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清除亚硝酸盐与阻断亚硝胺关系的研究

食品科技 2016年第11期41卷 279-283页

作者：张欧刘永东钟儒刚北京工业大学生命科学与生物工程学院北京100124

亚硝胺是一类具有很强致癌性的化合物,流行病学调查表明人类的胃癌、食道癌、肝癌、结肠癌和膀胱癌等都可能与N-亚硝胺有关,因此寻找和探讨阻断亚硝胺生成的物质和方法一直是食品研究的热点。在模拟胃液条件下,运用气相色谱-质谱联用(GC... 详细信息

亚硝胺是一类具有很强致癌性的化合物,流行病学调查表明人类的胃癌、食道癌、肝癌、结肠癌和膀胱癌等都可能与N-亚硝胺有关,因此寻找和探讨阻断亚硝胺生成的物质和方法一直是食品研究的热点。在模拟胃液条件下,运用气相色谱-质谱联用(GC-MS)和离子色谱(IC)技术,探讨了乙醇和乙酸对亚硝酸盐和二甲胺(DMA)共存体系中生成N-亚硝基二甲胺(NDMA)的影响,并通过机制研究深入探讨清除亚硝酸盐和阻断亚硝胺之间的关系。实验结果发现,在一定浓度范围内,乙醇和乙酸都能清除亚硝酸盐,然而它们对NDMA的生成却分别表现出抑制和促进的作用。由此可见,清除了体系中的前体物质亚硝酸盐,并不能说明该物质能够阻断亚硝胺的生成,两者之间是没有必然关系的。

关键词：乙醇乙酸 N-亚硝基二甲胺(NDMA) 亚硝酸盐亚硝胺清除阻断

Copper-coated Porous Polyimide as Ultralight and Safe Current Collectors for Advanced LIBs

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Chinese Journal of Polymer Science 2024年第4期42卷 521-531页

作者： Cun-Sheng liu Jun-Qi Hu Ting-Ting Mao Song-Yi Liao ru-Ming Feng Yi-dong liu yong-gang Min School of Materials and Energy Guangdong University of TechnologyGuangzhou510006China College of Chemistry and Chemical Engineering Zhongkai University of Agriculture and EngineeringGuangzhou510225China Shanwei Branch of Advanced Energy Science and Technology Guangdong Laboratory Shanwei516600China

Metallic copper is widely used as current collector(CC) for graphite anode of lithium-ion batteries(LIBs) due to its high electrical conductivity and electrochemical stability. However, the large volume density of commercial copper foil(~8.9 g·cm^(-3)) limits the increase of energy density of battery. Here, copper-coated porous polyimide(Cu@PPI) was prepared by vacuum evaporation as collector for the graphite anode. The sandwich structure connects the copper metal on both sides of the collector with excellent electrical conductivity. Compared to commercial Cu foil, Cu@PPI has lighter mass(≤3.9 mg for disc of 12 mm diameter versus 9.9 mg of ~10 μm Cu foil) and lower volume density(≤3.3 g·cm^(-3)). In addition, the porous structure allows of better adhesion of reactive substances and electrochemical properties than pure Cu foils. It is estimated that the energy density of Cu@PPI should be much higher than that of Cu foil. This strategy should be applicable for other current collectors.

关键词： Copper-coated Vacuum evaporation Porous polyimide(PPI) Current collector(CC) LIBs

Investigating the Absorption and Desorption Behavior of Methylene Chloride in the Poly(aryl ether ketone) Film with Different Crystallinities

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Chinese Journal of Polymer Science 2024年第2期42卷 239-246,I0009页

作者： Hong-ru Yang Jin-dong Zhang dong-Ting Gao gang liu Chun-Hai Chen Jia-Nan Yao Center for Advanced Low-Dimension Materials State Key Laboratory for Modification of Chemical Fibers and Polymer MaterialsCollege of Materials Science and EngineeringDonghua UniversityShanghai201620China

Poly(aryl ether keton e)(PAEK) films with different crystallinities were obtained by controlling the cooling rate,which were subjected to the absorption and desorption of methylene chloride(CH_(2)Cl_(2)).We employed attenuated total reflection Fourier transform infrared(ATR-FTIR)spectroscopy analyses to investigate the diffusion behavior of CH_(2)Cl_(2) in PAEK films with different *** to the Fickian diffusion model,the calculated diffu sion coefficients of CH_(2)Cl_(2) in PAEK films were observed to decrease with increasing *** effect of CH_(2)Cl_(2)absorption and desorption on the mechanical properties of PAEK films with different crystallinity was further analyzed using tensile *** tensile tests exhibited that CH_(2)Cl_(2) has two concurrent effects:plasticization and solvent-induced *** scanning calorimetry(DSC) and wide-angle X-ray diffraction(WXRD) techniques further confirmed solvent-induced crystallization *** results would be beneficial to understand the solvent resistance of PAEK materials and consequently provide the practical application conditions of PAEK with a theoretical basis.

关键词： Poly(aryl ether ketone) Diffusion behavior Infrared spectra Solvent-induced crystallization Mechanical properties

Dynamic Behaviour of Vortex Matter, Memory Effect and Mittag--Leffler Relaxation

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Chinese Physics Letters 2001年第2期18卷 269-271页

作者： liu gang HAN ru-Shan Department of Physics Peking UniversityBeijing 100871 China Institute of Atomic Energy P.O.Box 275(18)Beijing 102413

Using fractional Fokker-Planck equation and Langevin equation's Monte Carlo simulation,we find that when current density is less than critical current density,at the very beginning the motion for vortices is mainly within the pinning well with the typical relaxation time *** time t is longer than Tr,the vortex glass will distort between two adjacent pining wells and will lead to memory effect which is lacking in the Mott insulator and pancake *** inertial effect is not dominating as compared with the formation and growth of easy-flow *** random quenched disorder will lead to Mittag-Leffler relaxation.

关键词： equation relaxation vortex

Metabolism of benzo[a]pyrene in peroxynitrite/Fe(III) porphyrin system

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Journal of Environmental Sciences 2007年第4期19卷 385-386页

作者： LUO Yun-jing LIN Tai-feng ZHANG Shu-fen liu rui zhong ru-gang College of Life Science and Bioengineering Beijing University of Technology Beijing 100022 China.

The peroxynitrite/porphyrin biomimetic system was established to investigate the effects of peroxynitrite on benzo[a]pyrene （B[a]P） metabolism. Three model systems consisting of different iron porphyrins were compared, and the results showed that the peroxynitdte/T（p-Cl）PPFeCl system was the highest catalytic efficiency in the metabolism of B [a]P. We analyzed the B [a]P metabolites produced from this system by RP-HPLC method and firstly identified the formation of nitrobenzo[a]pyrenes which are the special metabolites of B [a]P induced by peroxynitrite.

关键词： peroxynitrite benzo[a]pyrene metabolism nitrobenzo[a]pyrenes

Microstructure and Wear Properties of Fe-based Amorphous Coatings Deposited by High-velocity Oxygen Fuel Spraying

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Journal of Iron and Steel Research International 2016年第7期23卷 699-704页

作者： gang WANG Ping XIAO zhong-jia HUANG ru-jie HE Remanufacturing Surface Engineering Technology Research Center Anhui Polytechnic University Institute of Advanced Structure Technology Beijing Institute of Technology

Fe-based powder with a composition of Fe_（42.87）Cr_（15.98）Mo_（16.33）C_（15.94）B_（8.88）（at.%）was used to fabricate coatings by high-velocity oxygen fuel *** effects of the spraying parameters on the microstructure and the wear properties of the Fe-based alloy coatings were systematically *** results showed that the obtained Fe-based coatings with a thickness of about 400μm consisted of a large-volume amorphous phase and some *** increasing the fuel and oxygen flow rates,the porosity of the obtained coatings *** coating deposited under optimized parameters exhibited the lowest porosity of 2.8%.The excellent wear resistance of this coating was attributed to the properties of the amorphous matrix and the presence of nanocrystals homogeneously distributed within the *** wear mechanism of the coatings was discussed on the basis of observations of the worn surfaces.

关键词： metallic glass high-velocity oxygen fuel Fe-based amorphous coating micro-hardness wear resistance

A method of 3D reconstruction based on panoramic cameras

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International Journal of Modeling, Simulation, and Scientific Computing 2015年第2期6卷 167-178页

作者： Hua-gang Liang Wen-Xiu Qian yong-Kui liu Feng ru School of Electronic and Control Engineering Chang’an University Xi’an Shaanxi710064P.R.China

In this paper,a method of 3D reconstruction from two images acquired by two panoramic cameras is ***,the features of the reconstruction object detected in each image are matched through the DP matching ***,optical correction is carried out on two cameras,and the internal parameters of panoramic cameras can be ***,according to the calibration method,the geometric relationship between corresponding points in space and in two panoramic images is *** results indicate that the method of 3D reconstruction based on two panoramic cameras is simple,and the accuracy can reach 98.82%.

关键词： Image processing camera calibration optical correction DP matching 3D reconstruction

nfluences of superheat and cooling intensity on macrostructure and macrosegregation of duplex stainless steel studied by thermal simulation

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Journal of Iron and Steel Research International 2021年第9期28卷 1125-1132页

作者： Hong-gang zhong Xiang-ru Chen Yan-jie liu Zhi-qiang Wei Hai-feng Yu Qi-jie Zhai Center for Advanced Solidification Technology Shanghai UniversityShanghai200444China Shanghai Institute of Materials Genome Shanghai200444China Research Institute Baoshan Iron&Steel Co.Ltd.Shanghai200431China

The influences of superheat and cooling intensity on macrostructure and macrosegregation of one new kind duplex stainless steel(DSS)were *** simulation equipment was applied to prepare samples,which could reproduce the industrial processes of DSS manufactured by a vertical continuous slab *** and macrosegregation were analyzed using the digital single lens reflex and laser-induced breakdown spectroscope(LIBSOPA-200),*** percentage of both chill zone and center equiaxed zone increases with the superheat decreasing,while that of the columnar zone *** is only equiaxed grain existing as the superheat is 10 and 20℃.The lower the superheat is,the coarser the gain size *** cooling intensity in mold could remarkably decrease the chill zone length and refine the grains in chill zone and center equiaxed *** influences of cooling intensity on macrosegregation are greater than those of *** macrosegregation of Si,Mn and Cr is slightly dependent on superheat,while that of Cu,Mo and Ni changes greatly with superheat increasing.

关键词： Continuous casting Solidification Thermal simulation Duplex stainless steel Macrosegregation

Use of a disposable circumcision suture device versus conventional circumcision： a systematic review and meta-analysis

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Asian Journal of Andrology 2017年第3期19卷 362-367页

作者： zhong-Chao Huo gang liu Xiao-Yan Li Fei liu Wen-Ju Fan ru-Hua Guan Pei-Feng Li De-Yang Mo yong-Zhi He Department of Urology People's Hospital of Guangxi Zhuang Autonomous Region Nanning 530021 Guangxi China Graduate School Guangxi University of Traditional Chinese Medicine Nanning 530200 Guangxi China Department of Operating Room People's Hospital of Guangxi Zhuang Autonomous Region Nanning 530021 Guangxi China Research Center of Medical Sciences The People's Hospital of Guangxi Zhuang Autonomous Region Nannmg 530021 Guangxi China Graduate School North China University of Science and Technology Tangshan 063000 Hebei China

This systematic review assessed the safety and efficacy of the disposable circumcision suture device （DCSD） and conventional circumcision （CC） in the treatment of redundant prepuce and phimosis. Two independent reviewers conducted a literature search for randomized controlled trials （RCTs） using the DCSD and CC for the treatment of redundant prepuce or phimosis in China and abroad. Nine RCTs （1898 cases） were included. Compared with the CC group, the DCSD group had a shorter operative time （standardized mean difference [SMD] = -21.44; 95% confidence intervals [95% CIs] [-25.08, -17.79]; P 〈 0.00001）, shorter wound healing time （SMD = -3.66; 95% CI [-5.46, -1.85]; P 〈 0.0001）, less intraoperative blood loss （SMD = -9.64; 95% CI [-11.37, -7.90]; P 〈 0.00001）, better cosmetic penile appearance （odds ratio [OR] =8.77; 95% CI [5.90, 13.02]; P 〈 0.00001）, lower intraoperative pain score, lower 24-h postoperative pain score, lower incidence of infection, less incision edema, and fewer adverse events. There were no differences between the CC and DCSD groups in the incidences of dehiscence, or hematoma. The results of this meta-analysis indicate that the DCSD appears to be safer and more effective than CC. However, additional high-quality RCTs with larger study populations are needed.

关键词： conventional circumcision disposable circumcision suture device meta-analysis phimosis redundant prepuce systematic review