Vegetative propagation of Dalbergia sissoo:effect of growth regulators,length,position of shoot and type of cuttings on rooting potential in stem cuttings

The effect of auxins （IAA or IBA at 100, 200, 500 mg.L J） on rooting and sprouting parameters differed significantly （p 〈 0.05）. Rooting and sprouting percentages were higher in some treatments while other parameters were significantly higher in other treatments. The results of the present study revealed that rooting was significantly （p 〈 0.05） affected by the length of cuttings, as well as the position of shoots and type of cuttings. On average, 86.0 per cent rooting was observed in the 30-cm long cuttings com- pared to the other two lengths of cuttings, i.e., 20 and 25 cm, irrespective of any auxin treatment. In a control set, without any auxin treatment, a maximum of 60.0% rooting was recorded in the 30-cm long cuttings and a minimum of 40.0% of the cuttings rooted in the 20-cm long cuttings. Similarly, cuttings collected from the lower and upper portions of shoots resulted in 72.5 and 52.5 per cent rooting respectively, irrespective of auxin treatments. Maximum rooting was observed in the lower portion （40.0%） of cutting com- pared to the upper portion （30.0%） in the control set without auxin treatment. Leafless branches produced maximum （72.0%） rooting compared to the leafy cuttings （35.0%）, irrespective of the auxin treatment. The leafy cuttings produces a minimum of 15.0% sprout- ing and rooting in the control set.

Effects of cutting types and hormonal concentration on vegetative propagation of Zanthoxylum armatum in Garhwal Himalaya,India

Experiments were carried out to define the effects of hormonal concentrations on semi-hard wood（SHW） and hard-wood（HW） branch cuttings of the Z.armatum. SHW and HW cuttings were collected in the month of March. The SHW and HW cuttings were treated with different concentration of indole-3-acetic acid and indole-3-butyric acid（IAA and IBA） and placed in vermiculite rooting medium for 90 days under 1-min misting after 10 min. Sprouting, rooting percentage, sprout number, sprout length, root number, and length were measured.The highest rooting and sprouting rate, 64.0 %, was obtained at the 0.3 % IBA treatment in the SHW cuttings.Similarly sprout length and number of roots per cutting were also higher at the 0.3 % IBA treatment in the SHW cuttings. The number of shoots per cutting was higher at the 0.3 % IAA treatment in the SHW cuttings. Root length per cutting was higher in 0.4 % IBA treatment in the SHW cuttings. The results indicated that 0.3 and 0.4 % IBA treatment produce higher rooting percentages as well as the number of roots and their length in SHW cuttings. The HW cuttings produced maximum rate of 18.0 % rooting in0.5 % IBA treatment. The control set and lower concentrations of IBA and IAA completely failed to root in the mist chamber.

Reconstructing the size of individual trees using log data from cut-to-length harvesters in Pinus radiata plantations: a case study in NSW, Australia

With their widespread utilization, cut-to-length harvesters have become a major source of ‘‘big data’’ for forest management as they constantly capture, and provide a daily flow of, information on log production and assortment over large operational areas. Harvester data afford the calculation of the total log length between the stump and the last cut but not the total height of trees. They also contain the length and end diameters of individual logs but not always the diameter at breast height overbark（DBHOB） of harvested stems largely because of time lapse, operating and processing issues and other system deficiencies. Even when DBHOB is extracted from harvester data, errors and/or bias of the machine measurements due to the variation in the stump height of harvested stems from that specified for the harvester head prior to harvesting and diameter measurement errors may need to be corrected. This study developed（1） a system of equations for estimating DBHOB of trees from diameter overbark（DOB） measured by a harvester head at any height up to 3 m above ground level and（2） an equation to predict the total height of harvested stems in P. radiata plantations from harvester data. To generate the data required for this purpose, cut-to-length simulations of more than 3000 trees with detailed taper measurements were carried out in the computer using the cutting patterns extracted from the harvester data and stump height survey data from clearfall operations. The equation predicted total tree height from DBHOB, total log length and the small end diameter of the top log. Prediction accuracy for total tree height was evaluated both globally over the entire data space and locally within partitioned subspaces through benchmarking statistics. These statistics were better than that of the conventional height-diameter equations for P. radiata found in the literature, even when they incorporated stand age and the average height and diameter of dominant trees in the stand as predictors. So this equation when used with harvester data would outperform the conventional equations in tree height prediction. Tree and stand reconstructions of the harvested forest is the necessary first step to provide the essential link of harvester data to conventional inventory, remote sensing imagery and Li DAR data. The equations developed in this study will provide such a linkage for the most effective combined use of harvester data in predicting the attributes of individual trees, stands and forests, and product recovery for the management and planning of P. radiata plantations in New South Wales, Australia.

Development of a Procedure to Maximize Production of Hardy Rootstocks of Citrus Using Stem Cuttings

Shoots of Citrus sp. Kuharske were used to develop protocols for rooting reportedly HLB resistance rootstocks under intermittent mist. Investigated were shoot maturity, nodes per cutting, leaves per cutting, effects of buds, auxin concentrations and auxin solvent. Shoot maturity was most influential for success, with cuttings taken below the first 30 cm of active terminal growth producing greater root generation. Use of a thickening agent (Natrosal) to dilute the commercial auxin was second most in importance for rooting success. Root mass increased with increasing number of leaves. Cutting stems between nodes or below the lowest bud were inconsequential. To produce maximum number of viable cuttings, single node-single leaf cuttings were preferred. Single bud cuttings produced one shoot after rooting. This was adventitious since multi-node cuttings usually sprouted new shoots that would need to be removed before budded. Evaluation of the best combination of auxin and cutting-related attributes were evaluated with four additional common rootstocks in June 2016. Rooting was 100% successful. A quick dip (0.5 s) in a 7500 ppm solution of Dip&Gro produced the most root generation in six weeks for all rootstocks. Root quantity varied by rootstock.

Frequently cutting restriction enzymes: Clearing the fog to see the ends

Telomeres, which are found at the ends of eukaryotic chromosomes, are composed of tandem arrays of repetitive sequences and safeguard genomic stability. Previous studies have revealed that telomeric repeats are also present at internal chromosomal loci in many eukaryotes. However, the biological role of these interstitial telomeric sequences (ITSs) remains unknown. The integrity of telomeric length and chromatin structure is required for telomere stability. However, the study of these telomeric features can be impeded by the presence of ITSs. Frequently cutting restriction enzymes have been revealed to be very useful tools for the study of the length and chromatin structure of telomeres independent of the presence of ITSs.

Incorporation of Cutting for Customized Suits

The theoretical male body size and its distribution plan are studied in consideration with the nation standard and the information provided by several garment companies. Through nine times tries of marking two suits with the CAD marking module, the fabric length and rates are derived. The formulas of the marking fabric length, the length total, and the girth total are obtained by using SPSS software. Moreover, by comparing the two incorporation methods of cutting in which one in the arithmetic sequence and the other in the geometric sequence, it is found that the one in the arithmetic sequence is better than the one in the geometric sequence.

基于形态学方法与边缘检测的原竹几何特征识别

为提高原竹初加工过程的自动化、智能化水平,针对竹节位置与原竹内外径的快速精准识别需求,提出了一种基于形态学方法与边缘检测的原竹几何特征识别方法。首先,通过对原竹图像进行预处理,去除背景干扰,获得原竹竹节及竹径截面前景信息。其次,基于边缘检测原理计算原竹竹节图片的梯度数值以判断竹节是否存在,并通过形态学方法确定竹节位置;采用Canny算法获得竹径截面图片的内外径轮廓,基于椭圆截面的最小二乘拟合得到内外径尺寸并分级。最后,进行了原竹竹节与内外径识别试验。结果表明:竹节识别速度为0.2 s/次,准确率为95.5%,内外径识别速度为0.2 s/次,准确率为98%,验证了该方法的有效性。

运营隧道防水板切割二衬的危害及整治方案研究

[目的]随着我国隧道建设步伐的加快,运营隧道中各类病害问题日益突显。尽管众多学者已对多种病害进行了深入研究,但针对防水板切割二衬的危害研究仍显不足。因此,有必要深入探究运营隧道中防水板切割二衬危害,并提出有效的整治方案。[方法]基于防水板的防水与受力作用机理,运用数值模拟技术,系统研究了运营隧道中防水板切割二衬的危害。重点分析了环向与纵向不同切割长度下,防水板拱部弯矩、衬砌Mises应力及位移等三项关键指标的变化规律。在此基础上,提出了一种新型整治设计方案,并通过对比防水板整治前后衬砌结构拱顶位移的变化,验证了该整治设计方案的合理性与优越性。[结果及结论]研究结果表明,随着防水板环向与纵向切割长度的增加,防水板拱部弯矩、衬砌应力及位移均呈现显著增长趋势。特别是防水板的纵向切割长度,对衬砌位移等三项指标的影响更为显著。通过综合分析弯矩、应力及位移的突变区域,发现防水板环向与纵向切割长度在2~3 m范围内时,对衬砌结构的受力及变形影响最为不利。

基于目标定尺的双偏心摆式飞剪机控制参数计算

研究了双偏心摆式飞剪连续定尺剪切原理,建立了目标定尺长度计算模型,形成比较完善的基于目标定尺长度的双偏心摆式飞剪传动控制参数计算方法。设定曲轴转动角速度曲线,建立速度方程式,解析求解得到曲轴转动角速度,从而得到角加速度、加减速时间、匀速转动角速度、匀速运行保持时间等控制参数。并通过某汽车板连续镀锌机组的双偏心摆式飞剪机进行编制程序和控制计算验证,计算速度快,精度高,完全满足工程需要。

基于切断称重法的并条机牵伸区内变速点分布

为探究并条机牵伸区内纤维变速点分布的特点,以纺制定重为15.35 g/5m的普梳条和15.03 g/5m的精梳条为例,采用FA320A型高速并条机进行实验,对罗拉牵伸区中的须条进行定长的切断称重得到纤维质量分布,以其纤维质量变化率分布表征变速点分布,并在此基础上借助数据处理的方法分别给出定量表征牵伸区内纤维变速点分布稳定性、集中性、前移性的理论计算公式,并通过并条实验对所给出的公式进行了验证分析。结果表明:该理论计算公式可以判断出变速点分布的位置及状态;在此实验中,精梳条中的纤维在距前罗拉钳口线5~15 mm处变速相对集中且前移、稳定性好;普梳条中的纤维变速点分布较为分散,且远离前罗拉钳口线。该研究为变速点分布理论的发展提供了参考,有助于预测成条质量,提高并条效率。

超大断面扁平结构隧道施工参数优化研究

基于某超大断面扁平结构隧道的上下台阶法施工段,采用数值模拟方法研究在该工程地质条件下台阶长度和锚杆纵距2种施工参数改变带来的影响。利用数值模型对不同台阶长度(分别为30,40,50,60 m)和不同锚杆纵距(分别为1.0,1.5,2.0 m)情况进行研究,对隧洞周边岩体中塑性区、围岩应力和围岩变形情况的分布规律进行分析,结合数值结果和现场监测数据验证了施工现场采用台阶长度为50 m和锚杆纵距为1 m的施工参数较合理。该研究成果可为超大断面扁平结构隧道的开挖和支护施工参数的合理选取提供参考。

一种定长制动软管自动切管机的研制

汽车制动软管是燃油汽车制动系统中用于传输或储存液压油、气体等介质,提供汽车制动器加力的可弯曲且有一定弹性的柔性导管,其质量好坏与汽车安全性能息息相关。生产出合格软管的关键环节,是将不定长的软管按规范裁剪成满足设计要求的定长管子。采用可编程控制器(Programmable Logic Controller,PLC)作为核心控制单元,利用市场上现有成熟、可靠的产品,设计出具有特殊功能的制动软管自动切管机,将定长管切割成2种长度,并自动计算每种管子的裁剪数量,成功提高切管速度和精度。

智能采掘装备在阶段空场嗣后充填法中的应用

随着国民经济建设的快速发展,地下矿产资源需求量不断增大,金、银、铜、铁等战略性矿产资源是国民经济的基础。为满足国家工业生产需求,需要提升地下矿山的开采效率,由于阶段空场嗣后充填采矿法便于实现机械化开采,在我国地下矿山得到了日益广泛的应用,但目前阶段其仍然存在关键环节和重点部位用人多、智能化程度较低、安全风险高等问题,如何实现安全、智能、绿色、高效开采是亟需解决的问题。本文详细介绍了采准、切割、回采三个环节智能采掘装备的特点及应用,提出了阶段空场嗣后充填采矿法的智能采掘方案,并已将该技术成功应用于矿山实际生产,实现了凿岩穿孔智能化、天井掘进无人化,对推动我国智能矿山建设提供了重要的技术装备支撑。

综采工作面静态膨胀预裂切顶卸压效果分析

为探究静态膨胀预裂切顶卸压在综采工作面初采初放中的应用效果,以三元煤业4308综采工作面为背景,在确定工作面静态膨胀预裂切顶卸压技术方案的基础上,利用FLAC 3D软件建立数值计算模型,分析了工作面初采悬顶长度随静态膨胀预裂切顶长度的变化规律。研究结果表明,无预裂以及静态膨胀预裂长度分别为7.5 m、15 m、25 m时,4308综采工作面的初采悬顶长度分别为40 m、32 m、27 m、26 m,静态膨胀预裂切顶卸压技术可以有效控制工作面初采悬顶长度;工作面初采悬顶长度随静态膨胀预裂切顶长度的增大先减小后不变,综合考虑经济成本,确定最佳静态膨胀预裂切顶长度为15 m。静态膨胀预裂切顶卸压技术具有放顶效果好、安全性高、施工简单等优点,能够满足安全生产的要求,可适用于矿井工作面顶板的初采初放。

激光切管机使用的影响因素及解决方法

激光切管机主要用于切割板材、管材等长度较长的材料,其对设备、工艺参数、操作细节等方面具有更高要求。分析激光切管机的工作原理、技术特点、辅助气体、切割功率、参数调用、切割方法以及使用过程中的影响因素,总结一套相对完整的工艺参数调整方法,旨在为相关领域的技术人员更安全方便地使用设备提供一定参考和借鉴。

主动柔性防护网锚杆锚固段长度设计研究

随着我国高速公路建设加速推进,越来越多的高速公路进入到运维期,路堑边坡会出现局部崩塌、岩石风化剥落等现象。对于存在落石风险的岩质边坡,工程中一般采用主动柔性防护网进行防护。文章结合工程实际技术指标,通过简化边坡局部崩塌计算模型,得出路堑边坡主动柔性防护网锚杆锚固段长度的简化算法,为锚杆锚固段的长度设计提供技术支持。

卷烟定长切丝技术对中支卷烟质量的影响

中支卷烟的制作工艺要求高。相比于常规切丝方法,定长切丝方法具有明显的优越性,特别是对标准差方面的检测能力更佳。为提高卷烟的制作技术水平,介绍定长切丝方法对中支卷烟的影响,期望能够为优化中支卷烟的制作工艺提供借鉴。

地稔不同插枝对根系生长及成活率的影响

地稔是集药用、观赏和果用为一体的新型多用途植物,人工栽培主要采用扦插育苗的方式,为促进地稔插枝的生根,研究了不同木质化程度和不同扦插长度对地稔成活和不定根形成的影响。结果表明,半木质化的插枝在发根量、根系总长、根系直径和成活率等方面均表现最佳,而未木质化的嫩枝根系发生时间虽然最早,但成活率却最低,高度木质化的插枝则根系生长最差;插枝长度以5~10 cm的发根量、总根长、根直径和成活率均最高,5 cm以下的扦插枝发根时间虽然最早,但根系直径最小、成活率也最低,10~15 cm的扦插枝则发根时间最晚、发根量和总根长最短。

矩阵算子法构建切削滑移线场的分析

刀具与切屑接触的摩擦因数呈不均匀分布增加了正交切削分析的难度,缺少一个完善的解析模型。针对于此,本文采用矩阵算子法构建了一种考虑在刀-屑接触面上变摩擦因数的滑移线场。通过Oxley的剪切切削理论找出工件表面材料塑性剪切变形的位置,为滑移线场的添加几何约束条件,从而求解滑移线参数。根据滑移线场,导出刀-屑接触长度,推算出切削力的解析式。模型计算结果与GH4169切削有限元仿真结果对比发现:刀-屑接触长度误差在9.8%内,两者的切削力在变化趋势上一致且数值上相近,验证了滑移线场的准确性。上述研究成果为变摩擦因数的正交切削分析刀-屑接触长度和切削力提供了理论方法。