对防腐处理前后遭细菌侵蚀的木材超微构造研究

用透射电镜观察了隧道式细菌在未经防腐剂处理的素材和处理过的木材[欧洲白桦(Betula pendula),欧洲赤松(Pinus silvestris)和挪威云杉(Picea abies)]中形成的腐朽现象,研究了细菌入侵木材细胞壁的过程。侵蚀是从木材细胞腔内开始,通过S_3层后,细菌在细胞壁的S_1层、S_2层及胞间层内移动并且分裂,引起木材细胞壁的降解。还观察了隧道式细菌、隧道的形态和超微结构。本研究表明具缘纹孔和单纹孔的纹孔膜比纹孔缘对细菌活动更有抗性。细菌可以侵入低浓度防腐剂(0.5％Tanalith NCA)处理过的木材,表明细菌具一定解毒能力。     

Effect of air velocity on deep body temperature and weight gain in the broiler chicken

Tunnel ventilation has been adopted as an effective approach to combatting heat stress in poultry. Setting tunnel air velocity to levels that ensure bird comfort, while optimizing performance is an important goal. In recent years, biotelemetry has provided a way to effectively evaluate the impact of management practices on poultry physiology. In this study, we present an approach for evaluating the effects of heat stress and tunnel ventilation on poultry deep body temperature (DBT) using biotelemetry. Three consecutive experiments were conducted using 6 broilers, each at the ages of 8.6, 9.0, and 9.4 wk. Experiments spanned approximately 12 h each and led to 18 data sets. DBT responses of birds under no ventilation rose by as much as 3°C as a result of step increases in ambient temperature. Birds exposed to tunnel ventilation maintained a lower DBT by as much as 0.9°C. During experiment days, birds exposed to tunnel ventilation consistently gained weight with a percentage weight gain ranging from 1% to 11%. Birds not exposed to tunnel ventilation behaved less consistently with some gaining as much as 14% while others lost as much as 9%. Although further studies are required to derive more comprehensive and more statistically significant results, this study provided preliminary data that is needed to warrant such studies, and a stepping stone for making optimal management and risk assessment decisions that are based on physiological needs of the birds.     

风沙流结构的风洞实验研究

在对室内风洞中的风沙流行实测的基础上，定量地考察了２０ｃｍ高度范围内的风沙流结构特征及分布规律。     

隧道洞口景观设计——以杭州西湖风景区五老峰隧道为例

洞口是隧道的标志,城市道路隧道洞口区域更是人们注意的焦点,重视其景观设计具有重要的意义。阐述了洞口景观设计的内容和方法,并结合杭州五老峰隧道介绍了如何在洞口景观设计中结合园林美学等知识,使洞口造型设计不仅满足其使用功能,而且更美观、更环保、更具人文特色。     

城市生活垃圾隧道式静态好氧堆肥试验研究

[目的]更好地处理城市生活垃圾。[方法]采用大型隧道仓,对未分类收集的高含水率的城市生活垃圾进行强制通风的静态高温好氧堆肥试验,观察氧浓度、温度、耗氧速率、含水率等指标的变化。[结果]大体积物料含量≤50%(体积比)、含水率≥65%(WB)、堆高2m的原垃圾堆,静置沥水3d后通风,堆体中起始平均氧浓度≥17%,4d后温度达50℃以上,55℃以上的高温持续7d,满足卫生化要求,第10～25天耗氧速率都较高,最高达1%(ΔO2)/min;堆肥前期含水率略有上升,后期下降。物料发酵20d左右出仓,有机质含量350g/kg左右,含水率≤50%(WB),有利于后续机械筛分和二次发酵。氧浓度的较低区和耗氧速率较高时段及高温段都有极好的相关性。[结论]直接用隧道仓进行城市生活垃圾高温好氧发酵是可行的。     

隧道式梗丝膨胀工序工艺参数优化

以梗丝的物理性能和感官质量为评价依据,对隧道式梗丝膨胀设备的工艺参数进行了优化,得到以下最适的工艺参数:来料含水率33％、蒸汽注入量30％,流化床一区热风温度145℃、二区热风温度130℃、热风回风风速10 m/s.优化后梗丝的物理性能和加工质量得到了一定的提高,整丝率达90.57％,含末率小于1.13％,梗丝填充值提...     

Environmentally friendly spray techniques for tree crops

Environmentally safe spray techniques have been developed to use minimal pesticide inputs and apply them only when and where needed with reduced losses to the environment. In this paper, two such systems are described: (1) shielded systems that recycle spray liquid that would otherwise be lost; (2) detection systems that recognise where there are gaps in crop rows for which spray is not needed. The results of studies by several research groups prove the relevance of these sprayers in reducing pesticide losses. Shielded spraying allows a reduction in chemical input in orchard protection by up to 85% by exploiting more uniform in-canopy spray distribution, recycling the spray that would otherwise be wasted. Sprayers with target detection systems apply spray only where target trees or bushes are present. This technique can reduce chemical consumption in orchards by 30% and decrease drift by 50%.     

隧洞掘进机(TBM)的洞外组装

概述了隧洞掘进机(TBM)的洞外组装,包括开敞式TBM的设备组成、组装前的准备工作、组装程序及关键性的技术措施。由于场地、机具、材料、人员和技术准备充分,TBM的洞外组装十分顺利。辽宁省水利水电工程局组织国内焊工,将国外焊接技术转化为国内严寒地区的焊接技术,成功地进行了刀盘焊接,基本实现了刀盘焊接的国产化,并在国内首次采用方便快捷的TBM滚轮(Dolly)步进技术。     

巷道式孵化的工艺技术探讨

巷道式孵化以其独特的气流方式区别于厢式孵化。巷道式孵化器的气流把含氧量最多的新鲜空气带给老的胚胎，把各阶段老胚胎释放的热量又供给需热的各阶段胚胎的发育，并始终保持着理想的设计温度。因而，所需功率相对较小，且孵化容量大，可以节约大量的能源，具有良好的经济性。讨论了进行巷道式孵化的孵化厅布局及孵化操作技术。中国农业大学正大肉鸡发展中心采用巷道式孵化器对７批艾维茵父母代种鸡的３２０万枚种蛋进行孵化，获得了优异的孵化成绩，受精蛋孵化率平均为９４．７５％，入孵蛋孵化率平均为８５．６７％，健雏率平均为９８．２８％。     

贫困地区区域旅游系统对重大机遇的滞后弱响应——以秦岭终南山公路隧道通车后的柞水旅游为例

对贫困地区而言,大交通线在使游客数量猛增从而带来发展机遇时,整个区域旅游系统还存在滞后弱响应问题。柞水县是陕南山区的国家级贫困县,西安附近有名的旅游区,旅游资源丰富,但由于秦岭阻隔以往其旅游业发展缓慢。构建区域旅游系统应激响应概念模型分析发现,面对秦岭终南山高速公路隧道即将通车的重要机遇和通车后的旅游"井喷",区域旅游系统内支持系统及供给系统响应迟滞而无力,国家干线到门口而区域旅游系统内部其它瓶颈因素依然存在,主客双方利益俱损,柞水县失去了一次很好的自身宣传机会。因此,作为贫困县在旅游业发展初期阶段必须在政府强力主导下发挥支持系统的能动性,努力增加产品、服务、基础设施、服务设施及信息等旅游供给,提高旅游服务水平,改善旅游环境和生态环境,充分利用国家交通干线带来的大好机遇。柞水的困境说明,类似情况下地方政府应该未雨绸缪、系统规划,提早科学应对,力图双赢。