Identifying multiple influential spreaders in complex networks based on spectral graph theory

One of the hot research topics in propagation dynamics is identifying a set of critical nodes that can influence maximization in a complex network.The importance and dispersion of critical nodes among them are both vital factors that can influence maximization.We therefore propose a multiple influential spreaders identification algorithm based on spectral graph theory.This algorithm first quantifies the role played by the local structure of nodes in the propagation process,then classifies the nodes based on the eigenvectors of the Laplace matrix,and finally selects a set of critical nodes by the constraint that nodes in the same class are not adjacent to each other while different classes of nodes can be adjacent to each other.Experimental results on real and synthetic networks show that our algorithm outperforms the state-of-the-art and classical algorithms in the SIR model.

The Research on Adaptive Control Modeling of a Liquid Fertilizer Spreader

This paper describes a general modeling and control approach for steering wheel variable rate liquid fertilizer applicator. An adaptive numerical modeling approach for describing the system input-output dynamics is proposed, and an optimal control that accounts for the control hardware limits is developed. Field tests have demonstrated the effectiveness of the theoretical development.

The Anterior Spreader Flap: A Minimally Invasive Alternative to the Auto Spreader Flap in the Treatment of Patients with Nasal Valve Dysfunction

We present a new method of treatment for nasal valve dysfunction caused by insufficiency or stenosis in a patient who refused open septum revision despite a significant degree of septum deviation. The Anterior Spreader Flap (ASF) technique was suggested as an alternative to open nasal septum revision and was performed under local anesthesia. Computational fluid dynamics (CFD) tests were performed pre- and post-operatively and our patient was asked to complete a self-assessment using a Visual Analog Scale (VAS) for nasal breathing (0 = free nasal breathing, 10 = complete nasal blockage) before and 12 months after surgery. The ASF is a minimally invasive endonasal procedure in which the caudal edge of the upper lateral cartilage is dissected from the septum, and folded inwards and fixed. The ASF allows for less airflow resistance and more free space. CFD techniques revealed a reduction in local pressure based on extended space. In addition, VAS scores improved from 9 to 2 points (right side) and from 8 to 2 points (left side). On the basis of these findings, the ASF technique can be considered a safe, minimally invasive spreader flap technique. It can easily be combined with other nasal surgical techniques, as it is necessary in most cases. In selected cases, the ASF may be performed as a single procedure in patients with nasal valve dysfunction caused by septum deviation as an alternative to open septum revision.

新型烧结机布料技术

介绍了由宽皮带给料机、多辊布料器、可调松料器组成的布料新技术 ,以及该技术在本钢一铁 1号烧结机上的使用情况。用它代替传统的泥辊给料反射板布料系统 ,烧结矿产量可提高 5 %左右 ,燃料消耗明显降低。

基于ANSYS的优化设计方法在GORGON项目管线吊装中的应用

传统的结构设计,一般是根据设计规范进行结构的总体布置、结构尺寸的选择以及结构强度的校核,设计的结构形式以安全实用为主,基本上都能满足生活生产的需要。而随着社会的不断的发展,原材料价格的不断上涨,结构的设计不仅要满足强度的要求,材料的节约使用也变得尤为重要,因此,满足上述综合条件的最优设计在生产过程中发挥着重要作用。ANSYS作为大型有限元分析软件在结构设计上可以做到最优设计。本文结合GORGON项目中撑杆设计,使用ANSYS对结构进行优化,最终确定最优设计方案,节约了材料,提高了生产效率。

50吨多功能设备吊装平衡梁的设计

本文选用H型钢设计了一种能够吊装多种直径设备的50吨平衡粱，并且经过了TUV公司检测。本文详述了该平衡梁的设计方法和检测方法。

Improving the performance of a thermoelectric power system using a flat-plate heat pipe

A gravitational flat-plate heat pipe is designed and fabricated in this paper to serve as a heat spreader to diffuse the local heat source to the hot side of the thermoelectric power module.Based on this, an experimental test for the thermoelectric power generation system is conducted to study the influences of the heat spreader on the temperature uniformity and power generation performance when exposing to a local heat source.In addition,the effects of the heating power, inclination angle, and local heat source size on the power generation performance of the thermoelectric power module using a flat-plate heat pipe as a heat spreader are examined and compared with that using a metal plate.The results indicate that the gravitational flat-plate heat pipe has considerable advantages over the metal plate in the temperature uniformity.The superiority of temperature uniformity in the improvement of power generation performance for the thermoelectric power system using a heat pipe is demonstrated.Particularly, the heat pipe shows good adaptability to placement mode and the local heat source size, which is beneficial to the application in the thermoelectric power generation.

水下生产系统跨接管场地吊装难点分析

针对水下生产系统跨接管在陆地建造过程中的吊装作业难点,着重分析如何降低大跨度柔性细长杆件跨接管吊装作业过程中的变形,以及降低吊装过程中吊机起吊高度等,提出使用多挡绳柱吊装撑杆并采用4点起吊的措施。应用SACS软件对跨接管吊装进行模拟计算,确定跨接管和撑杆总成的质量、重心,并由此确定吊钩、撑杆与跨接管之间的钢丝绳布置。根据计算结果中的吊绳力确定钢丝绳的规格,最终得出吊装过程中跨接管和撑杆的应力和变形情况。分析结果对后续水下生产系统跨接管、膨胀弯等细长管系结构吊装有一定的借鉴意义。

PYRENEES FPSO模块吊装框架的改装设计

介绍PYRENEES FPSO模块设计项目吊装框架的改装设计方案,在工期紧张的情况下,对原设计吊装框架进行改造,创新组合使用一个吊装框架与两个撑杆的三层吊装索具模式,充分利用已有材料,最大限度减少现场改造量,节省工期和费用,为项目的吊装提供保证。

造纸机械辊筒与烘缸动平衡技术的近期发展

本文对国内造纸机械辊筒与烘缸的动平衡技术的应用与发展作了概要的叙述。其中重点介绍了烘缸超低速(低于120r/min)动平衡技术与弧形辊简的动平衡技术的科研成果。最后对今后的研究工作提出了一些设想。

Discharge rate consistency of each channel for UAV-based pneumatic granular fertilizer spreader

Unmanned aerial vehicles(UAVs)are widely being used to spread granular fertilizer in China.Granular fertilizer spreaders equipped with UAVs are mainly centrifugal disc-type and pneumatic.The multichannel pneumatic granular fertilizer spreaders(MPGFSs)have a banded fertilizer deposition distribution pattern,which are more suitable for variable rate fertilization with high precision requirement than the circular deposition distribution pattern of disc-type granular fertilizer spreaders(DGFSs).However,the existing MPGFS has the disadvantage of inconsistent discharge rate of each channel,which affects the uniformity of fertilization.In order to explore the causes of inconsistent discharge rate of each channel,the discrete element method(DEM)and bench test were performed to analysis the discharge process of the fluted roller fertilizing apparatus and distribution of fertilizer in axial direction of fluted roller.The computational fluid dynamics(CFD)was used to simulate the airflow field of pneumatic system to analyze the influence of airflow on the movement of fertilizer particles.The simulation results of the discharge process of the fluted roller fertilizing apparatus showed that the filling velocity at the axial ends of the fluted roller fertilizing apparatus was lower than that of the middle.The reason was that the filling capacity was weak near the wall.The simulated results of the airflow field without partitions showed that the airflow provided by the axial flow fan was rotational,and this caused the particles to move irregularly in the throat,resulting in inconsistency discharge rate of each channel.Based on the analysis of reasons of inconsistent discharge rate of each channel,a MPGFS with partitions in the throat was developed.The discharge rate bench tests were carried out to optimize the partition spacing parameters,and fertilization test was performed to test the performance of the improved MPGFS.The discharge rate test results showed better consistency with partition.The coefficient of variation(CV)of the discharge rate of each channel was 20.16%without the partition and 7.70%with the optimal partition.The fertilizer spreading uniformity bench test results shown that the CV of spreading uniformity of MPGFS without partitions was 15.32%,and that MPGFS with partitions was 8.69%.The partitions design was beneficial to improve the consistency of each channel discharge rate and the uniformity of fertilization.The finding can provide a strong reference to design the MPGFS.

基于撑杆法的海缆平台抽拉设计分析

海缆第二端抽拉上平台是海洋油气及海上风电海缆安装工程的关键技术。本文对撑杆辅助海缆第二端抽拉方法展开研究,根据相关操作标准,完成了海缆U型弯及撑杆的设计;基于海缆第二端平台抽拉作业分析模型,建立了海缆路由及抽拉作业过程的基本数学模型;提出了一套海缆平台抽拉作业分析方法。以国内某工程海缆铺设项目为例,研究了海缆平台抽拉作业过程中船舶位置变化增量、撑杆高度变化增量与海缆抽拉长度变化增量的关系,发现三者比值在-1.000∶-1.024∶1.849至-1.000∶-2.985∶3.626时海缆平台抽拉作业是安全可行的;在此基础上开展了海缆张力安全系数、弯曲半径安全系数和最大轴向压力随海况变化的关系分析,发现海缆张力安全系数和弯曲半径安全系数随有义波高的增大而降低,而最大轴向压力则随有义波高的增大而增大,基于敏感性分析结果给出了海缆平台抽拉作业的合适天气作业窗口建议,即2.5 m有义波高、30°浪向内。本研究为典型海缆平台抽拉安全作业设计提供了参考。

COVID-19 Vaccine

A number of companies have announced the vaccines for COVID-19 pandemic that has caused extreme poverty, famine, and more than a billion people have lost livelihood all across the globe. Mass production of vaccine Sputnik V is underway at different locations to inoculate population in Russia, Philippines, Vietnam, Brazil, Saudi Arab, and United Arab Emirates (UAE), and India. mRNA based vaccine of Pfizer-BioNTech after passing phase 2 trial is ready for testing on thousands of volunteers. Oxford University-AstraZeneca vaccine is also under phase 3 trial in US, Brazil, and India. In September, Novavax Inc.’s vaccine will be ready for phase 3 trial. By early next year, two billions of doses will be ready of Novavax. Moderna Therapeutics conducting vaccine trial on 30 thousands volunteers, results will be known soon. Hundreds of thousand volunteers have registered already for vaccination in US and other parts of the world. SinoVac Biotech Ltd. has prepared a vaccine “CoronaVac” and inoculating volunteers in Indonesia and Brazil. CanSino Biologics Inc. in phase 2 trial on 508 volunteers found a satisfactory immune response to COVID-19 virus. Apart from vaccine preparation and availability, we provided data for therapy and treatment for COVID-19 and transmission and stability aspect of COVID-19 SARS-Cov-2 virus. The data and results presented in this article are very important and useful in containing, treating, and eliminating the pandemic COVID-19.

鱼骨型联钩撑杆的设计与应用研究

使用多钩头浮吊在码头进行FPSO模块集成施工已经十分普遍。随着FPSO规模不断扩大,模块重量也随之提高,如果超出浮吊单钩能力,可以采用联钩撑杆将双钩或多钩联动使用,相当于提高了浮吊的作业能力。以巴西FPSO P67/P70项目火炬塔吊装撑杆的设计为例,描述了单钩超重的情况下,采用双副钩连接撑杆的形式完成火炬塔的吊装施工方法;阐述了将若干散件的吊装撑杆整合在火炬塔联钩撑杆中,形成鱼骨型联钩撑杆的设计,最终实现一物多用功能,可为今后类似撑杆的设计提供参考和借鉴。

Enhancement of in-plane thermal conductivity of flexible boron nitride heat spreaders by micro/nanovoid filling using deformable liquid metal nanoparticles

With the fast development of integrated circuit devices as well as batteries with high energy densities,the thermal management of electronic components is becoming increasingly crucial to maintaining their reliable operations.Boron nitride nanosheets(BNNS),which have superhigh thermal conductivity along the in-plane direction while remaining electrically insulating,were widely regarded as an ideal filler for preparing high-performance polymer composites to address the‘‘thermal failure''issue.However,due to the instinctive rigidity of BNNS,the nanosheets are unable to form a tightly interfacial contact between the adjoining fillers,resulting in some micro-and nanovoids within the heat transfer pathways and severely limiting further thermal conductivity enhancement for BNNS-based composites.Herein,soft and deformable liquid metal(eutectic gallium-indium,EGaIn)nanoparticles were employed to fill the gaps between the adjacent BNNS with a rational design of mass ratios of BNNS and EGaIn,leading to a strongly synergistic effect with BNNS on thermal conductivity improvement.As a result,the composite film(BNNS:63 wt%and EGaIn:7 wt%)employing cellulose nanofibers(CNF:30 wt%)as the polymer matrix achieves superhigh thermal conductivity along the in-plane direction of up to(90.51±6.71)W·m^(-1)·K^(-1),showing the highest value among the BNNSbased composites with a bi-filler system as far as we know.Additionally,the film can work as a heat spreader for the heat dissipation of high-power light emitting diodes,outperforming tin foil in cooling efficiency.

多跨距吊装平衡梁介绍

在吊装作业中通常会使用到平衡梁。本文介绍了传统吊装中所使用的平衡梁,分析了其不足和弊端。本文提出一种新型的多跨距吊装平衡梁,可以做到单根平衡梁满足不同的吊装需求,弥补了传统吊装平衡梁的不足,减少资源浪费,提高生产功效,节省存储空间。

U型钢与工字钢扩杆支护在软岩支护中的应用

通过利用煤层动压注水、手镐配合风镐掘进、U型钢支架配合工字钢扩杆支护联合技术的实验,找到了解决芦沟煤矿巷道压力大、失修快、难以维护、使用周期短等难题的途径。

Fertilization strategy and application model using a centrifugal variable-rate fertilizer spreader

With the sustainable development of precision agriculture and the steady progress of variable-rate fertilization technology,the centrifugal variable-rate fertilizer spreader has attracted research attention due to its lower incidence of crush damage,high efficiency,and low cost.To improve fertilization accuracy and uniformity,spreading performance tests were conducted using this spreader in accordance with the test methods specified in ISO 5690 and ASAE S341.2,in which particle mass was weighed in a two-dimensional matrix of collection boxes.The effects of fertilization strategies that control the feed gate flow rate and the disc rotation speed on particle distribution,and application rate per unit area and effective swath width,were investigated.A variable-rate fertilization model was developed by analyzing the variation characteristics resulting from an increasing and decreasing application rate,and field experiments were conducted to verify its accuracy.The results indicated that when the feed gate flow rate was 300 g/s,the mean application rate was 26.47 g,the standard deviation is 2.81,and the coefficient of variation of particle distribution is at its minimum value of 14.25%.When the disc rotation speed was 600 r/min,the fertilizer was most evenly distributed with a coefficient of variation of 13.86%,and an average effective spreader swath width of 24.51 m.The proposed variable-rate fertilization model showed a high fitting degree with an S-shaped function curve for both increasing and decreasing distribution rates and the yielding coefficients of determination were more than 0.82 and 0.71,respectively.The average error between the model predictions and the test results was 9.47%,and the coefficients of determination for the increasing and decreasing distribution rates were 0.91 and 0.82,respectively,which confirmed the accuracy of the proposed variable-rate fertilization model.This investigation provided a theoretical basis for traditional empirical fertilization using centrifugal variable-rate fertilizer spreaders,and guides the selection of a multiple trajectory,variable-rate fertilization strategy.

A New K-Shell Decomposition Method for Identifying Influential Spreaders of Epidemics on Community Networks

An efficient method for the identification of influential spreaders that could be used to control epidemics within populations would be of considerable importance. Generally, populations are characterized by its community structures and by the heterogeneous distributions of out-leaving links among nodes bridging over communities. A new method for community networks capable of identifying influential spreaders that accelerate the spread of disease is here proposed. In this method, influential spreaders serve as target nodes. This is based on the idea that, in k-shell decomposition method,out-leaving links and inner links are processed separately. The method was used on empirical networks constructed from online social networks, and results indicated that this method is more accurate. Its effectiveness stems from the patterns of connectivity among neighbors, and it successfully identified the important nodes. In addition, the performance of the method remained robust even when there were errors in the structure of the network.

Event Detection and Identification of Influential Spreaders in Social Media Data Streams

Microblogging, a popular social media service platform, has become a new information channel for users to receive and exchange the most up-to-date information on current events. Consequently, it is a crucial platform for detecting newly emerging events and for identifying influential spreaders who have the potential to actively disseminate knowledge about events through microblogs. However, traditional event detection models require human intervention to detect the number of topics to be explored, which significantly reduces the efficiency and accuracy of event detection. In addition, most existing methods focus only on event detection and are unable to identify either influential spreaders or key event-related posts, thus making it challenging to track momentous events in a timely manner. To address these problems, we propose a Hypertext-Induced Topic Search(HITS) based Topic-Decision method(TD-HITS), and a Latent Dirichlet Allocation(LDA) based Three-Step model(TS-LDA). TDHITS can automatically detect the number of topics as well as identify associated key posts in a large number of posts. TS-LDA can identify influential spreaders of hot event topics based on both post and user information.The experimental results, using a Twitter dataset, demonstrate the effectiveness of our proposed methods for both detecting events and identifying influential spreaders.