Effect of moisture content of a wood matrix on a small-scale biodegradation system for organic solid waste

The optimum working moisture content of a wood matrix for the garbage automatic decomposer-extinguisher (GADE) machine was investigated using a small-scale degradation reactor. A formula feed for rabbits was used as the model waste. The degradation experiment was conducted under controlled conditions such as moisture content, environmental temperature, and airflow rate. The degradation rate was estimated precisely from weight loss and the CO₂ evolution rate. The degradation rate were nearly constant at a moisture content of 30%–80% on a-wet-weight basis. Microorganisms from the environment propagated in the reactor with no inoculums added. The number of microorganisms showed a trend similar to that of the degradation rate. The microorganism community changed according to the moisture content of the matrix and were considered to attain a constant degradation rate at a wide range of moisture content of a matrix.Part of this report was presented at the 49th annual meeting of the Japan Wood Research Society, Tokyo, April 1999     

Effects of wood species on degradation rates and bacterial communities in a small-scale biodegradation system for garbage using wood matrices

Simulated organic waste was biodegraded in a laboratory-scale machine using matrices prepared from four wood species to investigate the effects of wood species on the degradation rate and the bacterial community. The degradation rate, estimated by measuring weight loss and CO₂ evolution, was found to be equal among the four wood species. Changes in viable cell counts and microbial communities over time were examined. Viable cell counts were also similar among the wood species, but initial bacterial communities differed owing to differences in wood species, although these communities became similar with time. The sensitivity of isolates to wood extractives was examined using paper discs. The extractive-insensitive bacteria species were dominant at the initial stage of biodegradation. However, occupancy of sensitive bacteria increased with time. It was thought that antibacterial extractives were degraded or inactivated after some time.Part of this report was presented at the 50th annual meeting of the Japan Wood Research Society, Kyoto. Japan, April 2000     

温度对人工林落叶松材物理力学性能的影响

探讨在不同的干燥温度状态下,木材抗弯强度,抗弯弹性模量、横纹抗压强度的变化规律。试验结果显示,在中、低温区域,随着温度的升高,抗弯弹性模量、横纹抗压强镁呈降低趋势;在高温区域,随着温度的升高,抗弯强度被明显削弱,而纹抗压强度则得到增强。     

Stress relaxation of wood during elevating and lowering processes of temperature and the set after relaxation II: consideration of the mechanism and simulation of stress relaxation behavior using a viscoelastic model

Previously we showed that the relaxation modulusEt of water-saturated wood during temperature reduction maintained its initial value despite the decrease in temperature, although during temperature elevationEt showed a marked decrease. In the present study, to clarify the mechanism of relaxation during temperature elevation and reduction, Young's modulus was measured in stress relaxation experiments with changes in temperature, and relaxation behavior was simulated using a Maxwell model consisting of five elements. Furthermore, the dynamic Young's modulus and dynamic loss modulus were measured during both temperature elevation and reduction. The results obtained suggested that the unique relaxation behavior during temperature reduction was caused by decreases in Young's modulus and coefficient of viscosity (i.e., an increase in fluidity) compared with those during elevation of temperature. The decrease in Young's modulus and increase in fluidity were considered to be due to an unstable structure in wood that occurred during temperature reduction. This unstable structure probably develops in the nonequilibrium state of temperature toward a true equilibrium state. Wood should be more unstable during temperature reduction than during temperature elevation because of the decrease in molecular motion when the temperature is lowered.Part of this report was presented at the 49th annual meeting of the Japan Wood Research Society, Tokyo, April 1999     

温度对杉木林土壤呼吸的影响(英文)

Soil samples collected from the surface soil (0(10 cm) in an 88-year-old Chinese fir (Cunninghamia lanceolata) forest in Nanping, Fujian, China were incubated for 90 days at the temperatures of 15°C, 25°C and 35°C in laboratory. The soil CO2 evolution rates were measured at the incubation time of 2, 5, 10, 15, 20, 25, 30, 35, 40, 50, 60, 70, 80 and 90 days. The results showed that CO2 evolution rates of soil samples varied significantly with incubation time and temperature during the incubation period. Mean CO2 evolution rate and cumulative amount of CO2 evolution from soil were highest at 35°C, followed by those at 25°C, and 15°C. Substantial differences in CO2 evolution rate were found in Q10 values calculated for the 2nd and 90th day of incubation. The Q10 value for the average CO2 evolution rate was 2.0 at the temperature range of 15-25°C, but it decreased to 1.2 at 25- 35°C. Soil CO2 evolution rates decreased with the incubation time. The cumulative mineralized C at the end of incubation period (on the 90th day) was less than 10% of the initial C amounts prior to incubation.     

Buttock temperature in a sedentary posture on plywood flooring of varying thickness over the ONDOL heating system

This study investigated the thermophysiological responses of healthy subjects that sat on the plywood covering of the ONDOL floor heating system. Environmental chambers were constructed for this study, wherein ambient temperature, and wall and ceiling surface temperature were controlled at 24°C, and relative humidity was 50%. The temperature of supply water (t _sw) flowing into the floor coil was altered from 15°C to 40°C at 5°C intervals. The floor covering materials used in this experiment were mortar and three types of plywood with thicknesses of 2.7, 7.5, and 12mm. The floor surface temperatures (t _f) and the skin temperatures of eight subjects were measured while they were sitting on the floor. Buttock temperature, in particular, was monitored. This experiment yielded the following results: (1) t _f was 17.0°–35.2°C on mortar finishing and 19.1°–30.2°C on 12-mm plywood covering; (2) the buttocks skin temperature increased with t _sw higher than 30°C on mortar finishing and for t _sw higher than 30°, 25°, and 20° on 2.7-, 7.5-, and 12-mm plywood finishing, respectively; (3) the differences of buttock temperature when t _sw was varied between 15° and 40°C were 11.4°C on mortar, 7.9°C on 2.7-mm plywood, 6.5°C on 7.5-mm plywood, and 5.0°C on 12-mm plywood; (4) using regression analysis, the neutral point temperature of buttocks was determined to be 32.8°C.Part of this report was presented at the 53rd Annual Meeting of the Japan Wood Research Society, Fukuoka, Japan, March 2003     

温度对垂丝紫荆种子发芽的影响

试验研究了不同发芽温度对垂丝紫荆种子发芽的影响，主要包括发芽势、发芽率和发芽指数3个重要指标的变化。结果表明，与对照（20℃）相比较，不同发芽温度对垂丝紫荆种子发芽势、发芽指数的影响均达极显著水平，而对发芽率的影响不显著。其中15—25℃的变温处理是垂丝紫荆种子发芽的最佳温度。     

Mechanical properties of wood swollen in organic liquids with two or more functional groups for hydrogen bonding in a molecule

The modulus of elasticity and the modulus of rupture during static bending in the radial direction, and the viscoelastic properties in the radial direction in the temperature range 20°–100°C of hinoki (Chamaecyparis obtusa) swollen in organic liquids with two or more functional groups in a molecule were compared with those of wood swollen by moisture. The wood swollen in organic liquids in or near the swelling equilibrium, but not that swollen in organic liquids distant from the swelling equilibrium, showed higher moduli of elasticity and rupture than the wood swollen to a similar degree by moisture. This suggests that wood exists in an unstable state as it approaches the swelling equilibrium, rendering it highly flexible and weak. During the first viscoelastic measurements for wood swollen in various organic liquids, thermal softening was observed in 40°–60°C range and above 80°C, though this softening disappeared during the second measurement. The softening observed in the 40°–60°C range and above 80°C was thought to have been caused by the redistribution of liquid toward the equilibrium state at a higher temperature and the swelling accompanying an elevated temperature, respectively.Part of this report was presented at the 49th Annual Meeting of the Japan Wood Research Society, Tokyo, April 1999     

杨木材性对单板胶合的影响及胶合工艺

本文以组坯结构,涂胶量和热压条件等为单板胶合的相关因子进行６种杨木单板胶合的正交试验,研究了胶合工艺的适应性和较优的工艺条件。结果表明：由于选用的杨树组系,产地等不同,树种间的材性差异较大,所以难以找出一个通用的胶合工艺条件;在所试验的６个品系杨树中大部分以采用热压单位压力０．５￣０．８ＭＰａ,热压时间４０ｓ／ｍｍ、涂胶量２８０￣３４０ｇ／ｍ＾２,脲醛胶填料（面粉）加量１５份的调胶配比及等厚单板组     

胁迫温度短期冲击对松毛虫赤眼蜂羧酸酯酶活性的影响

以松毛虫赤眼蜂为对象,在不同温度胁迫短期冲击条件下对其羧酸酯酶比活力进行测定,结果表明:在15℃条件下,羧酸酯酶的比活力最高,为270.00±28.50;35℃条件下最低,为101.50±3.60;25℃条件下介于两者之间,为150.00±3.00;3种温度条件下的羧酸酯酶比活力存在显著差异(P0.05),且随着温度的升高羧酸酯酶比活力显著下降。     

Association between temperature,relative humidity and concentration of volatile organic compounds from wooden furniture in a model room

Abstract

Emissions of volatile organic compounds (VOCs) from wooden furniture in a child's room were investigated. A model room was set up in a 12?m³ test chamber, and in parallel, a scaled-down version was run in a 1?m³ test chamber. The latter had a steady climate of 23°C/50% relative humidity (RH), while the temperature and humidity conditions were varied in the 12?m³ chamber between 18 and 28°C, and 30 and 80% RH. Compounds found were α-pinene, β-pinene, 3-carene, limonene and hexanal. Variations in the climate showed that there is an association between temperature and room concentrations of all found VOCs. Changes in RH showed effect on hexanal concentration, and all monoterpene concentrations remained unaffected.     

温度对重组竹短期受压蠕变性能的影响

通过对重组竹受压试件进行短期蠕变试验,研究温度对重组竹受压试件蠕变特性及蠕变规律的影响.针对不同应力水平下温度对重组竹短期受压蠕变的影响,研究了在同一应力水平7.5％下,重组竹在5种不同温度下的24 h顺纹受压蠕变性能;进一步比较了重组竹在应力水平为7.5％,15％,30％且温度分别为25,50,75℃情况下的24 h...     

干藏条件下低温对平阴玫瑰花蕾的影响

试验测定了常温和低温处理下平阴玫瑰的若干生理指标。结果表明，与常温处理相比，低温处理的花蕾相对含水量较高，蛋白质、SOD、CAT的始降期较晚且变化较缓，POD、MDA和质膜透性比较低。说明，水分亏缺导致膜稳定性和完整性的破坏与膜脂过氧化作用加强是平阴玫瑰花蕾衰老的主要原因之一。低温处理花蕾是干藏保鲜的有效措施。     

连续平压法热压机热油二次循环系统温度控制技术的研究实践

连续平压法热压机各温度区的控制是实现人造板连续生产得以实施的最重要工艺参数保障措施之一,而热油二次循环系统是设定温度精确控制的最重要手段。基于长期实践经验和探索研究,采用PLC的运算和控制功能,利用PLC的脉宽调制,配置传动机构进行位移调控,从而实现压机各区域温度的精确控制,它有别于传统的热油二次循环系统热压温度控制模式。     

胁迫温度短期冲击对松毛虫赤眼蜂谷胱甘肽硫转移酶活性的影响

以松毛虫赤眼蜂为对象,对其不同温度条件下的谷胱甘肽硫转移酶比活力进行测定,结果表明:在15℃处理条件下,谷胱甘肽硫转移酶的比活力最低,为6.80±4.71;在35℃处理条件下最高,为98.22±1.76;25℃处理介于两者之间,为32.49±2.60;3种温度条件下的谷胱甘肽硫转移酶比活力存在显著差异(P0.05),且随着温度的升高比活力显著上升。     

温湿处理环境对木塑复合材弯曲性能的影响

木塑复合材在使用时应考虑不同的环境条件对材料性能的影响,本文研究了不同密度的聚丙烯基木塑复合材经高/低温和浸水处理后材料的弯曲性能的变化情况,为木塑产品的生产和应用提供依据。     

稻草覆盖对果园土壤温度与含水量的影响

在洮南市北部半山区的果树试验场,按果树树冠垂直投影筑树盘,对树盘进行稻草覆盖处理,研究其对土壤温度与含水量的影响。结果表明：覆草处理能够有效地提高土壤含水量,年平均含水量比清耕地高出16．0％;经覆草处理的土壤,生长前期土温上升缓慢,后期土温下降缓慢,越冬前,土温高于清耕地2．00℃,可减少低温对根系的危害。     

Effect of polyol on thermo-oxidative degradation of isocyanate resin for wood adhesives

The thermo-oxidative degradation of various polyol-added isocyanate resins for wood adhesives was studied using differential scanning calorimetry and thermogravimetry. The degradation of the resin cured with water began at 150°C. When a certain polyol was added to the resin at an NCO/OH ratio of 25 in addition to water, the cured resin began to degrade at 200°C. To clarify the cause of the good thermal stability in polyol-added resins, the effect of various polyols on the reactivity of isocyanate was investigated. It was found that the reactivity of isocyanate was enhanced by the addition of a dipropylene glycol and glycerin-type polyols. In addition, the effect of the NCO/ polyol-OH ratio was investigated using dipropylene glycoltype polyol. The reactivity of isocyanate increased with increasing polyol content. The thermal stability of the resin was improved to a certain degree by addition of a small amount of the polyol but deteriorated when a large amount of the polyol was added.Part of this paper was presented at the 48th annual meeting of the Japan Wood Research Society, Shizuoka, April 1998     

Effect of high temperature heat treatment on pH value of Masson Pine wood

Heat-treated wood has good dimensional stability,corrosion resistance and visual quality,but it is prone to mold,which limits its application.Based on the pH value of heat-treated wood,this study examines the factors affecting the pathogenesis causing heat-treated wood mold.Normally,the pH value of the heat-treated wood is between 4.38 and 5.10,which is suitable for the growth of mold.However,the pH of the heat-treated copper-containing material is between 6.63 and 7.12,which deviates the treated wood from the comfortable growth conditions for the mold,thereby reducing the occurrence of mold.     

高温少雨期环境因子对油茶果径生长的影响

为了探讨油茶高产稳产的水分生理生态基础,为油茶水分管理提供科学依据,在高温少雨期,以10年生油茶优良无性系为试验材料,设置无干旱胁迫、轻度干旱胁迫、中度干旱胁迫、重度干旱胁迫、浇后控水和自然状态6种土壤水分处理,观测土壤温度、气象因子和油茶果径生长量,研究环境因子对油茶果径生长的影响。结果表明:试验期(35d),各处理根据果径生长量由大到小排列,依次为轻度干旱胁迫(9.35mm)、无干旱胁迫(7.78mm)、中度干旱胁迫(3.95mm)、浇后控水(3.82mm)、自然状态(2.96mm)、重度干旱胁迫(0.90mm)。多重比较结果显示,除中度干旱胁迫与浇后控水处理间果径生长量差异不显著外,其它各处理间果径生长量差异显著。试验进行10d后重度干旱胁迫处理的果径出现负增长,20d后浇后控水处理的果径生长减缓,30d后重度干旱胁迫、浇后控水和自然状态处理的叶片出现暂时萎蔫发黄。相关性分析结果表明,果径生长量与土壤含水量、空气相对湿度呈正相关,与空气温度呈负相关。油茶果径生长对土壤水分、空气温度、空气相对湿度反应敏感,轻度干旱胁迫处理即土壤含水量为田间持水量的80%~90%为油茶果实生长最佳土壤含水量。