34 results on '"Jun-Bo Liu"'
Search Results
2. Simulation study on cuttings transport of the backreaming operation for long horizontal section wells.
- Author
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Yu-Fei Chen, Hui Zhang, Wen-Xin Wu, Jun Li, Yong Ouyang, Zong-Yu Lu, De-Xin Ma, Yong-Chuan Wu, Jun-Bo Liu, Ke-Rou Liu, and Zhuo-Xin Dong
- Subjects
PROPERTIES of fluids ,FACTOR analysis ,VELOCITY ,SENSITIVITY analysis - Abstract
The backreaming operation plays a significant role in safe drilling for horizontal wellbores, while it may cause severe stuck pipe accidents. To lower the risk of the stuck pipe in backreaming operations, the mechanism of cuttings transport needs to be carefully investigated. In this research, a transient cuttings transport with multiple flow patterns model is developed to predict the evolution of cuttings transported in the annulus while backreaming. The established model can provide predictions of the distribution of cuttings bed along the wellbore considering the bulldozer effect caused by large-size drilling tools (LSDTs). The sensitivity analyses of the size of LSDTs, and backreaming operating parameters are conducted in Section 4. And a new theory is proposed to explain the mechanism of cuttings transport in the backreaming operation, in which both the bit and LSDTs have the "cleaning effect" and "plugging effect". The results demonstrate that the cuttings bed in annuli is in a state of dynamic equilibrium, but the overall trend and the distribution pattern are obvious. First, larger diameters and longer drilling tools could lead to a higher risk of the stuck pipe. Second, we find that it is not the case that the higher flow rate is always better for hole cleaning, so three flow-rate intervals are discussed separately under the given conditions. When the "dangerous flow rate" (<33 L/s in Case 4) is employed, the cuttings bed completely blocks the borehole near the step surface and causes a stuck pipe directly. If the flow rate increases to the "low flow rate" interval (33e35 L/s in Case 4), a smaller flow rate instead facilitates borehole cleaning. If the flow rate is large enough to be in the "high flow rate" interval (>35 L/s in Case 4), the higher the flow rate, the better the cleaning effect of cuttings beds. Third, an interval of tripping velocity called "dangerous velocity" is proposed, in which the cuttings bed accumulation near the LSDTs is more serious than those of other tripping velocities. As long as the applied tripping velocity is not within the "dangerous velocity" (0.4e0.5 m/s in Case 5) interval in the backreaming operation, the risk of the stuck pipe can be controlled validly. Finally, through the factors analyses of the annular geometry, particle properties, and fluid properties in Section 5, it can be found that the "low flow rate", "high flow rate" and "dangers flow rate" tend to decrease and the "dangerous velocity" tends to increase with the conditions more favorable for hole cleaning. This study has some guiding significance for risk prediction and parameter setting of the backreaming operation. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
3. Learning representative features via constrictive annular loss for image classification.
- Author
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Jun-Bo Liu, Ya-Ping Huang, Qi Zou, and Sheng-Chun Wang
- Published
- 2019
- Full Text
- View/download PDF
4. Effect of Titanium Addition on Cracks of Fe-Cr-C Coating by Reactive Plasma Cladding
- Author
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Li Mei Wang, Jun Hai Liu, and Jun Bo Liu
- Subjects
Materials science ,Mechanical Engineering ,0211 other engineering and technologies ,chemistry.chemical_element ,02 engineering and technology ,engineering.material ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Cladding (fiber optics) ,Coating ,chemistry ,Mechanics of Materials ,021105 building & construction ,Reactive plasma ,engineering ,General Materials Science ,Composite material ,0210 nano-technology ,Titanium - Abstract
Fe-Cr-C and Fe-Cr-C-Ti coatings were prepared by reactive plasma cladding in this paper. The crack morphology and fracture surface of the Fe-Cr-C coating were observed by SEM. The effect of titanium addition on the crack of Fe-Cr-C coating was analyzed. The results show that the coating cracks mainly consist of crack perpendicular to the fusion line, defect-induced crack and intergranular crack. The crack rate of Fe-Cr-C-Ti coating was obviously decreased after Titanium was added. When the titanium content is below 8 wt.%, with the increase of titanium content, the crack rate of Fe-Cr-C-Ti coating decreases obviously. When titanium content is between 8wt.% and 13wt.%, there are no cracks in the Fe-Cr-C-Ti coating. When the titanium content exceeds 13 wt.%, with the increase of titanium content, a small number of cracks begin to appear. The addition of titanium increases the toughness of the Fe-Cr-C-Ti coating and reduces the stress concentration.
- Published
- 2021
5. Influence of Process Parameters on Microstructure of Reaction Plasma Cladding TiC-Fe-Cr Coating
- Author
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Li Mei Wang, Jun Bo Liu, and Jun Hai Liu
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Materials science ,Mechanical Engineering ,Plasma ,engineering.material ,Condensed Matter Physics ,Microstructure ,Cladding (fiber optics) ,01 natural sciences ,010305 fluids & plasmas ,Coating ,Mechanics of Materials ,Scientific method ,0103 physical sciences ,engineering ,General Materials Science ,Composite material - Abstract
In order to improve the quality and properties of the coating, a certain amount of Ti was added to the plasma cladding Fe-Cr-C coating in the early stage. And Fe-Cr-C-Ti composite powder was prepared by precursor carbonization-composition process. In situ synthesized TiC-Fe-Cr coatings were fabricated on substrate of Q235 steel by plasma cladding process with Fe-Cr-C-Ti composite powder. Microstructure of the coating with different process parameters, including cladding current, cladding speed, number of overlapping cladding layers, were analyzed by scanning electron microscope (SEM). The results show that the structure of the TiC-Fe-Cr coating is greatly affected by the fusion current, the cladding speed and the overlapping cladding process. In this test, when the cladding current of 300A and the cladding process parameter of the cladding speed of 50 mm/min are clad with three layers, a well-formed and well-structured TiC-Fe-Cr coating can be obtained. Which are the best synthetic process parameters in this test.
- Published
- 2021
6. [Extracorporeal shock wave therapy for chronic prostatitis / chronic pelvic pain syndrome: A meta-analysis]
- Author
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Bo, Liao, Xiao-Xi, Mou, Jun-Bo, Liu, Tao, Wu, and Shu, Cui
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Extracorporeal Shockwave Therapy ,Male ,Chronic Disease ,Humans ,Chronic Pain ,Pelvic Pain ,Prostatitis ,Randomized Controlled Trials as Topic - Abstract
To systematically evaluate the clinical efficacy of the extracorporeal shock wave therapy (ESWT) in the treatment of chronic prostatitis / chronic pelvic pain syndrome (CP/CPPS) and provide some evidence for the management of the disease.We searched the PubMed, Cochrane Library, EMbase, CNKI, VIP, WanFang Data and CBM databases on the internet, as well as the Journal of Clinical Urology and Chinese Journal of Urology manually for randomized controlled trials (RCT) on the treatment of CP/CPPS by ESWT published from their establishment till February 1, 2019. Two reviewers independently screened the literature, extracted the data and assessed the risk of bias of the included studies, followed by a meta-analysis with the RevMan 5.3 software.Totally 12 RCTs involving 838 CP/CPPS patients were included in this study. Compared with the controls, the patients treated by ESWT showed a significantly higher rate of overall effectiveness (OR = 8.75, 95% CI: 5.16 to 14.86, P0.000 01) and lower NIH-CPSI scores (MD = -5.10, 95% CI: -6.13 to -4.06, P0.000 01). Subgroup analyses manifested that a higher number of shock wave pulses (≥2 000) had a better therapeutic effect (MD = -4.99, 95% CI: -6.20 to -3.38, P0.000 01 in the2 000-pulse group; MD = -5.76, 95% CI: -7.09 to -4.42, P0.000 01 in the 2 000-pulse group).ESWT can raise the rate of overall clinical effectiveness and improve the symptoms of chronic prostatitis in the treatment of CP/CPPS. This conclusion, however, is to be further supported by more RCTs with higher quality, larger sample size and better design.
- Published
- 2020
7. Occurrence and distribution of phthalate esters in freshwater aquaculture fish ponds in Pearl River Delta, China
- Author
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Peng Cai, Yuanxiang Yang, Chun-Qiao Shan, Zhong-Bao Guo, Kaibin Li, Jun-Bo Liu, Xiao-Jiao Fu, Xiangping Nie, Yanfeng Lv, Guang-Ze Shi, Meng Gao, Zhang Cheng, Xiaoxun Xu, Zhanbiao Yang, and Xian Junren
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China ,Pearl river delta ,010504 meteorology & atmospheric sciences ,Health, Toxicology and Mutagenesis ,Fish pond ,Phthalic Acids ,Aquaculture ,010501 environmental sciences ,Toxicology ,Spatial distribution ,01 natural sciences ,chemistry.chemical_compound ,Rivers ,Diethylhexyl Phthalate ,Ponds ,0105 earth and related environmental sciences ,biology ,business.industry ,Phthalate ,Sediment ,Esters ,General Medicine ,biology.organism_classification ,Pollution ,Dibutyl Phthalate ,Congener ,chemistry ,Seafood ,Environmental chemistry ,Freshwater fish ,Environmental science ,business ,Estuaries ,Water Pollutants, Chemical ,Environmental Monitoring - Abstract
The concentrations, congener profiles and spatial distribution of 13 phthalate esters (PAEs) in the freshwater fish ponds in the Pearl River Delta (PRD) region were investigated in water and sediment samples collect from 22 sites during Jul. 2016-Sept. 2017. The di-2-ethylhexyl phthalate (DEHP) was the predominant compounds in both water and sediment samples, accounting for 70.1% and 66.1% of ∑PAEs, respectively. The DEHP concentrations in the water samples collected from the sites of Zhongshan (35.7 μg/L), Jingmen (17.3 μg/L) and Nanhai (14.2 μg/L) were higher than that collected from other sampling sites (p0.05), and exceed the Chinese environmental quality standards for surface water (DEHP, 8.00 μg/L). The concentrations of ΣPAEs (mean and median were 11.8 mg/kg dw and 7.95 mg/kg dw) in sediment was higher than that in sediment of river and estuary in the PRD region (p0.05). The median concentrations of DEHP and di-n-butyl phthalate (DBP) exceeded recommend environmental risk limit (ERL) that posed a potential risk to the aquaculture fish pond environment in the PRD.
- Published
- 2018
8. Impact of Structure Design of Artififical Upwelling Tube
- Author
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Lin Shan, Jin Ying Leng, Jia Wang Chen, Hao Cai Huang, Jun Bo Liu, and Ming Zhou Liu
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Air volume ,Oceanography ,Deep ocean water ,Structure design ,Upwelling ,Environmental science ,Tube (fluid conveyance) ,General Medicine ,Water volume ,Primary productivity ,Volumetric flow rate - Abstract
Deep ocean water (DOW) is cold, nutrient-rich and pathogen-free water, which can be transported to the surface by upwelling. Upwelling can change the temperature and nutrient distribution of the surrounding water, hence improves the marine ecological environment and the marine primary productivity. Two lake experiments were accomplished in Qiandao Lake .The first experiment was done with hard PVC upwelling tube, while in the second experiment , the upwelling tubes with different diameters (0.5 m, 1 m, 1.5 m and 2 m) were made of nylon ,which are supported by rings. It can be concluded that upwelling ratio (the ratio of water volume flow rate and air volume flow rate) of the hard PVC upwelling tube was higher than that of soft nylon upwelling tube, and in condition of soft nylon upwelling tube, upwelling ratio of 1 m diameter tube was higher than that of others, providing important guidance for the next sea trial.
- Published
- 2014
9. Pattern optimization and carbon emissions of coal supply in China
- Author
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Xiang-yang Xu, Jun-lian Gao, and Jun-bo Liu
- Subjects
business.industry ,Greenhouse gas ,Environmental engineering ,Environmental science ,Coal ,General Agricultural and Biological Sciences ,China ,business - Published
- 2019
10. Study on Industrialization of Mid-Low Grade Collophanite Flotation in Yunnan Province
- Author
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Jun Bo Liu, Quan Jun Liu, Rong Dong Deng, and Hong Xiao
- Subjects
Engineering ,Industrialisation ,Waste management ,business.industry ,Environment effect ,General Engineering ,Mill ,Laboratory experiment ,business - Abstract
Efficient reagents were used in the direct-reverse flotation process to process the mid-low grade Si-Ca collophanite. We got nice results in the laboratory experiment and expanding test. These results showed that our study was successful in technology, economy and environment effect. It also offers support for building flotation mill in future.
- Published
- 2013
11. Microstructure and Hardness of Fe-Based Coating by Plasma Cladding
- Author
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Li Mei Wang, Jun Sheng Jiang, and Jun Bo Liu
- Subjects
Materials science ,Scanning electron microscope ,Metallurgy ,Composite number ,General Medicine ,Electron microprobe ,engineering.material ,Cladding (fiber optics) ,Microstructure ,law.invention ,Optical microscope ,Coating ,law ,engineering ,Eutectic system - Abstract
Plasma cladding experiments were carried out on Q235 steel with Fe-Cr-Ti-C powder. Microstructure and micro-hardness of the composite coatings were investigated by means of optical microscopy (OM), scanning electron microscopy (SEM) and electron probe micro-analyzer (EPMA) and micro-hardness tester. The results indicated that the grains of the cladding coatings with Ti are much finer than that of the Fe-based cladding coating without Ti. Compared with the cladding coatings without Ti, there are more shingle crystals in the cladding coatings with Ti and the hard phase (Cr,Fe)7C3of the eutectic in the coatings increase gradually. The average hardness value of the four cladding coatings is respectively 486.5 HV0.1and 558.8 HV0.1.
- Published
- 2013
12. Cracking Behavior of Two Kinds of Plasma Cladding Layers by Precursor Carbonization-Composition Process
- Author
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Jun Bo Liu
- Subjects
Austenite ,Cladding (metalworking) ,Materials science ,Scanning electron microscope ,Metallurgy ,General Engineering ,Grain boundary ,Composite material ,Ferrotitanium ,Microstructure ,Eutectic system ,Carbide - Abstract
In-situ synthesized two kinds of Fe-Cr-C and Fe-Cr-C-Ti layers were fabricated on the base of Q235 steel by reactive plasma cladding process using composite powder prepared by precursor carbonization-composition process as raw materials. The composite powder is composed of ferrotitanium, chromium, iron and precursor sucrose. Microstructure of the layer was observed by scanning electron microscope (SEM). The phases in the layer were determined by X-ray diffraction (XRD). Results indicate that the Fe-Cr-C layer consists of primary (Cr,Fe)7C3 carbide, chrysanthemum-shaped eutectic (Cr,Fe)7C3 carbide and eutectic austenite. The cracks in Fe-Cr-C layer might originate at the interface of the layer and the base material as well as at the pores or edges of the layer. These cracks expand along primary (Cr,Fe)7C3 grain boundaries in a crystalline form. Because the grains of primary (Cr,Fe)7C3 are fiber-shaped and the fiber direction are perpendicular to the surface of the layer, so the cracks expand perpendicularly throughout of the Fe-Cr-C layer. The Ti addition into Fe-Cr-C plays an important role in synthesizing TiC and austenite, reducing primary (Cr,Fe)7C3 and improving the microstructure of eutectic (Cr,Fe)7C3. Therefore, Fe-Cr-C-Ti has good performance in toughness and crack-resistance.
- Published
- 2013
13. Gm-C Complex Band-Pass Filter with Tuning Circuit in 0.18μm CMOS
- Author
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Xiangning Fan, Jun Bo Liu, Kuan Bao, and Rui Wu
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Filter design ,Voltage-controlled filter ,Engineering ,business.industry ,Low-pass filter ,Electronic engineering ,Butterworth filter ,General Medicine ,business ,Band-stop filter ,Active filter ,All-pass filter ,m-derived filter - Abstract
This paper presents a 0.18μm CMOS based Gm-C complex band-pass (CBP) filter with tuning circuit. Active-Gm-C structure with Nauta transconductor and phase-locked loop (PLL) architecture are adopted by the filter and the tuning circuit respectively which can achieve accurate frequency response. The layout size is 970μm×920μm. Under a 1.8V supply voltage, measurement results show that the pass-band gain and the ripple of the filter is 3.1dB and 3dB respectively. The bandwidth after tuning is 32.5MHz, image rejection ratio (IRR) is about 47dB, and the power dissipation of the filter is about 21.6mW.
- Published
- 2012
14. Microstructure and Performance of Fe-Based Composite Clad Layer Fabricateded by Submerged-Arc Welding Added Alloy Powder
- Author
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Chi Yuan, Jun Bo Liu, and Li Mei Wang
- Subjects
Austenite ,Cladding (metalworking) ,Materials science ,Mechanical Engineering ,Metallurgy ,Alloy ,Composite number ,engineering.material ,Condensed Matter Physics ,Microstructure ,Submerged arc welding ,Mechanics of Materials ,engineering ,General Materials Science ,Graphite ,Composite material ,Ferrotitanium - Abstract
TiC particle reinforced Fe-based composite clad layer were in situ synthesized on surface of Q235 steel by Submerged arc Welding of the mixed powder of ferrotitanium, iron, chromium, nickel and colloidal graphite, etc. Microstructure of the clad layer were observed by scanning electron microscope (SEM) and Energy Disperse Spectroscopy (EDS). Wear resistance of the clad layer was tested on wear tester at room temperature compared with the base material Q235 steel. Microhardness of the clad layer was measured by microhardness tester. Results indicated that the fine TiC particles were formed by Submerged-arc Welding process, and the the TiC particles were dispersed in the matrix. The size of TiC particles was less than 2 μm. The microstructure of cladding layer consisted of TiC particles, martensite and austenite. The average microhardness of clad layer was HV0.2601, which was about 3 times as high as the based metal Q235. On the conditions of same wear and room temperature, the weight loss of the base material Q235 is 10-15 times as much as the composite clad layer. The weight loss increase of the clad layer has a little change with the increase of load and the change of load is not sensitive to the weight loss of the clad layer. The clad layer has good load characteristics.
- Published
- 2011
15. Microstructure and Performance of Multiple Tracks Lap-Joint Coating by Plasma Cladding
- Author
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Jun Bo Liu, Li Mei Wang, and Bao Xin Huang
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Cladding (metalworking) ,Materials science ,Lap joint ,Coating ,Carbon steel ,Metallurgy ,Alloy ,engineering ,General Medicine ,Plasma ,engineering.material ,Microstructure - Abstract
Plasma cladding multi-lap joint alloying was attained on low carbon steel with self-designed Fe-Cr-C alloy powder by plasma cladding equipment. The lap-joint proportion is 50%. Microstructure and performance of lap-joint had been analyzed and detected, rosette crystal grain are found in lap-joint area, The structure in this area are more fine and compact, The hardness has been increased.
- Published
- 2011
16. Crack Behavior of Fe-Based Coating by Plasma Cladding
- Author
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Li Mei Wang, Jun Bo Liu, and Bao Xin Huang
- Subjects
Materials science ,Coating ,engineering ,Forensic engineering ,General Medicine ,Fe based ,Plasma ,engineering.material ,Composite material ,Cladding (fiber optics) - Abstract
On the base of orthogonal comparison tests, influences of many kinds of factors on plasma cladding crack sensibility were studied. The results indicate that substrate and its surface state, processing parameter and components of plasma cladding coating have great effects on crack sensibility of plasma cladding coating. Through changing these factors, it is possible to reduce cracks and expand ranges of applications of this technology.
- Published
- 2011
17. TiC Particle Reinforced Reactive Plasma Cladding Composite Coating by the Precursor Carbonization-Composition Process
- Author
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Jun Bo Liu, Li Mei Wang, Guang Ming Cao, and Jun Sheng Jiang
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Cladding (metalworking) ,Austenite ,Materials science ,Coating ,Scanning electron microscope ,Composite number ,General Engineering ,engineering ,engineering.material ,Composite material ,Ferrotitanium ,Microstructure ,Carbide - Abstract
Fe-Cr-Ti-C composite powder was prepared by precursor carbonization-composition process using the mixture of ferrotitanium, chromium, iron powders and precursor sucrose as raw materials. In situ synthesized TiC particle reinforced composite coating was fabricated on substrate of Q235 steel by reactive plasma cladding process using Fe-Cr-Ti-C composite powder. Microstructure of the coating was observed by scanning electron microscope (SEM), the phases in the coating were determined by X-ray diffraction (XRD), and the wear resistance of the composite coating was evaluated under dry sliding wear test conditions at room temperature. Results indicate that the composite coating consists of in-situ the reinforcing TiC carbide, (Cr,Fe)7C3 eutectics and austenitic, and is metallurgically bonded to the Q235 steel substrate. TiC carbide in the composite coating showed the gradient distribution. TiC particles present granular in the fusion zone and central zone, and present dendritic in the surface of the composite coating. Hardness of the coating from surface to fusion zone is little difference, the average hardness of the coating is about HV0.2750, is as 3.2 times as the base. The wear mass loss of Q235 base material is 12 times as that of the composite coating.
- Published
- 2011
18. Microstructure and Wear-Resisting Property of Submerged-Arc Welding Fe-Cr-C Ceramic Coating Added Alloy Powder
- Author
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Li Mei Wang, Jun Sheng Jiang, and Jun Bo Liu
- Subjects
Austenite ,Materials science ,Mechanical Engineering ,Metallurgy ,Alloy ,Welding ,engineering.material ,Condensed Matter Physics ,Microstructure ,Submerged arc welding ,law.invention ,Iron powder ,Coating ,Mechanics of Materials ,law ,engineering ,General Materials Science ,Eutectic system - Abstract
Fe-Cr-C ceramic composite coating was fabricated on substrate of Q235 steel by submerged-arc welding process added alloy powder using the material of chromium powder, iron powder, colloid graphite powder and H08 welding wire. Microstructure and wear properties of the composite coating were investigated by means of X-ray diffraction (XRD), scanning electron micrograph (SEM), energy dispersive X-ray analysis (EDS) and microhardness tester. wearresisting property of the coating was tested at room temperature and dry sliding wear conditions. Results show that the composite coating consists of (Cr,Fe)7C3 eutectic phase and austenite. There are many dendrite crystal structure in the coating, and most of the dendrite crystal are parallel, pointing to the surface of the coating. The wear mass loss of the base body Q235 steel is 10 times higher as that of the composite coating. The coating has excellent wear-resisting property because there are many eutectic carbide (Cr,Fe)7C3. It can increase wear resisting property of the coating that the austenite could occurr strain and induced martensite in the coating during wear.
- Published
- 2011
19. Fe-Cr-C-TiC High-Chromium Fe-Based Ceramic Composite Coating Prepared by PTA Weld-Surfacing Process
- Author
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Li Mei Wang, Jun Bo Liu, and Chi Yuan
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Austenite ,Materials science ,Mechanical Engineering ,Metallurgy ,chemistry.chemical_element ,Substrate (printing) ,Welding ,engineering.material ,Condensed Matter Physics ,Microstructure ,Indentation hardness ,law.invention ,Chromium ,Coating ,chemistry ,Mechanics of Materials ,law ,engineering ,General Materials Science ,Composite material ,Ferrotitanium - Abstract
In situ synthesized Fe-Cr-C-TiC high-chromium Fe-based ceramic composite coating was fabricated on substrate of Q235 steel by plasma transferred arc (PTA) weld-surfacing process using the mixture of ferrotitanium, ferrochromium, ferroboron and ferrosilicium powders. The microstructure and wear properties of the composite coating were investigated by XRD, SEM, EDS, microhardness tester and wear tester. Results show that the coating consists of TiC, (Cr,Fe)7C3 and austenite. The coating is metallurgically bonded to the Q235 steel substrate. TiC particles formed by PTA weld-surfacing process present cubic, dendrite and flower-like shape. The wear resistance of the composite coating is approximately 11 times higher than that of the base body Q235. As the load increases, the wear mass loses slowly, which demonstrates the composite coating has excellent load character.
- Published
- 2011
20. Tic Particle Reinforced Iron Based Composite Coating by Submerged-Arc Welding Added Alloy Powder
- Author
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Jun Hai Liu, Jun Bo Liu, and Li Mei Wang
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Austenite ,Materials science ,Metallurgy ,Alloy ,General Engineering ,Welding ,engineering.material ,Microstructure ,Submerged arc welding ,law.invention ,Coating ,law ,engineering ,Particle ,Composite material ,Ferrotitanium - Abstract
TiC particle reinforced iron based composite coating were in situ synthesized on surface of Q235 steel by Submerged-arc Welding (SAW) using the mixture consisted of ferrotitanium, ferrochromium, iron and carbon powders. Microstructure of the coating was observed by scanning electron microscope(SEM)and X-ray diffraction(XRD). Microhardness was measured by microhardness tester. Results indicated that the fine TiC particles were formed by using SAW process and dispersed in the matrix. And the particles sizes were less than 2μm. Microstructure of coating consists of TiC particles, martensite and austenite. The microhardness of coating is HV575~HV617, which is about 3 times of that of the based metal.
- Published
- 2010
21. Microstructure and Wear Resistance of TiC+Cr7C3 Reinforced Ceramal Composite Coating Produced by PTA Weld-Surfacing Process
- Author
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Jun Bo Liu, Gui Xiang Song, Jun Hai Liu, and Jihua Huang
- Subjects
Austenite ,Materials science ,Scanning electron microscope ,Metallurgy ,General Engineering ,Substrate (printing) ,Welding ,engineering.material ,Microstructure ,Indentation hardness ,law.invention ,Coating ,law ,engineering ,Composite material ,Ferrotitanium - Abstract
A new type in situ reinforcing phase TiC+Cr7C3 ceramal composite coating was fabricated on substrate of Q235 steel by plasma transferred arc (PTA) weld-surfacing process using the mixture of ferrotitanium, ferrochromium, ferroboron and ferrosilicium powders. Microstructure and wear performance of the coating were investigated by means of X-ray diffraction (XRD), scanning electron micrograph (SEM), energy dispersive X-ray analysis (EDS), microhardness tester and wear tester. Results show that the composite coating consists of TiC, primary phase Cr7C3 , (Cr,Fe)7C3 and austenite. The composite coating is metallurgically bonded to the Q235 steel substrate. TiC particles present cubic and “dendrite flower-like” shape in the composite coating. The coating has high microhardness and excellent wear resistance under dry-sliding wear test conditions.
- Published
- 2010
22. Determination of the optical constants of solar-control amorphous silicon thin films on float glass
- Author
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Qiying Liu, Yong Liu, Gaorong Han, Chenlu Song, Lihong Ni, and Jun Bo Liu
- Subjects
Amorphous silicon ,Materials science ,Silicon ,business.industry ,Float glass ,chemistry.chemical_element ,Surfaces and Interfaces ,General Chemistry ,Molar absorptivity ,Condensed Matter Physics ,Surfaces, Coatings and Films ,law.invention ,Annealing (glass) ,chemistry.chemical_compound ,Optics ,chemistry ,law ,Ellipsometry ,Materials Chemistry ,Optoelectronics ,Thin film ,business ,Refractive index - Abstract
An improved method employing a modified Forouhi and Bloomer disperse model with a hybridized simulated annealing algorithm is implemented in this paper, allowing the determination of refractive index, extinction coefficient, and thickness of a-Si films at one time by fitting reflectance and transmitted spectra. The thickness of films obtained by this method has a reasonable agreement with the result by ellipsometric measurement, especially for samples with thickness in the range of 40-80 nm. The presented method exhibits low time consumption and cost, which implies a possibility of usage in real-time on-line measurement of solar-control coatings on float glass.
- Published
- 2009
23. Development of one corn ear and verification the three laws of inheritance
- Author
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Liang Zhao, Wen-Yao Zhao, and Jun-Bo Liu
- Subjects
Linkage (software) ,Genetics ,Inheritance (genetic algorithm) ,food and beverages ,General Medicine ,Biology ,Endosperm ,symbols.namesake ,Meiosis ,Chromosome (genetic algorithm) ,Mendelian inheritance ,symbols ,Hybrid corn ,Hybrid - Abstract
A new corn was developed as a lab material to verify the three Laws of Inheritance on only one F2 ear with correct segregation ratios of kernel traits. In order to investigate the three Inheritance Laws simultaneously with one ear, the sweet endosperm (Sn1), kernel color (C1) and the glutinous endosperm (Wx) were chosen as the original phenotypes. Gene Sn1sn1 is located on chromosome four, genes C(1c1) and Wxwx are located on chromosome nine. After several generations of continuous self-pollination and test crossing, direct crossing and back crossing, with strict selections, the homozygous parents were obtained. With different combinations of homozygous parents, different hybrids were developed. The segregation ratios of each phenotype on the same F2 ear are compared to the theoretical segregation ratios according to the corn gene exchange and gamete types and quantities produced through meiosis. The results showed three ratios of 3:1, two ratios of 9:3:3:1, and one ratio of linkage and exchange, with all the chi-square values smaller than the permitted ones. This means that only one ear of this new hybrid corn can be used as a new teaching aid to examine and verify the three Laws of Inheritance.
- Published
- 2009
24. Theoretical and experimental studies on the performances of barbital-imprinted systems
- Author
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Jun-Bo, Liu, Yan, Wang, Ting-Ting, Su, Bo, Li, Shan-Shan, Tang, and Rui-Fa, Jin
- Abstract
By using density functional theory, we studied the interaction process between barbital and 2-vinyl-4,6-diamino-1,3,5-triazine in acetonitrile at 333 K. Barbital and 2-vinyl-4,6-diamino-1,3,5-triazine were used as the template and functional monomer, respectively. The molecularly imprinted polymer microspheres containing barbital and 2-vinyl-4,6-diamino-1,3,5-triazine were synthesized through precipitation polymerization. After removing the template molecule barbital, the average diameter of the obtained molecularly imprinted polymers was 1.45 μm. By optimizing the molar ratio of barbital and the 2-vinyl-4,6-diamino-1,3,5-triazine, the resulting molecularly imprinted polymers showed the highest adsorption for the barbital. The analysis of the Scatchard plot revealed that the dissociation constant (Kd ) and apparent maximum adsorption quantity (Qmax ) of the molecularly imprinted polymers were 30.69 mg/L and 8.68 mg/g, respectively. The study of selective adsorption showed that molecularly imprinted polymers exhibited higher selectivity for barbtital than that for 1,3-dimethyl barbituric acid and pentobarbital. Herein, the studies can provide theoretical and experimental references for the barbital-imprinted system.
- Published
- 2015
25. Preparation of melamine molecularly imprinted polymer by computer-aided design
- Author
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Yan, Wang, Jun-Bo, Liu, Shan-Shan, Tang, and Rui-Fa, Jin
- Abstract
Melamine was chosen as template, methacrylic acid was chosen as functional monomer, and divinylbenzene, ethylene glycol dimethacrylate, trimethylolpropane trimethylacrylate were chosen as cross-linking agents, respectively. The WB97XD/6-31G(d, p) method was used to calculate the geometry optimization of the different imprinting ratios, the action sites, the bonding situation, and the optimization of the cross-linking agents. The nature of the imprinting effect was also studied by the atoms in molecules theory. The theoretical results showed that melamine interacts with methacrylic acid by hydrogen bonding, and the melamine molecularly imprinted polymers with a molar ratio of 1:6 have the most hydrogen bonds and the most stable structure. Divinylbenzene is the best cross-linking agent for the melamine molecularly imprinted polymers. The melamine molecularly imprinted polymers were synthesized by precipitation polymerization. The results showed that the maximum adsorption capacity for molecularly imprinted polymers towards melamine is 19.84 mg/g, and the adsorption quantity of the polymers to melamine is obviously higher than that of cyromazine, cyanuric acid, and trithiocyanuric in milk. This study could provide theoretical and experimental references for the screening of the imprinting ratio and the cross-linking agent for the given template and monomer system.
- Published
- 2015
26. Theoretical and experimental research on the self-assembled system of molecularly imprinted polymers formed by salbutamol and methacrylic acid
- Author
-
Jun-Bo, Liu, primary, Yang, Shi, additional, Shan-Shan, Tang, additional, and Rui-Fa, Jin, additional
- Published
- 2015
- Full Text
- View/download PDF
27. [Development of one corn ear and verification the three laws of inheritance]
- Author
-
Wen-Yao, Zhao, Jun-Bo, Liu, and Liang, Zhao
- Subjects
Databases, Genetic ,Quantitative Trait Loci ,Genes, Plant ,Molecular Biology ,Zea mays - Abstract
A new corn was developed as a lab material to verify the three Laws of Inheritance on only one F2 ear with correct segregation ratios of kernel traits. In order to investigate the three Inheritance Laws simultaneously with one ear, the sweet endosperm (Sn1), kernel color (C1) and the glutinous endosperm (Wx) were chosen as the original phenotypes. Gene Sn1sn1 is located on chromosome four, genes C(1c1) and Wxwx are located on chromosome nine. After several generations of continuous self-pollination and test crossing, direct crossing and back crossing, with strict selections, the homozygous parents were obtained. With different combinations of homozygous parents, different hybrids were developed. The segregation ratios of each phenotype on the same F2 ear are compared to the theoretical segregation ratios according to the corn gene exchange and gamete types and quantities produced through meiosis. The results showed three ratios of 3:1, two ratios of 9:3:3:1, and one ratio of linkage and exchange, with all the chi-square values smaller than the permitted ones. This means that only one ear of this new hybrid corn can be used as a new teaching aid to examine and verify the three Laws of Inheritance.
- Published
- 2008
28. [Preparation and identification of the oligonucleotide chip for detecting the virulence-associated genotypes and drug resistance of Helicobacter pylori]
- Author
-
Shu-Bin, Guo, Jun-Bo, Liu, Lin-Jie, Chen, and Sheng-Qi, Wang
- Subjects
Genotype ,Helicobacter pylori ,Virulence ,Clarithromycin ,Drug Resistance, Bacterial ,Point Mutation ,Microbial Sensitivity Tests ,In Vitro Techniques ,Polymerase Chain Reaction ,Anti-Bacterial Agents ,Oligonucleotide Array Sequence Analysis - Abstract
To develop an oligonucleotide microarray-based method for the simultaneous detection of Helicobacter pylori (Hp) infection, virulence-associated genotypes, and drug resistance.Hp was classified into cagA + and cagA- genotypes based on its virulence. Clarithromycin-resistance of Hp was identified by existence of point mutations in 23S rRNA. We constructed an oligonucleotide microarray chip to simultaneously diagnose Hp infection and detect its virulence-associated genotypes and mutations associated with clarithromycin-resistance. The diagnostic accuracy of the constructed microarray was tested with templates of wild type and mutated type.The oligonucleotide chip accurately detected cagA + and cagA- genotypes of Hp, as well as four common point mutations in 23S rRNA related to clarithromycin-resistance.Oligonucleotide microarray chip can be used to diagnose Hp infection and test its virulence-associated genotypes and drug resistance simultaneously.
- Published
- 2007
29. THEORETICAL STUDIES ON MOLECULAR IMPRINTED INTERACTION BETWEEN ENROFLOXACIN AND METHACRYLIC ACID
- Author
-
Yan-ling, Wang, primary, Jun-bo, Liu, additional, Jia-ni, Sun, additional, Shan-shan, Tang, additional, and Rui-fa, Jin, additional
- Published
- 2013
- Full Text
- View/download PDF
30. [Detection of P53 and K-ras gene mutations in lung cancer with oligonucleotide chip]
- Author
-
Jun-Bo, Liu, Ji-Pan, Xie, Zong-Liang, Zou, Lin-Jie, Chen, Long-Yun, Li, and Sheng-Qi, Wang
- Subjects
Genes, ras ,Lung Neoplasms ,Mutation ,Oligonucleotides ,Humans ,Tumor Suppressor Protein p53 ,Sensitivity and Specificity ,Oligonucleotide Array Sequence Analysis - Abstract
Different factors including hybridization solution components, hybridization temperature, and the concentration and proportion of the labelled primer, which affected the sensitivity and specificity of single mutation identification, were exploited. Asymmetric PCR increased the hybridization sensitivity, and the asymmetric multi-PCR did not affect the specificity, while the sensitivity was improved a little. Among 30 lung cancer samples detected with the oligonucleotide microarray, 12 was found P53 gene mutations and 5 had K-ras gene mutations. The P53 gene mutations identified by the oligonucleotide microarray was proved 80% same as the sequencing results. The obvious statistical relations of K-ras and P53 gene mutations with tumor type, tumor stage and smoking were not obtained because of less samples and mutation sites.
- Published
- 2002
31. Triple-differential cross section for single ionization of H2by electron impact
- Author
-
De-Jun Liu, Jia Ma, Jun-Bo Liu, Ya-Jun Zhou, and Yuan-Cheng Wang
- Subjects
Physics ,Scattering cross-section ,Cross section (physics) ,Ionization ,General Physics and Astronomy ,Molecule ,Incident energy ,Born approximation ,Atomic physics ,Ground state ,Electron ionization - Abstract
The triple-differential cross section (TDCS) for the (e, 2e) ionization of a hydrogen molecule is calculated using the molecule distorted-wave Born approximation (MDWBA). Distorted waves are obtained by solving momentum-space coupled-channel Lippmann—Schwinger equations, including the ground state and the lowest-lying electronic state of b3Σu. TDCSs at the incident energy 100 eV in coplanar asymmetric geometry are reported. The present calculations are compared with the available experimental measurements and the theoretical results.
- Published
- 2013
32. Molecular distorted-wave Born approximation for ionization of H2by electron impact
- Author
-
De-Jun Liu, Jun-Bo Liu, and Yajun Zhou
- Subjects
Physics ,Ionization ,Quantum electrodynamics ,Position and momentum space ,Electron ,Born approximation ,Condensed Matter Physics ,Mathematical Physics ,Atomic and Molecular Physics, and Optics ,Electron ionization ,Differential (mathematics) - Abstract
The molecular distorted-wave Born approximation is proposed to study the (e, 2e) reaction for H2 targets. The wave functions of the incoming and outgoing electrons are obtained by solving the Lippmann?Schwinger equations, and the T-matrix in the Lippmann?Schwinger equations is calculated in a momentum space static-exchange-optical model. Triple differential cross sections are computed for incident energies of 100 and 250?eV in coplanar asymmetric geometry. Comparison of the present calculated results with the available experimental data in the literature reveals that there is good agreement.
- Published
- 2012
33. Elastic scattering of electrons from water molecule
- Author
-
Jun-Bo, Liu, primary and Ya-Jun, Zhou, additional
- Published
- 2010
- Full Text
- View/download PDF
34. Elastic cross sections for electron–carbon scattering
- Author
-
Jun-Bo, Liu, primary, Yang, Wang, additional, and Ya-Jun, Zhou, additional
- Published
- 2006
- Full Text
- View/download PDF
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