Effect of oxalic acid and steam pretreatment on the primary properties of UF-bonded rice straw particleboards

The objective is to evaluate the effect of oxalic acid (OA) and steam-pretreatment on the primary performance of rice straw particleboards. In addition, the effect of various treatment conditions on carbohydrates released from rice straw particles was investigated. The results show that steam- and short durations of OA-treatment significantly improved the mechanical properties and dimensional stability of rice straw particleboards. However, steam-treated rice straw (without OA-treatment) panels exhibited even better performance when compared with OA-treated panels. OA-pretreatment time has a negative effect on performance of panels, whereas the effect of temperature on the performance of OA-treated panels was not significant, except for the linear expansion. OA-treatment accelerated carbohydrates extraction. The sugars released from the OA-treated rice straw particles increase with increasing treatment temperature and time. Carbohydrates extracted from rice straw particles could be a potential sustainable resource for biofuel or bio-based chemicals.     

多杀菌素对阿里山潜蝇茧蜂的亚致死效应

以对多杀菌素敏感的橘小实蝇实验种群做寄主饲养阿里山潜蝇茧蜂,毒力测定结果显示,多杀菌素对阿里山潜蝇茧蜂雌蜂和雄蜂的LC50分别为0.090 8 mg/mL和0.027 4 mg/mL,LD50分别为1.004 1 mg和0.804 3 mg。分别用1 000、2 000、3 000倍液的多杀菌素处理阿里山潜蝇茧蜂成蜂,与对照相比,不同倍液的多杀菌素亚致死剂量均使阿里山潜蝇茧蜂的寿命显著缩短;雌蜂的总产卵量、平均产卵量、寄生率、子代成蜂羽化率等均随着多杀菌素浓度的增大而减少;但子代雌雄性比之间差异不显著;阿里山潜蝇茧蜂寄生橘小实蝇卵的拟合方程符合Holling圆盘方程Ⅱ型,处理寄主的时间随着多杀菌素浓度的增大而增加、瞬时攻击率、搜寻效应等均随着多杀菌素浓度的增大而减少。结果表明,多杀菌素的亚致死剂量可通过缩短寿命、降低繁殖力、改变功能反应参数等影响阿里山潜蝇茧蜂,从而影响生物防治的效果。     

不同秧龄对双季机插晚稻生长特性与产量形成的影响

为解决长江中下游地区双季机插晚稻移栽秧龄过长的问题,选取温光特性及熟期各不相同的4个代表性品种为材料,研究不同秧龄移栽对双季晚稻生长及产量的影响。结果表明,随着移栽秧龄的增大,感温性水稻穂、成熟期均明显推迟,而感光型水稻生育期受影响较小;感温性迟熟品种25 天、30 天移栽产量显著下降,而感温性中早熟及感光性迟熟品种至30 天移栽产量才发生显著下降。最佳移栽秧龄为感温性晚稻15 天左右,感光性晚稻20 天左右。感温性品种作双季晚稻种植时应选用中早熟品种,而感光性品种可选用高产的中迟熟品种。     

转Bt杂交棉花新品种 ‘苏棉29’ 性状研究

客观分析杂交棉花新品种‘苏棉29’的性状,为棉花育种者制定合适的育种策略提供依据。基于江苏省棉花品种区域试验数据,采用Excel、G—GE等统计软件系统研究了新品种‘苏棉29’的丰产性、稳产性、产量构成因素及纤维品质、抗性等性状。结果表明：在江苏省区域试验中2年（2010、2011）平均,‘苏棉29’籽棉产量和皮棉产量为4185、1737kg／hm^2,分别较对照品种‘泗杂3号’增产10．6％和8．5％;生产试验中（2012）平均籽棉产量达到4176kg／hm^2,皮棉产量1744．5kg／hm^2;‘苏棉29’纤维品质各项指标均达国家Ⅲ级以上标准,高抗棉铃虫,兼抗棉花枯黄萎病。该品种在2013年通过江苏省农作物品种审定委员会审定。本研究从表型数据初步解析了该品种高产、稳产、抗病虫机理,将为进一步推广利用该品种奠定了基础。     

龙船花各器官中金属元素的火焰原子吸收光谱法测定

通过火焰原子吸收光谱法对龙船花各部位的K、Ca、Na、Mg、Fe、Mn、Zn、Cu、Cr、Ni的含量进行测定分析,为龙船花的生产实践及综合开发利用提供基础数据。结果表明,10种金属元素在各部位中的含量（平均值）高低顺序为：K＞Ca＞Na＞Mg/Fe＞Zn＞Mn＞Cu＞Cr＞Ni。同种元素在龙船花各部位的含量存在不同程度的差异。所测龙船花各部位中的Na、Ca、Fe、Cu、Zn、Ni的含量多数在一般植物体的正常含量范围内,K、Mg和Mn元素含量略低于一般植物含量,Cr元素含量略高于一般植物含量。     

闽台不同海拔乌龙茶品质差异研究

为研究闽台两地不同海拔乌龙茶的品质差异,分别对产自福建海拔高度为40、100、200、500、1000 m的铁观音茶和台湾海拔高度为40、1200、1500、1800、2200 m的乌龙茶品质进行感官审评及内含成分分析。结果表明,铁观音和乌龙茶感官品质得分随着海拔高度的升高而提高,产自海拔1000 m的铁观音和海拔2200 m的梨山乌龙茶品质最好,平地产乌龙茶品质相对较差;茶叶中的氨基酸含量随海拔高度的升高而增加,海拔1800 m以上的奇莱山和梨山乌龙茶氨基酸含量达到4.36%和4.27%。低山产和高山产乌龙茶内含成分差异明显,茶多酚、咖啡碱含量和酚/氨值随海拔高度的升高而下降。在海拔均为1200 m左右的台湾阿里山和福建漳平,相同品种制成的乌龙茶品质相当。     

Semi-Analytical Solutions for Two-Dimensional Transport and Transformation of Contaminants in Soil Medias Associated with Large-Strain Deformation

For the understanding of contaminant transport and transformation through landfill liner soils, most models are proposed with one-dimensional solutions. However, for large-scale contamination analysis, the one-dimensional analytical equations are not valid owing to the restriction of contaminants moving in horizontal direction. Thus, semi-analytical solutions for two-dimensional transport and transformation of contaminants through soil media with the consideration of large-strain deformation have been developed. To achieve this, Gibson’s large-strain consolidation theory is applied to capture the deformation of soil media under loading, with self-weight effects being taken into account. Transport and transformation of dissolved or sorbed contaminates in fully saturated finite soil medias are captured by extending a well-developed advection-dispersion model in two-dimensional space. The proposed analytical solutions are validated through simulating the process of coupled transport-transformation process of contaminants and consolidation of a finite soil layer. Profiles of contaminant concentration for different cases have been compared and discussed. The resulting simulation shows that large-strain deformation would restrict the transport and transformation of contaminants significantly, in both horizontal and vertical directions. Parameter studies also indicate that, with the increasing depth of soil layer, the breakthrough time for contaminants increases dramatically; diffusion coefficients affect the two-dimensional distributions of contaminant concentration and fate of contaminant in layered soil significantly. The numerical findings of this study can provide proper suggestions for the design of landfill liners.     

Effects of six years of simulated N deposition on gross soil N transformation rates in an old-growth temperate forest

Elevated atmospheric nitrogen(N) deposition has been detected in many regions of China, but its effects on soil N transformation in temperate forest ecosystems are not well known. We therefore simulated N deposition with four levels of N addition rate(N0, N30, N60, and N120) for6 years in an old-growth temperate forest in Xiaoxing'an Mountains in Northeastern China. We measured gross N transformation rates in the laboratory using ~(15)N tracing technology to explore the effects of N deposition on soil gross N transformations taking advantage of N deposition soils. No significant differences in gross soil N transformation rates were observed after 6 years of N deposition with various levels of N addition rate. For all N deposition soils, the gross NH_4~+ immobilization rates were consistently lower than the gross N mineralization rates,leading to net N mineralization. Nitrate(NO_3~-) was primarily produced via oxidation of NH_4~+(i.e., autotrophic nitrification), whereas oxidation of organic N(i.e., heterotrophic nitrification) was negligible. Differences between the quantity of ammonia-oxidizing bacteria and ammonia-oxidizing archaea were not significant for any treatment, which likely explains the lack of a significant effect on gross nitrification rates. Gross nitrification rates were much higher than the total NO_3~- consumption rates,resulting in a build-up of NO_3~-, which highlights the high risk of N losses via NO_3~- leaching or gaseous N emissions from soils. This response is opposite that of typical N-limited temperate forests suffering from N deposition,suggesting that the investigated old-growth temperate forest ecosystem is likely to approach N saturation.     

区域木材物流调配及监管系统的设计

为了加强林区区域内木材物流的调配及监管,在深入分析林权改革后的木材物流新特性后,应用长短信、数据库技术,建立了区域木材物流调配及监管体系,并完成了软件系统的开发。该系统在初步应用中,实现了多县木材物流数据共享,提高了车辆调配效率,加大了政府对木材物流的监管力度。     

阻断剂对三孢布拉霉菌产番茄红素的影响

为选取高效安全的阻断剂,本实验采用对比试验方法,首次选择茉莉茶茶渣、茶碱和烟酰胺三种阻断剂,研究其对三孢布拉霉(Blakeslea trispora)代谢合成番茄红素、β-胡萝卜素合成量和菌体生物量的影响,并进一步优化茶叶阻断剂促产番茄红素条件。研究结果表明:茶渣、茶碱、烟酰胺均可促进三孢布拉霉累积番茄红素。研究结果表明发酵40 h加入9 g·L~(-1)茶碱、8 g·L~(-1)茶叶、6 g·L~(-1)烟酰胺时,番茄红素的合成量分别是36.32、158.38、34.69 mg·L~(-1),β-胡萝卜素的含量分别是33.25、42.07、31.79 mg·L~(-1),菌体生物量分别是24.69、38.53、27.40 mg·L~(-1)。其中以茶渣阻断番茄红素环化成β-胡萝卜素效果最佳,对其进一步实验的茶渣最佳加入时间为48 h,最佳加入量为9 g·L~(-1)时,番茄红素生物合成量可达到205.49 mg·L~(-1)。研究结果为探索通过阻断番茄红素转化为胡萝卜素代谢路径提供了理论参考。