Phenolic antioxidants (hydrolyzable tannins, flavonols, and anthocyanins) identified by LC-ESI-MS and MALDI-QIT-TOF MS from Rosa chinensis flowers

Rosa chinensis (Yuejihua) is a well-known ornamental plant, and its flowers are commonly used in traditional Chinese medicine. Methanolic crude extracts of dried R. chinensis flowers were used for simultaneous determination of phenolic constituents by liquid chromatography-mass spectrometry (LC-MS) and matrix-assisted laser desorption/ionization quadrupole ion trap time-of-flight mass spectrometry (MALDI-QIT-TOF MS). A total of 36 known and unknown phenolics were identified as hydrolyzable tannins, flavonols, and anthocyanins, mainly including gallotannins (mono-, di-, or trigalloylglucopyranosides), ellagitannins, quercetin, quercetin/kaempferol mono- and diglycosides, and cyanidin/pelargonidin diglycosides. MALDI-QIT-TOF MS was applied not only to verify most phenolics isolated and identified by LC-MS but also to tentatively identify two ellagitannins (rugosins B and C) not isolated and unidentified by LC-MS. This study is the first to demonstrate the rapid and successful use of MALDI-QIT-TOF MS and LC-MS to directly and simultaneously identify phenolics in the crude extracts of R. chinensis flowers without any purification. The antioxidant activity of the crude extracts from R. chinensis flowers was also measured with three assay methods. The results showed that the phenolic antioxidants from R. chinensis flowers exhibited very strong radical scavenging effect and antioxidant power. High levels of flavonols and hydrolyzable tannins might be important bioactive principles in the dried R. chinensis flowers.     

The Software System for Computation and Drawing of Ship Properties

The softwa re system suggested in this paper is applied to replace the traditionalhanded-computation forms. It uses the cubic sample interpolation and numerical integral,and is writ-ten with FORTRAN according to the accurate formula. With this software system,the nine sorts ofcomputation results of ship properties can be obtained. The system is con nected through SCR filewith AutoCAD,and ean draw automatically eleven sorts of pictures according to the computation re-sults.     

Ecogeographic and genetic diversity based on morphological characters of indigenous rice (Oryza sativa L.) in Yunnan, China

Yunnan is one of the largest centres of genetic ecological diversity and the richest area for elite germplasm of rice (O. sativa L.) resources in the world. Its indigenous rice average diversity index of six ecological groups are, in turn, javanica (1.2319) > aman (1.1738) > communis (1.1726) > nuda (1.1618) > aus (1.1371) > boro (0.9889), and there are great differences between indica (1.1454) and japonica (1.2081). The indigenous rice in Yunnan can be divided into 58 varieties, almost the total number found in China, and the cultivars account for 8.6% of the total cultivars in China. A great difference in ecological diversity index of rice resources between prefectures or counties in Yunnan province also exists, with the southwest part (Lincang, Xishuangbanna, Dehong, Simao) and southeast part (Wenshan) having been found to be the largest centre of genetic diversity, as their average genetic diversity index ranges from 1.2735 to 1.2036, especially. The average diversity index of the Cangyuan, Gengma, Zhenkang, Yongde, Yingjiang, Jinghong, Menghai, Shuangjiang, Ruili, Longchuan, Mojiang, Wenshan and Guangnan counties, in particular, have an average diversity index ranging from 0.8 to1.0. On the contrary, in Diqing, Dongchuan, Kunming, Lijiang, Qujing, Chuxiong, it is comparatively low, i.e., 0.7843–1.1075. Differences in the ecological diversity index of rice resources between rice regions are small, only 1.1322 to 1.2849.     

青海省鱼卡–大柴旦盆地土壤盐分特征

通过野外调查、采样与室内分析,采用相关分析和因子分析法研究鱼卡-大柴旦盆地土壤盐分特征。结果表明:土壤盐分组成中,阴离子以Cl–和SO42–为主,阳离子以Na+和Ca2+为主;土壤全盐量与Cl–和SO42–的含量分别呈显著、极显著正相关关系;0~20 cm土层土壤全盐量约占剖面土壤全盐量的53%,土壤盐分呈现表聚性;土壤全盐量及各离子变异系数超过100%,土壤盐分含量空间变异大;因子分析结果表明Cl-、SO42-、K++Na+和Mg2+可作为研究区土壤盐渍化状况的特征因子;土壤盐分的物质来源是地下水中的化学物质,土壤盐渍化程度的主导因素是地下水位埋深,同时受到历史积盐影响。     

旱地冬小麦生育后期有关光合特性及光合产物分配规律研究

在大田自然干旱条件下旱作处理,冬小麦生育后期旗叶光合速率仍可达１４．２４μｍｏｌＣＯ２·ｍ＾－２·ｓ＾－１,在叶片水势达－１．８～－２．１ＭＰａ条件下,旗叶ＲｕＢｐ羧化酶活性可达２０～２３μｍｏｌＣＯ２·ｍｉｎ＾－１·ｇ＾－１ｄｗ;浇水处理小麦植株旗叶光合速率为１５．１５μｍｏｌＣＯ２·ｍ＾－２·ｓ＾－１水势达－１．６５～－１．８ＭＰａ条件下,旗叶ＲｕＢｐ羧化酶活性可达２２～２５μｍｏｌＣＯ２·ｍ     

双管离子选择性微电极制备方法研究

双管离子选择性微电极被广泛应用于植物细胞外离子流速和细胞内离子活度的测量,但双管离子选择性微电极(Ion-Selective Microelectrode,ISME)的制备过程繁琐,不可控因素多,制备成功率低。针对存在的问题,该研究提出了一种简易、快速的双管ISME制备方法。首先,介绍了双管微电极制备、硅烷化和电极尖端灌充液态离子交换剂(Liquid Ion Exchanger,LIX)的具体流程;其次,对制备的双管ISME的能斯特斜率和响应时间进行了测试。试验结果表明,使用蒸汽硅烷法对双管微电极进行硅烷化处理,最优硅烷化温度、二甲基二氯硅烷剂量和硅烷化时间分别为150℃、45μL和90min;制备的双管氢离子、钾离子、钙离子、氯离子选择性微电极的能斯特斜率分别为54.08、56.51、27.08和-58.80 mV/dec;4种双管ISME的响应时间介于0.20～0.42 s之间。研究结果表明,由该研究制备方法制作的双管ISME,可以满足植物细胞外离子流速和细胞内离子活度信息检测的要求。双管ISME的快速制备,降低了离子选择性微电极技术的应用难度,将有利于植物电生理检测试验的进行和离子选择性微电极技术在农作物育种、生理抗逆、植物营养吸收与同化等研究领域的应用。     

丙酮酸基对黄原胶/魔芋葡甘聚糖复配体系凝胶特性的影响

为了实现对复配凝胶体系状态的调控,扩展凝胶在食品中的应用,该研究通过酸性热处理调控黄原胶中丙酮酸基含量变化,研究其对黄原胶结构、流变特性及黄原胶(Xanthan Gum)与魔芋葡甘聚糖(Konjac Glucomannan)复配凝胶特性(如溶胶-凝胶转换温度、流变特性等)的影响.研究结果表明;XG螺旋结构随丙酮酸基减少...     

1988年沅江市稻蝗大发生原因分析及防治体会

1988年湖南省沅江市稻蝗大发生。本文从生境、气候、人为因子等方面分析了大发生原因,介绍了大面积防治的做法与体会。     

近 50年气候变化对中国小麦生产潜力的影响分析

为了定量评估气候变化背景下中国小麦生产潜力变化主要特征和气候归因,将1961-2010年分为1961-1990年和1991-2010年2个时段,对比分析近50年气候变化背景下中国农业气候资源变化,并基于IIASA最新开发的农业生态区模型AEZ 3.0模拟气候变化对中国小麦生产潜力的影响.结果表明,由于热量、水分条件以及小麦生育期的变化,近50年中国雨养和灌溉小麦单产潜力增加的区域主要为东北、华北和四川盆地,单产潜力减少的区域为西北和东南地区.中国冬小麦的适宜区域出现较明显的北扩南收态势,而雨养春小麦适宜面积在中国半湿润半干旱的过渡带显著减少.全国雨养小麦总生产潜力减少5％,而灌溉小麦总生产潜力变化不大.东北区域雨养和灌溉小麦总生产潜力增加都最为明显,是气候变化背景下实现中国小麦增产的重点区域.中国小麦生产需要合理利用气候资源和优化布局,以适应气候变化带来的影响.     

不同生态环境对甜高粱生长、糖锤度及产量的影响

试验选择8个代表性的甜高粱品种分别在半干旱地区、半湿润地区种植,研究两种生境对不同甜高梁品种苗期生长及成熟期农艺性状、生物产量、糖锤度的影响.结果表明:半干旱地区种植的甜高粱苗期生长速度高于半湿润地区,植株含水量低于半湿润地区;在成熟收获期,半干旱地区种植的甜高粱品种株高、茎粗均低于半湿润地区,生物产量均低于半湿润地区,茎秆含水量略有下降,茎秆糖锤度均高于半湿润地区,半干旱条件降低甜高粱的生物产量,增加茎秆汁液锤度.本试验为筛选适宜吉林省西部半干旱地区种植的甜高梁品种提供理论依据.