运材车辆驾驶室内噪声的测试与分析

汽车驾驶室因噪声直接危害驾驶人员的身体健康,引起生理和心理上多种疾病,还会诱发交通事故,影响工作效率,我国运材汽车均为载重汽车,由于车辆本身和使用条件等方面的原因,驾驶室内噪声较大,本文针对我国运材生产中经常使用的两种车型驾驶室内噪声的调查为基础,进行有关的试验测试,并利用频谱和相函数理论,建立了在多输入单输出情况下驾驶室内主要噪声源及试验系统模型,经过试验,对运材汽车驾驶室内噪声进行了评价,验证     

汽车用求救报警灯

汽车用求救报警灯专利号：９６２２６９１６．６本实用新型涉及一种报警装置，特别是当汽车遭遇他人劫持、或遇难时用以向外界发出求救报警信号，即汽车用求救报警装置。抢劫汽车的犯罪为多发生在汽车内，外界不易察觉，隐蔽性强，不利于公安机关和广大群众的有效打击和阻...     

谈浓烟对扑火人员的威胁

在扑教森林火灾的过程中,造成扑火人员伤亡绝大多数是由于火场上的浓烟。浓烟对扑火人员的威胁有两点:一是森林可燃物燃烧时浓烟中的有害气体直接造成扑火人员的伤亡;二是燃烧时浓烟将扑火人员熏倒窒息,再被烈火所烧,造成伤亡。下面就从这两点谈谈浓烟对扑火人员的威胁。一、浓烟中有毒气体对人的威胁森林植物燃烧会生成大量浓烟,并产生许多有害气体,这些气体对扑火人员的人身构成威胁,如:1.一氧化碳一氧化碳是森林燃烧时产生最多的有害气体。     

公路桥涵汽车用电子限高报警系统（Ⅱ）——激光超高报警系统的设计

公路桥涵车用激光超高检测设备,通过信号连接线与信号处理和声光显示装置相连,组成激光超高报警系统。一旦有超高车辆通过,遮住了激光对射线,即电子检测设备检测出异常情况,立即由报警提示装置发出声光报警信号。报警时间的长短可根据需要设定,并能自动恢复正常状态,反复使用,达到全天候保护桥梁和涵洞的目的。详细描述了激光超高报警系统中,声光显示与报警装置的特点以及设计与安装方法。     

车载超低容量喷雾机液位自动检测装置的研究

目前喷雾机的药箱一般内置于喷雾机罩内,不易观察其液位的情况,给施药人员带来很多不便。基于这些实际问题而设计出一套液位自动检测及报警的控制模块,即当药箱液位低于设定的阀值时报警装置启动,提示药液不足以进行药箱的换接,从而避免漏喷或施药量不足。     

石英钟式地震墙体稍微倾斜报警器

地震是不可避免的,现在的科学技术有许多地震在震前也是可以测出来的,但是准确的时间、地点和级别,不好确定,因此造成人员大规模的伤亡。为解决这一问题,科研人员研制了石英钟式的地震墙体稍微倾斜报警器,使用时固定在室内墙壁上,外表看上去是一个石英钟,它适合于在室内工作或休息的人员,     

汽车拖挂车运材安全装置

汽车拖挂车运材安全装置（１５３１００）南岔林业局王成玉（１５００８６）林业部哈尔滨林机所王锦康我国北方林区近年来广泛采用汽车拖挂车运原条或原木，由于林区道路等级较低，弯道半径小，再加上冰雪路面打滑等因素，有时就会产生翻车事故，造成人身伤亡与较大的经济...     

避火罩的开发和使用

扑救森林火灾是人与火的搏斗，稍有不慎就会发生人身伤亡事故。据统计，１９７６—１９９９年，我国因扑救森林火灾死亡约５００人。从统计资料来看，扑火人员伤亡原因主要是：①被火围困无法逃脱；②扑火人员自身疾病引发伤亡；③扑火过程中的摔伤砸伤；④在进入和撤离火场时交通事故所致；⑤其它原因。其中被大火围困无法逃脱窒息而烧死所占的比例最大。其原因，一是由于扑火人员缺乏扑火知识，不熟悉地形，当火场风向突变，大火袭来时惊慌失措造成的；二是由于缺少实用的自救装备。要减少这类伤亡事故，一方面要求参加扑火的人员必须进行…     

怎样使用汽车制动器

制动器的作用在汽车行驶中的重要性是众所周知的。但是,如何合理地使用汽车制动器,人们却有着不同的见解。本文仅就这一问题谈谈个人的一些看法。一、滥用制动器问题汽车驾驶室的制动踏板和加速踏板是作用相反的两个操纵部位。有些驾驶人员在驾驶车辆时松开加速踏板就踏上制动踏板,抬起制动     

解放牌汽车驾驶室采暖装置的研制

解放后,随着我国汽车工业的发展,作为国产主要机型的解放牌汽车,在国民经济的各个部门中得到了广泛的使用,但由于该车型的驾驶室原设计没有冬季的采暖装置,给地处高寒地带的驾驶人员,在冬季运行时增加了很大困难,影响了汽车利用率的提高。为此,笔者结合林业生产实际,经多次试验研制出解放牌汽车驾驶室采暖装置。现将其介绍如下:     

铁路起重机安全监控装置研制

介绍了一套铁路起重机安全监控装置,该装置可对铁路救援起重机在起吊作业中的重心偏移进行实时监测,当发生危险情况时能立即报警并停止起吊作业.     

A modeling analysis of the interaction between forest age and forest responsiveness to increasing CO2 concentration

Typically, forests have rotations of 10-200 years. On that time scale, anthropogenic increases in atmospheric carbon dioxide concentration ([CO2]) and the associated changes in climate are expected to be substantial. These changes will, therefore, almost certainly affect the growth of presently established forest stands. Most studies on the effects of increasing [CO2] on tree growth have been made with young plants. However, the growth of trees within a forest stand varies with age. As a consequence, it is difficult to infer from the available experimental data how rising [CO2] will affect forest productivity over a full rotation. In this study, various mechanisms that may account for the slowing of forest growth with age were introduced into the forest growth model CenW, to assess how these processes affect the modeled growth response to increasing [CO2]. Inclusion of allocation shifts with tree height, individual tree mortality, changing respiration load and nutrient dynamics or age-based reductions in photosynthetic capacity had only small effects on the response to increasing [CO2]. However, when photosynthesis of mature trees was decreased as a function of size, then the growth response to increasing [CO2] was reduced because, at the same age, trees were larger in elevated than in ambient [CO2]. No simple and generally valid interactions between increasing [CO2] and forest age were identified because of the large number of interacting processes, all of which are incompletely understood. Important age x climate change interactions on productivity must occur in real forests and need to be considered to understand likely future trends. However, these interactions are complex and difficult to test. It is therefore not yet possible to predict with confidence the modification of the CO2 response by forest age.     

轮胎红外测温防爆预警系统设计研究

针对高速公路上汽车爆胎事故频繁发生的现象,通过对轮胎生热机理、轮胎爆裂机理的研究,阐述轮胎红外测温防爆预警系统的结构、基本原理,完成轮胎红外测温防爆预警系统的硬件和软件设计。实验结果表明该系统可以实时监测轮胎表面温度的分布情况,当温度过高时自动报警,帮助驾驶员合理使用轮胎,实现轮胎防爆预警功能,避免因此而造成人员和财产损失,为车辆安全行驶,避免重大交通安全事故具有很大的社会和经济意义。研究表明,该系统对防止汽车爆胎的发生有着实际的应用价值。     

桉树爬树修枝机的设计与测试

为了实现快速修枝,结合桉树的通直度较其他林木高的特点,设计一种以两个对置分布的驱动轮作为攀爬驱动机构,从而使自身可以沿着树干直接往上爬升的爬树修枝机.该爬树修枝机主要由攀爬装置和修枝装置组成.对攀爬装置进行动力学分析,确定了驱动轮与树干之间的摩擦系数和攀爬装置夹紧力所要满足的关系式;根据滑切切割可降低切割阻力的原理,对...     

Lignification in beech (Fagus sylvatica) grown at elevated CO2 concentrations: interaction with nutrient availability and leaf maturation

Beech (Fagus sylvatica L.) seedlings were grown in an ambient or elevated CO2 concentration ([CO2]) either in small stands in microcosms for three to four seasons or individually in pots fertilized at different nutrient supply rates. Leaves at different stages of development, as well as stems and roots at the end of the growing season, were used for analysis of structural biomass and lignin. In elevated [CO2], lignification of leaves was slightly retarded compared with structural biomass production and showed a strong correlation with the activities of ionically, cell-wall-bound peroxidases but not with total soluble peroxidases or covalently wall-bound peroxidases. The effect of elevated [CO2] on lignin concentration of mature tissues was dependent on nutrient supply rate. In leaves and roots, elevated [CO2] increased the lignin concentration in dry mass in N-limited plants. In seedlings grown with high nutrient supply, the lignin concentration in dry mass was unaffected or diminished by elevated [CO2]. Because elevated [CO2] enhanced seedling growth in the high nutrient supply treatments, the total amount of lignin produced per seedling was higher in these treatments. We predict that long-term sequestration of carbon will increase as long as biomass production is stimulated by elevated [CO2] and that tissue quality will change depending on developmental stage and nutrient availability.     

Increased understanding of nutrient immobilization in soil organic matter is critical for predicting the carbon sink strength of forest ecosystems over the next 100 years

The terrestrial biosphere is currently thought to be a significant sink for atmospheric carbon (C). However, the future course of this sink under rising [CO2] and temperature is uncertain. Some contrasting possibilities that have been suggested are: that the sink is currently increasing through CO2 fertilization of plant growth but will decline over the next few decades because of CO2 saturation and soil nutrient constraints; that the sink will continue to increase over the next century because rising temperature will stimulate the release of plant-available soil nitrogen (N) through increased soil decomposition; that, alternatively, the sink will not be sustained because the additional soil N released will be immobilized in the soil rather than taken up by plants; or that the sink will soon become negative because loss of soil C through temperature stimulation of soil respiration will override any CO2 or temperature stimulation of plant growth. Soil N immobilization is thus a key process; however, it remains poorly understood. In this paper we use a forest ecosystem model of plant-soil C and N dynamics to gauge the importance of this uncertainty for predictions of the future C sink of forests under rising [CO2] and temperature. We characterize soil N immobilization by the degree of variability of soil N:C ratios assumed in the model. We show that the modeled C sink of a stand of Norway spruce (Picea abies (L.) Karst.) in northern Sweden is highly sensitive to this assumption. Under increasing temperature, the model predicts a strong C sink when soil N:C is inflexible, but a greatly reduced C sink when soil N:C is allowed to vary. In complete contrast, increasing atmospheric [CO2] leads to a much stronger C sink when soil N:C is variable. When both temperature and [CO2] increase, the C sink strength is relatively insensitive to variability in soil N:C; significantly, however, with inflexible soil N:C the C sink is primarily a temperature response whereas with variable soil N:C, it is a combined temperature-CO2 response. Simulations with gradual increases of temperature and [CO2] indicate a sustained C sink over the next 100 years, in contrast to recent claims that the C sink will decline over the next few decades. Nevertheless, in using a relatively simple model, our primary aim is not to make precise predictions of the C sink over the next 100 years, but rather to highlight key areas of model uncertainty requiring further experimental clarification. Here we show that improved understanding of the processes underlying soil N immobilization is essential if we are to predict the future course of the forest carbon sink.     

Canopy position and needle age affect photosynthetic response in field-grown Pinus radiata after five years of exposure to elevated carbon dioxide partial pressure

Photosynthesis of tree seedlings is generally enhanced during short-term exposure to elevated atmospheric CO2 partial pressure, but longer-term studies often indicate some degree of photosynthetic adjustment. We present physiological and biochemical evidence to explain observed long-term photosynthetic responses to elevated CO2 partial pressure as influenced by needle age and canopy position. We grew Pinus radiata D. Don. trees in open-top chambers for 5 years in sandy soil at ambient (36 Pa) and elevated (65 Pa) CO2 partial pressures. The trees were well watered and exposed to natural light and ambient temperature. In the fourth year of CO2 exposure (fall 1997), when foliage growth had ceased for the year, photosynthetic down-regulation was observed in 1-year-old needles, but not in current-year needles, suggesting a reduction in carbohydrate sink strength as a result of increasing needle age (Turnbull et al. 1998). In 5-year-old trees (spring 1997), when foliage expansion was occurring, photosynthetic down-regulation was not observed, reflecting significantly large sinks for carbohydrates throughout the tree. Net photosynthesis was stimulated by 79% in trees growing in elevated CO2 partial pressure, but there was no significant effect on photosynthetic capacity or Rubisco activity and concentration. Current-year needles were more responsive to elevated CO2 partial pressure than 1-year-old needles, exhibiting larger relative increases in net photosynthesis to elevated CO2 partial pressure (98 versus 64%). Lower canopy and upper canopy leaves exhibited similar relative responses to growth in elevated CO2 partial pressure. However, needles in the upper canopy exhibited higher net photosynthesis, photosynthetic capacity, and Rubisco activity and concentration than needles in the lower canopy. Given that the ratio of mature to juvenile foliage mass in the canopy will increase as trees mature, we suggest that trees may become less responsive to elevated CO2 partial pressure with increasing age. We conclude that tree response to elevated CO2 partial pressure is based primarily on sink strength and not on the duration of exposure.     

公路桥涵汽车用电子限高报警系统（Ⅰ）——电子限高报警装置的原理与基本要求

公路桥涵车用电子限高报警装置,是一种防止超高车辆撞坏桥涵的自动检测报警装置。文中描述这种专用电子限高装置的工作原理、基本要求以及常用的激光检测器与红外检测器的性能,为下一步进行设计公路桥涵车用电子限高报警装置提供必要的理论依据。