陕西飞播造林技术综述

本文主要从播区、树种、播期三个方面论述了陕西飞播造林的成就。对半干旱、半湿润、湿润三类地区飞播效果作了比较。对油松、华山松、马尾松、侧柏、漆树、踏郎、沙打旺等7个有代表性的飞播植物种的生物学特性和成苗规律进行了分析。按各地水热条件的不同,把播期划分为春、夏、秋三个季节。

Research of an Appropriate Sowing Quantity of Double-cropping Machine-transplanted Rice in Low and Medium Yielding District of Southern Jiangxi Province

[Objective] The aim was to research the appropriate seeding quantities of double-season machine-transplanted rice in middle and low-yielding district of southern Jiangxi Province. [Method] The research set five different seeding quantities treatments, and compared with conventional seedling treatment, and the appropriate seeding quantities of double season machine-transplanted rice in middle and lowyielding district of southern Jiangxi Province was discussed. [Result] The yields were highest when the seeding quantity was 70 g per tray of early rice by mechanical transplanting and 60 g per tray of late rice. The yield of early rice by mechanical transplanting showed significantly positive correlation with the number of productive ear and the number of seed per ear, and late rice yield showed significant correlation with the number of productive ear by mechanical transplanting. It is key for improving high yields by guaranteeing the number of productive ear. [Conclusion] The issue of proper sowing quantity should be taken into consideration for double-cropping rice in the region, which is crucial for high yields.

Spatial interpolation method based on integrated RBF neural networks for estimating heavy metals in soil of a mountain region

A novel spatial interpolation method based on integrated radial basis function artificial neural networks （IRBFANNs） is proposed to provide accurate and stable predictions of heavy metals concentrations in soil at un- sampled sites in a mountain region. The IRBFANNs hybridize the advantages of the artificial neural networks and the neural networks integration approach. Three experimental projects under different sampling densities are carried out to study the performance of the proposed IRBFANNs-based interpolation method. This novel method is compared with six peer spatial interpolation methods based on the root mean square error and visual evaluation of the distribution maps of Mn elements. The experimental results show that the proposed method performs better in accuracy and stability. Moreover, the proposed method can provide more details in the spatial distribution maps than the compared interpolation methods in the cases of sparse sampling density.

基于Landsat8影像的厚云及云影去除方法

Landsat系列卫星对推动遥感应用技术的发展起到了重要作用,其遥感图像数据在多领域得到了广泛应用。但是Landsat影像常受到云的污染,使得其在地表动态监测时有效性大大下降。本文首先利用云和云阴影匹配算法Fmask实现快速、准确地识别云与云影区域并进行掩膜,然后基于时空数据融合算法ESTARFM利用多时相MODIS和Landsat数据,对Landsat8影像缺失的云及云影区域进行插补。结果表明这是一种有效地去除云及云影的方法,对Landsat8数据的定量分析或时序研究具有重要价值。

Storage and Density of Soil Organic Carbon in Urban Topsoil of Hilly Cities:A Case Study of Chongqing Municipality of China

Rapid urbanization results in the conversion of natural soil to urban soil,and consequently,the storage and density of the soil carbon pools change.Taking Chongqing Municipality of China as a study case,this investigation attempts to better understand soil carbon pools in hilly cities.First,the vegetated areas in the study area were derived from QuickBird images.Then,topsoil data from 220 soil samples(0-20 cm) in the vegetated areas were collected and their soil organic carbon(SOC) densities were analyzed.Using the Kriging interpolation method,the spatial pattern of SOC was estimated.The results show that the SOC density exhibited high spatial variability in the urban topsoil of Chongqing.First,the SOC density in topsoil decreased according to slope in the order 2°-6° < 25°-90° < 0°-2° < 6°-15° < 15°-25°.Second,the newly developed areas during 2001-2010 had a lower SOC density than the areas built before 1988.Third,urban parks and gardens had a higher SOC density in topsoil,residential green land followed,and scattered street green land ranked last.For hilly cities,the variability of terrain affects the distribution of SOC.The Kriging results indicate that Kriging method combining slope with SOC density produced a high level of accuracy.The Kriging results show that the SOC density to the north of the Jialing River was higher than the south.The vegetated areas were estimated to amount to 73.5 km2 across the study area with an SOC storage of 0.192 Tg and an average density of 2.61 kg/m2.

A buffer insertion and simultaneous sizing timing optimization algorithm

A path-based timing optimization algorithm for buffer insertion and simultaneous sizing is proposed. Firstly, candidate buffer insertion location and buffer size for each branch in a given routing path were obtained via localized timing optimization. Then, through evaluating each potential insertion against design objectives, potential optimal buffer insertion locations and sizes for the whole routing tree were determined. At last, by removing redundant buffer insertion operations which do not maximize S （ so ）, given timing requirements are finally fulfilled through minimum number of buffers.

Fast wire segmenting algorithm considering layout density and signal integrity

A k-shortest path based algorithm considering layout density and signal integrity for good buffer candidatelocations is proposed in this paper. Theoretical results for computing the maximal distance betweenbuffers are derived under the timing, noise and slew rate constraints. By modifying the traditional uniformwire segmenting strategy and considering the impact of tile size on density penalty function, this work proposesk-shortest path algorithm to find the buffer insertion candidate locations. The experiments show thatthe buffers inserted can significantly optimize the design density, alleviate signal degradation, save thenumber of buffers inserted and the overall run time.

Using a 3D Interval Type-2 Fuzzy Interpolation System to Improve Modeless Robots Measurement and Calibration Accuracy

This paper is an extended research for a novel technique used in the pose error compensations of the robot and manipulator calibration process based on an IT2FEI （interval type-2 fuzzy error interpolation） method. Robot calibrations can be classified into model-based and modeless methods. A model-based calibration method normally requires that the practitioners understand the kinematics of the robot therefore may pose a challenger for field engineers. An alternative yet effective means for robot calibration is to use a modeless method; however with such a method there is a conflict between the calibration accuracy of the robot and the number of grid points used in the calibration task. In this paper, an interval type-2 fuzzy interpolation system is applied to improve the compensation accuracy of the robot in its 3D workspace. An on-line type-2 fuzzy inference system is implemented to meet the needs of on-line robot trajectory planning and control. The simulated results given in this paper show that not only robot compensation accuracy can be greatly improved, but also the calibration process can be significantly simplified, and it is more suitable for practical applications.

Uniform Convergence of Higher Order Fejér Interpolation Polynomials in a Complex Domain

For a Jordan domain D in the complex plane satisfying certain boundary conditions a function f B(D), we prove that the corresponding higher order Fejer interpolation polynomials based on Fejer points converge to f(z) uniformly on D. These extend some known results.

Treatment of subtrochanteric femoral fracture with long proximal femoral nail antirotation

Objective： Subtrochanteric femoral fractures are severe injuries. Although many treatment methods have been developed, controversy exists regarding the optimal management of these fractures. This study evaluated the clinical outcome of subtrochanteric femoral fractures fixed with long proximal femoral nail antirotation （PFNA-Iong）. Methods： Between October 2006 and February 2008, 25 patients with traumatic subtrochanteric fractures of the femur were treated with PFNA-long. Closed reduction and fixation were performed in 20 cases. In the remaining 5 cases, closed reduction was difficult, so limited open reduction was performed, with bone grafting in 4 cases and circumfer-ential wiring in 4 cases. Results： The average follow-up time was 16.1 months. All subtrochanteric femoral fractures healed uneventfully except one case of delayed union. The mean union time was 26.2 weeks. Technical difficulties with nail insertion were encountered in 3 cases. No implant failure was observed. Conclusion： PFNA-long is effective in treatment of subtrochanteric femoral fractures, with a high rate of bone union, minor soft tissue damage, early return to functional exercise and few implant-related complications.