不同品种甜菜类型甜菜光合特性的研究

水文研究了甜菜生育期中不同品种类型甜菜的光合特性，结果表明在生育前期，高糖型品种的叶绿素含量高，而生育中前期以丰产型高，标准型介于二者之间，ＲｕＢＰ竣化酶活性的动态变化亦显这种趋势；在叶丛形成期和块根增长期，丰产型品种光合速度最高，在糖分积累期则以高糖型品种光合速度高；不同品种不同叶位的叶绿素含量与光合速率中呈正相关。     

Fat reduction in emulsion sausage using an enzyme‐modified potato starch

BACKGROUND: A heat‐stable amylase‐modified potato starch (MPS) was prepared and used as a fat replacer in reduced‐fat emulsion sausages. The effects of fat level (50, 150 and 300 g kg^?1) and MPS addition (20 and 40 g kg^?1) on energy, colour, sensory, and textural properties of emulsion sausages were investigated. RESULTS: The addition of 20 or 40 g kg^?1 of MPS in reduced‐fat sausage (50–150 g kg^?1 fat) reduced total energy (15.1–49.4%), increased lightness, but lowered redness of the products (P < 0.05). The 150 g kg^?1 or 50 g kg^?1 fat sausages containing 20 g kg^?1 MPS had a similar hardness to the 300 g kg^?1 fat control (P > 0.05). Sensory evaluation indicated that the presence of MPS in reduced‐fat sausages increased (P < 0.05) the product's tenderness. CONCLUSION: Overall, the 150 g kg^?1 fat emulsion sausages with 20 g kg^?1 MPS were comparable to the 300 g kg^?1 fat control sausage in colour, texture profile, and sensory properties, but was lower in energy, suggesting that the MPS can be used as a potential fat replacer in sausage products. Copyright © 2008 Society of Chemical Industry     

蛋白氧化及对肉制品品质和功能性的影响

肉蛋白氧化及功能性和品质变化目前已经引起国内外关注。本文从氨基酸残基侧链的改变、羰基衍生物的产生、蛋白质聚合物的形成三方面阐述了肉中蛋白氧化的机理,同时对氧化给肉蛋白品质和功能性带来的影响进行了概括性论述。     

以美国加州为例分析建立南水北调工程"水银行"的可行性

美国加利福尼亚州北水南调工程的“水银行”是一种成功的调水工程管理模式,它以调水工程设施为依托,以“水银行”为水权交易的媒介,通过用水户间的水权流转实现有限水资源的合理再分配,它的成功经验为我国南水北调工程的水资源管理提供了借鉴作用。通过从建立“水银行”的软硬件条件等方面分析建立南水北调工程“水银行”的可行性。     

草莓红色素稳定性的研究

研究了草莓红色素的稳定性。结果表明 :pH值对草莓红色素的影响明显 ,在酸性条件下 ,该色素较稳定 ;金属离子Na+、Ca2 +、Zn2 +、Cu2 +对色素有增色作用 ,Al3+对草莓红色素的影响不大 ,而Fe3+则有明显的不良影响 ;食品中常用的葡萄糖、蔗糖对草莓红色素有一定的降解作用 ,而Vc、H2 O2 、Na2 SO3则有严重的破坏作用 ;低浓度的 ( <1 % )防腐剂苯甲酸钠对草莓红色素有增色作用 ,高浓度 ( >1 % )的则有明显的降解作用。     

Complexity and trends analysis of hydrometeorological time series for a river streamflow: A case study of Songhua River Basin,China

In China's national economic growth, an important role is being played by the Songhua River because of the river's abundant resources and natural conditions. Therefore, study of hydrometeorological time series is very important to understand the basin behaviour. This research uses the snow cover data derived from MODIS, streamflow, and meteorological records in the Songhua River Basin to evaluate similarity, complexity, and trends in the snow cover, temperature, precipitation, and streamflow. In this paper, we suggest a new method of ranking the statistics symbolic sequences to examine the degree of similarity (distance measurement) between meteorological stations and compare it with non‐parametric correlation methods and also investigate the deviations in the complexity of a hydrometeorological time series. Information‐based similarity index and multiscale entropy confirm that the hydrometeorological time series of different stations have self‐similarity and abundant complexity. Wavelet entropy is also used to investigate the basin behaviour by taking streamflow records and population. It is found that with the increase in population and urbanization, the complexity values are increased. The results also exhibit that due to increase in urbanization, it affects the hydrological process and nature of environment resulting in complex catchment behaviour. Furthermore, the streamflow trend results displayed significant decline (22.21 m³/s × year^?1) in the Songhua River. The results also indicated that the seasonal snow cover trend has no impact on changes of the streamflow. However, the decline of the streamflow may be influenced by the significant human activity upstream of the Songhua River.     

城市水系结构形态演变特征分析——以哈尔滨主城区为例

为研究哈尔滨主城区河网水系结构复杂性和水系连通性变化特征,本文根据哈尔滨主城区2006年和2015年的数据资料,从时间尺度和空间尺度采用Horton定律计算研究区域内10条沟、渠的水系结构参数。结果表明,从时间尺度分析,10年来,哈尔滨主城区河网水系结构复杂性降低,其中水系结构指标中的河网密度和水面率分别减少19.34%和39.31%;从空间尺度分析,间接与松花江相连的沟、渠和直接与其相连的沟、渠的结构复杂性相比,变化更为显著。采用水系连通性指标分别从时间和空间尺度对哈尔滨主城区水系连通性进行研究,经分析得出,2015年哈尔滨主城区水系连通性与2006年相比,结点数和河链数分别减少14.3%和18.9%;而空间尺度上,直接与松花江相连的沟、渠的结点数和河链数均大于间接与其相连的沟、渠。上述研究结果对今后哈尔滨主城区的规划设计具有一定的参考价值。     

基于两阶段模型的水土资源利用效率评价

传统数据包络分析(DEA)模型应用于水土资源利用效率测算时忽略了系统内部运行机理,根据这一不足,本研究针对水土资源利用的内部复杂性,将水土资源利用过程划分为水土资源开发与经济效益转化两个子阶段,考虑各阶段间关系及投入产出权重结构,构建基于合作博弈思想的两阶段水土资源利用效率测算模型;运用模型测评黑龙江省13个地级市水土资源利用整体及各阶段效率,并构建水土资源利用效率两阶段矩阵图。结果表明,黑龙江省水土资源开发程度整体偏高,但各地级市水土资源经济效益转化不均衡,且水土资源利用整体效率偏低,地区差异较大,水土资源未得到有效的优化配置。该文所构建的DEA模型通过分析影响区域水土资源利用效率的各个环节,可以为决策者提出针对性意见并提供科学依据。     

河冰三轴压缩强度特性及破坏准则试验研究

为研究河冰在复杂应力状态下的力学性质及破坏准则,对淡水柱状冰在恒定轴向加载速率(0.4 mm/min)下,分别进行温度-6、-12、-18和-24°C,围压500、1000和1500 kPa的常规三轴压缩试验。得到天然淡水柱状冰三轴压缩应力应变曲线,三轴压缩广义剪应力峰值与温度及围压的关系,以及三轴压缩能量耗散特征,并利用莫尔库仑准则分析温度和围压对河冰强度参数的影响规律。结果表明:在所选试验条件下,柱状冰主要发生单剪破坏和延性破坏;在恒定温度条件下,广义剪应力峰值随围压的增大呈现近似线性增加;在恒定围压条件下,广义剪应力峰值随温度的升高呈现近似线性减小;根据莫尔库仑理论解释柱状冰破坏准则,在4种试验冰温下,其内摩擦角分别为21°、45°、42°和52°,黏聚力分别为1191.6、513.2、861.6和933.4 kPa;从能量特征角度考虑,柱状冰三轴压缩耗散的能量随着围压的增大有逐渐增加趋势。     

黑龙江省灌区运行状况综合评价研究

针对灌区运行状况,借鉴国内外专家关于灌区评价所建立的指标体系,根据灌区评估的含义,选取黑龙江省11个灌区的9个指标作为评价指标,采用一种将遗传算法与投影寻踪模型相结合的优化新方法对灌区进行综合评价,克服了传统评价方法的计算结果不准确、计算过程繁琐的缺点,为灌区续建配套资金的分配提供科学依据。