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71.
The rapid development of online social networks leads to an explosion of information,however,there are great differences in the popularity of different messages,and accurate prediction is always a great difficulty is the current study.Popularity prediction of online content aims to predict the popularity in the future based on its early diffusion status.Existing models for popularity prediction were mostly based on discovering network features or fitting the equation into a varying time function that the accuracy of current popularity prediction model was not high enough.Therefore,with the help of the weak ties theory in sociology,the concept of tie strength was introduced and a multilinear regression equation was constructed combined with the early popularity.A TSL model to predict the popularity of Facebook’s well-known pages was proposed.The main contribution of this article was to solve the problem and few or no work based on sociology.A high linear correlation between the proportion of faithful fans was existed in Facebook homepage with frequent shares in the early and the future popularity.Compared with other baseline models,an experimental study of Facebook (including 1.54 million shares) illustrates the effectiveness of the proposed TSL model,and the performance is better than the existing similar methods.  相似文献   
72.
73.
Numerical simulation and experiments were introduced to develop AA4045/AA3003 cladding billets with different clad-ratios. The temperature fields, microstructures and mechanical properties near interface were investigated in detail. The results show that cladding billets with different clad-ratios were fabricated successfully. Si and Mn elements diffused across the bonding interface and formed diffusion layer. With the increase of clad-layer thickness, the interfacial region transforms from semisolid–solid state to liquid–solid state and the diffusion layer increased from 10 to 25 μm. The hardness at interface is higher than that of AA3003 side but lower than that of the other side. The bonding strength increased with the clad-layer thickness, attributing to solution strengthening due to elements diffusion. The cladding billets were extruded into clad pipe by indirect extrusion process after homogenization. The clad pipe remained the interfacial characteristics of as-cast cladding billet and the heredity of clad-ratio during deformation was testified.  相似文献   
74.
Solvent mass transfer plays a key role in a thermal gravity drainage process involving solvent. The diffusion coefficients of solvent in such a process are not well studied. This article presents the effective diffusion coefficients of solvent in bitumen-saturated sands under high temperature/pressure conditions measured using a CT scanning technique. Experimental results show that the effective diffusion coefficient of n-hexane in bitumen-saturated sands varied with the solvent concentration or with the viscosity of solvent–bitumen mixture (i.e., Dec0.4 or Deμm−0.46). The solvent concentration weighted diffusion coefficient of n-hexane in the bitumen under the condition 160–170°C/1,900 kPa had an order of magnitude of about 10−5 cm2/s for solvent volume concentration less than 0.2. The penetration distance of n-hexane in bitumen-saturated sands depended on the nonlinearity of diffusion and had a value of −2 cm after 1-day diffusion. The stronger the nonlinearity of diffusion, the shorter the penetration distance.  相似文献   
75.
Recently, various studies have been conducted on hydrogen energy as a means of replacing conventional fuels. Polymer electrolyte membrane water electrolyzers (PEMWEs) are being studied as a means of producing hydrogen for renewable energy. The PEMWE can be operated over a wider range than other types of water electrolyzers and can be connected to a renewable energy source, such as solar or wind. However, further studies are required because the water accompanying the hydrogen in the cathode presents a problem regarding hydrogen purity and storage. The phenomenon of water transport which is occurred on the PEMWE is analyzed by electro-osmotic drag and diffusion in the membrane. Electro-osmotic drag coefficients which are calculated by mass flow rate of discharged water with hydrogen are compared to the results of previous studies. The results of Electro-osmotic drag coefficient are different from previous studies at each operating condition. This difference is considered to be caused by the capacity of PEMWE such as active area and the number of cell.  相似文献   
76.
湿地水网规划和设计需要考虑防洪排涝、生物栖息地构建及水资源调度等多个因素的协调,单一维度的数值模型难以解决河网、湖区及工程调度等多种模拟对象的尺度协调问题。针对某感潮河网区域生态湿地公园的规划设计,利用MIKE Flood软件,构建一、二维耦合水动力模型,就河网规模、堰顶高程控制、生物栖息地构建等目标开展计算分析,通过方案比选确定相关工程规模,并通过区域微地形调整对鱼类和禽类栖息地水动力条件进行优化,使其满足生境构建要求。该结果不仅为相关设计单位提供了工作思路,所采用的建模方法和参数选取也可为类似项目参考。  相似文献   
77.
目的 验证15 nm厚度AlCrTaTiZrRu/(AlCrTaTiZrRu)N0.7的势垒层热稳定性和扩散阻挡性能。方法 采用直流磁控溅射技术在n型Si(111)基片上真空溅射沉积15 nm的AlCrTaTiZrRu(3 nm)/(AlCrTaTiZrRu)N0.7 (12 nm)双层阻挡层,随后在双层AlCrTaTiZrRu/(AlCrTaTiZrRu)N0.7薄膜的顶部沉积50 nm厚的Cu膜,最终制得Cu/AlCrTaTiZrRu/(AlCrTaTiZrRu)N0.7/Si复合薄膜试样。将样品在真空退火炉中分别进行600~900 ℃高温退火30 min,以模拟最恶劣的应用环境。用场发射扫描电镜(FE-SEM)、X射线衍射仪(XRD)、能谱分析仪(EDS)、四探针电阻测试仪(FPP)以及原子力显微镜(AFM)对试样的表面形貌、物相组成、化学成分、方块电阻和粗糙度进行表征分析。结果 沉积态AlCrTaTiZrRu/(AlCrTaTiZrRu)N0.7薄膜呈现非晶结构,与Cu膜和Si衬底的结合良好。在800 ℃退火后,Cu/AlCrTaTiZrRu/(AlCrTaTiZrRu)N0.7/Si薄膜系统结构完整,膜层结构界面之间未出现分层现象,表面Cu颗粒团聚现象加剧,Si衬底和Cu膜表面未发现Cu-Si化合物生成,薄膜方阻保持在较低的0.070 ?/sq;900 ℃退火后,薄膜系统未出现层间分离和空洞现象,Cu膜表面形成孤立的大颗粒Cu-Si化合物,薄膜电阻率大幅上升。结论AlCrTaTiZrRu/(AlCrTaTiZrRu)N0.7双层结构在800 ℃退火后仍能有效抑制Cu与Si相互扩散,其非晶结构增强了Cu/HEA/HEAN0.7/Si体系的热稳定性和扩散阻挡性。  相似文献   
78.
This article investigates nexuses between innovations in mobile money and financial inclusion. Demand and supply factors that affect the diffusion of mobile services as well as macro-level institutional and economic factors are taken in account. The focus is on 148 countries with data mostly consisting of 2010–2014 averages. The empirical evidence is based on Tobit regressions. The study finds that when the empirical analysis is robust to multicollinearity, two main tendencies are apparent: the significant findings of Lashitew et al. (2019) [1] are confirmed and many new significant estimated coefficients emerge. While this study confirms the findings of the underlying research, it also goes further to improve the harmony in narratives between the predictors and the outcome variables. Accordingly, by accounting for multicollinearity, the earlier findings are now more consistent across the set of predictors (i.e. demand and supply factors) and the attendant financial inclusion outcomes (i.e. mobile money accounts, mobile used to send money and mobile used to receive money).  相似文献   
79.
Diffusion behaviors in Mg–Sc hcp and bcc solid solutions between 773 and 873 K were investigated using both single-phase and multi-phase diffusion couple techniques. The EPMA detected composition-distance profiles were smoothed and fitted using the error function expansion (ERFEX). The interdiffusion coefficients were extracted using Sauer–Freise integral. The interdiffusion coefficients in hcp phase showed a slightly parabolic composition dependence at the Mg-rich part and the maximum value was around 2–3 at. % Sc. However, the interdiffusion coefficients in the bcc phase monotonously decreased with the increase of solubility of Sc. The determined inter- and impurity diffusion coefficients in the hcp Mg–Sc alloys were assessed to develop the atomic mobility database, and their validity was justified by reproducing the composition profiles and diffusion fluxes obtained in this diffusion couple experiment. Meanwhile, the development of bcc atomic mobility was realized via the Maclaurin approximation, extrapolation, and optimization. The results make up for the missing data of Mg–Sc diffusion kinetics.  相似文献   
80.
Diffusion couple technique has been utilized to study the interdiffusional behaviors of Zn–Cr system. Two intermetallic compounds (Zn13Cr, Zn17Cr) have been found in the diffusion zone between 598 K and 653 K. For the existence of Zn13Cr phase, the incremental diffusion couple has been used to confirm, and the results show that the Zn13Cr phase can be determined in the present work. However, the thickness of Zn13Cr is very thinner than that of Zn17Cr, which indicate the growth of Zn13Cr is very slow. The thickness of Zn17Cr satisfied the parabolic growth law. EPMA was used to obtain the composition profiles and the interdiffusion coefficients of Zn13Cr, Zn17Cr and Zn (hcp) have been extracted by forward simulation analysis embedded in ‘Pydiffusion’ code. The mechanical properties of Zn17Cr were also determined by nanoindentation technique, and the hardness and Young's modulus of Zn17Cr is 3.01 GPa and 165.78 GPa, respectively.  相似文献   
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