Hollows in jarrah (Eucalyptus marginata) and marri (Corymbia calophylla) trees: I. Hollow sizes, tree attributes and ages

One hundred and fifty-four jarrah (Eucalyptus marginata) and 85 marri (Corymbia calophylla) trees were measured and assessed, and the numbers and sizes of hollows in these trees were determined by destructive sampling; 665 hollows were located and measured. The relationship between tree diameter and tree age was determined from counts of annual growth rings on 162 of these trees. Large trees and trees with moderately senescent crowns individually bear the most hollows. Although the number of hollows found in individual trees increased with tree diameter, the distribution of tree diameters in the forest is skewed and the large number of small trees with diameters between 40 and 80 cm contribute approximately 50% of all hollows in the jarrah forest. The distributions of entry size, and of hollow depth, are highly skewed, with small hollows occurring more frequently than large hollows. Although jarrah trees bear more hollows than marri trees and the distribution of entry sizes is similar for both tree species, the hollows in jarrah are significantly smaller than the hollows in marri. Most hollows are cylindrical in shape, vertically oriented and occur in dead wood in the tree crown. Relatively few hollows (14%) occur in the tree bole or at crown break. Counts of hollows made from ground level are inaccurate as estimates of the actual number of hollows in trees.     

去除取样法估算鳄蜥的种群数量

一直以来对野外鳄蜥种群数量的调查主要使用样线法和标志重捕法。为了更好地估算鳄蜥的种群数量,本研究在2016年7月25日至31日使用去除取样法对广西大桂山鳄蜥国家级保护区内鱼散冲的1.9 km的样线进行了调查。结果显示,鱼散冲的鳄蜥种群数量为101只,种群密度为53只/km。鳄蜥由于其特殊的栖息环境和生活习性,适合于采用去除取样法调查其种群数量和密度。     

不同产地刺猬紫檀木射线组织比较解剖研究

以产自非洲国家的刺猬紫檀 (Pterocarpus erinaceus ) 木材为样品,测定分析木射线宽度与高度 的尺寸、细胞数目,木射线比率。结果表明：轴向薄壁组织带中的射线宽度尺寸均大于木纤维带中的射 线宽度尺寸。木射线的细胞数目及木射线比率则差异性小。从木射线组织解剖结果看,采自西非7 个国 家的刺猬紫檀应该同属一个木种。     

Retention behavior of size and aluminum components on handsheets in rosin-ester size/alum systems

Anionic emulsion sizes consisting of rosin triglyceride esters and partly fortified rosin acids (i.e., rosin-ester sizes), have recently been used as internal sizes for alkaline papermaking. In this study, handsheets were prepared from pulp suspensions with alum and a rosin-ester size under various conditions, and sizing degree and size and aluminum contents of the handsheets were determined. Aluminum compounds originating from alum added to the pulp suspensions behave as retention aids of the rosin-ester size even in alkaline papermaking under limited conditions. Carboxyl groups in pulp are the primary retention sites of aluminum compounds in pulp suspensions. They form cationic sites on pulp fibers, and thus the anionic size emulsion particles are adsorbed on pulp fibers by electrostatic interactions. However, the cationic charges of aluminum compounds on pulp fibers decrease and finally disappear completely with the lapse of time after the alum addition by forming ionic bonds between the cationic sites and OH^– ions. Thus, pH values of the pulp suspensions and timing of the size addition strongly influence the retention values of the rosin-ester size and the resultant sizing features.This research was presented in part at the 1995 autumn meetings of the Society of Fiber Science and Technology Japan in Hamamatsu, October 1995     

平原地区杨树人工林阳性冠幅与胸径关系的研究

通过对100株中林46杨树人工林的调查,研究了平原地区杨树人工林阳性冠幅与胸径之间的关系。结果表明:两者之间存在着相当紧密的线性相关关系,其相关线性模型为y=-2.254+0.432x,相关系数为0.9043。     

Effects of auxiliary data source and inventory unit size on the efficiency of sample-based coarse woody debris inventory

The efficiency of a sample-based inventory can be greatly improved if lower cost information on the study area is utilized. It has been observed that the use of airborne laser scanning (ALS) data in the design phase may improve the efficiency of dead wood (coarse woody debris, CWD) volume inventory notably, i.e. a smaller standard error of the mean is observed with the same inventory costs. In the present case, several auxiliary data sources were employed in the design phase by using ‘probability proportional to size’ sampling to select the sample units to be inventoried in the field. It was observed that a combination of ALS data with either aerial photographs or stand-register data can improve the sampling efficiency even more than the use of ALS as a single data source. Since these additional data sources are often gathered for the inventory of living trees, their use does not incur extra expenses for CWD assessment. Thus, the use of these data separately or together with ALS data can greatly improve the cost-efficiency of a CWD volume inventory. It was also observed that the size of the sample units has a slight effect on the sampling efficiency. Even though the improvement in the sampling efficiency was usually greater with larger sample unit sizes, the CWD volume inventory was most efficient with moderate grid cell sizes.     

松香酰胺在中性造纸施胶中的应用

利用松香与异腈酸的酰经反应在１００－１５０℃下合成了三个松香酰胺，并应用它们到中性造纸松香乳酸，ＰＨ４－８的抄造试验表明这些松香衍生物在这个ＰＨ范围内具有高的施胶效果。松香酰结构与酰胺化度对施胶效果有很大的影响。     

Preharvest application of methyl jasmonate (MeJA) in two plum cultivars. 1. Improvement of fruit growth and quality attributes at harvest

Two plum (Prunus salicina Lindl.) cultivars ‘Black Splendor’ (BS) and ‘Royal Rosa’ (RR) were treated with methyl jasmonate (MeJA) at 3 concentrations (0.5, 1.0 and 2.0 mM) along the on-tree fruit development: 63, 77 and 98 days after full blossom (DAFB). On a weekly basis, fruit samples were taken for measuring fruit size and weight and parameters related to quality. Results revealed that MeJA was effective in increasing fruit size and weight, the 0.5 mM being the most effective for BS cultivar and 2.0 mM for RR. At harvest, those fruit treated with 0.5 mM MeJA had the highest firmness and colour Hue values. Total acidity was also generally higher in MeJA-treated fruit than in controls, while the content of total soluble solids remained unaffected. In addition, total phenolics and total antioxidant activity were found at higher concentrations in 0.5 and 2.0 mM MeJA-treated than in control fruit over at last 3 weeks of fruit development for BS and RR cultivars, respectively. Overall results suggest that MeJA could be a promising preharvest tool to increase plum size and quality with enhanced bioactive compounds and antioxidant activity, although the optimum concentration is cultivar dependent.     

The measurements of acid detergent fibre in rapeseed by visible and near-infrared spectroscopy

Visible and near‐infrared spectroscopy (NIRS) calibrations for acid detergent fibre (ADF) in intact rapeseed (Brassica napus L.) were performed for two different sample volumes (10 ml, 500 seeds approximately; and 1 ml, 50 seeds approximately). The inclusion of brown and yellow‐seeded cultivars in this work has allowed the whole range of ADF currently described in the literature for this character to be covered. Chemometric techniques have been used for developing calibration equations for both procedures when measuring the two different seed sample volumes. On the basis of the coefficient of determination in the cross‐validation (R²cv) obtained for the 10 and 1 ml assays (0.80 and 0.73), and SECV/SEL ratios (2.30 and 2.57), respectively, both equations showed an accuracy sufficient for screening purposes in an ADF range from 6.80 to 13.46% dry wt, which is presented in this work.     

Design for Precision Measurement System Based on Machine Vision

It is difficult to measure the geometric quantity of small parts in finishing, assembling and measuring, because it's easy to break the workpieces' surface and alter their position by means of traditional contact measuring methods.There are some non contact measurers, such as,light feeler pin and interference microscope etc., because of it's high price and strict working conditions,so it's difficult to promote them in widely use. Precision measurement system based on machine vision has the advantages of non contact measuring as well as high performance and low price. Some problems, such as light source, algorithm of edge fitting, auto focusing,are discussed.