晚粳稻籽粒中砷、镉、铬、镍、铅等重金属含量的品种和粒位效应

选用籽粒着粒密度差异较大的密穗型品种秀水63和散穗型品种秀水11,种植于受重金属轻度污染的土壤,研究了晚粳稻籽粒中有毒重金属As、Cd、Cr、Ni、Pb含量的品种与粒位效应。结果表明,重金属含量的粒位间差异秀水63明显大于秀水11,As、Cd、Cr、Pb含量粒位间差异显著,Ni含量差异较小。穗上部籽粒As、Cd、Ni含量高于中部籽粒,穗下部籽粒最低,而Cr、Pb则正好相反。稻米中几种重金属含量与粒重的关系因重金属种类不同存在着差异,籽粒As、Cd、Ni含量与粒重呈正相关,而Cr和Pb含量与粒重呈负相关。秀水63和秀水11不同粒位的籽粒灌浆模式存在差异,下位粒灌浆速率较低,使粒重较上、中位粒低,导致粒重有较大的粒位差异,而这种差异也与穗部着粒密度有关,秀水63明显大于秀水11。籽粒As、Cd、Ni含量与最大灌浆速率(GRm)呈正相关,与到达最大灌浆速率时间(Tpoi)呈负相关,而Cr和Pb含量与以上两个籽粒灌浆特性参数分别呈负相关和正相关,说明籽粒As、Cd、Ni的积累与碳水化合物的积累具有相同或相近的模式,而Cr和Pb表现为不同的积累模式。

Implementation of Mooring Automatic Positioning System for Deepwater Semi-Submersible Platform Based on Dual-Stage Actuator

The automatic positioning control of mooring system for deepwater semi-submersible platform has become a key issue in the research and development field of deep-sea resources. The Dual- Stage Actuator (DSA) proposed in this paper can replace the single actuator to achieve the high speed and high precision positioning by cooperative control. The relative model and control algorithm of motion trajectory (CAMT) are designed and validated, which proves that the method proposed in this paper is effective.

变系数三阶周期边值问题的正解(英文)

研究了变系数非线性三阶周期边值问题的正解.非线性项可以关于空间变元奇异.利用适当的变换此问题被转换为一个Hammerstein积分方程,利用锥上的Guo-Krasno-selski不动点定理获得了1～2个正解的存在性.

Advancement in Wide Area Monitoring Protection and Control Using PMU’s Model in MATLAB/SIMULINK

A big step forward to improve power system monitoring and performance, continued load growth without a corresponding increase in transmission resources has resulted in reduced operational margins for many power systems worldwide and has led to operation of power systems closer to their stability limits and to power exchange in new patterns. These issues, as well as the on-going worldwide trend towards deregulation of the entire industry on the one hand and the increased need for accurate and better network monitoring on the other hand, force power utilities exposed to this pressure to demand new solutions for wide area monitoring, protection and control. Wide-area monitoring, protection, and control require communicating the specific-node information to a remote station but all information should be time synchronized so that to neutralize the time difference between information. It gives a complete simultaneous snap shot of the power system. The conventional system is not able to satisfy the time-synchronized requirement of power system. Phasor Measurement Unit (PMU) is enabler of time-synchronized measurement, it communicate the synchronized local information to remote station.

Anterolateral rotatory instability in vivo correlates tunnel position after anterior cruciate ligament reconstruction using bone-patellar tendon-bone graft

AIM To quantitatively assess rotatory and anterior-posterior instability in vivo after anterior cruciate ligament(ACL) reconstruction using bone-patellar tendon-bone(BTB) autografts, and to clarify the influence of tunnel positions on the knee stability.METHODS Single-bundle ACL reconstruction with BTB autograft was performed on 50 patients with a mean age of 28 years using the trans-tibial(TT)(n = 20) and trans-portal(TP)(n = 30) techniques. Femoral and tibial tunnel positions were identified from the high-resolution 3 D-CT bone models two weeks after surgery. Anterolateral rotatory translation was examined using a Slocum anterolateral rotatory instability test in open magnetic resonance imaging(MRI) 1.0-1.5 years after surgery, by measuring anterior tibial translation at the medial and lateral compartments on its sagittal images. Anterior-posterior stability was evaluated with a Kneelax3 arthrometer.RESULTS A total of 40 patients(80%) were finally followed up. Femoral tunnel positions were shallower(P < 0.01) and higher(P < 0.001), and tibial tunnel positions were more posterior(P < 0.05) in the TT group compared with the TP group. Anterolateral rotatory translations in reconstructed knees were significantly correlated with the shallow femoral tunnel positions(R = 0.42, P < 0.01), and the rotatory translations were greater in the TT group(3.2 ± 1.6 mm) than in the TP group(2.0 ± 1.8 mm)(P < 0.05). Side-to-side differences of Kneelax3 arthrometer were 1.5 ± 1.3 mm in the TT, and 1.7 ± 1.6 mm in the TP group(N.S.). Lysholm scores, KOOS subscales and reinjury rate showed no difference between the two groups.CONCLUSION Anterolateral rotatory instability significantly correlated shallow femoral tunnel positions after ACL reconstruction using BTB autografts. Clinical outcomes, rotatory and anterior-posterior stability were overall satisfactory in both techniques, but the TT technique located femoral tunnels in shallower and higher positions, and tibial tunnels in more posterior positions than the TP technique, thus increased the anterolateral rotation. Anatomic ACL reconstruction with BTB autografts may restore knee function and stability.

微机电系统中的微观黏滑、黏附与控制

微观黏滑和黏附失效是微机电系统中的常见现象,该现象主要是由于受包括静电力、范德华力及毛细力等各种表面力所起的主导作用而产生的.采用黏着接触理论和运动分析方法,得到了微观摩擦试验中黏滑出现的无量纲黏滑数,表微观黏滑是接触表面特性、形貌参数、接触载荷及滑动速度等综合作用的结果,进而获得黏滑现象的各种临界参数,提出了黏滑行为控制的表面修饰与形貌设计依据;针对微构件的黏附失效,采用Laplace公式并结合微构件的变形分析,探究了毛细力作用下微构件的变形特征与失稳行为,发现其变形过程中存在着不稳定的临界点,对应黏附行为的发生,进而提出了微构件防黏附的结构设计.

水平井挖掘正韵律厚油层潜力影响因素分析

用整装油藏资料建立了正韵律厚油层的概念模型,对水平井挖掘厚油层潜力的影响因素和技术参数界限进行了分析。研究结果表明,为提高油藏采收率,水平井注采井组中注水直井在上部注水效果较好;地层垂向渗透率应保持一个最佳值;无因次隔层面积最好大于6.9。采用水平井挖潜,无因次水平段长度应大于0.25;剩余油富集地层厚度应大于4.3m;厚油层整体含水率应低于95%;生产压差和产液速度应保持合理水平。

Far-Field Pattern Reconstruction from Positioning Errors Affected Near-Field Data Acquired via Helicoidal Scanning

In this paper, an effective technique to compensate the positioning errors in a near-field—far-field (NF-FF) transformation with helicoidal scanning for elongated antennas is presented and validated both numerically and experimentally. It relies on a nonredundant sampling representation of the voltage measured by the probe, obtained by considering the antenna as enclosed in a cylinder ended in two half-spheres. An iterative scheme is used to reconstruct the helicoidal NF data at the points fixed by the representation from the acquired irregularly spaced ones. Once the helicoidal data have been retrieved, those needed by a classical NF-FF transformation with cylindrical scanning are efficiently evaluated by using an optimal sampling interpolation algorithm. Some numerical tests, assessing the accuracy of the approach and its stability with respect to random errors affecting the data, are reported. Experimental tests performed at the Antenna Characterization Lab of the University of Salerno further confirm the validity of the proposed technique.

根据DNA的序列资料探讨翅子树族的系统位置(英文)

采用DNA分子测序技术对梧桐科5个族30个代表种的rbcL基因及核糖体DNA的内转录间隔区ITS序列包括ITS1、ITS2和5.8srRNA基因进行了序列分析.使用PAUP4.0b10软件对序列进行统计和分支分析,用启发式搜索方法寻找最简约树.从严格一致性树来看,梧桐科的全部代表类群主要被分为4支,一支仅为Sterculieae所构成;一支包括Helictereae的全部代表种;一支由Byttnerieae代表种所构成;最后一支由Dombeyeae和单属族翅子树族Pterospermeae所构成.rbcL和ITS系统树的不同仅表现在族内个别代表类群的位置和族的分支方式上.分析结果表明,与Helictereae相比,翅子树属Pterospermum与Dombeyeae有更近的亲缘关系.然而,在外部形态、内部解剖和胚胎学方面,二者之间又存在诸多差异,故支持将Pterospermum另立为Pterospermeae的观点.

Detection of rotor position by harmonic back EMF of hybrid step motor

The magnhc network model of a hybrid step motor is established by the air gap rate permeance method,and the expression of harmonic back EMF is deduced, and from the analysis above, a vovel use of harmonic backEMF sed to extract rotor peition is proposed and a new position sensor integral with the motoris designed .Experi-ments verified the correctness of the theorecal analysis. Ths type of rotor position sensor lays a foundation for closed-loop conrol of step motor.

Application of the Spectrum Peak Positioning Technology Based on BP Neural Network in Demodulation of Cavity Length of EFPI Fiber Optical Sensor

An Extrinsic Fabry-Perot Interferometric (EFPI) fiber optical sensor system is an online testing system for the gas density. The system achieves the measurement of gas density information mainly by demodulating the cavity length of EF- PI fiber optical sensor. There are many ways to achieve the demodulation of the cavity length. For shortcomings of the big intensity demodulation error and complex structure of phase demodulation, this paper proposes that BP neural net-work is used to locate the special peak points in normalized interference spectrum and combining the advantages of the unimodal and bimodal measurement achieves the demodulation of the cavity length. Through online simulation and actual measurement, the results show that the peak positioning technology based on BP neural network can not only achieve high-precision demodulation of the cavity length, but also achieve an absolute measurement of cavity length in large dynamic range.

An Analysis on Position Estimation, Drifting and Accumulated Error Accuracy during 3D Tracking in Electronic Handheld Devices

This work focuses on a brief discussion of new concepts of using smartphone sensors for 3D painting in virtual or augmented reality. Motivation of this research comes from the idea of using different types of sensors which exist in our smartphones such as accelerometer, gyroscope, magnetometer etc. to track the position for painting in virtual reality, like Google Tilt Brush, but cost effectively. Research studies till date on estimating position and localization and tracking have been thoroughly reviewed to find the appropriate algorithm which will provide accurate result with minimum drift error. Sensor fusion, Inertial Measurement Unit (IMU), MEMS inertial sensor, Kalman filter based global translational localization systems are studied. It is observed, prevailing approaches consist issues such as stability, random bias drift, noisy acceleration output, position estimation error, robustness or accuracy, cost effectiveness etc. Moreover, issues with motions that do not follow laws of physics, bandwidth, restrictive nature of assumptions, scale optimization for large space are noticed as well. Advantages of such smartphone sensor based position estimation approaches include, less memory demand, very fast operation, making them well suited for real time problems and embedded systems. Being independent of the size of the system, they can work effectively for high dimensional systems as well. Through study of these approaches it is observed, extended Kalman filter gives the highest accuracy with reduced requirement of excess hardware during tracking. It renders better and faster result when used in accelerometer sensor. With the aid of various software, error accuracy can be increased further as well.

Positioning in Dynamic Testing of Slender Bridges

The positioning combined with multi-functioning and interactive mechanics in dynamic testing of slender bridges are treated in present paper. The approach takes into account multiple functions in dynamic testing of slender bridges constructed of thin-walled structural members with their hierarchical configuration. Theoretical, numerical and experimental in situ assessments of the problem are presented. Some results of the application in situ are submitted.

不同利用方式与坡位土壤物理性质及养分特征分析

以四川盆地西缘山地的典型坡面为材料,研究了不同土地利用方式和地形部位条件下土壤物理性质和养分的分异特征,结果表明,3个坡面地形部位(上坡位,中坡位,下坡位) ,下坡位土壤物理结构性能较好,而人工林与坡耕地、荒草地相比较,人工林更能增强土壤的结构性。土壤养分分异特征表明,在不同利用类型条件下,土壤有机质、氮素和阳离子交换量CEC在人工林中含量最高,且与其他两种利用类型中的含量差异显著,有机质、碱解氮和CEC三者含量差异达到极显著水平。相关分析表明,土壤表层有机质、全氮、碱解氮呈极显著正相关。而坡面位置中,与上坡位,中坡位相比,下坡位土壤养分含量普遍要高,其中CEC含量差异达到极显著水平,相关分析表明,CEC与土壤粘粒呈极显著正相关。

Monitoring Zenithal Total Delays over the three different climatic zones from IGS GPS final products:A comparison between the use of the VMF1 and GMF mapping functions

The International GNSS Service(IGS) final products(ephemeris and clocks-correction) have made the GNSS an indispensable low-cost tool for scientific research, for example sub-daily atmospheric water vapor monitoring. In this study, we investigate if there is a systematic difference coming from the choice between the Vienna Mapping Function 1(VMF1) and the Global Mapping Function(GMF) for the modeling of Zenith Total Delay(ZTD) estimates, as well as the Integrated Precipitable Water Vapor(IPWV) estimates that are deduced from them. As ZTD estimates cannot be fully separated from coordinate estimates, we also investigated the coordinate repeatability between subsequent measurements.For this purpose, we monitored twelve GNSS stations on a global scale, for each of the three climatic zones(polar, mid-latitudes and tropical), with four stations on each zone. We used an automated processing based on the Bernese GNSS Software Version 5.2 by applying the Precise Point Positioning(PPP)approach, L3 Ionosphere-free linear combination, 7 cutoff elevation angle and 2 h sampling. We noticed an excellent agreement with the ZTD estimates and coordinate repeatability for all the stations w.r.t to CODE(the Center for Orbit Determination in Europe) and USNO(US Naval Observatory) products, except for the Antarctic station(Davis) which shows systematic biases for the GMF related results. As a final step, we investigated the effect of using two mapping functions(VMF1 and GMF) to estimate the IPWV,w.r.t the IPWV estimates provided by the Integrated Global Radiosonde Archive(IGRA). The GPS-derived IPWV estimates are very close to the radiosonde-derived IPWV estimates, except for one station in the tropics(Tahiti).

Laser Interferometer Based Measurement for Positioning Error Compensation in Cartesian Multi-Axis Systems

Accuracy is one of the most important key indices to evaluate multi-axis systems’ (MAS’s) characteristics and performances. The accuracy of MAS’s such as machine tools, measuring machines and robots is adversely affected by various error sources, including geometric imperfections, thermal deformations, load effects, and dynamic disturbances. The increasing demand for higher dimensional accuracy in various industrial applications has created the need to develop cost-effective methods for enhancing the overall performance of these mechanisms. Improving the accuracy of a MAS by upgrading the physical structure would lead to an exponential increase in manufacturing costs without totally eliminating geometrical deviations and thermal deformations of MAS components. Hence, the idea of reducing MAS’s error by a software-based alternative approach to provide real-time prediction and correction of geometric and thermally induced errors is considered a strategic step toward achieving the full potential of the MAS. This paper presents a structured approach designed to improve the accuracy of Cartesian MAS’s through software error compensation. Four steps are required to develop and implement this approach: (i) measurement of error components using a multidimensional laser interferometer system, (ii) tridimensional volumetric error mapping using rigid body kinematics, (iii) volumetric error prediction via an artificial neural network model, and finally (iv) implementation of the on-line error compensation. An illustrative example using a bridge type coordinate measuring machine is presented.

Semi-parametric Adjustment Model Methods for Positioning of Seafloor Control Point

This paper focus on solving the problem of seafloor control point absolute positioning with low vertical accuracy based on the survey ship sailing circle. The method of dealing with the systematic error based on a semi-parametric adjustment model was proposed. Firstly, the influence of sound velocity change on ranging error is analyzed. Secondly, a semi-parametric adjustment model for determining three-dimensional coordinates of seafloor control points was established. And respectively proposed solutions under two different conditions, the observation duration is an integral multiple or non-integer multiple of the long-period term of the ranging error. The simulation experiment shows that this method can obviously improve the accuracy of vertical solution of seafloor control point compared with the difference technique and the least-squares method when internal waves exist and observation duration is less than an integer multiple of the long-period term of the ranging error.

VLC-Based Indoor Positioning Algorithm Combined with OFDM and Particle Filter

Visible light communications(VLC) have recently attracted a growing interest and can be a potential solution to realize indoor positioning,however,the performance of existing indoor positioning system is limited by multipath distortion inside a room.In order to combat the effect of multipath distortion,this paper proposes an LED-based indoor positioning algorithm combined with hybrid OFDM(HOFDM),in which asymmetrically clipped optical OFDM(ACOOFDM) is transmitted on the odd subcarriers while using pulse amplitude modulated discrete multitone(PAM-DMT) to modulate the imaginary part of each even subcarrier.In this scheme,we take a combined approach where a received-signal-strength(RSS) technique is employed to determine the location of the receiver and realize the 3-D positioning by Trust-region-based positioning.Moreover,a particle filter is used to further improve the positioning accuracy.Results confirm that this proposed positioning algorithm can achieve high accuracy even with multipath distortion,and the algorithm has better performance when combined with particle filter.

儒家伦理何以可能

儒家伦理有确定的适用性,它的主体定位是古代社会中“士”以上阶层或士大夫阶层,孔子与孟子等早期儒家创始人物又将其叫做“君子”。显然,这是一种精英定位,旨在培养与实现士人的理想人格。因此它具有明显的非强制特征和非大众倾向,它在提升精英阶层道德境界的同时必然会对伦理在大众层面的普及与实施产生消极的影响。就伦理展开的外部条件而言,犹太教乃至整个亚伯拉罕系统宗教伦理的基石或平台是宗教,它可以通过上帝的监管、伦理诫示、宗教律法以及严守安息日制度等措施,将社会的基本成员甚至全体成员紧密地联结在一起,因此它是十分有效的。在早期中国社会,儒家伦理缺乏像犹太教那样的得以使伦理实现的宗教基石或宗教平台,而宗法家族制度和教育系统又因其自身的脆弱性难以独立支持儒家伦理的展开或实现。因此,尽管早期儒家伦理由思想层面向社会实践层面做了一定的转化,但从总体上说,它对于整个社会的意义是有限的。

A DETECTION METHOD OF HIGH RESOLUTION RADAR TARGETS BASED ON POSITION CORRELATION

This paper studies a detection method of targets of high resolution radar operating at the band of millimeter-wave(32-38GHz) under the background of the clutters, and proposes a new nonparametric detection method, which not only does less computation, but also is able to detect multiple extended targets radially distributed along distance "corridor", based on the position (range) correlation information of one-dimensional range images(or called range profiles) of high resolution radar targets. The experimental results, on the real echo data of tank illuminated by the millimeter-wave stepped frequency high resolution radar, have certified that such a method presented in this paper is a very effective detection method for multiple extended targets.