中文文本情感分析研究综述

对中文文本情感分析的研究进行了综述。将情感分类划分为信息抽取和情感识别两类任务,并分别介绍了各自的研究进展;总结了情感分析的应用现状,最后提出了存在的问题及不足。     

盲环境下数字图像的自动修复算法研究*

当前所有的数字图像修复算法都是一种半自动的方法,因为在对图像修复前,都是由用户给出想要修复的区域,而算法无法自动获取照片的破损所在。提出了盲环境下图像自动修复的概念,以基于数字图像的样本修复为基础,改进了基于纹理合成的图像修复算法。首次运用数字图像可信性评估体系于图像修复,并通过可信性综合度量模型判断确定待修复区域。实验证明,该算法最终达到了盲环境下的图像自动修复效果。     

一种有效的复杂地质体剖面图自动生成方法*

提出了一种基于平面隐函数的实体切割思想和区域自动识别技术的地质体剖面图生成方法。其主要步骤包括：采用平面隐函数实现平面和地质实体的求交运算,生成离散的交线;采用基于KD树的空间索引方法,确定交线的邻接关系,生成地质体轮廓线;封闭的轮廓线将平面划分为多个复杂的区域(内含孔、岛),采用图论的多叉树形式化表达区域存储和组织;最后对多叉树表示的区域进行矢量图案的填充。实验结果表明,该算法有较好的计算效率,是一种比较实用的地质体剖切方法。     

基于运动区域检测的运动目标跟踪算法*

针对传统基于模板匹配的运动目标跟踪算法存在着计算量大、模板漂移导致跟踪失败的问题,提出了一种基于运动区域检测的运动目标跟踪算法。该算法通过采用光流法对目标运动区域进行估计,计算出光流场区域的形心,确定待匹配图相匹配范围,再用模板框在已确定区域进行模板匹配跟踪。根据某开放实验室行人录像跟踪实验表明,本算法能够有效解决模板漂移问题,提高了跟踪实时性, 实现了视频对象目标的跟踪。     

Dietary evaluation of pregnant adolescents during first, second and third trimester

In order to identify risk of inadequate intake of calories and nutrients during pregnancy, 75 pregnant adolescents (14 to 18 years old) apparently healthy, from low socioeconomic level, in their first prenatal control (12 weeks) were studied by two 24 hour recalls and a food frequency questionnaire at each trimester. Nutritional status was assessed by body mass index (pregestation weight/height) and classified according to American Medicine Institute reference. Paired t-test, frequency distribution and ANOVA were used for statistical analysis. Low weight was found in 34.6% of adolescent at the first visit and 5.3% were overweight. Even though, caloric intake was below recommendation, significant increases were observed between first and second trimester for energy, carbohydrates, niacin and zinc (p < 0.001) and for fat, proteins, riboflavin, thiamin, vitamin C, calcium and iron (p < 0.05). From second to third trimester, differences (p < 0.05) were significant only for vitamin A. Between first and third trimester, differences were significant (p < 0.05) for energy, proteins, carbohydrates, niacin, riboflavin, zinc and for thiamin, vitamin A and calcium (p < 0.05). A high proportion of pregnant adolescent did not reach recommendations for energy, folate, calcium and zinc. Food intake pattern did not change significantly among trimesters. Mean total weight gain was 9.2 kg and 0.412 +/- 0.4 g/week. Newborn's mean weight was 3.221 +/- 418 grams. It is concluded that adolescents are at high nutritional risk and deficiency of dietary intake should be followed. Attention should be addressed from the preconceptional period to postpartum in order to improve maternal and fetal conditions.     

Assessment of olive cake as soil amendment for the controlled release of triazine herbicides

Organic matter-rich agricultural by-products are being produced in huge quantities and can be applied to soil as a disposal strategy. The application of two different rates (2 and 8% w/w) of olive cake to a Mediterranean calcareous soil resulted in an increased sorption of four triazine herbicides, which was higher for the more hydrophobic compounds (terbuthylazine and prometryn) and lower for the more polar ones (simazine and cyanazine). However, when the sorption coefficients were normalised to the total soil organic carbon (K(oc)), the results did not significantly differ between simazine and cyanazine which is an indication that the olive cake did not exert different sorption capacity for both compounds. On the contrary, K(oc) values for terbuthylazine and prometryn increased in the amended soils. Our results from experiments using mixtures of several pesticides suggest that competition for sorption sites resulted in a decrease of herbicide sorption. Desorption was hysteretical both for the amended and unamended soils, but the addition of olive cake at the highest dose diminished desorption of most of the herbicides. In conclusion, the addition of olive cake behaves as a promising method for reducing the risk of groundwater pollution by pesticides.     

麦达佩克铜选矿厂通过改进浮选过程提高铜回收的技术指标

该厂原选别流程南斯拉夫麦达佩克铜选矿厂分两期建成,目前每年可处理1100万吨贫铜矿石。第一期工程(一号浮选车间)于1961年投产,年处理能力为360万吨矿石。第二期工程又建了两个浮选车间(即二号和三号浮选车间),它们分     

测量数据采集传输中的串行通讯

介绍了串行通讯的原理以及利用VB和VC编程语言实现串行通讯的过程。针对全站仪、GPS、水准仪的指令及参数的不同导致程序庞大及应用不便等问题,介绍了清华山维软件的处理方法,较好地解决了这个问题。     

ESPCP电动潜油螺杆泵设计研究

电动潜油螺杆泵结合了潜油电机和螺杆泵特点,克服了地面驱动螺杆泵抽油杆偏磨、脱杆且不适应于斜井和定向井的弊端,同时又发挥了螺杆泵对高稠油、高含气、高含砂井较强适应性的特点.通过分析ESPCP电动潜油螺杆泵的性能特点,详细阐述了配套设计方案,简要分析了螺杆泵轴向力和扭矩的计算方法,以及低速六极电机的研制情况,重点介绍了减速器的设计,最后通过型式试验并分析试验数据得出了结论.     

Metabolism of SO₂ binding compounds by Oenococcus oeni during and after malolactic fermentation in white wine

Sulfur dioxide SO? is the key additive for the preservation of wines. Carbonyl and keto compounds in wine can bind to SO? and decrease its efficacy, resulting in higher total SO? requirements. Increased consumer demand for low sulfite and organic wines pose production challenges if SO? binders have not been properly managed during vinification. Malolactic fermentation (MLF) has been known to reduce bound SO? levels but detailed time course studies are not available. In this work, the kinetics of major SO? binding compounds and malic acid were followed during MLF in wine with 12 commercially available strains of Oenococcus oeni. Pyruvic acid, acetaldehyde and α-ketoglutaric acid were degraded to various degrees by O. oeni, but galacturonic acid was not. At the time of malic acid depletion, percent degradation of pyruvate, α-ketoglutaric acid and acetaldehyde was 49%, 14% and 30%, respectively. During MLF, the decrease in average bound SO? levels, as calculated from carbonyl metabolism, was 22%. The largest reduction in wine carbonyl content occurred in the week after completion of MLF and was 53% (107 mg/L to 34 mg/L) calculated as bound SO?. Prolonged activity of bacteria in the wines (up to 3 weeks post malic acid depletion) resulted only in reduced additional reductions in bound SO? levels. The results suggest that microbiological wine stabilization one week after malic acid depletion is an effective strategy for maximum removal of SO? binders while reducing the risk of possible post-ML spoilage by O. oeni leading to the production acetic acid and biogenic amines.