20 research outputs found

    汉语情感意义的机器标注研究初探

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    本文将情感计算引入到汉语的机器理解中,在已有的汉语机器理解研究的基础上,采用多重松弛迭代计算方法,对汉语情感意义的标注问题进行了研究,通过语境信息的利用,构建了一个实验性系统并取得了较准确的词语情感标注,为后续的句子情感意义的理解提供了基础,拓宽了汉语机器理解的研究范围。国家自然科学基金项目(项目号:69983006) 浙江省教育厅科研基金项目(项目号:20010335

    Rapid determination of 1,2-propylene glycol and glycerol in refill fluids for electronic cigarettes by Raman spectroscopy

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    为实现电子烟烟液主要成分的简便快速检测,建立了同时测定电子烟烟液中1,2-丙二醇和丙三醇含量的拉曼光谱分析方法,利用该方法测定了17个电子烟烟液; 样品,并与气质联用法进行了结果比较。结果表明:①1,2-丙二醇和丙三醇分别在0.125~0.956和0.106~1.120; g/mL时,以522和671 cm~(-1)特征信号峰强度绘制的标准工作曲线线性关系良好(R~2>; 0.999),单样本和独立样本t检验结果证实方法的准确性较高。②17个电子烟烟液样品中,1,2-丙二醇和丙三醇的含量分别为0.533~0.766; 和0.182~0.476; g/mL。该方法与气质联用法检测结果的配对样本t检验结果表明,在95%置信概率下,两种方法的定量结果一致。该方法不需进行样品前处理,更适用于批量; 电子烟烟液中1,2-丙二醇和丙三醇的快速定量分析。A simple and rapid Raman spectroscopy method for simultaneous; determination of 1,2-propylene glycol and glycerol in refill fluids for; electronic cigarettes was developed. Samples of 17 refill fluids were; analyzed by a portable Raman spectrometer,and the data were compared; with those determined by GC-MS. The results showed that: 1) The standard; curves of 1,2-propylene glycol and glycerol determined at the Raman; intensity of 522 and 671 cm~(-1) possessed good correlation coefficients; (R~2 above 0.999) in the content range of 0.125-0.956 and 0.106-1.120; g/mL,respectively. The results of one sample t-test and independent; sample t-test indicated that the Raman method was accurate. 2) The; contents of 1,2-propylene glycol and glycerol in 17 refill fluids were; in the range of 0.533-0.766 and 0.182-0.476 g/mL, respectively. The; result of paired sample t-test showed that the data determined by Raman; spectroscopy were consistent with those obtained by GC-MS at a; confidence level of 95%. Without sample pretreatment, Raman spectroscopy; method is simple to operate and more suitable for the rapid quantitative; determination of 1,2-propylene glycol and glycerol in batches of refill; fluids for electronic cigarettes.浙江中烟工业有限责任公司科技项

    Effects of spring rainfall distribution on soil respiration in a coastal wetland of the Yellow River Delta

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    Changes of rainfall seasonal pattern would affect carbon cycling in coastal wetlands by influencing the transport of water and salt in soils. Seed germination and plant growth in coastal wetlands are sensitive to rainfall availability in spring,but the underlying mechanism of spring rainfall distribution on soil respiration is still unclear. An in-situ spring rainfall control field experiment with five treatments (+73%,+56%,control,-56% and -73% in spring,but the annual total rainfall remained the same) were set up to explore the effects of spring rainfall distribution on soil respiration of a coastal wetland on the Yellow River Delta. Soil water content in spring significantly increased with the increasing rainfall partitioning in spring,while that in autumn significantly decreased. The seasonal variation of soil salinity was opposite to soil moisture, and soil salinity showed strongest fluctuations in spring compared with other seasons. The total belowground biomass and the proportion of belowground biomass in deep soil layer increased with the increasing spring rainfall partitioning,while the proportion of belowground biomass in shallow soil layer showed an opposite pattern. Mean annual soil respiration rate was decreased with the decreasing spring rainfall partitioning,and was significantly different between +73% and -73% treatments (P<0.05). Soil respiration rate differed among different seasons. Soil respiration rate in spring and summer increased with the increasing rainfall partitioning in spring,but decreased in autumn and winter. However,the positive effect of increased spring rainfall partitioning on soil respiration in spring and summer was much greater than the negative effect in autumn and winter. Mean annual soil respiration was closely related to soil moisture and soil salinity in spring,and remarkably affected by the proportion of belowground biomass of different soil layers and total belowground biomass

    Kinetic Study on the Thermal Denaturation of Rice Mitochondrial DNA

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    The thermal denaturation of the rice mitochondrial DNA in diFFerent solutions have been studied by using ultraviolet absorption spectrometry at 50 ℃, and their kinetic behaviour of the thermal denaturation has been discussed.The kinetic curves of the thermal denaturation of rice mitochondrial DNA in diFFerent solutions have been obtained, and the kinetic parameters and models have been calculated and established respectively.国家自然科学基

    离心机环境对锡熔体热对流及温度脉动的影响

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    晶体材料在现代科学技术中有着重要的应用;为获得高质量的半导体晶体材料;人们做了大量的工作.研究发现;在晶体生长过程中;熔体中存在的强迫对流和自然对流等流动对加速传热传质有利;但非定常的对流引起温度脉动会造成晶体缺陷;产生杂质条纹.随着航天事业的发展;人们开始利用卫星、飞船进行微重力条件下材料制备的研究;并取得一些成果;但成本非常昂贵.与此相反;德国的Mukller首先从超重角度来考虑这个问题;1980年;他们在离心机上做了垂直Bridgman方法的晶体生长;以高离心力来模拟超重力.实验发现;在

    制备丙烯-苯乙烯接枝共聚物的新方法研究

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    Effects of simulated precipitation changes on plant community characteristics of wetland in the Yellow River Delta, China

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    Under the changing climate scenario, changes in precipitation regimes are expected to alter soil water and salinity conditions, with consequences on the characteristics of plant community in estuarine wetland. Here, we used a six-year (2015-2020) precipitation manipulation experiment to examine how plant community characteristics responded to precipitation changes in the Yellow River Delta. The results showed that soil electrical conductivity significantly decreased, while soil moisture significantly increased with increasing precipitation. Precipitation changes altered plant community composition. Increased precipitation reduced the absolute dominance of Suaeda glauca and Suaeda salsa, but increased that of Triarrhena sacchariflora and Imperata cylindrica. Shannon index and Margalef richness index of plant community significantly increased with increasing precipitation. Compared with the control, both decreased and increased precipitation decreased the plant community abundance, frequency and coverage. The treatment of 60% increased precipitation significantly decreased plant community frequency by 54.9%, while the 60% decreased precipitation, 40% decreased precipitation, 40% increased precipitation and 60% increased precipitation treatment significantly decreased plant abundance by 38.9%, 33.8%, 35.8% and 45.7%, respectively. The aboveground biomass significantly increased with increasing precipitation, but aboveground plant biomass under 60% increased precipitation treatment being lower than that reducing under 40% increased precipitation treatment, probably due to the negative effects of flooding stress. In addition, Margalef richness index had a significantly positive relationship with aboveground biomass. Aboveground biomass, Shannon diversity index, Margalef richness index, and Simpson diversity index were negatively related to soil electrical conductivity, and aboveground plant biomass was positively related to soil moisture. Our results revealed that precipitation changes regulate growth characteristics, species composition, and diversity of plant community by altering soil water and salinity conditions in a coastal wetland
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