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Search Results: 1 - 10 of 104321 matches for " Zhang Guanjun "
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Using the biomarker bonded on the asphaltenes for biodegraded oil-source correlation
Guanjun Xu,Dajiang Zhang,Peirong Wang
Chinese Science Bulletin , 2003, DOI: 10.1007/BF03183303
Abstract: Ruthenium-ion-catalyzed oxidation (RICO) has been used to investigate asphaltenes from three oils with the same origin in the Juquan Basin and three oils with the same origin but with different degree of biodegradation in the Turpan Basin, Northwest China. The preliminary results showed that the biomarkers bonded on the asphaltenes with the same origin is similar and is correlated with the free biomarker in saturates. The bonded biomarkers have no relationship with the biodegradation. An application on the severely biodegraded oils is reported here. The biomarker and benzenecarboxylic methyl esters reflecting the structure of the asphaltenes after RICO should provide a new way for oil-source correlation and it should be specially useful for severely biodegraded oil-source correlation.
Symmetry protected skyrmions in 3D spin-orbit coupled Bose gases
Guanjun Chen,Tiantian Li,Yunbo Zhang
Physics , 2015, DOI: 10.1103/PhysRevA.91.053624
Abstract: We present a variational study of pseudo-spin $1/2$ Bose gases in a harmonic trap with weak 3D spin-orbit coupling of $\bmsigma\cdot\mathbf{p}$ type. This spin-orbit coupling mixes states with different parities, which inspires us to approximate the single particle state with the eigenstates of the total angular momentum, i.e. superposition of harmonic $s$-wave and $p$-wave states. As the time reversal symmetry is protected by two-body interaction, we set the variational order parameter as the combination of two mutually time reversal symmetric eigenstates of the total angular momentum. The variational results essentially reproduce the 3D skyrmion-like ground state recently identified by Kawakami {\it et al.}. We show that these skyrmion-like ground states emerging in this model are primarily caused by $p$ wave spatial mode involving in the variational order parameter that drives two spin components spatially separated. We find the ground state of this system falls into two phases with different density distribution symmetries depending on the relative magnitude of intraspecies and interspecies interaction: Phase I has parity symmetric and axisymmetric density distributions, while Phase II is featured with special joint symmetries of discrete rotational and time reversal symmetry. With the increasing interaction strength the transition occurs between two phases with distinct density distributions, while the topological 3D skyrmion-like spin texture is symmetry protected.
Magnetic and nematic phases in a Weyl type spin-orbit-coupled spin-1 Bose gas
Guanjun Chen,Li Chen,Yunbo Zhang
Physics , 2015,
Abstract: We present a variational study of the spin-1 Bose gases in a harmonic trap with three-dimensional spin-orbit coupling of Weyl type. For weak spin-orbit coupling, we treat the single-particle ground states as the form of perturbational harmonic oscillator states in the lowest total angular momentum manifold with $j=1, m_j=1,0,-1$. When the two-body interaction is considered, we set the trail order parameter as the superposition of three degenerate single-particle ground-states and the weight coefficients are determined by minimizing the energy functional. Two ground state phases, namely the magnetic and the nematic phases, are identified depending on the spin-independent and the spin-dependent interactions. Unlike the non-spin-orbit-coupled spin-1 Bose-Einstein condensate for which the phase boundary between the magnetic and the nematic phase lies exactly at zero spin-dependent interaction, the boundary is modified by the spin-orbit-coupling. We find the magnetic phase is featured with phase-separated density distributions, 3D skyrmion-like spin textures and competing magnetic and biaxial nematic orders, while the nematic phase is featured with miscible density distributions, zero magnetization and spatially modulated uniaxial nematic order. The emergence of higher spin order creates new opportunities for exploring spin-tensor-related physics in spin-orbit coupled superfluid.
Study on sterols from brown algae (Sargassum muticum)
Peirong Wang,Guanjun Xu,Lizeng Bian,Shuichang Zhang,Fuqing Song
Chinese Science Bulletin , 2006, DOI: 10.1007/s11434-006-2124-y
Abstract: Various Δ5-3β-sterenols, whose carbon numbers range from C19-C23 to C26-C30 and some compounds have many stereomers maximal up to six, have been detected out from the extract of brown algae (Sargassum muticum), which means that steranes with lower carbon numbers are likely different in the origin, and some corresponding sterol stereoisomers may have already existed in their precursor organisms. This provides some experimental evidence for supplementing and amending the traditional interpretation of the sterol stereoisomer transformation during the deposition and diagenesis of organic matter.
Using the biomarker bonded on the asphaltenes for biodegraded oil-source correlation
XU Guanjun,ZHANG Dajiang,Wang Peirong,
XUGuanjun
,ZHANGDajiang

科学通报(英文版) , 2003,
Abstract: Ruthenium-ion-catalyzed oxidation (RICO) has been used to investigate asphaltenes from three oils with the same origin in the Juquan Basin and three oils with the same origin but with different degree of biodegradation in the Turpan Basin, Northwest China. The preliminary resultsshowed that the biomarkers bonded on the asphaltenes with the same origin is similar and is correlated with the freebiomarker in saturates. The bonded biomarkers have norelationship with the biodegradation. An application on the severely biodegraded oils is reported here. The biomarkerand benzenecarboxylic methyl esters reflecting the structure of the asphaltenes after RICO should provide a new way for oil-source correlation and it should be specially useful forseverely biodegraded oil-source correlation.
Upregulation of excitatory neurons and downregulation of inhibitory neurons in barrel cortex are associated with loss of whisker inputs
Zhang Guanjun,Gao Zilong,Guan Sudong,Zhu Yan
Molecular Brain , 2013, DOI: 10.1186/1756-6606-6-2
Abstract: Loss of a sensory input causes the hypersensitivity in other modalities. In addition to cross-modal plasticity, the sensory cortices without receiving inputs undergo the plastic changes. It is not clear how the different types of neurons and synapses in the sensory cortex coordinately change after input deficits in order to prevent loss of their functions and to be used for other modalities. We studied this subject in the barrel cortices from whiskers-trimmed mice vs. controls. After whisker trimming for a week, the intrinsic properties of pyramidal neurons and the transmission of excitatory synapses were upregulated in the barrel cortex, but inhibitory neurons and GABAergic synapses were downregulated. The morphological analyses indicated that the number of processes and spines in pyramidal neurons increased, whereas the processes of GABAergic neurons decreased in the barrel cortex. The upregulation of excitatory neurons and the downregulation of inhibitory neurons boost the activity of network neurons in the barrel cortex to be high levels, which prevent the loss of their functions and enhances their sensitivity to sensory inputs. These changes may prepare for attracting the innervations from sensory cortices and/or peripheral nerves for other modalities during cross-modal plasticity.
Research of the Effects of Dielectric Barrier Discharge on Human Lymphocytes
Xingmin Shi,Guanjun Zhang,Xili Wu,Zhengshi Chang
Biotechnology Frontier , 2013,
Abstract: Peripheral blood lymphocytes (PBLC) isolated from 20 healthy adult volunteers’ blood samples were treated with low-temperature plasma induced by dielectric barrier discharge, in order to investigate the effect of plasma on PBLC. Three experimental groups of PBLC treated with plasma were classified according to their locations laid on the bottom electrode, i.e., the electrode center, the electrode edge (2.5cm away from electrode center) and the electrode outside (on a platform with the same height to bottom electrode and 5.0cm away from electrode center) group, and one control group was without plasma treatment. Three different treatment time intervals were set as 5, 15 or 30s, respectively. Based on the statistical analysis of experimental results, it is revealed that, while the lymphocytes were more than 5cm away from electrode center or the treatment time was less than 5s, their function did not change significantly. Otherwise, the larger the dosage of employed plasma along with longer treatment time was; the more significantly its function reduced. Furthermore, the lymphocytes apoptosis and necrosis caused by Low-temperature plasma maybe result in the degradation of lymphocytes function.
Application of backflush and micro-flow techniques to the analysis of C5—C13 hydrocarbons in crude oils and its geochemical significance
Wang Peirong,Zhao Hong,Xu Guanjun,Zhu Cuishan,Xiao Tingrong,Zhang Min,Zhang Bin
自然科学进展 , 2007,
Abstract: An Agilent 6890N GC equipped with both FID and Agilent 5975 MSD analyzer has been employed to analyze C5—C13 hydrocarbon fractions of crude oils. A technical combination of program temperature volatilizer injection, backflush and micro-flow controller afforded a fine separation of C5—C13 compounds on a PONA column with the heavy part of crude oils being cut off before entering the analytical column. Both GC-FID chromatogram and GC-MS mass chromatograms (MID and full scan) could be obtained at the same time. The retension time differences of nC6—nC13 alkanes between GC and TIC were in the range of 0.02—0.58 minutes. Totally 286 peaks have been assigned group compositions. Results on 8 typical oil samples from CNPC Key Laboratory Crude Oil Library showed that the characteristics of C6—C13 hydrocarbon group composition could be used in oil-oil correlation studies.
Hydrothermal Synthesis of Nitrogen-Doped Titanium Dioxide and Evaluation of Its Visible Light Photocatalytic Activity
Junjie Qian,Guanjun Cui,Mingjun Jing,Yan Wang,Min Zhang,Jianjun Yang
International Journal of Photoenergy , 2012, DOI: 10.1155/2012/198497
Abstract: Nitrogen-doped titanium dioxide (N-doped TiO2) photocatalyst was synthesized from nanotube titanic acid (denoted as NTA; molecular formula H2Ti2O5?H2O ) precursor via a hydrothermal route in ammonia solution. As-synthesized N-doped TiO2 catalysts were characterized by means of X-ray diffraction, transmission electron microscopy, diffuse reflectance spectrometry, X-ray photoelectron spectroscopy, electron spin resonance spectrometry and Fourier transform infrared spectrometry. It was found that nanotube ammonium titanate (NAT) was produced as an intermediate during the preparation of N-doped TiO2 from NTA, as evidenced by the N1s X-ray photoelectron spectroscopic peak of NH4
TESTING STUDY AND APPLICATION OF SHAPE STEEL PULLOUT IN SMW CONSTRUCTION METHOD
SMW工法型钢起拔试验研究及应用

Zhang Guanjun,Xu Yongfu,Fu Deming,
张冠军
,徐永福,傅德明

岩石力学与工程学报 , 2002,
Abstract: Through simulation test and engineering practice,the reaction law between shape steel and cement-soil is explored and the verification method of the shape steel recovery in SMW construction method is put forward,too.
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