代谢综合征及其组分与脑卒中发病关系的前瞻性队列研究

目的:探讨代谢综合征(metabolic syndrome,MS)及其组分与脑卒中发病风险的关联。方法:采用前瞻性队列研究方法比较脑卒中发病与未发病人群人口统计学信息、行为生活方式、饮食习惯、疾病史、MS相关指标之间差异。采用Cox比例风险回归模型分析MS组分及其交互作用与脑卒中发病的关联。结果:脑卒中发病人群的年龄、腰围(waist circumference,WC)、体重指数(body mass index,BMI)、血压(blood pressure,BP)、总胆固醇(total cholesterol,TC)、甘油三酯(triglycerides,TG)、空腹血糖(fasting plasma glucose,FPG)值均高于未发病人群。校正混杂因素后,MS、WC、TG、BP、FPG均与脑卒中发病风险增加相关,其中BP异常与脑卒中发病的联系最强。WC、TG、BP、FPG两两之间均不存在相乘交互作用及相加交互作用。结论:MS与脑卒中发病风险增加相关。WC、TG、BP和FPG是脑卒中发病的独立危险因素。BP异常对脑卒中发病的影响最大。

Molecular Dynamics-Based Simulation of Polyethylene Pipe Degradation in High Temperature and High Pressure Conditions

High-density polyethylene(HDPE)pipes have gradually become the first choice for gas networks because of their excellent characteristics.As the use of pipes increases,there will unavoidably be a significant amount of waste generated when the pipes cease their operation life,which,if improperly handled,might result in major environmental contamination issues.In this study,the thermal degradation of polyethylene materials is simulated for different pressures(10,50,100,and 150 MPa)and temperatures(2300,2500,2700,and 2900 K)in the framework of Reactive Force Field(ReaxFF)molecular dynamics simulation.The main gas products,density,energy,and the mean square displacement with temperature and pressure are also calculated.The findings indicate that raising the temperature leads to an increase in the production of gas products,while changing the pressure has an impact on the direction in which the products are generated;the faster the temperature drops,the less dense the air;both temperature and pressure increase impact the system’s energy conversion or distribution mechanism,changing the system’s potential energy as well as its total energy;the rate at which molecules diffuse increases with temperature,and decreases with pressure.The results of this investigation provide a theoretical basis for the development of the pyrolytic treatment of polyethylene waste materials.

The Riesz Decomposition of Set-Valued Superpramart

The paper proves the convergence theorem of set-valued Superpramart in the sense of weak convergence under the X* separable condition. Using support function and results about real-valued Superpramart, we give the Riesz decomposition of set-valued Superpramart.

E-learning平台在专升本流行病学教学中的调查分析

本研究通过电子问卷调查了204名继续教育学院专升本学生应用E-learning平台学习流行病学课程的情况。结果显示:大部分学生对使用E-learning平台感到较为满意,且95%的学生自主学习能力有所提高。但整体上使用E-learning平台的主动性较差,需增加E-learning平台的趣味性和互动性,并对课后习题附以注释,以帮助学生领会要点。

含碳硼烷耐高温有机硅树脂的合成与表征

以1,2-二(4-羟基苯基)-碳硼烷和甲基乙烯基二氯硅烷为单体,在三乙胺为缚酸剂的条件下进行缩聚反应,得到聚乙烯基甲基硅氧烷-碳硼烷V-PMSCB。采用红外、核磁和GPC对V-PMSCB结构和相对分子质量进行表征,结果表明聚合物结构与设计结构完全一致,且其数均分子量为5.8×10^(4)。利用红外、差示扫描量热分析和热重分析(TGA)研究了该树脂与含氢硅油的固化工艺,得知其固化工艺为60℃/3 h, 115℃/2 h, 140℃/1 h。通过对该固化产物PMSCB进行TGA分析,可知其具有优异的热稳定性和热氧稳定性,其在空气中5%热失重温度高于1000℃,1000℃时的残碳率高达99.07%。

Incidence trends and age distribution of colorectal cancer by subsite in Guangzhou,2000-2011

Introduction:Colorectal cancer(CRC) is the third most common cancer in China.The incidence of CRC has been increasing in recent years.The aim of this study was to explore the incidence trends and the age distribution of CRC by subsite in Guangzhou between 2000 and 2011.Methods:A total of 22,432 incident cases of CRC between 2000 and 2011 from Guangzhou Cancer Registry were identified.Crude incidence and age-standardized rates(ASRs),using the Segi’s world standard population,were calculated for CRC and CRC subsites.The incidence trend was analyzed and the annual percentage change(APC) in incidence was calculated by using JoinPoint software.Results:The crude incidence increased significantly from 23.4/10~5 in 2000 to 37.4/10~5 in 2011 for males and from20.9/10~5 to 30.5/10~5 for females.The ASRs of CRC incidence stabilized during the period of 2000-2011 for both males and females.The ages at the onset of CRC for both males and females during 2010-2011 were significantly higher compared with those during 2000-2002(males:f = 1.95,P = 0.05;females:f = 6.03,P < 0.01).For males aged50-64 years,the CRC incidence increased by 8.50%annually(P = 0.04) during 2000-2004 and by 1.68%annually(P = 0.03) during 2005-2011.For females aged 65 years and older,the CRC incidence increased by 5.77%annually(P = 0.03) during 2000-2004.There were no significant changes for the CRC incidences in males aged 49 and younger and 65 years and older and females aged 64 years and younger during 2000-2004,or for those in all females as well as males aged 49 years and younger and 65 years and older during 2005-2011.The percentage of colon cancer in all CRCs increased significantly for both males and females between the periods of 2000-2002 and 2010-2011.The ASRs of descending colon and sigmoid colon cancer incidences increased significantly for females during 2005-2011(APC,5.51%and 1.08%,respectively,both P < 0.05).Conclusions:The crude incidence of CRC increased significantly between 2000 and 2011 because of the aging,whereas the ASRs kept stable.The percentage of colon cancer in all CRCs increased significantly.Further surveillance,research,and intervention are needed to identify the causes of these changes and to reduce the incidence and mortality of CRC.

Review of deep ultraviolet photodetector based on gallium oxide

Ultraviolet(UV) photodetectors(PDs) have drawn great attention in recent years due to their potential application in civil and military fields. Because of its ultrawide bandgap, low cost, strong radiation hardness, and high thermal and chemical stability with high visible-light transparency, Ga_2O_3 is regarded as the most promising candidate for UV detection.Furthermore, the bandgap of Ga_2O_3 is as high as 4.7–4.9 eV, directly corresponding to the solar-blind UV detection band with wavelength less than 280 nm. There is no need of doping in Ga_2O_3 to tune its bandgap, compared to AlGaN, MgZnO,etc, thereby avoiding alloy composition fluctuations and phase separation. At present, solar-blind Ga_2O_3 photodetectors based on single crystal or amorphous Ga_2O_3 are mainly focused on metal–semiconductor–metal and Schottky photodiodes.In this work, the recent achievements of Ga_2O_3 photodetectors are systematically reviewed. The characteristics and performances of different photodetector structures based on single crystal Ga_2O_3 and amorphous Ga_2O_3 thin film are analyzed and compared. Finally, the prospects of Ga_2O_3 UV photodetectors are forecast.

Progress of power field effect transistor based on ultra-wide bandgap Ga_2O_3 semiconductor material

As a promising ultra-wide bandgap semiconductor, gallium oxide(Ga_2O_3) has attracted increasing attention in recent years. The high theoretical breakdown electrical field(8 MV/cm), ultra-wide bandgap(～ 4.8 eV) and large Baliga's figure of merit(BFOM) of Ga_2O_3 make it a potential candidate material for next generation high-power electronics, including diode and field effect transistor(FET). In this paper, we introduce the basic physical properties of Ga_2O_3 single crystal, and review the recent research process of Ga_2O_3 based field effect transistors. Furthermore, various structures of FETs have been summarized and compared, and the potential of Ga_2O_3 is preliminary revealed. Finally, the prospect of the Ga_2O_3 based FET for power electronics application is analyzed.

2010–2014年广州市结直肠癌发病率的时空分析

背景与目的结直肠癌(colorectal cancer,CRC)是一种常见的恶性肿瘤。本研究分析了2010–2014年广州地区结直肠癌发病率的时空分布。方法结直肠癌发病数据来自广州癌症登记系统。采用空间自相关分析和回顾性时空扫描评估CRC病例的时空聚集分布。结果 2010–2014年期间,在广州共登记了14,618例CRC病例,粗发病率为35.56/100,000,世界人口标化发病率(age?standardized rate of incidence by the world standard population,ASRIW)为23.58/100,000。粗发病率从2010年(32.88/100,000)到2014年(39.36/100,000)增长了19.70%,平均年变化率(average annual percentage change,AAPC)为4.33%。ASRIW的AAPC无统计学意义。空间自相关分析显示了广州市中心城区为一个CRC的发病热点,该区域包括了位于白云区西南部、海珠区西北部以及荔湾和越秀区的交界部的共25条街道。CRC发病聚集区的时空扫描分析确定了3个高发和5个低发病聚集区。高发聚集区位于中心城区,包括白云、海珠、荔湾和越秀区之间的交界地区。结论本研究展示出了广州地区CRC发病率的时空聚集模式。该数据可为CRC筛查中合理分配健康资源提供参考信息。

Rheo-optic in situ synchronous study on the gelation behaviour and mechanism of waxy crude oil emulsions

An improved rheo-optic in situ synchronous measurement system was employed to investigate the gelation behaviour and mechanism of waxy crude oil emulsions. By combining transmitted natural light and reflected polarized light microscopy, a multiangle composite light source was built to achieve the simultaneous observation of wax crystals and emulsified water droplets, as well as their dynamic aggregation process. Main outcomes on the microscopic mechanism were obtained by developed microscopic image processing method. It was found that the microstructure of W/O waxy crude oil emulsion has the evolution of “individual structure--homogeneous aggregate structure--heterogeneous coaggregate structure--floc structure” during the static cooling, which results in the four stages during gelation process. Different from previous studies, the aggregation of emulsified water droplets was found to be more significant and contributes to the formation and development of the wax crystals-emulsified water droplets coaggregate, which plays a decisive role in the further evolution of the gelled microstructure. Time series microscopic images show the dynamic aggregation of emulsified water droplets and wax crystals. Two different aggregation behaviours between wax crystals and water droplets were observed. That wax crystals can not only embed in gaps between adjacent water droplets and enhance the structure, but also surround the outside of the water droplets and continue to grow resulting in the interconnection of different coaggregates to form a larger floc structure. In addition, correlation between viscoelasticity and microstructure evolution of waxy crude oil emulsions of different water contents was discussed. With increasing water contents, the microstructure is changed from wax crystal flocculation structure as the main skeleton and the emulsified water droplets embedded in it, into the aggregation of emulsified water droplets occupying the main position. When the number of wax crystals and water droplets reaches a certain ratio, did wax crystals form coaggregates with emulsified water droplets, and the remaining wax crystals formed an overall flocculation structure, the viscoelasticity of the waxy crude oil emulsion is the highest.

多固废胶凝材料力学性能及水化机理研究

以油页岩渣、矿渣和锂渣为主要原料,制备多固废胶凝材料。研究锂渣掺量对胶砂试块力学性能的影响,并利用X射线衍射(XRD)、傅里叶红外光谱(FT-IR)、扫描电镜(SEM)等分析油页岩渣-矿渣-锂渣碱胶凝材料的水化反应机理。结果表明,保持矿渣掺量不变,随着锂渣掺量的增加,胶砂试块各龄期抗压、抗折强度大致呈逐渐降低趋势,胶凝材料中较适宜的锂渣掺量为7%,此时胶砂试块28 d抗压强度可达到54.26MPa。油页岩渣-矿渣-锂渣碱胶凝材料的水化产物主要是水化硅铝酸钙(C-A-S-H)、水化硅酸钙(C-S-H)和水化硅铝酸钠(N-A-S-H)凝胶,多种水化产物相互交织,促进试块强度增长。

TLSmell: Direct Identification on Malicious HTTPs Encryption Traffic withSimple Connection-Specific Indicators

Internet traffic encryption is a very common traffic protection method.Most internet traffic is protected by the encryption protocol called transport layersecurity (TLS). Although traffic encryption can ensure the security of communication, it also enables malware to hide its information and avoid being detected.At present, most of the malicious traffic detection methods are aimed at the unencrypted ones. There are some problems in the detection of encrypted traffic, suchas high false positive rate, difficulty in feature extraction, and insufficient practicability. The accuracy and effectiveness of existing methods need to be improved.In this paper, we present TLSmell, a framework that conducts maliciousencrypted HTTPs traffic detection with simple connection-specific indicators byusing different classifiers based online training. We perform deep packet analysisof encrypted traffic through data pre-processing to extract effective features, andthen the online training algorithm is used for training and prediction. Withoutdecrypting the original traffic, high-precision malicious traffic detection and analysis are realized, which can guarantee user privacy and communication security.At the same time, since there is no need to decrypt the traffic in advance, the effi-ciency of detecting malicious HTTPs traffic will be greatly improved. Combinedwith the traditional detection and analysis methods, malicious HTTPs traffic isscreened, and suspicious traffic is further analyzed by the expert through the context of suspicious behaviors, thereby improving the overall performance of malicious encrypted traffic detection.

Digital Simulation of Projective Non-Abelian Anyons with 68 Superconducting Qubits

Non-Abelian anyons are exotic quasiparticle excitations hosted by certain topological phases of matter.They break the fermion-boson dichotomy and obey non-Abelian braiding statistics:their interchanges yield unitary operations,rather than merely a phase factor,in a space spanned by topologically degenerate wavefunctions.They are the building blocks of topological quantum computing.However,experimental observation of non-Abelian anyons and their characterizing braiding statistics is notoriously challenging and has remained elusive hitherto,in spite of various theoretical proposals.Here,we report an experimental quantum digital simulation of projective non-Abelian anyons and their braiding statistics with up to 68 programmable superconducting qubits arranged on a two-dimensional lattice.By implementing the ground states of the toric-code model with twists through quantum circuits,we demonstrate that twists exchange electric and magnetic charges and behave as a particular type of non-Abelian anyons,i.e.,the Ising anyons.In particular,we show experimentally that these twists follow the fusion rules and non-Abelian braiding statistics of the Ising type,and can be explored to encode topological logical qubits.Furthermore,we demonstrate how to implement both single-and two-qubit logic gates through applying a sequence of elementary Pauli gates on the underlying physical qubits.Our results demonstrate a versatile quantum digital approach for simulating non-Abelian anyons,offering a new lens into the study of such peculiar quasiparticles.

结直肠癌初筛阴性人群再次参加结直肠癌筛查的时间间隔研究

结直肠癌(CRC)是我国居民消化系统患病率第一的恶性肿瘤,并且发病率在整个人群中呈上升趋势,严重威胁人民群众的健康,因此,制定合理的筛查指南对于降低我国结直肠癌的疾病负担至关重要。本文主要关注结直肠癌筛查初筛阴性人群,探究该人群再次参加结直肠癌筛查的时间间隔,本文检索了国内外最近的文献,总结了不同风险人群使用不同筛查方法初筛阴性后再次参加筛查的时间间隔,为我国结直肠癌筛查指南的制定提供参考。

Tunable coupling between Xmon qubit and coplanar waveguide resonator

Realization of a flexible and tunable coupling scheme among qubits is critical for scalable quantum information processing.Here,we design and characterize a tunable coupling element based on Josephson junction,which can be adapted to an all-to-all connected circuit architecture where multiple Xmon qubits couple to a common coplanar waveguide resonator.The coupling strength is experimentally verified to be adjustable from 0 MHz to about 40 MHz,and the qubit lifetime can still be up to 12μs in the presence of the coupling element.

Efficient Preparation of Nanoparticle-Reinforced Nickel-based Composite Coating with Highly Preferred(220)Orientation

Nanoparticle-reinforced metal matrix composite coatings have significant potential in mechanical part surface strengthening owing their excellent mechanical properties.This paper reports a phenomenon in which the grain orientation gradually evolves to(220)as the deposition current density increases when preparing nanoparticle-reinforced nickel-based composite coatings through jet electrodeposition(JED).During the preparation of the Ni-SiC composite coatings,the deposition current density increased from 180 A/dm2 to 220 A/dm2,and TC(220)gradually increase from 41.4%to 97.7%.With an increase of TC(220),the self-corrosion potential increases from−0.575 to−0.477 V,the corrosion current density decreases from 9.52μA/cm^2 to 2.76μA/cm^2,the diameter of the corrosion pits that after 10 days of immersion in a 3.5 wt%NaCl solution decreases from 278–944 nm to 153–260 nm,and the adhesion of the coating increases from 24.9 N to 61.6 N.Compared a conventional electrodeposition(CED),the Ni-SiC composite coating using JED has the advantages of a smooth surface morphology,high corrosion resistance,and strong adhesion,which are more obvious with an increase in TC(220).

Spatio-temporal analysis of the incidence of colorectal cancer in Guangzhou,2010-2014

Introduction: Colorectal cancer(CRC) is a common type of neoplasm. This study examined the spatio?temporal distribution of the CRC incidence in Guangzhou during 2010–2014.Methods: Colorectal cancer incidence data were obtained from the Guangzhou Cancer Registry System. Spatial autocorrelation analysis and a retrospective spatio?temporal scan were used to assess the spatio?temporal cluster distribution of CRC cases.Results: A total of 14,618 CRC cases were registered in Guangzhou during 2010–2014, with a crude incidence of 35.56/100,000 and an age?standardized rate of incidence by the world standard population(ASRIW) of 23.58/100,000. The crude incidence increased by 19.70% from 2010(32.88/100,000) to 2014(39.36/100,000) with an average annual percentage change(AAPC) of 4.33%. The AAPC of ASRIW was not statistically significant. The spatial autocorrelation analysis revealed a CRC incidence hot spot in central urban areas in Guangzhou City, which included 25 streets in southwestern Baiyun District, northwestern Haizhu District, and the border region between Liwan and Yuexiu Dis?tricts. Three high? and five low?incidence clusters were identified according to spatio?temporal scan of CRC incidence clusters. The high?incidence clusters were located in central urban areas including the border regions between Bai?yun, Haizhu, Liwan, and Yuexiu Districts.Conclusions: This study revealed the spatio?temporal cluster pattern of the incidence of CRC in Guangzhou. This information can inform allocation of health resources for CRC screening.

A New Hybrid Hierarchical Parallel Algorithm to Enhance the Performance of Large-Scale Structural Analysis Based on Heterogeneous Multicore Clusters

Heterogeneous multicore clusters are becoming more popular for high-performance computing due to their great computing power and cost-to-performance effectiveness nowadays.Nevertheless,parallel efficiency degradation is still a problem in large-scale structural analysis based on heterogeneousmulticore clusters.To solve it,a hybrid hierarchical parallel algorithm(HHPA)is proposed on the basis of the conventional domain decomposition algorithm(CDDA)and the parallel sparse solver.In this new algorithm,a three-layer parallelization of the computational procedure is introduced to enable the separation of the communication of inter-nodes,heterogeneous-core-groups(HCGs)and inside-heterogeneous-core-groups through mapping computing tasks to various hardware layers.This approach can not only achieve load balancing at different layers efficiently but can also improve the communication rate significantly through hierarchical communication.Additionally,the proposed hybrid parallel approach in this article can reduce the interface equation size and further reduce the solution time,which can make up for the shortcoming of growing communication overheads with the increase of interface equation size when employing CDDA.Moreover,the distributed sparse storage of a large amount of data is introduced to improve memory access.By solving benchmark instances on the Shenwei-Taihuzhiguang supercomputer,the results show that the proposed method can obtain higher speedup and parallel efficiency compared with CDDA and more superior extensibility of parallel partition compared with the two-level parallel computing algorithm(TPCA).

A Multilevel Hierarchical Parallel Algorithm for Large-Scale Finite Element Modal Analysis

The strict and high-standard requirements for the safety and stability ofmajor engineering systems make it a tough challenge for large-scale finite element modal analysis.At the same time,realizing the systematic analysis of the entire large structure of these engineering systems is extremely meaningful in practice.This article proposes a multilevel hierarchical parallel algorithm for large-scale finite element modal analysis to reduce the parallel computational efficiency loss when using heterogeneous multicore distributed storage computers in solving large-scale finite element modal analysis.Based on two-level partitioning and four-transformation strategies,the proposed algorithm not only improves the memory access rate through the sparsely distributed storage of a large amount of data but also reduces the solution time by reducing the scale of the generalized characteristic equation(GCEs).Moreover,a multilevel hierarchical parallelization approach is introduced during the computational procedure to enable the separation of the communication of inter-nodes,intra-nodes,heterogeneous core groups(HCGs),and inside HCGs through mapping computing tasks to various hardware layers.This method can efficiently achieve load balancing at different layers and significantly improve the communication rate through hierarchical communication.Therefore,it can enhance the efficiency of parallel computing of large-scale finite element modal analysis by fully exploiting the architecture characteristics of heterogeneous multicore clusters.Finally,typical numerical experiments were used to validate the correctness and efficiency of the proposedmethod.Then a parallel modal analysis example of the cross-river tunnel with over ten million degrees of freedom(DOFs)was performed,and ten-thousand core processors were applied to verify the feasibility of the algorithm.

The Influence of the Microstructure of W/O Emulsion of Waxy Crude Oil on Its Rheology

In this article, the viscosity-temperature characteristics of W/O waxy crude oil emulsion under different microstructures were studied, and the characteristics of the microstructure were described by the analysis of the dispersed phase parameters including the average particle size, the degree of dispersion, and the nonuniformity of average particle size. On this basis, we discuss the effects of temperature, shear rate and the microstructure on the apparent viscosity of Daqing crude oil emulsion. The results showed that with the increasing of stirring speed, the number of droplets and the degree of dispersion phase dispersion increased, average droplet size and nonuniformity of average particle size reduced;the average particle size of the dispersed phase decreased by 0.5 μm, and the abnormal point increased by about 1°C. For emulsions with the same microstructure, as the temperature or shear rate rising, the rate and percentage of the reduction in apparent viscosity decreased. At the same temperature or shear rate, the reduction rate in apparent viscosity increases with the average particle size of dispersed phase decreases, in contrast to the percentage of reduction in apparent viscosity, which revealed a definitive correlation between average particle size of dispersed phase and the apparent viscosity in the non-Newtonian fluid that from 34°;C to 48°;C;the absolute value of Pearson’s correlation coefficient was above 0.8, which was highly negatively correlated;as the temperature rose, the absolute value of Pearson’s correlation coefficient decreased from 0.839 to 0.216.