电阻测长法在锚杆质量检测中的应用

本研究课题来源于洛阳邦强机械有限公司的项目合作,主要是针对锚杆质量检测问题。本文主要介绍了电阻测长法在锚杆长度检测中的应用,提出一种新的锚杆长度测量方法,具有方便、快捷、无损等优势,并在实际工程应用中得到了充分的验证。

高温气冷堆包覆燃料颗粒尺寸的光电测长法

包覆燃料颗粒是高温气冷堆燃料元件的重要组成部分，燃料颗粒（直径约１ｍｍ）的尺寸是重要的性能指标。光电测长法采用分辨率为０．０２μｍ的高精度光栅作为传感器，接触式直接量测被测物体，最大限度地减少了测量误差。光电测长系统由光电传感器测试头、样品工作台、台式光栅数显表和微机数据采集处理系统组成。测量２００个包覆燃料颗粒尺寸需要３０ｍｉｎ。测量的重复性偏差为０．０５μｍ。

弓高弦长法测量直径中的最佳测量点的选择

弓高弦长法测圆直径的一个重要问题,是如何选取最佳测量点。本文从误差的传递着手,严密推证了弓高及弦长测量的标准差取不同值时最佳测量点的位置。在一般情况下弓高及弦长的标准差相同(σ_h-σ_s)时,最佳测量点的位置应为 h=(2^(1/2))/2S(=2/3D)处。值得注意的是用弓高弦长法对最佳测量点的测量,其标准差为直接测量直径时标准差的0.866倍。

胶凝砂砾石弹性模量测试方法的试验研究

胶凝砂砾石作为一种低强度、低弹性模量的新型筑坝材料,目前尚无统一的测试标准,采用不同测试方法的结果势必有很大差异,从而会影响胶凝砂砾石坝的设计。为此,分别采用通长变形、中部变形、端部变形及内部埋设差动式电阻应变计4种测试方法对胶凝砂砾石材料的弹性模量进行对比试验,并评估了弹性模量测试加荷速率的控制、预压次数及割线法的适用性等问题。结果表明,端部测长法比较适用于胶凝砂砾石弹性模量的测试,对于规范和统一胶凝砂砾石弹性模量的测试以及胶凝砂砾石坝的进一步发展起到了促进作用。

石油油井的抽油杆测长自动控制系统

在油田抽油行业中，抽油杆的损耗极其严重，若维修过的抽油杆在长度上发生变化时，其长度就需要重新被测量，以便于掌握提升出或下入到井VI的抽油杆的长度。CCD（电荷耦合器件）图像测长法是一种非接触式的测量方法，解决了油田现场这一溯量难题。而且将CCD和编码器同时使用，不仅克服了机械损耗缺点，可以提高系统在野外作业的可靠性，而且此测量方法准确、简便，大大的提高了工作的效率。

浅谈喷钼、喷陶瓷试样磨损量的测定

喷铝、喷陶瓷材料因其具有较好的耐磨性而被广泛用于制造活塞环等零部件.一般来说,材料的耐磨性是根据其磨损量来判断的,因此,正确测量材料的磨损量至关重要.在对喷钼、喷陶瓷材料进行加油润滑磨损试验时发现:用常用的称重法测量磨损量时常常出现增重或失重现象,使试验无法真实反映材料的耐磨性.本文就此现象进行了试验分析,对喷钼、喷陶瓷材料磨损量的测定方法进行了探讨.

混凝土骨料碱活性试验方法研究与成果应用

由碱骨料反应造成的混凝土膨胀、开裂甚至破坏已经引起了各国的普遍重视,目前碱活性检验方法主要有岩相法、化学法和测长法等,这些方法对保证混凝土耐久性起到积极作用,但也存在其本身缺陷。对2类骨料碱活性试验方法的可靠性分别进行了研究,结果表明,ASTM C1260(快速砂浆棒法)对碱骨料的判定过于严格;ASTM C586碳酸盐骨料潜在碱活性标准试验方法(岩石柱法)中圆柱体试件试验的可靠性和可操作性不如棱柱体试件。研究成果应用于对进沪骨料、核电工程用骨料和高速铁路工程用骨料的碱活性评定工作中,有利于工程采取积极的预防措施,避免遭受碱骨料破坏损失。

A systematic scheme for monitoring waterbird populations at Shengjin Lake,China:methodology and preliminary results

Changes in the areas and quality of wetland habitat makes it imperative to monitor trends in the number of wintering waterbirds and their distribution in the Yangtze River floodplain, the most important waterbird region in eastern China, so that effective science-based action can be taken to ensure the survival and future recovery of the waterbirds of the region. However, obtaining accurate data on the number of waterbirds and distribution, which can be confidently compared across years and sites, is complicated by a number of factors which can affect count quality. It is essential to employ a survey methodology which maximizes count accuracy and precision and minimizes the bias inherent in counting waterbirds;failure to achieve these goals will lead to incorrect results and analytical problems. Recently we developed a systematic waterbird survey methodology which was tested, with promising results, in the winters of 2008/2009 and 2009/2010 at Shengjin Lake, an important wetland in the Yangtze River floodplain. The methodology involves dividing the lake into discrete survey areas, each containing a number of subareas, with clear boundaries, which were surveyed separately. Data, which included information on counts, distributions, the environment and disturbance, were collected in a standardized manner to maximize precision and minimize bias. We use the results from the surveys of the first two winters to provide examples of how the data can be employed to provide detailed information on the number of waterbirds, their distributions and habitat usage. Finally, we discuss the importance of wider application of the methodology throughout the Yangtze River floodplain to underpin a much needed floodplain-wide waterbird monitoring program.

Method of Growth in Finding the Test Cube of Industrial Robots

In order to find the test cube for industrial robots as specified by ISO 9283, a seed cube is grown up in an irregular working space of the robot, provided that the corners of the cube do not exceed the boundary of the working space. All possible cubes are searched, and the cube with the maximum volume is selected. The calculation examples show that the method of growth can be used for a variety of industrial robots. The method of growth can determine the test cube and test points of irregular working space according to ISO 9283, and can avoid blindness and randomness in the selection of test points.

Annoyance-type speech emotion detection in working environment

In order to recognize people＇s annoyance emotions in the working environment and evaluate emotional well- being, emotional speech in a work environment is induced to obtain adequate samples of emotional speech, and a Mandarin database with two thousands samples is built. In searching for annoyance-type emotion features, the prosodic feature and the voice quality feature parameters of the emotional statements are extracted first. Then an improved back propagation （BP） neural network based on the shuffled frog leaping algorithm （SFLA） is proposed to recognize the emotion. The recognition capability of the BP, radical basis function （RBF） and the SFLA neural networks are compared experimentally. The results show that the recognition ratio of the SFLA neural network is 4. 7% better than that of the BP neural network and 4. 3% better than that of the RBF neural network. The experimental results demonstrate that the random initial data trained by the SFLA can optimize the connection weights and thresholds of the neural network, speed up the convergence and improve the recognition rate.

Determination of Lycopene Concentration in Dog Plasma by RP-HPLC

A method for determination of lycopene concentration in dog plasma wasestablished. Methods RP-HPLC was used; the mobile phase consisted of methanol-acetonitrile-methylenechloride (40:30:30, V/V) , the wavelength of detection was 472 nm, the column temperature wasambient temperature, and the flow rate was 1.0 mL·min^(-1). Results The standard curve was linearin the range from 0.012 4 to 0.496 μg·mL^(-1) with r=0.9992. The average extraction recovery was97.6% +-4.2%. The intra-day and inter-day RSD were 1.52% -4.95% and 2.31% -7.38%, respectively.Conclusion This method is sensitive, rapid, reproducible, and of good selectivity for the analysisof lycopene in dog plasma.

Accurate quantification of astaxanthin from Haematococcus crude extract spectrophotometrically

The influence of alkali on astaxanthin and the optimal working wave length for measurement of astaxanthin from Haematocoecus crude extract were investigated, and a spectrophotometric method for precise quantification of the astaxanthin based on the method of Boussiba et al. was established. According to Boussiba＇s method, alkali treatment destroys chlorophyll. However, we found that： 1） carotenoid content declined for about 25% in Haematococcus fresh cysts and up to 30% in dry powder of Haematococcus broken cysts after alkali treatment; and 2） dimethyl sulfoxide （DMSO）-extracted chlorophyll of green Haematococeus bares little absorption at 520-550 nm. Interestingly, a good linear relationship existed between absorbance at 530 nm and astaxanthin content, while an unknown interference at 540-550 nm was detected in our study. Therefore, with 530 nm as working wavelength, the alkali treatment to destroy chlorophyll was not necessary and the influence of chlorophyll, other carotenoids, and the unknown interference could be avoided. The astaxanthin contents of two samples were measured at 492 nm and 530 nm; the measured values at 530 nm were 2.617 g/100 g and 1.811 g/100 g. When compared with the measured values at 492 nm, the measured values at 530 nm decreased by 6.93% and 11.96%, respectively. The measured values at 530 nm are closer to the true astaxanthin contents in the samples. The data show that 530 nm is the most suitable wave length for spectrophotometric determination to the astaxanthin in Haematococcus crude extract.

An influence function method based subsidence prediction program for longwall mining operations in inclined coal seams

The distribution of the final surface subsidence basin induced by longwall operations in inclined coal seam could be significantly different from that in flat coal seam and demands special prediction methods. Though many empirical prediction methods have been developed, these methods are inflexible for varying geological and mining conditions. An influence function method has been developed to take the advantage of its fundamentally sound nature and flexibility. In developing this method, significant modifications have been made to the original Knothe function to produce an asymmetrical influence function. The empirical equations for final subsidence parameters derived from US subsidence data and Chinese empirical values have been incorpo- rated into the mathematical models to improve the prediction accuracy. A corresponding computer program is developed. A number of subsidence cases for longwall mining operations in coal seams with varying inclination angles have been used to demonstrate the applicability of the developed subsidence prediction model.

Monitoring the Modal Frequency and Velocity Variations of Bridges under Ambient Excitation

We conducted a long-term monitoring experiment on the Lutuanxilu Bridge located in Changping District of Beijing, employing our recently developed real-time bridge monitoring system based on the Guralp CMG-6TD broadband seismometer. We identified the modal parameters with the stochastic subspace identification( SSI) algorithm,and continuously monitored the temporal velocity variation with coda wave interferometry.The results show that:( 1) the highly sensitive Guralp CMG-6TD broadband seismometer,which records the three-component vibration signal within broad frequency range,is well suited for long-term bridge health monitoring.( 2) With the continuous vibration signal from ambient excitation,the stochastic subspace algorithm can robustly identify the low-order modal parameters and the coda wave interferometry can accurately monitor the tiny velocity variation.( 3) The elastic modulus of bridge materials changes significantly associated with varying temperature,leading to diurnal velocity variation with amplitude of approximately 1%. The velocity variation shows strong negative correlation with temperature fluctuation. Meanwhile,the modal frequencies remain quite stable,suggesting that the velocity variation may be a more sensitive quantitative damage index.( 4) While the modal frequencies reflect the integrated health status of the bridge,the velocity variation can be utilized to monitor the local elastic modulus. Therefore,it is crucial for bridge health monitoring to continuously monitor the two key damage indexes under ambient excitation.

Laboratory Detection and Diagnosis of Filoviruses

Ebola virus(EBOV) and Marburg virus(MARV),belonging to the Filoviridae family,emerged four decades ago and caused severe viral hemorrhagic fever in human and other primates.As high as 50-90% mortality,filoviruses can cause significant threats to public health.However,so far no specific and efficient vaccine has been available,nor have other treatment methods proved to be effective.It is of great importance to detect these pathogens specific,rapidly and sensitively in order to control future filovirus outbreaks.Here,recent progresses in the development of detection and diagnosis methods for EBOV and MARV are summarized.

A New Method for Measuring the Stitch Length of Weft Knitted Fabric in a Static Environment

It is essential to measure the stitch length of weft knitted fabric in a static environment for economy and improving productivity. The image inputted was dealt with the digital image processing techniques： the paper carried out the transformation of grey scale; then removed impurities with filtering; the characteristic of the stitch structure was abstracted by using the Fourier transform technique. To obtain the stitch length more accurately, we should establish ageometric medal of the stitch lined on the digital image processing, which provides a way to transform the stitch length in the two-dimenslon space into a three-dimension space. This study provides a new methed for measuring the stitch length without damaging the fabric.

Methods of data processing in multi-wavelength thermometry

Three kinds of methods for processing the data of the multi-wavelength pyrometer are presented in this paper and are named curve auto-search method, curve auto-regression method and neural network method. Tbe experimental results indicate that the calculated temperature and the spectral emissivity compared with the true target temperature and spectral emissivity have significant deviation using the curve auto-search and the curve auto-regression methods. However, the calculated temperature and the spectral emissivity with higher accuracy can be obtained using the neural network method.

Scheme for Implementing Quantum Search Algorithm in a Cluster State Quantum Computer

Using cluster state and single qubit measurement one can perform the one-way quantum computation. Here we give a detailed scheme for realizing a modified Grover search algorithm using measurements on cluster state. We give the measurement pattern for the cluster-state realization of the algorithm and estimated the number of measurement needed for its implementation. It is found that O（2^3n/^2n^2） number of single qubit measurements is required for its realization in a cluster-state quantum computer.

Implementation of Efficient Burst Assembly Algorithm with Traffic Prediction

This paper reports on the implementation of efficient burst assembly algorithms and traffic prediction. The ultimate goal is to propose a new burst assembly algorithm which is based on time-burst length （hybrid） threshold with traffic prediction to reduce burst assembly delay in OBS （Optical Burst Switching） networks. Research has shown that traffic always change from time to time, hence, any measure that is put in place should be able to adapt to such changes. With our implemented burst assembly algorithm, the traffic rate is predicted and the predicted rate is used to dynamically adjust the burst assembly length. This work further investigates the impact of the proposed algorithm on traffic self similarity.