利用高氯酸作为氟离子选择性电极法的新介质测定食品中的微量氟

对HCLO4作为新介质在氟离子选择性电极法中测定食品中的微量氟做了探索和研究。在0.35 MOL/L HCLO4介质中,氟离子浓度在1.0×10-2~1.0×10-6MOL/L范围内呈良好的线性关系,线性相关系数R=0.999 7。利用本法测定了牛奶、卷心菜中氟离子的含量,其结果与现有其他文献方法相当,但本法试验操作大为简化。测定的相对标准偏差在1.54%~2.30%之间。在该介质中测定微量氟操作简便、快速,具有较高的精密度和准确度。所以,HCLO4溶液可作为氟离子选择性电极的测定介质。     

Estimation of surface soil organic matter using a ground-based active sensor and aerial imagery

Active canopy sensors are currently being studied as a tool to assess crop N status and direct in-season N applications. The objective of this study was to use a variety of strategies to evaluate the capability of an active sensor and a wide-band aerial image to estimate surface soil organic matter (OM). Grid soil samples, active sensor reflectance and bare soil aerial images were obtained from six fields in central Nebraska before the 2007 and 2008 growing seasons. Six different strategies to predict OM were developed and tested by dividing samples randomly into calibration and validation datasets. Strategies included uniform, interpolation, universal, field-specific, intercept-adjusted and multiple-layer prediction models. By adjusting regression intercept values for each field, OM was predicted using a single sensor or image data layer. Across all fields, the uniform and universal prediction models resulted in less accurate predictions of OM than any of the other methods tested. The most accurate predictions of OM were obtained using interpolation, field-specific and intercept-adjusted strategies. Increased accuracy in mapping soil OM using an active sensor or aerial image may be achieved by acquiring the data when there is minimal surface residue or where it has been excluded from the sensor’s field-of-view. Alternatively, accuracy could be increased by accounting for soil moisture content with supplementary sensors at the time of data collection, by focusing on the relationship between soil reflectance and soil OM content in the 0–1 cm soil depth or through the use of a subsurface active optical sensor.     

微波消解-石墨炉原子吸收光谱法测定食糖中的铅

建立微波消解-石墨炉原子吸收光谱法测定食糖中铅的方法。样品经硝酸和过氧化氢消解,所得溶液蒸发浓缩后定容至25mL,分取适量用石墨炉原子吸收光谱法测定,得到铅的质量浓度在0．0—40．0ug/L范围内呈线性,相关系数为0．9992,检出限（S／N=3）为1．500ug/kg,回收率为98．0％～103．0％;用标准物质进行对照,其测定值均在给定的标准值范围之内。表明该方法具有简便、快速、安全、准确的特点,适合测定食糖中的铅含量。     

基于硅烷化GC谱图法的卷烟化学成分随贮存温度变化规律研究

[目的]研究卷烟贮存温度对卷烟质量的影响,为企业贮存提供参考依据。[方法]利用硅烷化G C方法对不同贮存温度下卷烟烟丝样品中的主要化学成分进行检测,并通过主成分分析、皮尔逊相似度分析等方法对得到的色谱数据进行处理。[结果]卷烟化学成分随贮存温度的变化而变化,30~40℃为烟丝化学成分显著性变化的临界变化温度范围。硅烷化G C谱图研究卷烟化学成分随贮存温度的变化规律,可发现不同贮存温度对卷烟品质造成的影响。[结论]硅烷化G C谱图法灵敏度高,将该方法与感官评吸结合起来,可有效判别卷烟贮存质量变化的有效温度范围。其可作为卷烟品质稳定性判断的辅助手段。     

Dating Works of Art through Their Natural Radioactivity: Improvements and Applications

The method for approximately dating white lead, which is based upon the decay of lead-210 present in recently refined lead, has been modified to circumvent potential interferences. The modified method has been applied to additional samples of known age and finds increased utility through special treatment of the obtained data. The method was also successfuilly applied to a number of interesting problems of authentication.     

Calcium-41 concentration in terrestrial materials: prospects for dating of pleistocene samples

Calcium-41 has been suggested as a new tool for radiometric dating in the range of 10(5) to 10(6) years. The concentration of cosmogenic calcium-41 in natural samples of terrestrial origin has now been determined by high-sensitivity accelerator mass spectrometry after pre-enrichment in calcium-41 with an isotope separator. Ratios of calcium-41 to total calcium between 2 x 10(-14) and 3 x 10(-15) were measured for samples of contemporary bovine bone and from limestone deposits. Some prospects for the use of calcium-41 for dating Middle and Late Pleistocene bone and for other geophysical applications are discussed.     

基于相似性分析的中低分辨率复合水稻种植面积测量法

 【目的】利用遥感技术获取大范围水稻种植面积是遥感技术在农业领域的主要应用方向之一。本研究的目的是探索利用多尺度遥感数据复合测量水稻种植面积的方法。【方法】以SPOT5数据的水稻识别结果作为样本,构建图像相似性指数,通过支持向量机（SVM）混合像元分解模型,对MODIS-EVI时间序列数据进行水稻的种植面积测量。【结果】通过江苏省邳州市的试验研究得出：（1）在野外经验支持下,从MODIS-EVI时间序列数据中构建的水稻种植相似性指数可以有效反映水稻在整个研究区的空间分布情况;（2）利用图像相似性选取训练样本,能有效地提高MODIS-EVI数据的水稻种植面积的测量精度,当图像相似性指数越小,即图像相似性越高,提取的水稻种植面积也越准确;（3）通过与随机样本测量结果对比分析,基于相似样本的测量方法有着更高的稳定性;（4）该方法在不同种植结构分区内有着相似的总量精度与像元精度变化规律,均能获得较高的测量精度。【结论】基于相似样本的水稻种植面积测量方法,有助于发挥MODIS长时间序列优势,提高水稻种植面积遥感测量精度和稳定性,可以作为替代随机选取样本的方法之一。     

Combining LiDAR intensity with aerial camera data to discriminate agricultural land uses

In recent years, an increase has occurred in the use of new sensors such as digital measurement cameras or LiDAR (Light Detection And Ranging) devices in remote sensing studies. This situation has encouraged the development of new possibilities for data use. Currently, it is common to perform combined flights where digital cameras take images that record spectral information while LiDAR sensors produce point clouds with positional, spectral and echo information. The goal of this study was to assess the possibility of combining LiDAR intensity with the spectral information provided by digital cameras to increase crop classification accuracy. Due to the geometric characteristics of the LiDAR data collection process, LiDAR intensity was normalized before combining it with the spectral information from the camera. Two different geometric methods were used for this purpose. Both methods were based on the relative position of each point and the position of the sensor at the time of data recording. To analyze the effects of normalization, land-use samples with different radiometric behaviors were taken. The samples were used to assess the degree of variation in the intensity values of a same geographic area acquired in different flight strips by comparing the coefficient of variation of raw intensity data and normalized intensity data. Supervised classifications with the maximum likelihood algorithm were performed to assess the suitability of combining LiDAR intensity with digital images. These results were compared with those obtained using only information from the multispectral camera and showed an increase in accuracy of up to 40% in land-use discrimination after introducing normalized LiDAR intensity values. The combination of both data types allowed the classification of eight types of land use with an accuracy over 92%.     

Early-season crop type mapping using 30-m reference time series

Early-season crop type mapping could provide important information for crop growth monitoring and yield prediction, but the lack of ground-surveyed training samples is the main challenge for crop type identification. Although reference time series based method(RBM) has been proposed to identify crop types without the use of ground-surveyed training samples, the methods are not suitable for study regions with small field size because the reference time series are mainly generated using data set with low spatial resolution. As the combination of Landsat data and Sentinel-2 data could increase the temporal resolution of 30-m image time series, we improved the RBM by generating reference normalized difference vegetation index(NDVI)/enhanced vegetation index(EVI) time series at 30-m resolution(30-m RBM) using both Landsat and Sentinel-2 data, then tried to estimate the potential of the reference NDVI/EVI time series for crop identification at early season. As a test case, we tried to use the 30-m RBM to identify major crop types in Hengshui, China at early season of 2018, the results showed that when the time series of the entire growing season were used for classification, overall classification accuracies of the 30-m RBM were higher than 95%, which were similar to the accuracies acquired using the ground-surveyed training samples. In addition, cotton, spring maize and summer maize distribution could be accurately generated 8, 6 and 8 weeks before their harvest using the 30-m RBM; but winter wheat can only be accurately identified around the harvest time phase. Finally, NDVI outperformed EVI for crop type classification as NDVI had better separability for distinguishing crops at the green-up time phases. Comparing with the previous RBM, advantage of 30-m RBM is that the method could use the samples of the small fields to generate reference time series and process image time series with missing value for early-season crop classification; while, samples collected from multiple years should be further used so that the reference time series could contain more crop growth conditions.     

Identification by ENDOR of Trp191 as the free-radical site in cytochrome c peroxidase compound ES

The chemical identity of the amino acid free-radical site that represents one of the two oxidizing equivalents stored in the H2O2-oxidized intermediate (compound ES) of the mitochondrial heme enzyme, cytochrome c peroxidase (CcP) has been sought for almost a quarter of a century. Site-directed mutagenesis alone cannot yield this answer. Low-temperature 35-gigahertz (Q-band) electron nuclear double resonance (ENDOR) spectroscopy was used to examine compound ES prepared from proteins containing specifically deuterated methionine or tryptophan, as well as the amino acid replacement Trp51----Phe. The results definitely identify the site of the radical in compound ES as tryptophan, most likely Trp191.     

辐照孜然的ESR法鉴定及原初吸收剂量的估算

 【目的】检测孜然是否经过辐照处理并估算孜然原初吸收剂量;【方法】以孜然为对象,采用电子自旋共振波谱（ESR）技术研究孜然在0～15.0 kGy剂量范围内ESR波谱特征变化,分析辐照剂量与信号强度的关系以及贮藏时间对自由基浓度的影响,并采用附加剂量法估测孜然样品的原初吸收剂量;【结果】辐照后孜然的ESR波谱信号强度随辐照剂量增加而增大,经过220 d贮藏期后仍能应用ESR波谱法检测孜然是否经过辐照处理。附加剂量法能够用于辐照孜然的剂量估算,其中利用3次多项式在不同贮藏时间里（10 d,20 d和30 d）拟合估算出的每个样品的剂量值与原初剂量的偏差均在1 kGy范围内,比用对数方程拟合估算出的剂量值更为准确;【结论】ESR波谱技术能够定性和定量鉴定辐照孜然。     

基于Landsat ETM数据的落叶松林生物量估算模式

根据全国森林清样调查围场满族自治县的落叶松林样地数据,应用与之同期的ETM遥感影像,探讨基于ETM数据的落叶松林生物量的估算方法和模式 根据ETM各波段数据的特点,选用和开发18个变量,逐样点比较生物量与变量之间的关系,并对影响生物量的因子进行逐步回归分析,结果表明ETM3数据是落叶松林生物量的最好估计因子,生物量与ETM3数据有双曲函数关系,与1/ETM3呈极显著正相关,相关系数为0 878,在ETM3波段辐射亮度范围内生物量随ETM数据的增大而减小 并给出了用ETM3数据估算落叶松林生物量的模型     

动力学直接光度法测定血清中痕量铜

研究了氨水介质中铜（Ⅱ）催化过氧化氢氧化苯基荧光酮褪色这一新指示反应及影响反应速度的因素，建立了动力学直接光度法测定痕量用的新方法．该方法灵敏度为３．２ｍｇ·Ｌ－１，测定范围为０—０．０１６ｍｇ·Ｌ－１，操作简便，快速．该法用于测定血清中痕量铜，获得满意结果．     

A feasibility study of the classification of Alpaca (Lama pacos) wool samples from different ages,sex and color by means of visible and near infrared reflectance spectroscopy

The usefulness of classifying the Alpaca wool samples according to their color, sex and location is associated with their economic value in the market, hence adequate methods for rapid classification are needed to assess the of wool value. This study evaluated the potential of the visible and near infrared (vis–NIR) spectroscopy combined with multivariate statistical analysis to classify Alpaca (Lama Pacos) fiber samples according to age (1 and 2–3-year-old), sex (Male and Female) and color (Black, Brown, LF and White). Samples (n = 291) were scanned in reflectance mode in the wavelength range of 400–2500 nm using a monochromator instrument (FOSS NIRSystems6500, Inc., Silver Spring, MD, USA). Principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) were used to classify fiber samples. Cross-validation was used for validation of classification models developed. Results showed that PLS-DA correctly classified 100% of fiber samples into ages, intermediate classification rates were obtained for color, while lower classification rates were obtained for the discrimination of wool samples according to sex. The results from this study suggested that vis–NIR spectroscopy in combination with multivariate data analysis can be used as a rapid method to classify Alpaca fiber samples according to age, sex and color.     

太湖平原地区不同土地利用类型对水质的影响

为探讨不同土地利用类型对太湖流域水质状况的影响,以太湖腹部平原区为例,基于典型年地表河流水质监测数据,结合TM影像解译结果所反映的土地利用状况,分别从区域和水质站点周边缓冲区两个方面,计算不同土地利用类型与水质状况的灰色关联序,以反映土地利用类型对地表水质的影响,为太湖腹部平原区的土地利用与水污染防治提供参考。结果表明:河流水质整体上与土地利用类型的灰色关联度最大的是城镇用地,其次是水田和旱地,水域和林地的灰色关联度最低;丰水期、枯水期的不同水质指标与土地利用的灰色关联序有一定区别,而水质站点缓冲区土地利用为样本时,水质指标受城镇用地影响最大,其次为耕作用地,最低为水域。     

长白侧柏资源及其生长规律的调查

本文采用标准地调查法对长白侧柏资源状况进行了研究,通过调查掌握了该种在高寒、高海拔山区的生长规律及生态环境。     

上海东海大桥海上风电场水下噪声特性分析

随着对清洁能源利用的逐步重视,我国海上风电产业发展迅猛。人为活动所产生的水下噪声是近几年备受关注的环境问题,而我国对海上风电场水下噪声的相关科学研究却几乎一片空白,因此实验对上海东海大桥海上风电场运行期噪声进行了实地调查采样,并进行数据分析。分别研究了不同单机容量风电机的噪声特性,并对风电场内单个风机分不同深度进行了噪声特性研究,还对不同噪音测量方法进行了对比。结果表明:风电机噪音具有低频及低能级水平的特点,主要频率在400 Hz以内,声压级在81~101 d B之间。海水流速一定时,不同深度风电机水下噪声频谱特性基本一致;当海水流速增大,会导致频谱部分主频峰值的丢失或偏移。噪声记录使用的抛锚定点测量法空间自由度高,但测量时间较被动;漂流法测量路线单一,但测量时间自由度较高。     

小麦根尖染色体制片及植株倍性鉴定

[目的]探讨小麦根尖染色体制片的最佳技术参数,并对小麦远杂组培苗进行倍性鉴定。[方法]以品种郑麦9023为材料,通过种子催芽、种子根根尖压片试验对小麦根尖的染色体制片方法进行探讨,找出最适合的技术参数,用于小麦远杂组培苗的根尖染色体压片试验,并对其倍性进行鉴定。[结果]利用冰水混合物处理根尖可代替浓度0.1%秋水仙素的作用;根尖的酸解时间宜控制在9.5～10.0min;夏季染色时间宜在5 min以内,冬季染色时间宜在10～15 min。经染色体压片计数得到该小麦组培苗的染色体数为21条,鉴定其为小麦单倍体苗,可进行下一步育种。[结论]该研究对指导单倍体育种具有重要作用。     

基于TM影像的永济市土地利用变化分析

利用永济市1990年和2008年两期TM数据,在遥感图像处理软件ERDAS IMAGINE的支持下,采用RS和GIS相结合的技术方法,通过土地利用动态度模型、土地利用程度时空演变模型的引入,定量分析了18年来永济市土地利用的时空演变。研究表明,该地区城乡居民建设用地增加非常快,耕地面积增加,未利用地大幅减少,林草地减少幅度不大,水域面积呈现萎缩的现象。18年间土地利用动态度变化较小,其综合土地利用动态度为1.73%,耕地和林草地年变化速度最慢,建设用地年变化速度最快,未利用地和水域年变化速度相对居中。土地利用综合指数分别是252.52和263.87,土地利用指数逐渐增大,从土地利用程度指数极限来看,该区域的开发程度已达到中等水平状态。1990~2008年土地利用程度变化量都大于零,反映该区域土地利用处于发展期。     

Suspended particulate matter: concentration in the major oceans

Quantitative data from over 500 concentrates of suspended particulate material has been summarized statistically for the Atlantic, Pacific, and Indian oceans, the Gulf of Mexico, and the Caribbean Sea. From clear ocean water a majority of samples were in the range of 0 to 9.9 milligrams per 200 liters and the next largest number were in the range of 10 to 19.9 milligrams per 200 liters. Certain areas of cloudy or nepheloid water, observed photographically, contain relatively more samples in heavier concentration ranges and have larger mean values than clear ocean water.