棉花黄枯萎病拮抗菌株的筛选及抗菌蛋白的分离纯化研究

从棉花植株根部筛选的108株芽孢杆菌中,通过对棉花黄枯萎主要病原菌大丽轮枝菌拮抗效果的复筛,分离到一株LC-105菌株,其抑菌圈达到20 mm以上;本研究从该菌株的发酵代谢产物中,分离出活性拮抗物质,进一步通过DEAE-Sephadex A-50离子交换层析和Sephacryl-S100凝胶层析对其代谢产物进行了分离纯化,证明该拮抗物质为一种蛋白质,最后通过聚丙烯酰胺凝胶电泳证实了所分离物质的纯度达到电泳纯.     

关于江西省企业原料林发展问题的思考

对江西省企业原料林建设问题进行了调查研究,从基地规模、建设方式等和融资方式等3个方面,对基地林建设的发展状态进行了分析,并在此基础上总结出存在的主要问题,如林地流转费用高、集约化经营程度低、投融资不畅、创新能力弱等;提出了加快江西省企业原料林基地建设的对策建议,为国内其它区域的原料林发展提供一定的经验借签。     

混凝土生产质量隐患的分析与预防

混凝土是当前使用非常广泛的结构材料。本文主要从混凝土生产的角度分析影响混凝土质量的各种因素,并提出了合理可行的建议与预防措施,保证混凝土生产的安全耐久、经济合理。     

建筑防水工程的质量控制

建筑防水是一门综合性、实用性很强的工程技术,对建筑工程的使用功能起着至关重要的作用。根据近几年的施工实践,对建筑屋面、地下室、厕浴间以及储水池等提出建筑防水工程质量控制要点。     

聚乙烯亚胺-纤维素的合成及对胆红素吸附性能

以聚乙烯亚胺(PEI)为功能基团、微晶纤维素(MCC)为载体通过环氧氯丙烷将PEI接枝到MCC上,制得功能高分子吸附材料PEI-MCC,通过红外光谱、元素分析、X射线衍射对PEI-MCC进行结构表征;测定其对胆红素的吸附性能。结果表明PEI-MCC的合成条件为:在N2保护下,环氧化纤维素(EC)与PEI的质量比为1∶6,反应介质为pH值11的氢氧化钠水溶液40 mL,反应温度70℃,反应时间12 h;过滤产物,水洗至中性,40℃真空干燥24 h,得微黄色固体粉末PEI-MCC,此时结晶度为78.36%,含氮量5.27%。静态吸附测得PEI-MCC对胆红素吸附容量为9.23 mg/g,吸附达平衡的时间为4 h。     

木质纤维制造缓冲材料的应用研究

利用木质纤维材料,通过筛选合适的胶黏剂和发泡剂,采用合理的工艺制造出环保型木质纤维缓冲材料.通过静态压缩试验对制成的环保型木质纤维缓冲材料静态缓冲性能进行了试验研究.研究结果表明,所制成的环保型木质纤维缓冲材料具有良好的缓冲性能,可以部分替代泡沫塑料作为新型环保的缓冲材料.     

豫东平原杨农复合系统物质生产与碳截存

农林复合系统由于林分、农作物和土壤之间的相互作用而对储藏和固定碳具有巨大的潜力.其已经成为减少大气CO2浓度、解决全球气候变暖问题的重要土地利用方式之一,将会对陆地生物圈中通量的输入和碳的长期贮藏产生重要的影响.对豫东平原农区5,9,11和13年4个不同林龄的杨农间作复合系统的生物量、生产力和碳截存量进行测定和研究,结果表明:豫东平原农区5,9,11和13年4个不同年龄段的杨农间作复合系统的总生物量分别为33.03,103.06,124.30和154.60 t·hm-2.4个年龄的杨农间作复合系统平均净生产力分别为19.95,29.30,33.24和56.94t·hm-2a-1.豫东平原农区5,9,11和13年4个年龄的杨农间作复合系统总碳截存量分别达到了19.86,52.42,62.45和76.44 t·hm-2.     

Biased estimation of forest log characteristics using intersect diameters

Logs are an important structural feature of forest ecosystems, and their abundance affects many resources and forest processes, including fire regimes, soil productivity, silviculture, carbon cycling, and wildlife habitat. Consequently, logs are often sampled to estimate their frequency, percent cover, volume, and weight. The line-intersect method (LIM) is one of the most widely used methods to obtain these estimates and has been shown to produce unbiased estimates of log characteristics. With the traditional LIM the diameters of each log at the point of its intersection with the sampling transect are used to estimate log characteristics. Based on a simulation study and a large set of empirical data, we found that use of intersect log diameters to define size classes provided biased estimates of log characteristics. The bias varied by diameter class. Results from the simulation study showed that log frequency and volume were overestimated in small-diameter log classes and underestimated in large-diameter classes. Similarly, results from our empirical analysis showed a 40% overestimate of log volume in the smallest diameter class (15–25 cm), and a 31% underestimate of volume in the largest diameter class (>50 cm). Just as size classes of snags and trees are best defined by their diameter-at-breast height (DBH), size classes of logs should be defined by their large-end diameters (LEDs). When large-end diameters of logs were used instead of diameters measured at the point of transect intersection, bias was substantially reduced or eliminated. These results indicate that line-intersect sampling could be substantially improved by including measurements of LEDs to estimate log characteristics. Our results have far-reaching implications for estimates of log characteristics, such as estimates of fuel loading and subsequent wildfire risk, carbon source and sink dynamics, silviculture, nutrient cycling, and habitat for wildlife. Without our suggested correction to line-intersect sampling, many forest resources associated with log characteristics will not be estimated accurately, affecting a plethora of log-based management and research programs.     

Utilization of pine (Pinus pinea L.) cone in manufacture of wood based composite

Physical and mechanical properties of medium density fiberboards (MDF) made from various mixtures of wood fibers and stone pine (Pinus pinea L.) cones were evaluated using European standards. MDF panels were manufactured using standardized procedures that simulated industrial production at the laboratory. Six panel types were made from mixtures of wood fiber/cone flour, 100/0, 90/10, 80/20, 70/30, 60/40, and 50/50 percents, respectively. Addition of the cone flour into the MDF significantly reduced formaldehyde emission from the panel. In addition, the addition of 10% cone flour also improved water resistance of the MDF panels made using urea–formaldehyde (UF) resin. However, further addition of the cone flour into the panel negatively influenced their water resistance. Flexural properties and internal bond strength decreased with the increase of cone flour content in the panel. The UF resin is the main source of formaldehyde emission from the UF-bonded wood-based panels. Depending on addition of the cone flour in the panels, the formaldehyde emission values ranged from 2.6% to 55.3% lower than the panels made from 100% wood fiber. Based on the findings obtained from this study, pine cone can be used as a renewable biological formaldehyde catcher as an alternative to the traditional formaldehyde catchers for E1 Class MDF manufacture.     

长寿命路面结构研究

长寿命路面是适合我国超重载交通的一种路面结构形式,参考国外长寿命路面设计思想,给出长寿命路面精确定义,提出长寿命路面设计标准,并在结构设计和材料方面提出要求.结合许尉高速公路建设,提出长寿命路面一种具体形式.