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Characterization of partially reduced graphene oxide as room temperature sensor for H2

Le-Sheng Zhang, Wei D. Wang, Xian-Qing Liang, Wang-Sheng Chu, Wei-Guo Song, Wei Wang, Zi-Yu Wu
2011 Nanoscale  
Synthesis of Graphene Oxide and reduced graphene oxide (RGO) Graphene oxide (GO) was synthesized accordingly to a modified Hummers' method. 1,2 Typically, 1.5 g graphite obtained from Beijing Chemical agents Co. was pretreated in a concentrated sulfuric acid (35 ml) solution added with sodium nitrate (0.75 g) at room temperature. 16 hours later, 4.5 g KMnO 4 was added to the mixture at around 0 °C which was assisted by an ice bath and continuously stirred for 2 hours. After the mixture was
more » ... ed to be stirred at room temperature for another 3 hours, the slurry was pureed into 200 ml ice water. Then the solution was further reacted at 98°C for 15 mins. After that, the excess hydrogen peroxide (3%) was added to the mixture followed by overnight stirring. The mixture was then filtered through Nylon Millipore filter and washed by 10% HCl solution and excess water to remove the acid. Finally, the solid was vacuum dried at 80 °C overnight to obtained GO. Electronic Supplementary Material (ESI) for Nanoscale This journal is Reduced graphene oxide was produced by heating the as-prepared GO at different temperature (300°C, 500°C, 700°C, 900°C ) to obtained RGO-300, RGO-500, RGO-700, RGO-900 respectively, in a tube furnace. The ratio of H2/Ar is 1:3 controlled by a mass flow controller. Charaterization The microscopic features of the samples were characterized by transmission electron microscopy (TEM, JEOL JEM-1011) and high-resolution TEM (HRTEM, JEOL JEM-2010). For the XPS analysis, a Kratos AXIS 165 multitechnique electron spectrometer was used. XANES experiments were performed on the Soft X-ray Magnetic Circular Dichroism (SXMCD) station of National Synchrotron Radiation Lab (NSRL) at Hefei. The samples were loaded in an ultrahigh-vacuum chamber at a vacuum of <5 × 10-7 Pa. All spectra were acquired in the total electron yield (TEY) mode with an experimental resolution of 0.2 eV at room temperature. All 13C and 1H magic angle spinning nuclear magnetic resonance (MAS NMR) spectra were recorded on a Bruker Avanc II WB 400 MHz spectrometer with a 4 mm Bruker MAS NMR probe. Each spectrum was acquired using a π/2 pulse, pulse delay time of 5 s at the 13C resonance frequency of 100.6 MHz and 1H resonance frequency of 400.1 MHz. The spinning speed is 6 kHz or 10 kHz. All the 13C and 1H spectra were referenced to tetramethylsilane (TMS). The gas-sensitivity measurements were conducted in a home made sensor testing system, and the sensor film were prepared by spin coating a drop of as-prepared N,N-dimethylformafide suspension of 5μl RGO (1 mg/ml) on a commercial sensor electrode (UST, Germany). Hydrogen, carbon monoxide and methane were used as the testing gas and were introduced into the testing chamber by mass flow controller with a concentration of 500 ppm, 2500 ppm and 5000 ppm, respectively. For the investigation of the influence of the temperature to the sensitivity, the measurements were carried out at 25 °C, 47 °C and 132 °C, respectively. The electronic conductivity is measured by sourcemeter (KEITHLEY, Model 2400). The conductivity of the sensor film was measured by two probe method. In the sensor device, a 21 v voltage was applied and the current flow was measure. The resistance of the RGO sensor films was obtained according to the formula below: R=U/I
doi:10.1039/c1nr10187k pmid:21566828 fatcat:ylmbmcypizfgfpqn5eiua7wqma

Acetylene hydrochlorination over bimetallic Ru-based catalysts

Jinli Zhang, Wei Sheng, Cuili Guo, Wei Li
2013 RSC Advances  
doi:10.1039/c3ra42867b fatcat:gfsenxz6gfae7j6ot2np4mrghi

Prediction of Pancreatic Cancer by Serum Biomarkers Using Surface-Enhanced Laser Desorption/Ionization-Based Decision Tree Classification

Yun Yu, Sheng Chen, Li-Shun Wang, Wen-Li Chen, Wei-Jian Guo, Hua Yan, Wei-Hua Zhang, Cheng-Hong Peng, Sheng-Dao Zhang, Hong-Wei Li, Guo-Qiang Chen
2005 Oncology  
sion tree algorithm to be able to separate pancreatic cancer from controls. A double-blind test was used to determine the sensitivity and specifi city of the classifi cation model. Results: A panel of six biomarkers was selected to set up a decision tree as the classifi cation model. The model separated effectively pancreatic cancer from control samples, achieving a sensitivity of 88.9% and a specifi city of 74.1%. The double-blind test challenged the model with a sensitivity of 80% and a
more » ... i city of 84.6%. Conclusion: The SELDI ProteinChip combined with an artifi cial intelligence classifi cation algorithm shows great potential for the diagnosis of pancreatic cancer. Abstract Objective: In order to improve the prognosis of pancreatic cancer patients, it is crucial to explore novel tools for its early diagnosis. Here, we attempted to screen serum biomarkers to distinguish pancreatic cancer from noncancer individuals. Methods: 47 serum samples from pancreatic cancer patients, 39 of whom had small surgically resectable cancers, were collected before surgery, and an additional 53 serum samples from age-and sexmatched individuals without cancer were used as controls. The surface-enhanced laser desorption/ionization (SELDI) ProteinChip was applied to analyze serum protein profi ling. 54 samples (27 with pancreatic cancer and 27 controls) were analyzed in the training set by a deci-
doi:10.1159/000084824 pmid:15864000 fatcat:vmnzxovhzzbvlahxktxw2v7f7y

Screening of environmental response genes related to dental fluorosis

Guo-Qiang Hou, Jun-Ling Liu, Yao-Yong Yu, Tao Xia
2005 Wei sheng yan jiu = Journal of hygiene research  
ACKNOWLEDGMENTS The authors would like to express their sincere thanks to Dr Qingyi Wei for his critical review of the manuscript.  ... 
pmid:16329592 fatcat:juatlm7ab5cxhgazeyhcylfre4

Longitudinal serum autoantibody repertoire profiling identifies surgery-associated biomarkers in lung adenocarcinoma

Yang Li, Cheng-qiang Li, Shu-juan Guo, Wei Guo, He-wei Jiang, He-cheng Li, Sheng-ce Tao
2020 EBioMedicine  
Autoantibodies against tumor associated antigens are highly related to cancer progression. Autoantibodies could serve as indicators of tumor burden, and have the potential to monitor the response of treatment and tumor recurrence. However, how the autoantibody repertoire changes in response to cancer treatment are largely unknown. Sera of five lung adenocarcinoma patients before and after surgery, were collected longitudinally. These sera were analyzed on a human proteome microarray of 20,240
more » ... combinant proteins to acquire dynamic autoantibody repertoire in response to surgery, as well as to identify the antigens with decreased antibody response after tumor excision or surgery, named as surgery-associated antigens. The identified candidate antigens were then used to construct focused microarray and validated by longitudinal sera collected from a variety of time points of the same patient and a larger cohort of 45 sera from lung adenocarcinoma patients. The autoantibody profiles are highly variable among patients. Meanwhile, the autoantibody profiles of the sera from the same patient were surprisingly stable for at least 3 months after surgery. Six surgery-associated antigens were identified and validated. All the five patients have at least one surgery-associated antigen, demonstrating this type of biomarkers is prevalent, while specific antigens are poorly shared among individuals. The prevalence of each antigen is 2%-14% according to the test with a larger cohort. To our knowledge, this is the first study of dynamically profiling of autoantibody repertoires before/after surgery of cancer patients. The high prevalence of surgery-associated antigens implies the possible broad application for monitoring of tumor recurrence in population, while the low prevalence of specific antigens allows personalized medicine. After the accumulation and analysis of more longitudinal samples, the surgery-associated serum biomarkers, combined as a panel, may be applied to alarm the recurrence of tumor in a personalized manner. Research supported by grants from National Key Research and Development Program of China Grant (No. 2016YFA0500600), National Natural Science Foundation of China (No. 31970130, 31600672, 31670831, and 31370813), Open Foundation of Key Laboratory of Systems Biomedicine (No. KLSB2017QN-01), Science and Technology Commission of Shanghai Municipality Medical Guidance Science &Technology Support Project (16411966100), Shanghai Municipal Education Commission-Gaofeng Clinical Medicine Grant Support (20172005), Shanghai Municipal Commission of Health and Family Planning Outstanding Academic Leaders Training Program (2017BR055) and National Natural Science Foundation of China (81871882).
doi:10.1016/j.ebiom.2020.102674 pmid:32113159 pmcid:PMC7047177 fatcat:2iyodkozcfgcjgbrtuqb5yqqli

Semi-Supervised Clustering with Contrastive Learning for Discovering New Intents [article]

Feng Wei, Zhenbo Chen, Zhenghong Hao, Fengxin Yang, Hua Wei, Bing Han, Sheng Guo
2022 arXiv   pre-print
Most dialogue systems in real world rely on predefined intents and answers for QA service, so discovering potential intents from large corpus previously is really important for building such dialogue services. Considering that most scenarios have few intents known already and most intents waiting to be discovered, we focus on semi-supervised text clustering and try to make the proposed method benefit from labeled samples for better overall clustering performance. In this paper, we propose Deep
more » ... ontrastive Semi-supervised Clustering (DCSC), which aims to cluster text samples in a semi-supervised way and provide grouped intents to operation staff. To make DCSC fully utilize the limited known intents, we propose a two-stage training procedure for DCSC, in which DCSC will be trained on both labeled samples and unlabeled samples, and achieve better text representation and clustering performance. We conduct experiments on two public datasets to compare our model with several popular methods, and the results show DCSC achieve best performance across all datasets and circumstances, indicating the effect of the improvements in our work.
arXiv:2201.07604v1 fatcat:l2p3ck2fjzaqbjn7aohdn6isry

Emerging mechanisms of T-tubule remodelling in heart failure

Ang Guo, Caimei Zhang, Sheng Wei, Biyi Chen, Long-Sheng Song
2013 Cardiovascular Research  
(From Wei et al. 60 ) A. Guo et al. Figure 6 6 Progressive T-tubule remodelling of left-ventricular myocytes in pressure overload rat cardiomyopathy.  ...  Guo et al. Table 1 1 of Cheng and Lederer 5 .)  ... 
doi:10.1093/cvr/cvt020 pmid:23393229 pmcid:PMC3697065 fatcat:wbqh4ghzpfbafhacylct3usnoe

Energy band of graphene ribbons under the tensile force [article]

Yong Wei, Guo-Ping Tong, Sheng Li
2008 arXiv   pre-print
According to the tight-binding approximation, we investigate the electronic structures of graphene ribbons with zigzag shaped edges (ZGRs) and armchair shaped edges (AGRs) drawn by the tensile force, and obtain the analytic relations between the energy bands of pi-electrons in ZGR, AGR and the tensile force based on only considering the nearest-neighbor interaction and the hydrogen-like atomic wave function is considered as pi-electron wave function. Importantly, we find the tensile force can
more » ... en an energy gap at the K point for ZGR and AGR, and the force perpendicular to the zigzag edges can open energy gap more easily besides the gap values of ZGR and AGR at the K point both increase as the tensile force increases.
arXiv:0804.4720v1 fatcat:6i55ijgmpfh2nlzzsyh4j2rkv4

Stabilization of Gob-Side Entry with an Artificial Side for Sustaining Mining Work

Hong-sheng Wang, Dong-sheng Zhang, Lang Liu, Wei-bin Guo, Gang-wei Fan, KI-IL Song, Xu-feng Wang
2016 Sustainability  
A concrete artificial side (AS) is introduced to stabilize a gob-side entry (GSE). To evaluate the stability of the AS, a uniaxial compression failure experiment was conducted with large and small-scale specimens. The distribution characteristics of the shear stress were obtained from a numerical simulation. Based on the failure characteristics and the variation of the shear stress, a failure criterion was determined and implemented in the strengthening method for the artificial side. In an
more » ... rimental test, the distribution pattern of the maximum shear stress showed an X shape, which contributed to the failure shape of the specimen. The shear stress distribution and failure shape are induced by a combination of two sets of shear stresses, which implies that failure of the AS follows the twin shear strength theory. The use of anchor bolts, bolts, and anchor bars enhances the shear strength of the artificial side. When this side is stable, the components can constrain the lateral deformation as well as improve the internal friction angle and cohesion. When the AS is damaged, the components prevent the sliding of broken blocks along the shear failure plane and improve the residual strength of the artificial side. When reinforced with an anchor bar, the AS is still stable even after mining operations for three years. a certain value, the Tresca material will yield and slide along the maximum shear stress direction. In the Mohr criterion [4], the failure of a certain point in the material is mainly determined by the maximum principal stress and the minimum principal stress. The failure of a Mohr material is independent of the intermediate principal stress. The ultimate shear strength of the material is closely related to the cohesion and the internal friction angle in Coulomb criterion [5] . These three representative strength criteria only consider the influence of normal stress in a shear stress plane. Thus, these strength criteria consider only the maximum and minimum principal stress, but not the intermediate principal stress, and are known as single shear strength theory. Yu (1983) proposed a generalized twin shear strength theory that is appropriate for a material that has different strength in tension and compression [6] [7] [8] [9] . The failure mode of the AS is affected by many factors [10] [11] [12] , especially dynamic load induced by blasting which can cause significant damage to AS. In this study, we determined the failure characteristics and the variation of shear stress of the concrete AS of the GSE, which were affected by the coal mining. To achieve this, a uniaxial compression failure experiment was conducted with large and small-scale specimens. The distribution characteristics of shear stress were obtained from a numerical simulation. Based on the results, a failure criterion was determined and implemented in a strengthening method for the artificial side. Structural Model of the Artificial Side A schematic diagram of a GSE is presented in Figure 1 . The immediate roof above the AS prevents ground movement and rock deformation induced by GSE formation. The stiffness of the main roof and immediate roof are assumed to be much greater than that of the AS and the rigid floor that supports it. Thus, deformation occurs at the upper boundary of the artificial side, and the vertical displacement at the lower boundary is ignorable. Based on these conditions, a structural model of the AS was established, as shown in Figure 2 .
doi:10.3390/su8070627 fatcat:j4bffj4mvjf57focm26ypell5a

May Measurement Month 2017: an analysis of blood pressure screening results in China—East Asia

Xin Chen, Shao-Kun Xu, Yan Li, Chang-Sheng Sheng, Qian-Hui Guo, Wei Yu, Wei-Hua Li, Guo-Bao Tang, Hai-Feng Zhang, Yin Dong, Sheng-Huang Wang, Hong-Yu Wang (+5 others)
2019 European Heart Journal, Supplement  
doi:10.1093/eurheartj/suz088 fatcat:g44kwmiuvjardnkj4npsfawlsi

Mono dispersed SnO2 nanoparticles on both sides of single layer graphene sheets as anode materials in Li-ion batteries

Le-Sheng Zhang, Ling-Yan Jiang, Hui-Juan Yan, Wei D. Wang, Wei Wang, Wei-Guo Song, Yu-Guo Guo, Li-Jun Wan
2010 Journal of Materials Chemistry  
doi:10.1039/c0jm00672f fatcat:qi6f26ysfrgitdlbgwkqjei7vu

Study of coded source neutron imaging based on a compact accelerator

Wang Sheng, Zou Yu-Bin, Wen Wei-Wei, Li Hang, Liu Shu-Quan, Wang Hu, Lu Yuan-Rong, Tang Guo-You, Guo Zhi-Yu
2013 Wuli xuebao  
Compact accelerator based neutron source has lower cost and better flexibility than nuclear reactor. Neutron imaging using such a neutron source has attracted more and more attention in recent years, in spite of its relatively low neutron fluence. In order to keep a definite neutron flux above a reasonable level on a compact accelerator based neutron imaging system, one could not set the collimation ratio to be as high as the reactor neutron source to obtain a high resolution. Coded source
more » ... increase the collimation ratio without reducing the neutron flux much. It may benefit neutron imaging system in the case of low yield neutron source. Since 2005, several laboratories in Germany and USA have carried out simulation and experiments of coded source neutron imaging. Those experiments are based on the reactor neutron sources, which have high neutron yield and low scattered neutron background. Recently, a preliminary coded source neutron imaging experiment was carried out on PKUNIFTY (Peking University Neutron Imaging Facility), which is based on a 2 MeV deuteron RFQ accelerator. It is the first time that coded source neutron imaging has been applied to an accelerator-based neutron source. Projections of coded neutron source are taken with a neutron yield of 2.6 × 10 11 s −1 . With Wiener filter deconvolution and Lucy-Richardson maximum likelihood iteration algorithm, the experimental projections are reconstructed successfully. Because the accumulated neutron fluence is low and the neutron background is high, the signal-to-noise ratio of reconstructed images is not good enough, which will be improved by reducing the neutron background.
doi:10.7498/aps.62.122801 fatcat:qmxhmoewwzdwlj6zofdyuje26u

Enhanced Wave-Absorption Properties of Nanocomposites Based on the Synthesized Bi2S3Nanorods and Polyvinylidene Fluoride

Xin Luo, Guang-Sheng Wang, Hao-Yue Guo, Xiao-Juan Zhang, Wen-Qiang Cao, Yun-Zhao Wei, Lin Guo, Mao-Sheng Cao
2014 ChemPlusChem  
In this study, Bi 2 S 3 nanorods were synthesized on a large scale through a simple hydrothermal method at low temperature. To investigate the wave-absorption properties of Bi 2 S 3 nanorods, the homogeneous nanocomposites consisting of the nanorods and paraffin or polyvinylidene fluoride (PVDF) matrix were fabricated and characterized. The results indicated that the introduction of Bi 2 S 3 nanorods to PVDF significantly enhanced the wave-absorption properties of the absorber. The loss
more » ... m of Bi 2 S 3 /PVDF nanocomposites with different loadings was discussed and some theories were also employed to explain the mechanism of the enhancement based on the experimental results. [a] X.
doi:10.1002/cplu.201402050 fatcat:4ocgzb77jngr3kkhgtqw3gk7vy

Reactive oxygen species inhibits Listeria monocytogenes invasion into HepG2 epithelial cells

Guo-wei Chen, Man Wu, Wu-kang Liu, Man-man Xie, Wei-sheng Zhang, En-guo Fan, Qing Liu
2018 Food Science & Nutrition  
O RCI D Guo-wei Chen Qing Liu Lm-ATCC 43251 was provided by Shanghai Prajna Biology Technique Co., Ltd.  ... 
doi:10.1002/fsn3.615 pmid:30258592 pmcid:PMC6145247 fatcat:gmujzjzcvnbsdk4o33bvm54bp4

Isolation, screening nd characterization of hydrogen-oxidizing bacteria in soybean rhizosphere

Xin-Du Chen, Wei-Wei Wang, Li-Wei Guo, Ben-Tao Xiong, Bo Fu
2007 Ying yong sheng tai xue bao = The journal of applied ecology  
Soil hydrogen-oxidizing bacteria can utilize soil gaseous hydrogen as an energy source to assimilate carbon dioxide. In this paper, a gas-cycle incubation system (H2 treatment system) which can provide stable H2 flow (41.6-125 micromol x L(-1)) via H2O electrolysis was developed, and a mineral salt agar medium (MSA) was used to separate the hydrogen-oxidizing bacteria in soybean rhizosphere. A total of 40 bacterial strains were isolated from the incubation system, and their hydrogen uptake was
more » ... easured. 20 of the strains could utilize hydrogen and grow autotrophically, which were preliminarily identified as hydrogen-oxidizing bacteria. Their colony form and physiological-biochemical characteristics were studied.
pmid:18062315 fatcat:qqro3w4wu5gprchs6jbxunrbvq
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