粪水离心分离机的研制

从生产实践出发,根据畜禽粪便处理的需要,设计了9LF-4.0型离心机。锥形转鼓是离心力自动卸料离心机中的关键部件。文中叙述了转鼓的强度计算、振动计算、减振设计、锥角与过滤介质的选用等。通过猪场粪水和鸡场粪水的离心试验表明该机能满足畜禽场粪水固液分离的需要,并具有结构简单、价格低廉、操作方便、能连续作业等优点。     

粪水离心分离机的研制

从生产实践出发,根据畜禽粪便处理的需要,设计了9LF-4.0型离心机。锥形转鼓是离心力自动卸料离心机中的关键部件。文中叙述了转鼓的强度计算、振动计算、减振设计、锥角与过滤介质的选用等。通过猪场粪水和鸡场粪水的离心试验表明该机能满足畜禽场粪水固液分离的需要,并具有结构简单、价格低廉、操作方便、能连续作业等优点。     

削度方程的研究

从削度方程的概念入手，对削度方程的结构形式进行了深入研究，提出了具有最佳结构的削度方程的一般形式，并以湖南省杉木为例，确定了最佳削度方程的具体形式。试验结果表明，建立的新模型要优于以往发表的任何削度方程     

白桦树高级单株木材种出材率表的编制

本文利用白桦的测径样木，结合最优的削度方程，编制了白桦树高级单木材种出材率表，精度较高。可在生产实践中加以应用。     

摩擦式自锁装夹切削锥形孔件的方法

摩擦式自锁装夹切削，是一种针对壁厚较薄，而孔径较大的锥形孔件能获得外观光洁，无接刀痕迹，内外径同轴度高，工件无变形无夹伤，生产效率高的制造方法。     

Growth, survival, and root system morphology of deeply planted Corylus colurna 7 years after transplanting and the effects of root collar excavation

Urban trees are frequently planted with their root collars and structural roots buried well below soil grade, either because of planting practices, nursery production practices, or both. These deeply planted structural roots can impair tree establishment and are thought to reduce tree growth, lifespan, and stability, although research has provided few and contradictory results on these questions to date. This study examines container-grown (55 L) Turkish hazel trees (Corylus colurna L.), planted either at grade, 15 cm below grade, or 30 cm below grade into a well-drained silt loam soil, over nearly 8 years. Five years after planting, in 2004, remediation treatments (root collar excavations) were performed on two replicates of each below-ground treatment. Subsequently, all trees were subjected to flooding stress by being irrigated to soil saturation for approximately 6 weeks. In 2006, flooding stress was repeated. Trees root systems were partially excavated in 2007, and root architecture was characterized. Deep planting did not affect trunk diameter growth over 8 years. Survival was 100% for the first 5 years; however, one 30 cm below grade tree died after flooding in 2004 and another died after the 2006 flooding. Photosynthesis was monitored during the 2004 flooding and all trees experienced decline in photosynthetic rates. There was an apparent slight delay in the decline for trees with excavated root collars and those planted at grade. Girdling roots reduced trunk taper and occurred primarily on unremediated trees planted 30 cm below grade.

Selected individual roots were excavated and followed from the root ball and were observed to gradually rise to the upper soil regions. Analysis of roots emerging from excavation trench faces indicated that vertical root distribution at approximately 1.25 m from the tree trunks was the same regardless of planting depth. Longterm consequences of planting below grade are discussed.     

Modelling the influence of site and weed competition on juvenile modulus of elasticity in Pinus radiata across broad environmental gradients

Data from a nationwide set of Pinus radiata D. Don plots established at a range of conventional stand densities were analysed at age 6 to (i) determine how environment and competition from weeds influence dynamic modulus of elasticity (E) of the lower stem base, (ii) develop a predictive multiple regression model of E for basal stemwood and (iii) identify significant direct and indirect environmental influences (through stem slenderness) on E using path analysis.Site had a highly significant (P < 0.001) influence on E, which exhibited a 3-fold range from 1.6 to 5.3 GPa, across 30 sites. When compared to the weed-free controls, weed competition had a significant (P < 0.0001) and substantial effect on E, increasing values by on average 16% (2.76 GPa vs. 2.38 GPa).The positive linear relationship between stem slenderness (determined as tree height/ground-line tree diameter) and E was by far the strongest relationship (R² = 0.71; P < 0.001) among the 20 variables that were significantly related to E. A multiple regression model that included stem slenderness, mean minimum air temperature in mid-autumn, T_min, as positive linear relationships and net nitrogen (N) mineralisation in a negative linear form accounted for 86% of the variance in E. A cross-validation indicated that this model was stable and unbiased, with the validation accounting for 82% of the variance in E. The final path analysis model included T_min, net N mineralisation, below canopy solar radiation and stem slenderness as significant (P < 0.05) direct influences on E. Below canopy radiation, maximum air temperature during mid-summer, soil total phosphorus and carbon:nitrogen ratio were indirectly associated with E through their significant (P < 0.05) direct relationship with stem slenderness.These results provide considerable insight into how environment regulates E of juvenile P. radiata. Low fertility sites that have warm air temperatures and either a high canopy leaf area index, or high levels of woody weed competition, are most likely to produce trees with high stem slenderness and high E. Conversely, sites that are cool over summer and autumn and high in fertility, with low levels of intra- or inter-specific competition for light are likely to produce trees with low stem slenderness and low E.     

水电站高压岔管多节锥管过渡段的几何构形设计方法

 由于目前对高压钢岔管多节锥管过渡段的构形设计方法从整体上看不具有控制性的几何曲面构形,为此本文提出以单叶双曲回转面为多节锥管过渡段的近似曲面来进行构形的方法。     

日本落叶松削度方程和林分材种出材率表的研究

本文论述了削度方程的类型及其在研制材种出材率表中的重要意义，结合全林分生长模型，林分自然稀疏模型以及林分结构模型编制了日本落叶松林分材种出材率表。经检验精度符合要求。从而为及时准确地掌握林分的材种结构及变化，进行林分材种结构调整，落实限额采伐森林面积提供了重要的理论依据。     

圆锥形喷嘴水头损失的计算公式与试验研究

根据水力学基本原理和水头损失的概念,推导出圆锥形喷嘴水头损失大小的计算公式。实验结果表明：该计算公式的计算值与实测值的拟合效果较好,且与实测值相对误差的平均值仅为7．12%。故该计算公式具有广泛的实用性。