基于MVC模式的ITHelp在线服务模块设计与实现

分析了ITHelp在线服务模块的建设需求,对ITHelp进行了功能分解和详细设计。研究了MVC开发模式,提出了基于SSI的ITHelp实现方案。结果表明, ITHelp模块功能完备、实用性强,提高了信息化工作效率,实现了信息在线共享。     

基于功能替代的实时事务调度

实时数据库事务除满足一般的一致性（完整性）限制外必须满足时限，故高成功率的调度策略是系统的关键，该文提出了一种基于功能替代性的事务模型，它定义事务为若干任务（事务步）的集合，每个任务又由若干功能等价的子事务组成，在每个任务（事务步）中取一个子事务就组成该事务的一个替代，该模型具有较强的描述能力，文章研究了事务预分析的策略与方法，分析了事务的可调度性，在此基础上，给出了相应的调度策略与方法，替代成为事务调度和并发控制的基本单位，一个替代成功执行则该事务可提交，但某替代夭折时还可选另外的替代，只有当全部替代都失败或超过（或必定会超过）截止期时，该事务才夭折，事务的替代特性使事务的执行有多条路径，提高了事务的适应能力和应力能力，从而提高了事务的成功率，文章还针对一个实验系统进行了模拟实验与性能分析。     

土壤中红外光谱库支持下的局部建模集优化

土壤中红外（MIR）光谱能快速、无污染、低成本地估算土壤有机碳等理化属性。随着各种尺度土壤光谱库的建立,使用其进行快速土壤分析引起广泛关注,但光谱库的通用模型在局部尺度上的预测效果不理想。开发“局部化”光谱建模方法是提高土壤光谱库性能的有效途径。本文提出了一种新的方法,通过光谱相似度计算和建模子集构建,旨在从库中快速建立最优局部建模集以提高预测精度。比较了欧氏、马氏、余弦三种距离算法衡量待测样本与库样本之间的相似度并生成距离矩阵;使用连续统去除法从距离矩阵中提取库容曲线中的特征点。利用偏最小二乘回归建立土壤MIR光谱与有机碳含量间的定量关系。结果表明,三种距离算法结合连续统去除得到的第一特征点均可得到较佳的预测精度。马氏距离不仅模型精度最高（R² = 0.764,RMSE = 1.021%）而且用到的库样本数最少（14%库容）。本方法可改善MIR光谱分析的成本效率并能提高局部尺度的预测能力。     

经大过渡电阻接地短路时相电压补偿式方向元件性能的研究

本文对提高相电压补偿式方向元件在经过渡电阻单相接地短路的灵敏度问题进行了研究，分析了在正反方向发生短路时补偿电压的特点，提出了基于零序补偿电压的判断各种非对称接地短路的一个补充判据，并且把它实用化．仿真验证了此判据的有效性．     

Sintering and dielectric properties of Al2O3 ceramics doped by TiO2 and CuO

The effects of CuO and TiO₂ additives on the microstructure and microwave dielectric properties of Al₂O₃ ceramics were investigated. Al₂O₃ ceramics with CuO and TiO₂ additions can be well sintered to achieve 93∼98% theoretical densities below 1,360 °C due to Ti₄Cu₂O liquid phase sintering effect. The Qf values decreased with increasing CuO and TiO₂ content, due to the formation of the second phase Ti₄Cu₂O. However, the varying behaviors of the dielectric constant (ɛ _r ) and temperature coefficients (τ _f ) were associated with phase constitutions, as a result of the change of CuO and TiO₂content. The τ _f can be shifted close to 0 ppm/°C by controlling the content of CuO and TiO₂. The specimens with 0.5 wt.% CuO and 7 wt.% TiO₂ sintered at 1,360 °C for 4 h showed ɛ _r of 11.8, Qf value of 30,000 GHz, and τ _f of −7 ppm/°C.     

Identifying Language Origin of Named Entity With Multiple Information Sources

To identify the language origin of a named entity, morphological information associated with its letter spelling, such as letter N-grams, is commonly employed. However, with this information only, named entities with similar spellings but from different language origins are difficult to differentiate. In this paper, a measure of "popularity," in terms of frequency or page count of the named entity in language-specific Web search, is proposed for identifying its language origin. Morphological information, including letter or letter-chunk N-grams, is used to enhance the performance of language identification in conjunction with Web-based page counts. Six languages, including English, German, French, Portuguese, Chinese, and Japanese (Chinese and Japanese named entities are shown in their corresponding phonetic alphabets, i.e., Pinyin and Romaji), are tested. Experiments show that when classifying four Latin languages, including English, German, French, and Portuguese, which are written in Latin alphabets, features from different information sources yield substantial performance improvements in the classification accuracy over a letter 4-gram-based baseline system. The accuracy increases from 75.0% to 86.3%, or a 45.2% relative error reduction.     

湖南地区5种常见食用菌的营养成分分析

目的对湖南地区常见的5种食用菌中所含基本营养成分、矿物质元素、氨基酸及脂肪酸的含量进行检测和分析。方法依据国家标准斱法,采用气相色谱-质谱联用仪、电感耦合等离子体质谱仪、全自动氨基酸分析仪等进行成分分析。结果 5种食用菌在营养成分上存在一定的差异,其水分含量为86.0～92.8 g/100g,蛋白质含量为2.3～3.8g/100g,脂肪含量为0.2～0.5g/100g,膳食纤维含量为2.1～4.1g/100g,灰分含量为0.6～1.0 g/100 g, 5种食用菌均富含钾和磷,香菇富含铁、锌、锰,双孢菇富含钙、铁、铜。杏鲍菇的必需氨基酸与非必需氨基酸的比值高于其他4种食用菌。5种食用菌中脂肪酸以亚油酸为主,其中釐针菇同时含有亚油酸和α-亚麻酸2种必需脂肪酸。结论 5种食用菌可视为高蛋白低脂肪、高钾低钠食物,在营养价值斱面各具优势,为人们更合理科学的使用食用菌提供参考依据。     

水产品中常见酚类化合物检测方法研究进展

作为当前被广泛关注的水体污染物之一,酚类化合物分布广泛、种类繁多、危害性高。酚类化合物不仅可通过生活饮用水直接进入人体,也可经水体及水体微生物转移到水产品中,在水产品中富集,并通过食物链对人体造成潜在的危害,因此对水产品中酚类化合物的研究具有极其重要的意义。本研究综合调研了水产品中常见酚类化合物的研究现状,重点聚焦了常见酚类化合物相关检测技术进展,以期探寻便捷、高效、灵敏的酚类化合物检测技术,为研究和制定水产品中酚类化合物检测方法标准提供依据。     

Survey of Seawater Intrusion in the Pearl River Basin and Modeling Bromate Formation during Ozonation of the Raw Water

Bromate formation has been identified as a significant barrier in the application of ozone during water treatment the downstream region of the Pearl River Basin that contains high levels of bromide. Seawater intrusion will increase bromide concentration in the inshore surface water. In this study, seawater intrusion in the Pearl River Basin was surveyed and modeling bromate formation during ozonation of the raw water affected by seawater intrusion was studied. Bromate formation models were developed to simulate the effects of the characteristics of water quality and the operating parameters of treatment processes on bromate formation during preozonation process and postozonation process. The results show that the downstream of the Pearl River Basin is affected seriously by seawater intrusion and the bromide mainly comes from seawater. Some empirical models were developed to estimate the concentration of bromate in ozonated surface raw water affected by seawater intrusion during the treatment process.     

能力验证乳粉中乳酸菌计数不确定度的评定

目的对能力验证乳粉样品中乳酸菌计数进行不确定度评定。方法依据能力验证作业指导书和GB4789.35-2010《食品安全国家标准食品微生物学检验乳酸菌检验》进行测定,再根据JJF 1059.1-2012《测量不确定度评定与表示》对不确定度来源进行分析和评定。结果乳酸菌计数过程中,分散性对结果不确定贡献较大,因此测定结果的不确定度采用检测结果的分散性进行评定。6份样品乳酸菌计数结果扩展不确定度为分别为0.02012、0.04337、0.01992、0.03296、0.02182和0.031379(P=95%,k=2.09)。结论此方法适用于类似检测条件下乳酸菌计数不确定度的评定。