松墨天牛对焉尾松树的危害与综合防治技术

指出了松墨天牛是危害焉尾松树正常生长的主要害虫,又是松材线虫病的主要传媒昆虫,对我国松林资源构成严重威胁,针对其生物特性及危害特点进行了长期观察研究,结合实践中的防治措施,探讨了相应的综合防治办法,使防治区天牛的种群数量得到了有效控制.     

19种木兰科树种早期生长比较

该文对中山市树木园木兰园中其中19种木兰科树种的早期生长进行了比较研究。结果表明:合果木和灰木莲生长速度最快;鹅掌楸、亮叶含笑、灰绒含笑生长较快;观光木、云南拟单性木兰、乐昌含笑、大叶木莲、火力楠、白玉兰、黄兰、海南木莲、乐东拟单性木兰、苦梓含笑、阔瓣含笑生长中等,其他生长较慢。     

库车坳陷克深地区现今地应力场及储层裂缝数值模拟

克深三维区目前处于勘探开发的前期,需要明确地应力场及地下储层裂缝的分布规律,指导开发工作,但该区存在地层埋深大、取心困难、成像测井资料缺乏等实际情况,应力场研究及裂缝预测难度大。利用有限元分析方法,以井点现今地应力值为约束进行了克深三维区现今地应力场的数值模拟,同时建立了应力应变与裂缝参数的定量关系模型,利用古今应力场结合法对克深三维区的裂缝参数进行了预测,模拟结果显示构造高部位和断层带是低应力值区及裂缝的有利发育区。裂缝的数值模拟结果与测井解释结果对比表明,预测结果与实钻吻合度较高,裂缝预测效果较好。     

中职学校德育课课程改革初探

随着新一轮的中职学校德育课课程改革的深入开展和中职学生主体意识的增强,传统的德育课教学有许多方面需要进一步改进和完善.在中职学校德育课教学中实施高效良性的师生互动,能提高德育课的教学实效和学生的思想道德素质,为学生职业生涯发展奠定基础.     

Nutrient cycling and biomass flows in a low-quality forest stand improvement system in the Lesser Khingan Range of China

The material flow and bulk internal flow analyses were used to establish a material accumulation and cycling model for a low-quality forest stand improvement system and a series of processes were considered. The model was applied in a one-hectare low-quality forest plot in the Lesser Khingan Range of China. Results showed that during 1997–2007, the stands absorbed 270.19 kg of N, 74.28 kg of P, and 124.39 kg of K from soils, 51.82 kg of N and 2.38 kg of P were directly absorbed by foliage, and 16.25 kg of K was released to soils by eluviation. Until 2007, the accumulated nutrients in the stands included 236.91 kg of N, 65.28 kg of P, and 108.55 kg of K. When horizontal strip clearcutting was applied in 2007, 50% accumulated nutrients in the stands were shifted due to harvesting operations, and 212.74 kg of N, 26.97 kg of P, and 98.88 kg of K were accumulated in soils, declining by 9.47% for N, 3.68% for P, and 17.60% for K, respectively, compared with year 1997. 94.61 t per hectare of biomass was generated, of which the biomass in stands accounted for 87.36%. The felled tree biomass was 36.89 t per hectare, of which 84.90% and 10.03% of biomass were utilized in terms of logs and other means, and the rest was left on site.     

通过使用窄带通滤波器和小波分析用以检测共轭耦合点谐波电压的跳变来实现孤岛检测

此文表述了基于编码的使用窄带通滤波器和小波滤波器用以在Simulink中实现孤岛检测的功能。分布式电网的拓扑结结构由并网逆变器和LCL滤波器构成。比例谐振控制器用以来控制逆变器。窄带通滤波器用来提取所有信号中的基波分量。开关断开用以来模拟孤岛现象,并采用两种方法来检测孤岛的发生。第一种采用窄带通滤波器来检测特定的共轭耦合点上的谐波电压在孤岛前和孤岛后的变化,第二种采用小波滤波器来检测谐波电压的跳变。     

农业院校蛋白质与酶工程课程创新实验教学改革

蛋白质与酶工程是天津农学院农学与资源环境学院的一门必修专业课程,同时也是一门实践性很强的学科。在蛋白质与酶工程的教学实践和改革创新过程中,由于课时限制,使得理论学习与实践教学不能完美衔接。该文对蛋白质与酶工程课程内创新实验教学的组织与实施进行了简述,通过教学改革创新实践,收到了学生良好的反馈,并积极地参与其中,同时该体系也为农业院校的蛋白质与酶工程课程实践教学改革提供了有益参考。