密度与环境因子对蒙古黄芪育苗影响研究

为了明确育苗时密度与环境因子对蒙古黄芪生长特征影响,本试验以蒙古黄芪为研究对象,通过单因素田间随机区组试验,测定蒙古黄芪株高、茎粗、根粗和根长4个指标。结果表明,密度对蒙古黄芪影响最大,其次是湿度,最后是光照和电导率。密度与蒙古黄芪株高、茎粗、根粗呈现负相关性,与根长呈正相关性(P<0.05),密度为400株/m ²时,株高、茎粗及根粗最大,密度为1000株/m ²时根长最大。     

酸改性麦麸挂面配方的研究

为改善挂面制品的营养保健功能,研发谷物加工副产物的深加工产品,将经过超声波-酸解法改性处理后的麦麸粉添加到面粉中用于制作酸改性麦麸挂面。通过单因素试验及正交试验优化确定酸改性麦麸挂面的最优配方。结果表明,在面粉100 g的基础上,酸改性麦麸粉添加量为6%（相当于面粉质量的百分比）、水添加量为56%、食盐添加量为3.5%、食碱添加量为0.4%、羧甲基纤维素钠添加量为0.4%,此条件下制得的挂面品质良好,且外观、适口性较好。     

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。     

福建省将乐县金溪建电站前后雨水情变化分析

本文通过对将乐县金溪建电站前的1953～1978年、建电站后的1990～2009年雨水情进行分析,结果表明:自然状态下的将乐县(1953～1978年)无论雨水大小,每年都有洪水超过警戒水位,年最大洪水发生时间在4～7月;1953～1978年有16年的当年最大洪峰水位发生在当年最大日降雨量当日至第16日内,频率为61.5...     

Physiological processes associated with salinity tolerance in an alfalfa half‐sib family

We previously reported an alfalfa half‐sib family, HS‐B, with improved salt tolerance, compared to parental plants, P‐B. In this study, we conducted additional experiments to address potential physiological mechanisms that may contribute to salt tolerance in HS‐B. Vegetatively propagated HS‐B and P‐B plants were treated with a nutrient solution (control) or a nutrient solution containing NaCl (EC = 12 dS/m). Shoots and roots were harvested at various time points after treatment for quantification of proline, soluble sugar, and H₂O₂ using spectrophotometers. Subcellular localization and quantification of Na in roots were conducted using a Na⁺‐specific dye under a confocal microscope. HS‐B produced 86 and 89% greater shoot and root dry biomass, respectively, compared to parental plants, P‐B, under salinity in the greenhouse. Under saline conditions the HS‐B shoots accumulated 115% and roots 55% more soluble sugars than P‐B counterparts. The non‐saline HS‐B shoots, however, showed 72% less soluble sugars than the non‐saline P‐B plants. Under saline conditions HS‐B accumulated 39% less proline in shoots, while roots accumulated 56% more proline, compared to their P‐B parents. HS‐B plants also showed a greater reduction of stomatal conductance under mild saline stress. HS‐B shoots and roots contained 3–4 times less reactive oxygen species (H₂O₂) after salt treatment compared to P‐B plants. Sodium localization and distribution analysis using Na⁺‐specific dye revealed HS‐B plants accumulated 88% and 48% less Na⁺ in stele and xylem vessels compared to P‐B. The study provides insights into the potential mechanisms that may contribute to salt tolerance in HS‐B: maintaining RWC by accumulating soluble sugars while reducing transpiration, maintaining healthy status by reducing oxidative stresses, and preventing salt toxicity by reducing accumulation of Na⁺ inside root cells and xylem.     

维药菊苣提取物对Balb/c小鼠肝纤维化的治疗作用研究

目的 探讨维药菊苣正丁醇提取物（CGB）抗雄性小鼠肝纤维化的治疗作用。方法 采用刀豆凝集素（Con A）在Balb/c雄性小鼠诱导肝纤维化，造模成功后第6周分别用低剂量（100 mg/kg）和高剂量（500 mg/kg）CGB干预治疗，并以秋水仙碱（0.1 mg/kg）做阳性对照。治疗第10周处死小鼠留取肝脏组织和血清，比较各组小鼠肝功能、关键性肝纤维化指标。病理分析肝脏组织变化和TGF-β1/Smad信号通路相关因子表达差异。结果 与模型组比较，CGB治疗组的肝功能指标（ALT，AST）和血清肝纤四项指标（PC-Ⅲ、CIV、LN和HA）指标不同程度降低（P＜0.05）；肝组织TGF-β1蛋白表达下降，Smad7蛋白表达升高（P＜0.05）。肝脏组织病理显示，不同剂量CGB治疗均能一定程度上减缓小鼠肝纤维化的发展。结论 CGB具有抗肝纤维化的活性，影响TGF-β1/Smad信号通路可能是其潜在的抗肝纤维化作用机制。     

梨树栽培管理关键技术

指出了梨树具有高度的营养价值、经济价值、生态价值,从林地的选择、林地整地、苗木栽植、树园管理、树形期修剪、果实采收贮运及梨树栽培管理技术等方面提出了关键技术实施要点,并对梨树的发展前景做出了评估.     

湘沙猪配套系的育种实践

文章在阐述配套系的定义、培育配套系的优势和主要技术环节基础上，全面介绍了湘沙猪配套系培育的背景、育种方案的制定、育种素材的收集、优势杂交组合筛选、专门化品系选育、配合力测定、繁育体系建设及示范推广等内容。同时提出开展配套系育种，必须得到政府部门的大力支持，要有地方猪种等育种资源，要有优秀的技术创新团队，要采取“产学研推”管理模式，要有充足科研经费做保障等建议。