Analysis on Fuji Apple Tree Structures and Related Factors under Different Pruning Modes

To determine the correlations between the tree structuresof Fuji apple with different pruning modes and each factor, the data about 3 tree structures which were free spindle short shoot, free spindle long shoot and slenderspindle short shoot in Xingtang County of Hebai Province were investigated, then by SPSS anal- ysis, the correlations between the taperingness and each growth factor of inserted small branch were compared. The results showed that the taperingness of central trunk of free spindle dwarf-shoot Fuji apple treeshad negative correlations with each factor of inserted small branch, while the taperingness of central trunk of free spin- dle long-shoot Fuji apple treeshad positive correlations with each factor of inserted small branch, the taperingness of central trunk of slenderspindle short-shootFuji ap- ple treeshad negative correlation with total thickness of inserted small branch, but had positive correlations with other factors. This study can provide a scientifictheo- retical basis for the pruning technology of high-density planting trees grafting by dwarfing self-rooted rootstock.

调动生活经验 帮助理解词意——《我们爱老师》教学片断与评析

《我们爱老师》(第一册)一课要理解的词有“辛勤”、“关心”等。课堂上老师可以这样引导学生理解这两个词: (为丰富学生的感性认识,课前教师可带学生到公园参观。) 师:“辛勤”是什么意思? 生:“辛”就是辛苦。 师:那么“勤”呢?

Design of research platform on telerobot system based on virtual reality technology

A design strategy for a research platform of a telepresence telerobot system based on virtual reality technology is put forward. The design frame of the system is described, and its important core techniques are described. An octrees data structure is utilized to build kinematic and dynamic modeling of the virtual simulation environment, Delphi+OpenGL+3DS MAX are adopted to carry through the virtual modeling and visible simulation exploitation of the slave-robot and its environment. Photo-correction is adopted to correct positioning deviation of the virtual geometric model and modeling errors. The cost of software and hardware equipment for the research platform realized is low. The master/slave robot (manipulator) system and all software in the system were designed and manufactured by our research group. The performance of the system has reached the level required for research. An indispensable experiment base is provided for the research of a telepresence telerobot system based on virtual reality technology.

Nitrogen Mineralization of Prunings of Six N_2-Fixing Hedgerow Species in a Dry Valley of the Jinsha River

A litterbag experiment of 12 weeks was conducted to study nitrogenmineralization process of prunings of six nitrogen-fixing hedgerowspecies in a dry valley of the Jinsha River. Prunigns wereincorporated into soil or used as mulch. The results indicated thatpruning N of the six hedgerow species was mineralized fast in thefirst week and then decreased slowly in the rest of the study period.When prunings were incorporated into soil, the amount of nitrogenmineralized by the end of the first week accounted for 69.9/100,58.2/100, 54.5/100, 43.0/100, 29.6/100 and 20.6/100 of the total N inprungins of Desmodium rensonii, Tephrosia candida, Leucaenaleucoephala, Albizia yunnanensis, Acacia dealbata, and Acaciamearnsii, respectively.

Fruit production and quality improvement in aonla （Emblica Officinalis Gaertn.） through canopy management

In order to maintain the health and vigour and to sustain the productivity, a pruning experiment was conducted on four year old ＂Balwant＂ cultivar of aonla grown in laterite soil, planted at a spacing of 5m×5m. To find out the best pruning method, six levels of pruning was performed i.e., （1） Light judicious pruning, （2） Detopping of primary branches at 8 feet from ground level ＋ removal of all secondary branches, （3） Detopping of primary branches at 8 feet from the ground level ＋ removal of all secondary branches at 2 feet from the base of primary branches, （4） Detopping of primary branches at 8 feet from the ground level ＋ removal of all secondary branches at 1 feet from the base of primary branches, （5） Light judicious pruning ＋ Detopping of plant canopy of at 8 feet from the ground level, （6） No pruning （control）. Results of three consecutive years of investigation revealed that light judicious pruning of thin, overlapping, criss-crossed, dead, unproductive and looping branches gave highest fruit yield in all the three years and resulted 64.4 percent yield increment over control when average of three years was considered. Severe pruning of primary and secondary branches caused drastic reduction of yield for two consecutive years after pruning. Judicious pruning helped to produce better sizeable and quality fruits.

Risk Assessment Based on Fault Tree Analysis for Damaged Pipe Repair During Operation in Petrochemical Plant

In petrochemical plant, the in-operation repairing is usually a repairing strategy with pressured inoperation repairing for avoiding huge economic losses caused by unplanned shutdown when some slight local leakage happens in pipes. This paper studies the effects of repairing strategies on the failure probability of the pipe systems in process industries based on the time-average fault tree approach, especially the in-operation repairing strategies including pressured in-operation repairing activities. The fault tree model can predict the effect of different repairing plans on the pipe failure probability, which is significant to the optimization of the repairing plans. At first pipes are distinguished into four states in this model, i.e., successive state, flaw state, leakage state and failure state. Then the fault tree approach, which is usually applied in the studies of dynamic equipment, is adopted to model the pipe failure. Moreover, the effect of pressured in-operation repairing is also considered in the model. In addition, this paper proposes a series of time-average parameters of the fault tree model, all of which are used to calculate node parameters of the fault tree model. At last, a practical case is calculated based on the fault tree model in a repairing activity of pipe thinning.

Biochar and alternate partial root-zone irrigation greatly enhance the effectiveness of mulberry in remediating lead-contaminated soils

Aims Soil lead contamination has become increasingly serious and phytoremediation can provide an effective way to reclaim the contaminated soils.This study aims to examine the growth,lead resistance and lead accumulation of mulberry(Morus alba L.)seedlings at four levels of soil lead contamination with or without biochar addition under normal or alternative partial root-zone irrigation(APRI).Methods We conducted a three-factor greenhouse experiment with biochar(with vs.without biochar addition),irrigation method(APRI vs.normal irrigation)and four levels of soil lead(0,50,200 and 800 mg·kg^(-1)).The performance of the seedlings under different treatments was evaluated by measuring growth traits,osmotic substances,antioxidant enzymes and lead accumulation and translocation.Important Findings The results reveal that mulberry had a strong ability to acclimate to soil lead contamination,and that biochar and APRI synergistically increased the biomass and surface area of absorption root across all levels of soil lead.The seedlings were able to resist the severe soil lead contamination(800 mg·kg^(-1) Pb)by adjusting glutathione metabolism,and enhancing the osmotic and oxidative regulating capacity via increasing proline content and the peroxidase activity.Lead ions in the seedlings were primarily concentrated in roots and exhibited a dose–effect associated with the lead concentration in the soil.Pb,biochar and ARPI interactively affected Pb concentrations in leaves and roots,translocation factor and bioconcentration.Our results suggest that planting mulberry trees in combination with biochar addition and APRI can be used to effectively remediate lead-contaminated soils.

Study on Machining Properties of Eucalyptus urophylla× E.grandis:Ⅱ.Shaping,Boring,Mortising and Turning

The research method of this paper is based on the standards of American Society for Testing and Materials (ASTM). Four items that contain boring, mortising, shaping and turning are selected to study the machining properties of E. urophylla × E. grandis plantation wood. The reasons for machining defects are analyzed. The resultshows thatE. urophylla × E. grandis planted in South China isa good specieswith great potential for solid wood utilization.