基于压电陶瓷的地聚合物砂浆强度发展监测研究

将压电陶瓷(PZT)智能骨料成对嵌入地聚合物砂浆试件内部,利用主动感应法监测不同龄期地聚合物砂浆压电应力波信号,将时域信号图分析和小波包能量分析相结合,探讨了压电信号能量变化与地聚合物砂浆强度变化的对应关系。时域信号图分析表明,随着地聚合物砂浆养护龄期的增加,压电陶瓷智能电压幅值逐步增加,反映了地聚合物砂浆抗压强度的变化过程。小波包能量分析表明,随龄期的增加,地聚合物砂浆抗压强度变化过程与压电信号幅值计算总能量具有一致性。基于地聚合物砂浆抗压强度试验结果与压电陶瓷应力波所计算的能量值,拟合出地聚合物砂浆强度与压电应力波信号计算总能量的相关函数关系。     

基于解析信号小波的变压器局部放电故障诊断

应用解析信号小波来分析变压器局部放电,提取信号在各尺度的幅值包络、相位和瞬时频率。并将该特征参数用于故障诊断。仿真结果表明：该方法用于变压器局部放电故障诊断中是行之有效的。     

塑料光纤传感器在烟草机械故障诊断的应用研究

基于塑料光纤传感器在烟草机械的故障监测诊断方法。通过塑料光纤传感器采集了烟草机械轴承的状态信号,研究了振动信号的时域信号和频域信号。结果表明:内圈故障和外圈故障对轴承带来的冲击最大,振动幅值相对于滚子故障轴承更高。均值、峰值指标和波形指标不适用于轴承的故障状态识别,峰值、脉冲指标和裕度指标适合识别内圈故障和外圈故障的轴承,有效值和峭度指标适合区分内圈故障、外圈故障、滚子故障和正常状态的轴承。正常状态轴承信号谐波分量最少,内圈故障和滚子故障轴承信号的谐波分量最多。滚子故障轴承信号的谐波分量幅值最小,外圈故障轴承信号的谐波分量幅值最大。     

轮胎包络特性及冲击特性的影响因素研究

以215/55R17轮胎为研究对象,研究不同的充气压力与负荷对轮胎包络特性及冲击特性的影响。结果表明：在低速包络试验中,轮胎的径向力峰值随充气压力的增大而增大,随负荷的增大而减小,纵向力峰峰值随充气压力与负荷的增大而增大,但变化幅度不大;在冲击试验中,轮胎的径向力峰值与纵向力峰峰值随充气压力的增大而增大,径向力峰值随负荷的变化受到速度的影响但变化幅度较小,纵向力峰峰值随负荷的增大而增大。     

煤矿井下人员呼救报警系统测距法定位算法

对矿井下人员定位方式和算法进行了研究,分别介绍了TOA(Time of arrival)定位视距LOS和非视距NLOS 2种场景下的定位数学模型。依据基站接收到的由井下人员携带的报警设备发出的脉冲响应电平值来判断该信号场景,在非视距场景下使用测量值减去误差值的方式,转化为视距场景下的数学模型进行计算。通过实际测试证明:定位算法具有算法简单、计算量小、精度高等优点,具有一定实用价值。     

声波在钻柱中传输数值模拟研究

本文针对声波信号在钻柱中传输建模与分析,采用有限元法建立钻柱模型,并分析声信号在钻柱中传输特性。使用方波作为径向激励信号,对钻柱接收端声波信号进行数值模拟。结果表明:声波在钻柱中的传输声波信号随着时间的增长而衰减,持续出现不同的振动幅值,是一条包络呈指数衰减的信号。模拟结果与理论分析相符,该建模方法有效。     

基于静电信号的流化床反应器结块预警

利用经验模态分解(EMD)信号处理方法解析静电信号,提取高相关系数的本征函数(IMF),并通过IMF的幅值变化实现流化床内的结块预警。在冷模实验中,基于静电压信号IMF6瞬时幅值的变化可在结块产生前10～15min进行预警;而在工业装置中,以静电压信号IMF1的瞬时幅值作为特征参数,同样实现了结块的提前预警,相比于较为先进的壁温检测法,能提前1.2～3.5h进行结块预警。     

一种设有声控报警安全装置的注塑机

本实用新型为一种设有声控报警安全装置的注塑机，包括设有电器控制单元的注塑机。其特征在于，在注塑机上还设有声控报警安全装置。该装置包括音频接收仪、音幅接收仪、模数转换器和信号放大器。音频接收仪和音幅接收仪分别与模数转换器电气连接，将音频和音幅转换为电信号，模数转换器与信号放大器电气连接，     

客户接收概率在玻纤制品质量管理中的应用

为了在玻璃纤维生产中提高发现问题的能力,在玻璃纤维制品中应用了接收质量限AQL值、抽样检验、二项式计算接收、概率等原理,将玻纤制品的检测数据转化成可以量化且直观的百分比数值,用来判断客户的接收情况,从而达到降低质量问题发生的概率,起到玻纤制品生产中问题产生的预警作用。     

测试最大输出电平的新方法

<正> 目前国内测试磁带最大输出电平(MOL)的方法十分繁琐。例如使用丹麦B&K公司的1027音频信号发生器、2010频率分析仪和1617带通滤波器组成的测试系统时,测试的步骤是,调整录音输入电平,使磁带重放信号的三次谐波失真达到3％,此时输出电平和参考电平之差即为MOL。在实际测试中,往往输入电平的变化会相应改变基波输出电平和三次谐波电平,为     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况。按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、环氧树脂、不饱和聚酯树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍。     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.