桥梁结构动态应变监测信息的分离与提取

对工作应变传感器和温度应变传感器的数据进行了对比分析,利用能量谱比指标将监测系统输出的原始应变数据按照温度、应力和测量噪声3种类型在频域中进行分类,分别确定了温度变形与结构应变的分界频率.提出了一个多分辨递阶方法,可将3类不同信息分离并提取出由结构应力导致的应变信息,在分离信息基础上考察了干扰部分和温度应力部分对疲劳评估的影响.研究结果表明,2个分界频率值对同类桥梁有较强的参考价值,提出的算法具有多分辨和递阶的特征,适合于海量应变数据的压缩与预处理,便于在结构健康监测系统软件中集成.虽然变温变形部分的能量很大,但其对疲劳评估产生的误差很小;而干扰信息虽然能量很小,但对疲劳评估产生的影响很大,其主要原因是干扰信息使得应力应变中提取的应变幅发生偏移.     

Nanoscale imaging magnetometry with diamond spins under ambient conditions

Magnetic resonance imaging and optical microscopy are key technologies in the life sciences. For microbiological studies, especially of the inner workings of single cells, optical microscopy is normally used because it easily achieves resolution close to the optical wavelength. But in conventional microscopy, diffraction limits the resolution to about half the wavelength. Recently, it was shown that this limit can be partly overcome by nonlinear imaging techniques, but there is still a barrier to reaching the molecular scale. In contrast, in magnetic resonance imaging the spatial resolution is not determined by diffraction; rather, it is limited by magnetic field sensitivity, and so can in principle go well below the optical wavelength. The sensitivity of magnetic resonance imaging has recently been improved enough to image single cells, and magnetic resonance force microscopy has succeeded in detecting single electrons and small nuclear spin ensembles. However, this technique currently requires cryogenic temperatures, which limit most potential biological applications. Alternatively, single-electron spin states can be detected optically, even at room temperature in some systems. Here we show how magneto-optical spin detection can be used to determine the location of a spin associated with a single nitrogen-vacancy centre in diamond with nanometre resolution under ambient conditions. By placing these nitrogen-vacancy spins in functionalized diamond nanocrystals, biologically specific magnetofluorescent spin markers can be produced. Significantly, we show that this nanometre-scale resolution can be achieved without any probes located closer than typical cell dimensions. Furthermore, we demonstrate the use of a single diamond spin as a scanning probe magnetometer to map nanoscale magnetic field variations. The potential impact of single-spin imaging at room temperature is far-reaching. It could lead to the capability to probe biologically relevant spins in living cells.     

Homozygous HOXA1 mutations disrupt human brainstem, inner ear, cardiovascular and cognitive development

We identified homozygous truncating mutations in HOXA1 in three genetically isolated human populations. The resulting phenotype includes horizontal gaze abnormalities, deafness, facial weakness, hypoventilation, vascular malformations of the internal carotid arteries and cardiac outflow tract, mental retardation and autism spectrum disorder. This is the first report to our knowledge of viable homozygous truncating mutations in any human HOX gene and of a mendelian disorder resulting from mutations in a human HOX gene critical for development of the central nervous system.     

A simple interspike interval analyzer for study of neuronal spike trains

Summary A simple, low cost interspike interval analyzer for the analysis of trains of nerve impulses is described. The analyzer is built with readily available integrated circuits and has been used to analyze spike trains in the lateral vestibular nucleus of cats.Acknowledgment. This research is supported in part by Higher Degrees and Research Grant No. 158/363 to J.C.H. from the University of Hong Kong.     

Multiple phosphoglucomutase alleles inToxorhynchites splendens (Diptera: Culcidae)

Summary Multiple phosphoglucomutase (E.C. 2.7.5.1) alleles are found in the mosquitoToxorhynchites splendens. The sample studied reveals 3Pgm alleles whose frequencies are in good accord with Hardy-Weinberg expectations. The most frequent allele is that controlling a phenotype with an intermediate electrophoretic mobility. EachPgm allele determines a two-band electrophoretic pattern.This work is supported in part by a University of Malaya research grant to the senior author.     

奥美拉唑配合胃腔降温治疗老年急性上消化道大出血疗效观察附45例报告

急性上消化道大出血是老人急症之一。３年来我院收治４５例,年龄６０～９１岁,平均年龄７０３岁。３７例经纤维胃镜检查：消化性溃疡２４例;急性胃粘膜病变、糜烂性胃炎１０例;胃癌２例;肝硬化并食道静脉破裂１例。大部分病人由于出血量多,入院时多处于休克状态,病情危重,需及时抢救。在综合疗效法基础上,联合应用奥美拉唑及胃腔降温,疗效满意,成功率达９５６％,２４ｈ内大部分患者止血。其作用机理：奥美拉唑是质子泵抑制剂,抑制Ｈ＋Ｋ＋－ＡＴＰ酶活性,对胃酸分泌有强而持久的抑制作用,使血小板能很好地凝集形成凝血块,减少Ｈ＋回渗致胃粘膜产生糜烂和溃疡,有利于止血。胃腔降温也可抑制胃酶分泌,抑制胃蛋白酶活性及血块溶解;冰冻盐水加入去甲肾上腺素、凝血酶等局部应用,可起到协同止血作用     

Plasma Modification of Wool: The Effect of Plasma Gas on the Properties of the Wool Fabric

The wool fabrics were treated with low temperature plasma (LTP) using three different gases, namely (ⅰ) oxygen, (ⅱ) nitrogen and (ⅲ) 25％ hydrogen/75％ nitrogen gas mixture. After LTP treatment, the low stress mechanical properties, surface properties and thermal properties of the fabrics were investigated by kES-F (Kawabata Evaluation System) Instruments composing of KES-FBI for tensile and shear property measurement, KES-FB2 for pure bending measurement, kES-FB3 for compression measurement, KES-FB4 for surface friction and surface roughness measurement, and KES-F7 for thermal property measurement. The first four instruments were used for investigating the charaeterlstlc aspect related to fabrle hand while the last one was mainly for the fabric comfort. The properties of LTP treated fabrics under the effect of different gases were compared with the untreated fabric quantitatively.     

浇铸成形环氧树脂基复合材料板的制备技术

以环氧树脂、甲基四氢苯酐、石英砂为主要原料,通过正交实验,采用浇铸法制备了环氧树脂基复合材料,对其硬度、耐强酸强碱性、抗有机溶剂腐蚀性能、热变形温度(0.45 MPa)、复合材料内部有无气泡进行了测试和研究.讨论了环氧树脂、石英砂用量、最终烘烤温度3个因素对复合材料板性能的影响,得到最优化的配方比例.在此基础之上,研究了复合材料板的耐强酸、强碱性和抗有机溶剂腐蚀性.结果表明,环氧树脂添加量为总质量的14%,石英砂用量为总质量的70%,最终烘烤温度200℃,复合材料板巴氏硬度达到54 HBa,热变形温度(0.45 MPa)达到240℃.制备的复合材料板具有较好的耐强酸强碱性和抗有机溶剂腐蚀性能.