Rice Drying,Storage and Processing: Effects of Post-Harvest Operations on Grain Quality

Various post-harvest processes of rice are commonly employed, especially during the off-season, to ensure its consumption feasibility, which often affect the grain quality. Different forms of drying, storage and processing of rice are evaluated to identify their effects on grain quality. Microwave drying has emerged as an alternative to the widely-used intermittent-drying and fixed-bed-dryer methods of drying paddy rice. Control of drying-air temperatures (between 40 °C and 60 °C) according to the rice variety can improve quality, especially for exotic varieties. Keeping stored grain in hygroscopic balance, with water content between 11% to 15%, at temperatures between 16 °C and 20 °C and with intergranular relative humidity near 60%, allows 12 months of storage in a controlled environment without significant deterioration. Other innovations, notably the application of artificial refrigeration to grain stored in bulk in vertical cylindrical silos and the use of impermeable packaging for storage, ensure the conservation of grain mass. The different stages and equipments used to obtain polished, brown and parboiled rice result in significant changes in the nutritional value of rice because of the removal of the outermost layers of the grains. Polishing reduces the nutritional value and physical homogeneity of rice. Brown rice retains more bioactive compounds and nutrients because it does not lose the outer layer of the grains in the polishing processes. Parboiled rice, although less nutritious than brown rice, has better grain integrity and milling yield and less loss of nutrients than white rice.     

应用反射光谱法估测矿区附近农田土壤As, Cu污染

Concentrations of Iron (Fe), As, and Cu in soil samples from the fields near the Baoshan Mine in Hunan Province, China, were analyzed and soil spectral reflectance was measured with an ASD FieldSpec FR spectroradiometer (Analytical Spectral Devices, Inc., USA) under laboratory condition. Partial least square regression (PLSR) models were constructed for predicting soil metal concentrations. The data pre-processing methods, first and second derivatives (FD and SD), baseline correction (BC), standard normal variate (SNV), multiplicative scatter correction (MSC), and continuum removal (CR), were used for the spectral reflectance data pretreatments. Then, the prediction results were evaluated by relative root mean square error (RRMSE) and coefficients of determination (R²). According to the criteria of minimal RRMSE and maximal R², the PLSR models with the FD pretreatment (RRMSE = 0.24, R² = 0.61), SNV pretreatment (RRMSE = 0.08, R² = 0.78), and BC-pretreatment (RRMSE = 0.20, R² = 0.41) were considered as the final models for predicting As, Fe, and Cu, respectively. Wavebands at around 460, 1 400, 1 900, and 2 200 nm were selected as important spectral variables to construct final models. In conclusion, concentrations of heavy metals in contaminated soils could be indirectly assessed by soil spectra according to the correlation between the spectrally featureless components and Fe; therefore, spectral reflectance would be an alternative tool for monitoring soil heavy metals contamination.     

不同盐分胁迫对美洲红树耐盐性和耐早性的影响

为了提高树木对干旱、盐碱环境的适应性，苗木时期人为制造一定程度的不良环境，饭炼苗木时不良环境的适应能力，从而提高造林后林分的效益和稳定性。该试验分为前处理和本处理，前处理设淡水区、1／2海水区（含盐1．7％）和海水区（含盐3．4％），生长45d后，进行本处理，统一用舍盐浓度7％的盐水进行浇灌。结果表明：经过前处理的1／2海水区中生长的苗禾其叶、茎、根的生长量均超过淡水区中生长的苗木。说明一定程度的耐盐饿炼能够增强苗木对盐碱、干旱环境的适应能力。     

Pre processing Subsystem of Recognizing Free Handwritten Chinese Character

The paper gives out an efficient and utility pre processing subsystem of on line recognizing free handwritten Chinese character, which includes the processes of data acquisition, normalizing character image, deleting the same points, inserting data points, linking strokes, extracting line segments and canceling useless line segments, and presents or improves a set of strategy and algorithm that has been applied in the subsystem. The results of preliminary experiments show that the subsystem has advantages of high degree of steadiness and tolerance to strokes variance.     

生物质能源树种光皮树苗木生长规律及育苗技术研究

通过对赣南乡土生物质能源树种、食用油料树种光皮树的种子预处理、种子主要参数测定、以及对苗木物候、苗木根系生长、苗木生长节律进行研究,从而得出光皮树实用的、较为系统的育苗技术。     

链式剖鱼机的研制与试验研究

针对目前淡水鱼加工机械化程度低、劳动强度大的现状,研制了用于淡水鱼前处理加工的剖鱼机.在研究剖鱼机剖切方式、喂料机构、剖切可靠性、剖切过程对鱼体的损伤程度等的基础上,试制了剖鱼机并进行了试验.试验结果表明,研制的剖鱼机喂料方便、可靠,剖切速度为800尾/h,剖切率达83.9%,剖切质量好.     

超高效液相色谱-串联质谱法测定鸡蛋中氯霉素的两种前处理方法比较

为选择氯霉素超高效液相色谱串联质谱分析前处理方法,分别对乙酸乙酯提取,正己烷液液萃取净化和乙腈提取,LC-Si固相萃取柱萃取净化(GB/T22338-2008方法),两种前处理方法进行对比分析。结果显示:乙酸乙酯提取法的检测限为0.1μg/kg,在0.5~10ng/mL范围内线性关系良好,r>0.99,回收率为98.2%~104.8%,RSD为1.5%~7.2%;乙腈提取法的检测限为0.05μg/kg,在0.25~10ng/mL范围内线性关系良好,r>0.995,回收率为100.0%~104.0%%,RSD值为0.5%~2.1%。结果表明:两种方法的线性范围、回收率、检测限和相对偏差均能满足畜产品检验要求。乙酸乙酯提取法步骤简单,样品处理效率高,乙腈提取法虽步骤繁琐,但结果的精密度和灵敏度更高。     

前处理及初始油炸温度对油炸薯片品质的影响

通过一系列实验及定量分析,探讨了不同的漂烫温度、漂烫时间和初始煎炸温度对油炸薯片的含油率、色泽及质构的影响。     

基于分形维数的图像纹理分析

利用分数维能够把图像的空间信息和灰度信息有机结合起来的特性,提出了一种基于分形维数的图像纹理分析方法.为了更准确地描述纹理表面的粗糙度,该方法首先将纹理图像进行6种灰度变换并计算其相应的分形维数,同时采用H lder指数作为描述图像纹理的奇异性特征,然后利用提取的纹理特征对图像进行纹理分割.实验结果表明:采用该方法所分割的图像能很好地体现图像的纹理分布.     

Jacobi和Gauss-Seidel迭代法的预处理

对部分Jacobi和Gauss-Seidel迭代法发散的线性方程组进行了相应的预处理,通过完全选主元的方法将线性方程组的系数矩阵对角最大化,从而达到Jacobi和Gauss-Seidel迭代收敛的目的．