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Chemical vapor deposition growth of monolayer MoSe2 nanosheets

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Nano Research 2014年第4期7卷 511-517页

作者： Jonathan C. Shaw Hailong zhou yu Chen Nathan O. Weiss yuan Liu yu huan. Xiangfeng Duan Department of Chemistry and Biochemistry University of California Los Angeles CA 90095 USA Department of Materials Science and Engineering University of California Los Angeles CA 90095 USA California NanoSystems Institute University of California Los Angeles CA 90095 USA

The synthesis of two-dimensional （2D） layered materials with controllable thickness is of considerable interest for diverse applications. Here we report the first chemical vapor deposition growth of single- and few-layer MoSe2 nanosheets. By using Se and MoO3 as the chemical vapor supply, we demonstrate that highly crystalline MoSe2 can be directly grown on the 300 nm SiO2/Si substrates to form optically distinguishable single- and multi-layer nanosheets, typically in triangular shaped domains with edge lengths around 30 btm, which can merge into continuous thin films upon further growth. Micro-Raman spectroscopy and imaging was used to probe the thickness-dependent vibrational properties. Photoluminescence spectroscopy demonstrates that MoSe2 monolayers exhibit strong near band edge emission at 1.55 eV, while bilayers or multi-layers exhibit much weaker emission, indicating of the transition to a direct band gap semiconductor as the thickness is reduced to a monolayer.

关键词： chemical vapor deposition molybdenum diselenide two-dimensional materials transition metaldichalcogenide layered materials semiconductor

Improving slurryability, rheology,and stability of slurry fuel from blending petroleum coke with lignite

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Petroleum Science 2015年第1期12卷 157-169页

作者： Jun-Hong Wu Jian-Zhong Liu yu-Jie yu Rui-Kun Wang Jun-Hu zhou Ke-Fa Cen State Key Laboratory of Clean Energy Utilization Zhejiang University

Petroleum coke and lignite are two important fossil fuels that have not been widely used in China. Petroleum coke-lignite slurry （PCLS）, a mixture of petro- leum coke, lignite, water, and additives, efficiently utilizes the two materials. In this study, we investigate the effects of the proportion （7） of petroleum coke on slurryability, rheo- logical behavior, stability, and increasing temperature characteristics of PCLSs. The results show that the fixed- viscosity solid concentration （COo） increases with increasing 7. The ~Oo of lignite-water slurry （LWS, ~ = 0） is 46.7 %, compared to 71.3 % for the petroleum coke-water slurry （PCWS, c~ --- i00 %）, while that of PCLS is in between the two values. The rheological behavior of PCLS perfectly fits the power-law model. The PCWS acts as a dilatant fluid. As decreases, the slurry behaves first as an approximate Newtonian fluid, and then turns into a pseudo-plastic fluid that exhibits shear-thinning behavior. With increasing ct, the rigid sedimentation and water separation ratio （WSR） increase, indicating a decrease in the stability of PCLS. When α is 60-70 %, the result is a high-quality slurry fuel for industrial applications, which has high slurryability （ω0 = 57-60 %）, good stability （WSR 〈 2 %）, and superior pseudo-plastic behavior （n = 0.9）.

关键词： Petroleum coke Lignite Coal-water slurry Rheological characteristics Slurry stability

Updatable Identity-Based Hash Proof System Based on Lattices and Its Application to Leakage-Resilient Public-Key Encryption Schemes

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Journal of Computer Science & Technology 2018年第6期33卷 1243-1260页

作者： Qi-Qi Lai Bo Yang Yong yu Zhe Xia Yan-Wei zhou yuan Chen School of Computer Science Shaanxi Normal University Xi'an 710119 China State Key Laboratory of Information Security Institute of Information Engineering Chinese Academy of Sciences Beijing 100093 China School of Computer Science and Technology Wuhan University of Technology Wuhan 430070 China State Key Laboratory of Integrated Services Networks Xidian University Xi'an 710071 China

Identity-based hash proof system is a basic and important primitive. Ittographic schemes and protocols that are secure against key-leakage attacks. In thisupdatable identity-based hash proof system, in which the related master secret keyis widely utilized to construct cryp-paper, we introduce the concept ofand the identity secret key can beupdated securely. Then, we instantiate this primitive based on lattices in the standard model. Moreover, we introduce anapplication of this new primitive by giving a generic construction of leakage-resilient public-key encryption schemes withanonymity. This construction can be considered as the integration of the bounded-retrieval model and the continual leakagemodel. Compared with the existing leakage-resilient schemes, our construction not only is more efficient but also can resistmuch more key leakage.

关键词： public-key encryption identity-based hash proof system lattice updatable leakage-resilience

Grape seed proanthocyanidin protects liver against ischemia/reperfusion injury by attenuating endoplasmic reticulum stress

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World Journal of Gastroenterology 2015年第24期21卷 7468-7477页

作者： Zhen-Chao Xu Jie Yin Bo zhou yu-Ting Liu yue yu Guo-Qiang Li Liver Transplantation Center First Affiliated Hospital of Nanjing Medical University Department of Respiratory Medicine Jinling Hospital

AIM: To explore the effect of grape seed proanthocyanidin(GSP) in liver ischemia/reperfusion(IR) injury and alleviation of endoplasmic reticulum ***: Male Sprague-Dawley rats(220-250 g) were divided into three groups, namely, sham, IR, and GSP groups(n = 8 each). A liver IR(70%) model was established and reperfused for 6 h. Prior to reperfusion, the GSP group was administered with GSP(100 mg/kg) for 15 d, and liver histology was then investigated. Serum aminotransferase and inflammatory mediators coupled with superoxide dismutase and methane dicarboxylic aldehyde were detected. Western blot was conducted to analyze the expression of glucoseregulated protein 78, CCAAT/enhancer-binding protein homologous protein, activating transcription factor-4, inositol-requiring enzyme-1, procaspase-12, and nuclear factor-κb. Apoptotic cells were detected by TUNEL ***: The serum aminotransferase, apoptotic cells, and Suzuki scores decreased in the GSP group compared with the IR group(P s < 0.05). The methanedicarboxylic aldehyde level was decreased in the GSP group, but the superoxide dismutase level was reversed(P s < 0.05). Similarly, GSP downregulated the proinflammatory factors and upregulated the levels of anti-inflammatory factors(Ps < 0.05). Western blot data showed that GSP increased glucose-regulated protein 78 expression and suppressed expression of CCAAT/enhancer-binding protein homologous protein, activating transcription factor-4, inositol-requiring enzyme-1, procaspase-12, and nuclear factor-κb compared with the IR ***: GSP possesses antioxidative, anti-inflammatory, and antiapoptotic effects by relieving endoplasmic reticulum stress through regulation of related signaling pathways to protect the liver against IR injury.

关键词： Anti-apoptosis Endoplasmic reticulumstress Grape seed proanthocyanidin Inflammation Ischemia/reperfusion injury

IntervalSketch:面向数据流的间隔项近似统计方法

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计算机科学 2024年第4期51卷 4-10页

作者：陈昕杨陈翰泽周嘉晟黄家卿余佳硕朱龙隆张栋福州大学计算机与大数据学院福州350108 泉城省实验室济南250100 福州大学至诚学院福州350002

流式数据库在数据库中的占比逐渐增加,在流式数据库的数据流中提取所需信息是一项重要任务。文中研究了数据流的间隔项,并将其应用到了网络场景中。其中间隔项指在数据流中以固定时间间隔到达的元素对,这是第一项在数据流中定义和统计... 详细信息

流式数据库在数据库中的占比逐渐增加,在流式数据库的数据流中提取所需信息是一项重要任务。文中研究了数据流的间隔项,并将其应用到了网络场景中。其中间隔项指在数据流中以固定时间间隔到达的元素对,这是第一项在数据流中定义和统计间隔项的工作。为了高效统计间隔项的top-K,提出了IntervalSketch。IntervalSketch首先基于模拟退火对数据流分块以加快统计速度,其次利用Sketch进行间隔项的存储,最后通过特征分组存储策略降低Sketch存储间隔项的空间开销,提升了统计间隔项的精度。IntervalSketch在两个真实数据集上进行了大量对比实验,实验结果表明,在同样内存的情况下,IntervalSketch明显优于基线方案,其中处理时间为基线方案的1/3~1/2,平均绝对误差、平均相对误差约为基线方案的1/3。

关键词： Sketch 数据库数据挖掘

Effects of fuel salt composition on fuel salt temperature coefficient(FSTC)for an under-moderated molten salt reactor(MSR)

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Nuclear Science and Techniques 2018年第8期29卷 126-135页

作者： Xiao-Xiao Li yu-Wen Ma Cheng-Gang yu Chun-Yan Zou Xiang-zhou Cai Jin-Gen Chen Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China CAS Innovative Academies in TMSR Energy System Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China

With respect to a liquid-fueled molten salt reactor(MSR),the temperature coefficient of reactivity mainly includes the moderator temperature coefficient(MTC)and the fuel salt temperature coefficient(FSTC).The FSTC is typically divided into the Doppler coefficient and the density *** order to compensate for the potentially positive MTC,the FSTC should be sufficiently negative,and this is mostly optimized in terms of the geometry aspect in pioneering ***,the properties of fuel salt also directly influence the ***,the effects of different fuel salt compositions including the^(235)U enrichment,heavy metal proportion in salt phase(HM proportion),and the^7Li enrichment on FSTC are investigated from the viewpoint of the essential six-factor *** analysis is based on an undermoderated *** respect to the Doppler coefficient,the temperature coefficient of the fast fission factors(a_T(ξ))is positive and those of the resonance escape probability(a_T(p)),thermal reproduction factor(a_T(g)),thermal utilization factor(a_T(f)),and total non-leakage probability(a_T(λ))are *** respect to the density coefficient,a_T(p)and a_T(g)are positive,while the others are *** results indicate that the effects of the^(235)U enrichment and HM on FSTC are mainly reflected in a_T(e)and a_T(p),which are the dominant factors when the neutron spectrum is relatively ***,the^7Li enrichment influences FSTC by a_T(f)and a_T(λ),which are the key factors in a relative soft *** order to obtain a more negative FSTC for an under-moderated MSR,the possible positive density coefficient,especially its a_T(p),should be ***,a lower^(235)U enrichment(albeit higher than a certain value,5 wt%in this article)along with a lower HM proportion and/or a higher^7Li enrichment are *** analyses provide an approach to achieve a more suitable fuel salt composition with a sufficiently negative FSTC.

关键词：液体燃料温度系数反应堆熔融盐节制 MTC MSR

武汉和宁夏地区‘威代尔’干白葡萄酒挥发性风味物质差异分析

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中国酿造 2024年第3期43卷 109-115页

作者：侯雨君余仲谋周慧敏孟琳廖晓利辛海平中国科学院武汉植物园湖北武汉430074

以武汉和宁夏2个不同产区的2022年‘威代尔’干白葡萄酒为实验材料,通过顶空-固相微萃取(HS-SPME)与气相色谱-质谱(GC-MS)联用方法,分析两地‘威代尔’干白葡萄酒挥发性物质的差异性。结果表明,两个产区的‘威代尔’干白葡萄酒中共检出... 详细信息

以武汉和宁夏2个不同产区的2022年‘威代尔’干白葡萄酒为实验材料,通过顶空-固相微萃取(HS-SPME)与气相色谱-质谱(GC-MS)联用方法,分析两地‘威代尔’干白葡萄酒挥发性物质的差异性。结果表明,两个产区的‘威代尔’干白葡萄酒中共检出了713种挥发性风味物质。不同产区的‘威代尔’干白葡萄酒挥发性风味物质种类基本相同,但各成分的含量有明显区别,影响两款葡萄酒风味的主要差异性挥发风味物质有36种。风味组学桑基图分析结果表明,两个产区的差异物质主要集中在果香、生青味、甜香、蜡香、药草香、木香等感官风味。通过正交偏最小二乘法判别分析(OPLS-DA)及变量投影重要性(VIP)分析值,鉴定了1-庚醇,5-甲基-2-庚-4-酮,β-苯乙酸乙酯等8种挥发性风味物质作为区分宁夏和武汉‘威代尔’干白葡萄酒风味差异的主要特征标志物。该研究有效实现了对武汉威代尔及宁夏威代尔的葡萄酒挥发性风味物质进行鉴定和区分,解释了其风味差异的来源。

关键词：葡萄酒挥发性风味物质不同产区差异物质正交偏最小二乘判别分析

Effectiveness of the combination of workshops and flipped classroom model to improve tube fixation training for nursing students

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World Journal of Clinical Cases 2022年第8期10卷 2447-2456页

作者： yu-Cui Wang Hui-Lin Cheng yu-Mei Deng Bao-Qi Li Xue-Zhen zhou Department of Surgery Sun Yat-Sen Memorial HospitalSun Yat-Sen UniversityGuangzhou 510120Guangdong ProvinceChina Department of Stomatology Sun Yat-Sen Memorial HospitalSun Yat-Sen UniversityGuangzhou 510120Guangdong ProvinceChina Cardiovascular Surgery ICU Sun Yat-Sen Memorial HospitalSun Yat-Sen UniversityGuangzhou 510120Guangdong ProvinceChina Department of Nursing Sun Yat-Sen Memorial HospitalSun Yat-Sen UniversityGuangzhou 510120Guangdong ProvinceChina

BACKGROUND Tube indwelling is a key procedure in modern *** tube setup is necessary to prevent unplanned *** training for tube fixation is timeand resource-consuming,and optimal modes of training are currently being *** studies have compared workshops and flipped classroom models separately using conventional teaching strategies,but no study has examined a combination of both teaching models in nursing *** To compare the effectiveness of workshops vs workshops combined with the flipped classroom model for improving tube fixation training for nursing *** This was a prospective cohort *** this study,149 nurses who joined our hospital in 2019 underwent training using workshops combined with the flipped classroom model(experimental group),while 159 nurses who joined the hospital in 2018 received only workshop-based training(control group).The combination of workshops with the flipped classroom training model was divided into two modules:pre-class and in-class *** participation of nurses in the training activities,onsite assessment of training,nurses’evaluation of their training,and related indicators of tube quality management were *** The average age of nurses in the control group was 22.94±0.94 years and that of nurses in the experimental group was 25.42±3.23 years(P<0.01).The qualified rate of after-class assessments for the experimental and control groups was 100.00%(average score:94.01±2.78 points)and 91.82%(average score:84.24±2.94 points),respectively(P<0.01).Most nurses in the experimental group completely agreed that the combined training was helpful to cultivate clinical thinking and independent learning ability and to master knowledge of tube *** addition,the training content within the pre-class teaching video,pre-class tube atlas,pre-class main instructor guidance,in-class demonstration,and in-class practice was very *** experimental group had higher ev

关键词： Flipped classroom teaching Nursing Tube fixation Workshop

Effect of Nb on corrosion behavior of inner bottom plate of cargo oil tankers

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Journal of Iron and Steel Research International 2019年第6期26卷 611-620页

作者： Xiang-yu Xu Long Tian yun zhou Ming-yu Sun Xue-min Wang Cheng-jia Shang R.D.K. Misra Collaborative Innovation Center of Steel Technology University of Science and Technology Beijing Beijing 100083 China Tianjin Long March Launch Vehicle Manufacturing Co. Ltd. Tianjin 300462 China Institute of Research of Iron and Steel (IRIS) Sha-steel Zhangjiagang 215625 Jiangsu China Center for Structural and Functional Materials Research and Innovation Department of Metallurgical and Materials Engineering University of Texas at El Paso El Paso TX 7996& USA

The effect of Nb on the corrosion resistance of steels in simulating an oil-corrosion environment was investigated by means of microstructure observation, electrochemical test, dissolved Nb content measurement and Nb segregation observation. The results show that the microstructure of the experimental steels is mainly ferrite with a little pearlite. The dissolved Nb contents of the experimental steels are 0.0235 and 0.0458 wt.%, respectively, while the undissolved Nb content is nearly the same. In addition to enhancing mechanical properties of the steel, dissolved Nb improves the corrosion resistance by enriching Nb in the rust layer. Nb oxides in the rust layer cause a decrease in the corrosion rate due to a decrease in the anodic reaction kinetics. The segregation of Nb at the grain boundaries suppresses the corrosion. Moreover, Nb is enriched at the bottom of the corrosion pit and prevents any further corrosion.

关键词： Low-alloy steel Acid corrosion Pitting corrosion Electrochemical impedance spectroscopy segregation