6种葡萄籽中水解氨基酸和游离氨基酸含量测定及比较

以异硫氰酸苯酯为柱前衍生试剂,采用Thermo Acclaim^(TM) 120 C_(18)色谱柱(250mm×4.6mm,5μm),流动相A为pH 6.5的乙酸钠缓冲溶液,流动相B为甲醇—乙腈—水(体积比20:60:20),在流速1.0mL/min,梯度洗脱,柱温30℃,检测波长254nm的条件下,建立了高效液相色谱法测定葡萄籽中水解氨基酸和游离氨基酸的含量。结果表明,在试验浓度范围内,17种氨基酸的R^2均>0.999 0;水解氨基酸的加样回收率为92.0%～104.6%,RSD为0.83%～4.07%;游离氨基酸的加样回收率为95.2%～102.4%,RSD为1.06%～3.98%。同时,6种葡萄籽中水解氨基酸的含量为130.46～163.24 mg/g,游离氨基酸的含量为2.04～5.13mg/g;用于酿造白葡萄酒的雷司令、赛美容和贵人香3种葡萄籽中游离氨基酸含量较高,用于酿造红葡萄酒的黑皮诺、蛇龙珠和赤霞珠3种葡萄籽中水解氨基酸含量较高。该方法稳定可靠,可用于葡萄籽中水解氨基酸和游离氨基酸的含量测定。

东北中部春玉米超高产群体养分管理模式的研究与验证

【目的】研究如何在肥料总量控制甚至减少的前提下,通过优化养分管理措施、提高种植密度,进一步挖掘东北中部黑土区春玉米的产量和肥料效应潜力,为春玉米超高产条件下养分高效利用提供理论指导。【方法】试验于2005—2013年在吉林省农安县靠山镇进行,在大田条件下设置2种模式,分别为普通高产养分管理模式(HYNM)和超高产养分管理模式(SHYNM),以先玉335和郑单958为供试材料,系统监测群体产量构成及养分偏生产力,剖析不同产量群体氮、磷、钾养分吸收、分配和转运特征。【结果】在东北中部黑土雨养区,超高产养分管理模式(SHYNM)下全区测产玉米单产达15017 kg/hm^2(先玉335),其产量构成为收获穗数76154穗/hm^2,穗粒数583,千粒重337.9 g。与普通高产群体相比,超高产群体对氮、钾肥的相对需求比例明显变大。群体氮素和磷素的吸收高峰在6展叶至12展叶阶段和吐丝期至乳熟期,钾素吸收高峰在6展叶至12展叶阶段。通过大区和生产两个阶段田间实证,超高产养分管理技术显著提高了花后养分累积量和对籽粒养分的贡献率,可以实现在15000 kg/hm^2产量水平下,氮、磷、钾肥的偏生产力分别达50.2、100.5、100.5 kg/kg。品种间比较,先玉335比郑单958具有更好的产量表现,且植株养分向籽粒的转运效率更高,其籽粒中的氮、磷、钾累积量均高于郑单958。【结论】在合理提升密度的基础上,以“减控总肥量、分段供氮、花前重施磷钾”为主要原则的养分管理技术模式,配合化控措施,延缓了玉米生育后期叶片的衰老,保证了后期干物质积累,在显著增加收获穗数的同时,保证千粒重和穗粒数不降低,在生产中稳定实现了14500~15000 kg/hm^2产量水平,同时实现了氮磷钾养分的高效利用。

长期玉米连作下不同产量水平0-100 cm土层黑土与淡黑钙土理化性状差异

【目的】比较长期玉米连作条件下,0—100 cm土层黑土和淡黑钙土土壤物理和化学性状的差异,分析影响产量的主导因素,为黑土地保护与利用提供理论指导。【方法】在吉林省中部黑土区和西部淡黑钙土区,各选取玉米连作种植年限超过15年的代表性地块18个,在每个地块采集深度为0—10、10—20、20—30、30—50、50—70和70—100 cm的土壤样品,并进行土壤理化性状分析。按照高、中、低3个产量水平将土壤样品划分为3组,综合比较黑土和淡黑钙土不同产量水平0—100 cm土层土壤理化性状的差异。【结果】中部黑土0—100 cm土壤肥力指标均高于西部淡黑钙土,其0—100 cm土层土壤氮、磷、钾素储量分别为12.3、4.8、175.1 t/hm2,分别比西部淡黑钙土高2.4%、13.3%、43.5%。黑土和淡黑钙土20—100 cm土层有机质和全氮含量均以高产田最高;高产田与中产田耕层(0—20 cm)土壤全量和速效氮、磷、钾含量均明显高于下层(20—100 cm)。中部黑土20—30 cm存在一个较明显的保水保肥层,30 cm以下土层的土壤理化性状与产量多呈显著相关,0—100 cm土层土壤pH为5.15~7.07,高产田土壤固、液、气三相比例更理想,0—100 cm各土层广义土壤结构指数(GSSI)的高低表现为高产田>中产田>低产田,高产田土壤含水量高于其他两个产量水平,高产田与中产田0—100 cm各土层土壤全磷含量较为接近,二者耕层速效钾含量明显高于低产田。西部淡黑钙土无明显的保水保肥层,20—30 cm土层的理化指标与产量密切相关,0—100 cm土层土壤pH为6.61~8.31,高产田70—100 cm土层硝态氮累积量仅占0—100 cm土体总量的5.2%,而中、低产田该比例分别为22.3%和22.7%,硝态氮下移趋势明显。黑土与淡黑钙土区0—20 cm土壤均呈现酸化趋势,尤其是黑土区低产田表层土壤酸化现象明显。【结论】中部黑土区30—50 cm土层土壤理化指标对产量影响较大,高产田20 cm以下土层养分持续供应能力是其实现稳定高产的重要保证。西部淡黑钙土区20—30 cm土层理化指标对产量影响较大,土壤结构是影响产量的核心指标,持续土壤培肥是实现高产的重要措施。

有序介孔钴基Co@C@CNTs复合材料可控制备和表征

以钴作为金属节点,二甲基咪唑(2-MI)为有机配体,十六烷基三甲基溴化铵(CTAB)为表面活性剂,碳纳米管(CNTs)为模板,采用牺牲模板法制备了具有大孔径的钴基Co@C@CNTs复合材料。采用X-射线衍射、扫描电镜、N_(2)物理吸附以及热重等对其进行表征,考察CNTs加入量对钴基复合材料孔结构的影响。结果表明,CNTs的加入可以有序扩大Co@C的孔径和孔容。CNTs的最佳掺杂量为0.84 g,此时Co@C@CNTs的孔径(6.6 nm)和孔容(0.4250 cm^(3)/g)较大,均大于Co@C的孔径(2.9 nm)和孔容(0.2175 cm^(3)/g)。

人工固态纳米通道:用于分析检测的新型传感器

受生物体内离子通道的启发,科学家们构建了一系列具有相似作用的人工纳米通道。固态纳米通道以离子电流为检测信号,可以为化学传感提供快速、高灵敏度的检测结果。固态纳米通道机械性能好、稳定性高、结构可调节和容易功能化,在化学传感器中引起极大关注。在多种探针的作用下,固态纳米通道传感器对离子、小分子、核酸、蛋白质等多种靶标物质具有特异性识别作用。

安装环境对电子侦察比幅测向精度的影响分析

针对舰载雷达对抗侦察装备部署过程中的性能改变问题,通过建模与仿真分析了安装环境对电子侦察比幅测向精度的影响。首先,建立了侦察天线在舰艇上的安装位置模型,采用电磁场分析软件仿真了反射信号存在区域及其引起的侦察天线方向图畸变;然后,通过半实物仿真方式进行了不同条件下的对比测试,确认了反射影响程度,分析了反射信号对比幅测向精度的影响。仿真结果表明:当安装环境中存在反射信号时,会造成舰载雷达对抗侦察装备测向性能下降,并且随反射影响程度的变化而变化。所得结论可为舰载电子对抗装备使用提供参考。

新文科背景下休闲管理泛在教学资源体系优化研究

目前,传统学习经由网络学习、移动学习发展到泛在学习,与此同时,现代信息技术赋能教学方式和教学资源随之作出调整和改革。休闲旅游专业建设是幸福产业发展的重要支撑,在新文科建设、休闲康养发展以及多重外部环境的共同影响和支持下,地方院校从供给侧入手协同共建泛在教学资源,以提升和优化其服务经济社会的能力。加强现代信息技术与休闲管理学科专业的深度交叉融合,推动实施能力本位导向的教学改革,基于教育云搭建政行企校共建共享的泛在教学资源库,基于共享经济理念提升闲置优质教研资源的变现能力,是构建多方协同、共建共享休闲管理学科专业体系的关键路径。

不同耕作方式对玉米根系特性及养分吸收转运的影响

【目的】耕作方式影响玉米根系的生长发育及养分吸收,比较东北中部雨养区不同耕作制度下玉米根系生长和养分吸收特征,为建立合理的耕作方式提供理论依据和技术支撑。【方法】2011―2012年,在吉林省连续进行了2年的田间定位试验,设置4种耕作方式:浅灭茬后直接播种(对照,T1),苗带深松后镇压(T2),行间深松且苗带镇压(T3),苗带行间全部深松(T4)。在6展叶期、吐丝期和生理成熟期,取0-60 cm土层的植株根系样品,分析玉米产量、养分吸收转运及根系生长发育特征。【结果】不同耕作方式下玉米产量差异显著(P <0.05),两年平均值表现为T3> T2> T1> T4,T2处理和T3处理的产量分别比T1处理增加8.1%和10.2%。与T1处理相比,T2和T3处理均增加了玉米吐丝后氮磷钾养分累积量,吐丝后累积养分对籽粒的贡献率显著增加(P <0.05)。T2和T3处理下的氮、磷、钾累积量对籽粒的贡献率分别比T1处理增加了0.4%~3.6%、16.9%~33.8%、70.5%~82.1%,T3处理增幅高于T2处理。T2和T3处理显著增加了玉米各生育期的总根干重、总根长和总根表面积(P <0.05),其中,6展叶期至成熟期,总根干重、总根长、总根表面积的增幅分别为9.8%~22.8%、16.1%~33.1%、19.9%~38.2%。T2和T3处理在各土壤剖面的根系形态均优于T1处理,其中以T2处理最佳,且在20-40 cm土层间差异最为显著(P <0.05)。与T1处理相比,T3处理下各生育时期在20-40 cm土层的根干重、根长、根表面积平均增幅为34.1%、48.3%、47.8%,根直径平均增幅为22.1%。【结论】与浅灭茬后直接播种相比,苗带行间全部深松不利于根系发育,而行间深松且苗带镇压方式促进了根系的生长发育和纵向延伸,尤其是在20-40 cm土层根系干重、根长和根表面积明显增加,有利于根系对深层土壤养分的吸收利用,进而提高玉米花后累积养分对籽粒的贡献率,增加产量。

固体电蓄热式散热器保温材料性能分析

分别以硅酸铝棉和气凝胶做为固体电蓄热式散热器绝热保温材料,通过模拟计算得出了不同厚度保温材料所对应的散热器外壳热工性能特性,计算并比较了两种保温材料不同厚度的经济性.结果表明,气凝胶较硅酸铝棉具有更加优良的绝热保温特性以及经济性,是一种优良的固体电蓄热式散热器的保温材料.

张家口某小区供热系统节能改造分析

通过对北方严寒地区供热系统节能改造的研究,以张家口市某小区为例进行供热系统节能改造分析,对改造前后耗能量以及庭院管网输热能力等数据的整理分析。结果表明,改造后的供热系统庭院管网输热能力指标均符合相关规范规定,改造后冬季供暖用水量比改造前节省了23%,用电量比改造前节省了20%。供暖系统冬季供暖费用比改造前减少了40.56万元,改造后热用户认为供暖季室内温度较舒适和舒适的比例比改造前提高了58%,节能效果显著。

金属结合剂金刚石工具的胎体组织结构与力学性能设计

针对金属结合剂金刚石工具的特点,文章改变传统的"经验型"设计方式,以胎体的把持力与磨损性为控制要素,以胎体的组织性能为设计核心,采用细颗粒的预合金粉末组合,获取精细化的物相组织,调控胎体的综合力学性能。实施"定量化"设计,使胎体的烧结致密度>98.5%,抗弯强度超过1200 MPa,硬度达到HRB96～103。按量化设计指标生产制备花岗岩圆盘锯,在锋利度及使用寿命方面均取得了良好的实用效果,为金属结合剂金刚石工具的量化设计提供了有益参考。

Morphological Structure and Genetic Mapping of New Leaf-Color Mutant Gene in Rice (Oryza sativa)

Leaf-color mutations are a widely-observed class of mutations, playing an important role in the study of chlorophyll biosynthesis and plant chloroplast structure, function, genetics and development. A naturally-occurring leaf-color rice mutant, Baihuaidao 7, was analyzed. Mutant plants typically exhibited a green-white-green leaf-color progression, but this phenotype was only expressed in the presence of a stress signal induced by mechanical scarification such as transplantation. Prior to the appearance of white ~eaves, mutant plant growth, leaf color, chlorophyll content, and chloroplast ultrastructure appeared to be identical to those of the wild type. After the changeover to white leaf color, an examination of the mutated leaves revealed a decrease in total chlorophyll, chlorophyll a, chlorophyll b, and carotenoid content, a reduction in the number of chloroplast grana lamella and grana, and a gradual degradation of the thylakoid lamellas. At maturity, the mutant plant was etiolated and dwarfed compared with wild-type plants. Genetic analysis indicated that the leaf mutant character is controlled by a recessive nuclear gene. Genetic mapping of the mutant gene was performed using an F2 population derived from a Baihuaidao 7 ~ Jiangxi 1587 cross. The mutant gene was mapped to rice chromosome 11, positioned between InDel markers L59.2-7 and L64.8-11, which are separated by approximately 740.5 kb. The mutant gene is believed to be a new leaf-color mutant gene in rice, and is tentatively designated as gwgl.

Source-Sink and Grain-Filling Characteristics of Two-Line Hybrid Rice Yangliangyou 6

With two-line hybrid rice Yangliangyou 6 （YLY6） and Liangyoupeijiu （LYPJ） and three-line hybrid rice Shanyou 63 （SY63） as materials, the source, sink and flow characteristics in association with grain filling were investigated. The seed-setting rate, grain filling degree and grain yield of YLY6 and SY63 were significantly higher than those of LYPJ. The export and transformation percentages of the matter in culms and sheaths of YLY6 and SY63 were significantly higher than those of LYPJ. Activities of sucrose synthase, adenosine diphosphoglucose pyrophosphorylase, starch synthase and starch branching enzyme in grains were higher for YLY6 and SY63 than for LYPJ, and were very significantly correlated with maximum grain filling rate, mean grain filling rate, grain filling degree and grain weight. The spikelet number, grain yield and total sink load per area of vascular bundle and phloem of YLY6 and SY63 were significantly smaller than those of LYPJ, and the greater the load, the lower seed-setting rate and the poorer grain filling. The transportation rate per area phloem of YLY6 was greater than that of LYPJ or SY63. The results suggest that YLY6 possesses strong source, great sink activity and efficient flow, which lay a physiological base for its high seed-setting rate and good grain filling.

Causes of Poor Grain Plumpness of Two-Line Hybrids and Their Relationships to the Contents of Hormones in the Rice Grain

This study was designed to elucidate the grain filling characteristics and the causes of poor grain plumpness of some two-line hybrid rice combinations and their hormonal mechanism. Six varieties, including three two-line hybrid rice combinations, that show differences in seed-setting and grain filling, were used. And the contents of starch, sucrose, zeatin （Z） ＋ zeatin riboside （ZR）, indole-3-acetic acid （IAA）, and abscisic acid （ABA）, the ethylene evolution rate, activities of sucrose synthase （SuSase） and starch synthase （StSase） in grains, the seed-setting and grain filling rate were investigated. The correlations amongst these were analyzed. The results showed that the poor grain filling of two-line hybrids was mainly attributed to the higher unfilled grain rate and the lower filling degree of inferior grains. During the early and mid grain filling periods, the sucrose content in inferior grains was greater than that in superior grains for the combinations with poor grain filling, indicating that the substrate concentration was not the principal factor for their slow grain filling and poor grain plumpness of the inferior grains of two-line hybrids. Z ＋ ZR, IAA, and ABA in superior grains were obviously greater than those in inferior grains at early grain filling stage. The maximum and mean contents of Z ＋ ZR, IAA, and ABA were positively very significantly correlated with the maximum and mean grain-filling rate, filling degree, and grain weight. The evolution rate of ethylene was greater in inferior grains than in superior grains and greater for the combinations with poor grain plumpness than those with good grain plumpness at the early or mid filling stages. The evolution rate of ethylene was negatively and significantly correlated with the grain filling rate, the grain filling degree, and the grain weight. Spraying ethephon （ethylene-releasing agent） at the early grain filling stage increased the evolution rate of ethylene, reduced the ABA content and activities of SuSase and StSase, and decreased the grain filling degree and the grain weight. The results were reversed when cobatous nitrate （an inhibitor of ethylene synthesis） was applied. The results suggested that the hormones and their balance play a role in the regulation of grain filling and enzymatic activities, and the poor grain filling is attributed to the low contents of Z ＋ ZR, IAA, and ABA, and the high evolution rate of ethylene in the inferior grains of some two-line hybrid rice combinations. The results suggested that hormones play important roles in the grain filling of some two-line hybrid rice combinations, and their filling degree can be improved by regulating the hormonal contents.

针对民族学生“化工原理”课程教学方法浅谈

化工原理课程(化工单元操作)是化工类专业学生的一门重要而经典的基础课,同时又是理论性和实践性结合很强的一门课。其课程特点是概念和公式较多,同时需要建立工程思维。本文结合我校少数民族较多,学生的国语水平并不是很好的实际情况,对如何进行化工原理教学作了具体探讨。

斜拉索辅助人行悬索桥总体设计

宁德市人行悬索桥计算跨径为311.5 m,采用斜拉索辅助桥面主缆受力结构体系。斜拉索主塔纵桥向间距191 m,横桥向采用外圆内方造型。桥面系通过纵向主缆与纵、横梁联合受力,纵、横梁固定在主缆上。人行道板采用防腐木板。桥梁施工顺序为锚碇及主塔基础及塔身、主缆、纵横梁、风缆、桥面防腐木及栏杆,然后斜拉索施工。考虑施工过程,采用桥梁专用有限元软件Midas/Civil 2019,构建了全桥计算分析模型。计算结果表明:桥梁结构整体刚度大,各构件受力合理,应力与活载下变形均满足相关规范规程要求。

基桩质量检测的组合技术及应用

在工程建设中,对地下基桩的无损检测常采用应力波法、声波透射法、抽芯法、磁测井法等单一方法。以江苏省盐城市某住宅小区地库工程桩基检测为依托,选用低应变动测法、磁梯度法检测组合进行分析,得出了合理的检测结论,消除了工程潜在的隐患,证明了采用多种检测方法组合的必要性,为类似工程基桩质量检测提供借鉴和参考。

High Conversion Efficiency and Power Stability of 532 nm Generation from an External Frequency Doubling Cavity

We present a high-efficiency 532 nm green light conversion from an external cavity-enhanced second harmonic generation(SHG)with a periodically poled KTP crystal(PPKTP).The cavity is a bow-tie ring configuration with a unitized structure.When the impedance matching is optimized,the coupling efficiency of the fundamental is as high as 95%.Taking into account both the high power output of the second harmonic and the stability of the system,we obtain over 500 mW green passing through the output cavity mirror,corresponding to a net conversion efficiency higher than 75.2%.Under these operating conditions,the power stability is better than±0.25%during 5 h.It is the highest conversion efficiency and power stability ever produced in the bow-tie ring cavity with PPKTP for 532 nm generation.

独塔人行悬索桥升级改造设计

陕西省汉中市独塔人行悬索旧桥锚碇端部间距为69.394 m,总宽2.15 m,钢桁架主梁和吊杆锈蚀严重。为提升汉中市独塔人行悬索桥的景观效果,在充分论证和有限元分析基础上,提出该桥的升级改造方案。利用原有的主塔、主缆、锚碇,拆除锈蚀严重的钢桁架主梁、吊杆和木质桥面板,采用纵横梁格体系主梁和玻璃桥面板,增设了抗风主索和抗风拉索。采用桥梁专用有限元分析软件Midas/Civil 2019,构建旧梁拆除和新桥计算分析模型。计算结果表明:桥梁旧桥拆除施工顺序可行,新桥各构件应力和变形满足规范要求。