Metabolic responses of lactating dairy cows to 14-day intravenous infusions of glucagon.

Twenty cows were assigned at parturition to two groups to study metabolic effects of continuous intravenous infusions of glucagon. Groups were control cows and cows treated with glucagon at 10 mg/d for 14 d starting at d 21 postpartum. Daily blood samples and nine liver biopsies were taken from d 7 to 49 postpartum. Plasma glucagon increased six- to seven-fold during infusions of treated cows. Plasma insulin was increased heterogeneously by glucagon infusions. Plasma glucose increased 11.5 and 9.0 mg/dl during wk 1 and 2 of glucagon infusions. No other plasma metabolites tested (nonesterified fatty acids, beta-hydroxybutyrate, and urea N) were affected by glucagon infusions. Liver glycogen decreased by d 2 of glucagon infusion but was repleted to preinfusion values by d 7 and increased to 169% of the preinfusion baseline values at 3 d after cessation of glucagon. Milk production decreased transiently during glucagon infusions. Both milk production and milk protein percentage decreased during glucagon infusion, which could imply a decreased availability of amino acids for milk protein synthesis. Feed intakes did not increase during glucagon infusions, which was in contrast to the control group. Results indicated that glucagon infusions caused liver glycogenolysis initially and probably enhanced gluconeogenesis but glucagon did not appear to increase lipolysis from adipose tissue in these early lactating dairy cows.     

岩屑自然伽马录井技术研究及应用

如何解决PDC钻头钻井条件下岩屑细碎甚至呈粉末状给岩屑录井带来的困难已成为录井行业急待解决的问题。该文作者结合录井工作实践,大胆借鉴有关测井理论,提出了一种全新录井技术岩屑自然伽马录井技术;阐述了岩屑自然伽马录井理论与实验方法,给出了具体实验数据和结果,并与电测数据进行了对比。通过实践表明,该岩屑自然伽马录井方法与电测自然伽马相比具有较好的一致性,对于今后解决细碎岩屑录井识别岩性问题,提供了理论依据,且增加了岩屑录井识别岩性的手段。     

基于BP网络的油气层模式识别技术

文章介绍了如何通过A／D转化把录井参数波形转化为数字资料，并采用模式识别的方法自动识别油气层。准确地识别油层、油水同层、水层、干层等。将BP神经网络的识别方法应用于石油勘探，相比其他解释方法更科学。利用三层的前馈阶层网络对油气层自动识别，不仅缩减了工作量，而且还能精确了解解释结果。一个好的识别模型可以轻易地达到事半功倍的效果，实例证明利用BP神经网络判别油气层效果是令人满意的技术。     

龙王庙组气藏高温高压酸性大产量气井完井难点及其对策

为了实现对四川盆地安岳气田下寒武统龙王庙组气藏的安全高效开发,减少因冲蚀、腐蚀、丝扣渗漏和完井工艺不合理等因素所导致的安全屏障失效和环空异常带压等问题,在分析该气藏完井主要技术难点的基础上,重点进行了完井方式优选、管柱材质实验评价与优选、管柱丝扣密封性能评价、井下管柱结构优化设计以及管柱抗冲蚀性能评价等方面的研究与现场试验。形成了一套适合于高温、高压、含酸性介质、大产量气井的配套完井技术:(1)优选了适合的完井方式、管柱材质和扣型;(2)形成了不同配产条件下的管柱结构;(3)制订了针对直井和斜井的完井工艺及完井过程施工质量控制措施。现场应用效果表明,该配套技术有效降低了大产量生产对管柱和井下工具的冲蚀以及射孔作业对生产封隔器密封性能的影响,提高了完井施工质量,对于减少后期生产过程中环空异常带压具有较好的效果。可为类似气田的开发提供参考。     

中扬子地区陡山沱组页岩储层中黄铁矿特征及其油气意义

黄铁矿是富有机质沉积的特征矿物,是恢复沉积环境的重要指标,也可以指示页岩的含油气性。基于氩离子抛光-扫描电镜（Ar-SEM）技术获得陡山沱组页岩高分辨率扫描电镜图像,利用 ImageJ 软件统计和分析草莓状黄铁矿粒径大小,探讨黄铁矿含量和吸附气含量之间的关系。 结果表明：①陡山沱组页岩中草莓状黄铁矿粒径小,代表其经历了较长时间的静水缺氧沉积环境,对有机质的富集和保存均有利,为页岩气的形成提供了良好的沉积条件;②陡山沱组页岩储层中黄铁矿含量与吸附气含量呈正相关关系,根据黄铁矿的含量可以预测页岩吸附气;③铁含量越高越有利于有机质富集,而有机质含量的高低直接影响着页岩气的生成能力和赋存能力,根据平面上黄铁矿的富集程度可以预测页岩含气区。     

Generalized-Extended-State-Observer and Equivalent-Input-Disturbance Methods for Active Disturbance Rejection: Deep Observation and Comparison

Active disturbance-rejection methods are effective in estimating and rejecting disturbances in both transient and steady-state responses.This paper presents a deep observation on and a comparison between two of those methods:the generalized extended-state observer(GESO) and the equivalent input disturbance(EID) from assumptions,system configurations,stability conditions,system design,disturbance-rejection performance,and extensibility.A time-domain index is introduced to assess the disturbance-r...     

对称非线性包层平板多量子阱波导TE模的传播特性

分别用精确计算和方均根近似方法得到了包层及衬底均为非线性Ｋｅｒｒ型介质、芯区为多量子阱的对称平板波导中ＴＥ模的传播特性。数值计算表明,当芯区多量子阱的层数较多时,方均根近似方法得到的结果与用精确方法得到的结果一致,此时多量子阱波导可以等效为均匀介质。对于自聚焦情况,在合适的光功率下,当分界面处包层（及衬底）的有效折射率与芯区折射率相等时,芯区的场分布呈均匀分布而两侧的场呈指数式衰减;功率继续增大时,场分布的极值进入芯区两侧,而芯区场分布呈下凹形。对于自散焦情况,波导对导波场有较强干线性波导的束缚作用,且随光功率的增大而增强。     

功率MOSFET零温度系数点的研究

为研究功率MOSFET零温度系数点（Zero Temperature Coefficient,ZTC）,不同栅极电压对温度系数的影响,本文基于阈值电压和迁移率的温度关系并结合功率MOSFET输出特性模型,得到了随栅极电压变化而出现的三种不同温度系数。利用实际测试验证了温度系数的变化规律,结果表明：在小栅极电压条件下,线性区和饱和区均为正温度系数;随栅极电压增大,线性区先进入负温度系数,饱和区仍然为正温度系数,并因此产生了零温度系数点;随栅极电压进一步增大,线性区和饱和区都进入负温度系数。同时根据测试数据,分析了ZTC在不同栅极电压条件下随温度的变化原因,并基于测试数据讨论了迁移率随栅极电压和温度的变化关系。     

Generation of coherent radiation in XUV by fifth- and seventh-order frequency conversion in rare gases

Results of experimental studies of the generation of coherent radiation in the XUV by high order optical nonlinearities in the rare gases are described. Fifth- and seventh-harmonic conversion and six wave mixing of harmonic pulses from an Nd:YAG laser were used to produce radiation at several discrete wavelengths between 38 and 76 nm. Experimental measurements of fifth-haxmonic conversion of pump pulses at 266.1 nm in helium are compared with theoretical predictions. Discrepancies between theory and experiment are observed at high laser powers, and the role of competing processes is discussed.     

景洪水电站右冲沙底孔坝段加固处理设计

景洪水电站碾压混凝土重力坝坝顶高程612m，最大坝高110m，坝顶总长704m，其中右冲沙底孔坝段坝轴线方向长23．5m，水流向长270．7m。鉴于右冲沙底孔坝段，在施工期兼作一期、二期纵向围堰，在运行期又作为厂房右端墙的一部分，两侧将承受不同频率洪水位下的水压力，可能存在侧向失稳的问题，需对其侧向稳定性和基础应力进行复核计算。经复核计算发现，在二期导流期间，右冲沙底孔D0＋065m～D0＋240m段建基面抗倾覆稳定不能满足规范要求，且右侧垂直拉应力较大，有可能对坝体结构产生破坏。因此，有针对性地采取了一系列工程措施对右冲沙底孔D0＋065m～D0＋240m段进行了综合性的加固处理，从而确保了二期导流期间右冲沙底孔的安全及工程施工的顺利进行。