q is sufficiently close as y→∞,and the approximation degree of the solution and Q is the same as that of initial data and Q,besides the energy distribution ofεis consistent with the distribution of the soliton Q in H^(2).

关键词： Camassa-Holm equation pseudo-conformal transformation the decomposition of solution soliton

Efficient Helicopter-Satellite Communication Scheme Based on check-Hybrid LDPC Coding

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Tsinghua Science and Technology 2018年第3期23卷 323-332页

作者： ping Wang Liuguo Yin Jianhua Lu Department of Electronic Engineering Tsinghua University Beijing 100084 China EDA Laboratory Research Institute of Tsinghua Universityin Shenzhen Shenzhen 518057 China. School of Information Science andTechnology Tsinghua University Beijing 100084 China EDA Laboratory Research Institute ofTsinghua University in Shenzhen Shenzhen 518057 China Department of Electronic Engineering Tsinghua University Beijing 100084 China

When implementing helicopter-satellite communications, periodical interruption of the received signal is a challenging problem because the communication antenna is intermittently blocked by the rotating blades of the helicopter. The helicopter-satellite ch.nnel model and the Forward Error Control（FEC） coding countermeasure are presented in this paper. On the basis of this model, check-Hybrid（ch） Low-Density Parity-check（LDPC）codes are designed to mitigate the periodical blockage over the helicopter-satellite ch.nnels. The ch-LDPC code is derived by replacing part of single parity-check code constraints in a Quasi-Cyclic LDPC（QC-LDPC） code by using more powerful linear block code constraints. In particular, a method of optimizing the ch-LDPC code ensemble by search.ng the best match.ng component code among a variety of linear block codes using extrinsic information transfer charts is proposed. Simulation results show that, the ch-LDPC coding scheme designed for the helicopter-satellite ch.nnels in this paper achieves more than 25% bandwidth efficiency improvement, compared with the FEC scheme that uses QC-LDPC codes.

关键词： helicopter-satellite communications check-hybrid Low-Density Parity-check(LDPC) codes Extrinsic Information Transfer(EXIT) iterative decoding

ch.nging Rules of Bonding Electron Pair Correlation Energies of ch_3X (X=F,OH,nH_2) Systems

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ch.nese Journal of Structural chemistry 2004年第5期23卷 525-531页

作者： ZHUOShu-ping SIWei-Jiang JUGuan-Zhi SchoolofchemicalEngineering ShandongUniversityofTechnologyZiboShandong255049China StateKeyLaboratoryofCoordinationchemistry DepartmentofChemistryNanjingUniversityNanjingJiangsu210093China

The pair correlation energy of bonding electrons is used and analyzed in the cal- culation of ch and CY (Y = F, O, n) bonding electron pairs in ch3X (X = F, OH, nH2) isoelec- tronic systems based on intra- and interpair correlation energy results at both MP2-OPT2/6- 311++G(d) and MP2-OPT2/cc-pVtz levels with MELD program. Comparison of two set results shows that cc-pVtz and 6-311++G(d) give more correlation energy of valence electrons and innermost core electron pairs, respectively in these systems, resulting that the total correlation energy with cc-pVtz basis of each system is larger than that with 6-311++G(d). Investigations of pair correlation energy show that with the decrease of electronegativity of X atom and the increase of H atoms in these ch3X (X = F, OH, nH2) systems, the pair correlation energy of 1sC2 of the C atoms is transferable, and the correlation energy of ch bonding electron pair with little ch.nges is of approximate transferability, while those of CY (CF, CO, Cn) bonding electron pair decrease in a large extent from ch3F through ch3OH to ch.nH2 molecules. It is suggested that the study of pair correlation energy of bonding electrons will further deepen the understanding of electron corre- lation effect from traditional chemical bonding concept.

关键词： pair correlation energy bonding electron pair ch3X systems

Synthesis, Structure characterization and Biological Activity of Layered Vanadium Oxides [nH_3(ch_2)_2nH(ch_2)_2nH_3][V_6O_(14)]

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chemical Research in ch.nese Universities 2005年第5期21卷 509-511页

作者： FU ping-ping WAnG Xin-long WAnG En-bo QIn chao XU Lin Institute of Polyoxometalate chemistry Department of Chemistry Northeast Normal University Changchun 130024 P. R. China ch.na-Japan Union Hospital Jilin University Changchun 130024 P. R. China

A new layered vanadium oxide [ nH3 （ ch2 ）2nH（ ch2 ）2nH3 ] [ V6O14 ] （ compound 1 ） was synthesized and characterized by elemental analysis, IR spectrometry and single crystal X ray diffraction. The compound crystallizes ina monoclinic space group P2（1）/n with a = 1.0254（2） nm, b =0.6739（2） nm, c = 1.2400（2） nm, ,8 = 93.88 （ 3 ） °, V = 0. 8549 （ 3 ）nm^3, Z = 2, R1 = 0. 0366, wR2 = 0. 1038. Compound 1 consists of two-dimensional mixed-valence vanadium oxide layers parallelling to the bc plane. The anti-tumor activity of the compound was estimated in three human tumor cell lines in vitro.

关键词： Polyoxometalate,Vanadium oxide Crystal structure Anti-tumor activity

Molecular outflows and gas rotation associated with G20.08–0.14n

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Research in Astronomy and Astrophysics 2013年第11期13卷 1295-1306页

作者： nai-ping Yu Jun-Jie Wang national Astronomical Observatories Chinese Academy of Sciences nAOC-TU Joint Center for Astrophysics

We present the results of a high-resolution study with the Submillimeter Array （SMA） toward the massive star-forming complex G20.08-0.14n. With the SMA data, we have detected and analyzed the transitions in the 12CO （3-2） and 12CO （2-1） molecular lines as well as chaCn. The millimeter observations reveal highly collimated bipolar molecular outflows, traced by high-velocity 12CO （2-1） and 12CO （3-2） emissions. Using a rotation temperature diagram, we derive that the rota- tional temperature and the column density of chaCn are 244 K and 1.2 ~ 1015 cm-2, respectively. We also suggest that the minor outflow is probably driven by the hy- percompact （HC） HII region A that is inside. We find the molecular gas （traced by ClrO, SO, ch3OH and SO2） surrounding G20.08-0.14n appears to be undergoing bulk rotation. The HchII region A that is inside is most probably the main source of accretion and heating for G20.08-0.14n.

关键词： ISM: individual objects (G20.08-0.14n) -- ISM: molecules -- radiolines: ISM -- stars: formation-- ISM: kinematics and dynamics