关键词： admixtures   cement/cementitious materials  

摘要： The stringent early-age strength requirements for production of prestressed hollowcore (HC) slabs have restricted the use of alternative cementitious materials, such as ground granulated blast furnace slag (GGBS). In the present paper, an experimental study conducted in a precast factory is described in which GGBS-concrete HC slabs with 30 and 50% GGBS are compared with concrete slabs made from control samples (using 100% CEM II A-L cement, as used in summer mixes). The use of a novel admixture, thermal curing and a new early-age strength determination technique enables confirmation of the development of the required very early strength, such that cutting and lifting of the HC slabs can occur within 20 h of pouring. The HC slabs are instrumented to study the internal temperatures in the different slabs, leading to early-age strength development whereby these slabs are tested for immediate transportability and ultimate capacity. Further, the control and 30% GGBS slabs are tested for early-age creep under a flexural test in the factory. At later ages, using the new technique for making cube specimens, cubes and cores cut from the actual HC slabs are shown to have similar 28-day strengths and density.

关键词： Apriori算法   慢性萎缩性胃炎   慢性非萎缩性胃炎   数据挖掘   关联规则分析  

摘要： 目的:探讨慢性胃炎患者其他体检结果间的关联规则.方法:将慢性胃炎患者分为男性慢性非萎缩性胃炎、男性慢性萎缩性胃炎、女性慢性非萎缩性胃炎、女性慢性萎缩性胃炎四组分别进行回顾性研究,利用Apriori算法对每组体检数据进行数据挖掘,分析其间的关联规则.结果:男性慢性非萎缩性胃炎、男性慢性萎缩性胃炎、女性慢性非萎缩性胃炎、女性慢性萎缩性胃炎体检者其他体检结果出现频率由高到低前三项分别为"脂肪肝(55.56％)、甲状腺结节(42.86％)、反流性食管炎(33.33％)","脂肪肝(57.65％)、甲状腺结节(55.16％)、前列腺增生(33.10％)","乳腺增生(51.72％)、甲状腺结节(48.28％)、子宫肌瘤(34.48％)","甲状腺结节(62.50％)、乳腺增生(51.67％)、乳腺增生并发甲状腺结节(39.17％)";具有强关联规则的前三项分别为"高脂血症=>脂肪肝(87.50％)、骨量匮乏=>脂肪肝(87.50％)、颈动脉硬化并斑块形成=>脂肪肝(83.33％)","肥胖=>脂肪肝(89.19％)、高脂血症=>脂肪肝(87.32％)、高尿酸血症=>脂肪肝(80.26％)","颈动脉硬化并斑块形成=>甲状腺结节(100％)、肾囊肿=>甲状腺结节(100％)、结肠息肉=>甲状腺结节(100％)","高尿酸血症=>甲状腺结节(92.86％)、肺结节=>甲状腺结节(86.36％)、宫颈囊肿=>乳腺增生(85.71％)".结论:男、女,慢性萎缩性及非萎缩性胃炎患者其他体检结果存在差别,可为胃炎预防、治疗等相关研究提供参考,具有重要研究意义.

关键词： HIsarna   in-situ   fluxing   calcination   ironmaking   reaction kinetics   high-temperature reactions  

摘要： This work investigates the melting behaviour of iron ore with calcium-based fluxes, including lime, limestone and basic oxygen furnace (BOF) steelmaking slag. With an aim to explore the potential kinetic benefits that can be obtained through the formation of a liquid medium on the overall productivity of HIsarna. A HT-CLSM was used to rapidly heat and observation the interface between a given pair of chosen materials in-situ. Through this method, the rate at which the reaction progressed and the possible disruptive phenomenon that may occur was observed directly. The molten interface of fluxed materials is compared against each other offering insight into relative dissolution rate. Each flux shows promise of increasing ore fluidity to a varying degree with limestone generating above a 60% liquid fraction in the 1400 degrees C reaction temperature.

关键词： Paper sludge   biodiesel   Pichia kudriavzevii   pre-treatment  

摘要： This study comprises the production and characterization of biodiesel, synthesized from the microbial oil of oleaginous yeast Pichia kudriavzevii NCIM 3653 which was cultivated using paper mill sludge extract as a substrate. The paper mill sludge subjected to sonication pre-treatment released the highest amounts of carbohydrates and sugars. Optimization of various parameters such as fermentation time and C/N ratio was carried out to increase the lipid yield. Pichia kudriavzevii cultivated in a medium with a C/N ratio of 200 for 120h gave the highest lipid yield of 2.35g/L. The effect of the addition of glycerol and yeast extract as additional carbon and nitrogen sources in the medium was studied. The extracted microbial oil was subjected to different analytical techniques such as gas chromatography-mass spectrometry and Fourier transform infrared spectroscopy to test its practicability in biodiesel synthesis. The principal fatty acid methyl esters in the oil were found to be palmitic acid, oleic acid, and stearic acid methyl esters. The percentage of saturated fatty acids in the oil was found to be high, thus indicating its suitability in biodiesel production. The properties of the potential biodiesel complied with the standards laid out by American Society for Testing Materials (ASTM) and European Nations (EN).

关键词： Sintering   alternative fuel   combustion efficiency   pollutant emissions   semi-coke   climate change   human health   environment  

摘要： Various kinds of fuel such as high rank coal and coke breeze have been adopted over the years. However, their low combustion efficiency levels have given rise to the production of alternative fuels such as charcoal, biomass, semi-coke breeze, solid waste and gas, but the most extensively applied in recent times is semi-coke due to its high combustion efficiency and low pollutant emission level as compared to the other alternative fuels. The aim of this work is to review alternative fuels reported in literature as effective and efficient in powering sinter plants. This review presents problems that may occur with the adoption of each kind of alternative fuel, and their relative combustion efficiencies as compared to the other. Also, the kind of alternative fuel utilized in powering sinter plants may contribute to escalation of climate change and its variability or result in their drastic reduction.

关键词： Electric arc furnace   DRI   HBI   yield of steel   electric power consumption   electrode consumption  

摘要： The data obtained on 220-T ultra-high power electric arc furnace (EAF) were analysed in order to study the impact of DRI quality on the steelmaking process parameters and consumption of lime, coke, oxygen, natural gas, electrical energy and electrodes. In addition, the effects of charging methods and proportions of DRI in an EAF were studied. It was found that by increasing the proportion of non-high quality reduced pellets and/or HBI to 45% of the metallic charge, the steel yield decreased to 85.32% and increased to 87.57% when between 75 and 100% continuous feeding of high quality reduced pellets. This resulted in saving 21 min in tap-to-tap time and 7% of the electrode consumption. Charging high proportion of non-high quality DRI from 45% to 100% in EAF, leads to a loss of 4 tons/heat in liquid steel, and an increase in lime consumption from 4 to 6 kg/ton liquid steel.

关键词： 现代   城市轨道交通   规划设计   交通衔接  

摘要： 有关城市轨道交通中的概念,最先起源于上个世纪30年代的日本,伴随着实时间的逐渐推移,有关城市轨道交通理论的研究逐渐的进入白热化的发展阶段,逐渐呈现出具有地方特色,多元化发展格局的交通规划,城市轨道交通相关的研究,在我国起步属于一个比较晚的阶段,城市轨道交通在我国的城市发展中,在交通规划融合中起到了非常关键的桥梁作用。

关键词： compact DC electron gun   terahertz source   Smith-Purcell radiation  

摘要： An alternative technique to verify terahertz (THz) Smith-Purcell radiation (SPR) was proposed by using different grating periods. A compact DC electron gun, serving as a THz source, was modified to generate continuous 35 keV electron beam that passes by a metal-coated silicon grating in order to induce SPR. A design on beam optics to generate high-brightness beam was carried out by using Computer Simulation Technology (CST) Studio Suite(R) software package. The optimization of beam parameters was obtained and experimentally performed. Results show that the root-mean-square (rms) beam size (diameter) is about 1 mm when supplying beam current of 200 mu A, and rms beam emittance is about 3 pi mm mrad. The CST simulation software was, furthermore, employed to observe radiation spectra when using different grating structures. A liquid-helium cooled silicon bolometer together with a low-pass filter was used to detect radiation power. The results reveal that incoherent THz signal with power of 1.5 mu W cm(-2) is observed when the continuous-beam current is about 200 mu A. The dependence of THz frequency and power on the grating period, that is associated to the SPR, was also investigated in this work.

关键词： 体重   肌酐   尿素氮   收缩压  

摘要： 探究高血压患者同型半胱氨酸(Hcy)与其他生化指标的相关性。方法:本次102例患者,时间2018年2月至2020年7月,依据血清Hcy水平分为两组(每组51例),正常水平(Hcy≤15μmol)为对照组,高水平(Hcy>15μmol)为试验组。比较两组相关性。结果:两组临床资料无差异想(P>0.05);两组生化指标除去白细胞(WBC)、血常规(RBC)水平值无差异(P>0.05);其余生化指标,试验组与对照组均存在相关性(P<0.05);因变量与自变量均存存在相关性(r=0.225,P=0.00;r=0.523,P=0.001;r=0.314,P=0.002)。结论:高血压Hcy水平与生化指标存在相关性。

关键词： SUMO   DNA-protein crosslink   DPC repair   Top1   Top1cc   Siz2   Ulp1   Wss1   Tdp1   STUbL   Flp-nick  

摘要： Endogenous metabolites, environmental agents, and therapeutic drugs promote formation of covalent DNA-protein crosslinks (DPCs). Persistent DPCs compromise genome integrity and are eliminated by multiple repair pathways. Aberrant Top1-DNA crosslinks, or Top1ccs, are processed by Tdp1 and Wss1 functioning in parallel pathways in Saccharomyces cerevisiae. It remains obscure how cells choose between diverse mechanisms of DPC repair. Here, we show that several SUMO biogenesis factors (Ulp1, Siz2, Slx5, and Slx8) control repair of Top1cc or an analogous DPC lesion. Genetic analysis reveals that SUMO promotes Top1cc processing in the absence of Tdp1 but has an inhibitory role if cells additionally lack Wss1. In the tdp1 Delta wss1 Delta mutant, the E3 SUMO ligase Siz2 stimulates sumoylation in the vicinity of the DPC, but not SUMO conjugation to Top1. This Siz2-dependent sumoylation inhibits alternative DPC repair mechanisms, including Ddi1. Our findings suggest that SUMO tunes available repair pathways to facilitate faithful DPC repair.