钙对低氧胁迫下黄瓜幼苗根系碳水化合物代谢的影响

以对低氧敏感的中农8号黄瓜品种为材料,研究了钙对低氧胁迫下幼苗根系淀粉、蔗糖、果糖、葡萄糖含量及蔗糖合酶(SS)、蔗糖转化酶(INV)、磷酸蔗糖合成酶(SPS)和葡萄糖激酶(GK)活性的影响。结果表明:与通气对照相比,低氧胁迫处理后幼苗根系淀粉含量降低,蔗糖和果糖含量增加,SS和GK活性增加,INV活性降低,胁迫初期SPS活性增加,后期降低;低氧胁迫下营养液加钙处理缓解了低氧胁迫对幼苗生长的抑制作用,根系SS、SPS、INV和GK活性增加,蔗糖和果糖含量显著高于单纯低氧胁迫处理,葡萄糖含量低于单纯低氧胁迫处理;而低氧胁迫下营养液缺钙处理加重了低氧胁迫对黄瓜幼苗的伤害。表明在低氧胁迫下,钙参与了调节黄瓜幼苗根系碳水化合物代谢,对提高幼苗低氧胁迫的适应性起着重要的作用。     

丰产剂2号蘸花对番茄果实各部位糖分及淀粉含量的影响

研究了丰产剂2号蘸花对不同发育期番茄果实单果质量、果实各部位糖分组成和含量及淀粉含量的影响。结果表明:丰产剂2号蘸花明显提高单果质量;在番茄果实各发育期,丰产剂2号蘸花的果实各部位糖分组成和含量的总体变化趋势与对照基本相同,果柄维管束中主要含蔗糖,果实其他部位主要含果糖和葡萄糖,果糖和葡萄糖含量在成熟时达到最高;但丰产剂2号蘸花处理的果实中果糖和葡萄糖含量增幅高于对照,说明丰产剂2号蘸花处理可以全面提高番茄果实中可溶性糖的含量。而丰产剂2号蘸花处理对淀粉含量的影响不明显。     

重金属铅和镉对玉米品质的影响

盆栽条件下,研究了铅与镉胁迫对富友1号玉米籽粒中蛋白质含量、脂肪含量和淀粉含量的影响。铅胁迫试验设0,250,400,550,700,850,1000μg·g-1(以纯铅计)7种浓度处理;镉胁迫试验设0,8,16,24,32,40,48μg·g-1(以纯镉计)7种浓度处理。结果表明:在重金属胁迫下,玉米籽粒蛋白质、脂肪含量变化均呈先升后降趋势,在铅胁迫下,700μg·g-1处理蛋白质含量最高,为100mg·g-1;在镉胁迫下,32μg·g-1处理的蛋白质含量最高,为115mg·g-1。淀粉含量变化趋势与此相反,其中铅胁迫下的淀粉含量分别是724,715,713,712,709,715,725mg·g-1;镉胁迫下的淀粉含量分别是724,711,710,708,692,704,705mg·g-1。     

北方粳稻籽粒多胺合成与灌浆的关系

以不同水稻品种为试材,研究了籽粒多胺含量与灌浆进程的关系,结果表明:在灌浆期 ,籽粒多胺含量依次为:腐胺穴PUT雪>亚精胺SPD>精胺SPM;随花后时间的推移,各种胺 含量逐渐减小。势粒中,SPD与PUT变化趋势大致相同,在雪灌浆期呈下降趋势;在灌浆 后期,各品种籽粒SPD和PUT含量差别不大,SPM含量下降幅度较PUT和SPD小。常规稻沈 农8714与沈农 8801在不同灌浆阶段SPD含量均高于杂交稻辽优18与辽优3225。弱势粒 中, 不同品种多胺含量在整个灌浆期间差别均较大, PUT、SPD和SPM含量降低速度均 较快, 而且峰谷出现的时间也提前。PUT含量最高时灌浆速率最大沈农8801, SPM 对 灌浆后期籽粒充实起主要作用。     

磁场处理种子对玉米籽粒灌浆过程和产量性状的影响

玉米种子经0.003mT,50mT和100mT的磁场处理后，灌浆速度增大，籽粒中营养物质含量增高；穗粒数、粒重等性状得以改善，双穗率增加，空秆和倒折率降低，产量提高2.06%-9.46%；与对照相比丹玉13号0.003mT、掖单19号100mT处理的增产效果达到了5％显水平，掖单19号0.003mT达到1％显水平。     

不同耕作方式对旱地土壤酶活性动态的影响

结合中长期田间定位试验,研究了传统耕作(T)、免耕(NT)、免耕结合秸秆覆盖(NTS)以及秸秆还田(TS)处理下春小麦生长期内土壤过氧化氢酶、脲酶、蔗糖酶和碱性磷酸酶等活性的动态变化趋势.结果表明:(1)各种酶的活性随着小麦生育期的变化呈现出明显的规律性变化,并且四种耕作方式下各种酶活性的变化趋势基本一致.土壤过氧化氢酶和蔗糖酶活性呈现先上升,在灌浆期出现峰值后逐渐下降的变化规律.土壤脲酶和碱性磷酸酶活性呈现先上升,在拔节期出现峰值后逐渐下降,而在灌浆期到收获后又处于回升阶段.(2)在春小麦的各生育期:与T相比较,NT、NTS以及TS处理均可使土壤酶活性增加.     

杜洛克母猪乳中常规成分含量测定

此试验选用杜洛克母猪作为研究对象．对其分娩后5d内及第20d的乳中蛋白质、脂肪、乳糖含量进行删定。结果表明．随时间延长乳中蛋白质含量呈下降趋蛰．乳糖含量呈上升趋势，脂肪含量1～5d升高而5～20d下降。     

灌浆结实期冷型小麦叶片氮含量变化的研究

通过多年田间小区试验,研究了不施肥、单施磷肥、单施氮肥和氮磷配施等四种施肥条件下,灌浆结实期冷型小麦和暖型小麦叶片氮含量的差异。结果表明,开花期,在不施肥和氮磷配施条件下,冷型小麦冠层顶三叶的氮百分含量均显著高于暖型小麦;在单施磷肥时,旗叶的氮百分含量也较高;在单施氮肥时,倒三叶、下部叶的氮百分含量显著高于暖型小麦。花后前28天,冷型小麦陕229的冠层顶三叶氮百分含量均显著高于暖型小麦,小偃6号的旗叶在花后前14天、倒二叶在花后前28天、倒三叶在花后前21天也高于暖型小麦。增施氮肥时,冷型小麦下部叶的氮百分含量也明显高于暖型小麦。这为冷、暖型小麦冠层温度的差异提供了氮营养基础。     

丰产剂2号蘸花对番茄果实发育过程中库强度的影响

以自然坐果的番茄为对照,研究了丰产剂2号蘸花处理对番茄果实发育过程中库强度和果实内酸碱环境的影响。结果表明:丰产剂2号蘸花处理对番茄果实发育早中期的果实内糖的组成和含量、酶的活性没有明显的影响,果实发育至成熟期显著提高了果糖含量和葡萄糖含量,增强了转化酶的活性。试验证明外源提供类生长激素增强了番茄果实的库强度,增加了果糖和葡萄糖在果实中的积累。在整个果实发育的过程中,果实内pH值逐渐下降,但丰产剂2号处理没有改变pH值,证明植物体能维持相对平衡的体内环境来保证各种代谢反应的顺利进行。     

亚高温处理对番茄叶片光合作用及糖类的影响

以辽园多丽番茄为试材,在植株第1花序开花时,对其进行2h,4h,6h和8h的短时间35℃昼间亚高温处理(以25℃处理为对照),研究较短时间亚高温处理对番茄叶片光合作用及蔗糖代谢的影响。结果表明:35℃亚高温处理2h,番茄叶片净光合速率(Pn)明显下降,而气孔导度(Gs)、胞间CO2浓度(Ci)、蒸腾速率(Tr)明显升高,气孔限制值(Ls)减小,认为Pn的降低主要由非气孔限制因素引起的。在亚高温处理8h范围内,叶片中果糖、葡萄糖含量均较对照降低而蔗糖含量升高,转化酶(Inv)活性先升高后降低,蔗糖合成酶(SS)活性、蔗糖磷酸合成酶(SPS)活性均降低,认为短时间35℃昼间亚高温处理对番茄叶片光合作用及蔗糖代谢酶活性的影响导致叶片中蔗糖代谢发生改变。     

Medical displays in the healthcare system

Abstract— As the healthcare system changes and progresses, the need for different types of high‐performing displays is also evolving. There are three categories of displays: (a) embedded (as part of life saving devices), (b) informative (for patient data and history, and managing workflow), and (c) imaging (high performing for diagnosis). The challenges of AMLCDs, which are the display of choice at the moment mainly in digital imaging, will be discussed. These challenges include very high resolution, high brightness, and wide viewing angle. The current performance of AMLCDs and the areas which they need to improve will be reviewed. A brief summary of the standards used to specify medical (diagnostic) displays will follow. A look into the future will predict the role of displays in hospitals.     

Resolution consideration in spatially variant sensors

Log polar transformations for space variant systems have been proposed and used in active vision research. The idea is to generate an image with a varying resolution over a wide angle field of view. The fovea is of high resolution and the periphery is of exponentially reduced resolution. The justifications for such a sensor are: (i) it provides high resolution and a wide viewing angle; (ii) feature invariance in the fovea simplifies foveation; (iii) it allows multi-resolution analysis; and (iv) it is cheaper and more efficient to build a variable resolution sensor over a particular field of view rather than a uniform high resolution sensor. The receptor density of the human retina is very high, i.e. of the order of 10⁸ receptors at the fovea. The question is, what resolution should space variant active vision systems have? Real visual sensors have been implemented but is the resolution produced high enough? This paper investigates the resolution requirements of a space variant sensor by simulation for a tracking system using raytracing.     

High power devices in wide bandgap semiconductors

Silicon carbide (SiC) semiconductor devices for high power applications are now commercially available as discrete devices. Recently Schottky diodes are offered by both USA and Europe based companies. Active switching devices such as bipolar junction transistors (BJTs), field effect transistors (JFETs and MOSFETs) are now reaching the market. The interest is rapidly growing for these devices in high power and high temperature applications. The main advantages of wide bandgap semiconductors are their very hi...     

剖析高性能存储系统中的存储区域网络

高性能存储系统（High Performance StorageSystem,简称HPSS）是专门为高性能计算机环境设计、管理和访问超大规模数据的层次化并行存储系统,可以在高性能计算机、磁盘、网络磁盘阵列、磁带库之间迁移大型的数据对象,支持高效的串、并行输入／输出及远程数据并行传输,数据传输速度只受底层计算机、网络和存储设备的限制。对HPSS以网络为中心体系结构进行了深入的研究与剖析,描述了目前存储区域网络（SAN）技术在HPSS中的应用情况,得出有助于构建高性能计算环境存储系统的看法和结论。     

高可用性集群系统在烟草系统中的应用

介绍了传统的集群系统,并详细介绍了IBMHACMP高可用性集群系统在烟草系统中的应用。     

高速网络接口卡DMA引擎的设计与实现

随着DMA技术在高速网络接口卡设计中的广泛应用,DMA引擎已成为高速网络接口卡的一个重要组成部分。该文提出了一种面向高速网络接口卡的DMA引擎的实现方案,并将之成功地应用于千兆位以太网网络接口卡的具体实现中。     

一种应用于谐振式微型光学陀螺的高频锁相放大器的设计

谐振式微型光学陀螺(R-MOG)是利用光学Sagnac效应实现对转动检测的一种高精度的惯性传感器件.在R-MOG系统中,信号处理具有非常重要的地位.根据R-MOG系统中,集成光学环形谐振腔的谱线宽度高达几十MHz以及R-MOG输出信号具有弱信号、大噪声特点,设计了一种用于提取被噪声淹没的微弱信号的高频锁相放大器.在对高频锁相放大器各部分电路进行具体设计和分析的基础上,完成了对整体电路的性能测试.测试结果表明,研制的锁相放大器在载波频率为30MHz时的等效输入噪声为11nV/Hz.将整个电路应用于R-MOG系统中,解调出的信号效果良好.     

Changes in contrast sensitivity function produced by VDT use

The threshold for detecting sine wave contrast gratings (contrast sensitivity function, of CSF) were obtained before and after reading text on a CRT screen as well as reading print for 30min. Small but statistically significant decreases in the CSF (increased detection threshold) were observed after reading text on the CRT screen. Reading print produced no reliable changes. The decrease in the CSF produced by reading Videotext were confined to the low (0·5 cyc/deg) and high (12 and 16 cyc/deg) spatial frequencies, and represented changes of between 15–25%. The results for the high frequency roll off were said to reflect the combined outcome of fatigue in the high spatial frequency channels as well as in the accommodative mechanisms (instrument myopia) of the visual system. Decreases in sensitivity to low spatial frequencies were more difficult to account, and were said to reflect possible changes in the responsivity of the visual ‘transient’ mechanisms.     

数字化超声探伤仪中超声信号高速采集技术

探讨了数字式超声探伤仪设计中一种对超声信号进行高速采集技术。根据超声回波信号重复性的特点,利用一只高速A/D(60MHz)转换芯片在N组特定时序信号的控制下对超声回波信号进行采集,并在CPLD(复杂可编程逻辑器件)的控制下实现高速数据缓冲存储,再利用相位合成技术对转换后的N组数据进行数据合成与波形重建,从而实现了数倍于A/D转换芯片速率的高速数据采集,达到等效A/D转换速率N×60MHz。该方案成本低,可靠性高,尤其适合于高速、高准确度的超声无损检测系统中。     

Automation of three-dimensional cell culture in arrayed microfluidic devices

The increasing interest in studying the interactions between cells and the extracellular matrix (ECM) has created a need for high throughput low-cost three-dimensional (3D) culture systems. The recent development of tubeless microfluidics via passive pumping provides a high throughput microchannel culture platform compatible with existing high throughput infrastructures (e.g., automated liquid handlers). Here, we build on a previously reported high throughput two-dimensional system to create a robust automated system for 3D culture. Operational controls including temperature and sample handling have been characterized and automated. Human mammary fibroblasts (HMFs) suspended in type I collagen are loaded and cultured in microchannel arrays and used to optimize the system operational parameters. A Peltier cooler maintains the collagen as a liquid at 4 °C during cell seeding, followed by polymerization at 37 °C. Optimization of this platform is discussed (e.g., controlling collagen contraction, increasing cell viability, preventing the removal of microchannel contents), and 3D distribution of HMFs is examined by fluorescent microscopy. Finally, we validate the platform by automating a previously developed 3D breast carcinoma coculture assay. The platform allows more efficient 3D culture experiments and lays the foundation for high throughput studies of cell-ECM interactions.