几种工程措施对黄土区陡峭边坡植被盖度的影响及其机理

陡削以兰州新区的一段陡峭边坡作为试验地点,通过分析在植被重建初期经人工整地后形成的4种微地形(大圆形坑、小圆形坑、条形坑和原状坡面)的植被盖度特征及环境因子(土壤硬度和水分、地表和空气温度、坡位、无纺布)对植被盖度的影响,探寻能有效提高植被盖度的几种工程改造措施。研究表明:①铺设了无纺布坡面的植被盖度显著大于对照坡面;陡峭边坡不同坡位的植被盖度:下坡位>中坡位>上坡位(P<0.05),这与自然坡面植被盖度分布规律一致。②3种微地形的植被盖度均显著大于陡峭坡面,其中条形坑的土壤水分和植被盖度最大,最大盖度维持的时间最长。③微地形和坡面的植被盖度均与土壤水分呈显著正相关,与空气温度、地表温度均呈显著负相关;微地形的土壤硬度(3kg·cm^-2)适宜植物生长,大于该值会对植被生长产生抑制作用;铺设无纺布有利于促进上坡位的植被生长,使坡面植被分布更均匀。研究结果表明,在陡峭边坡坡度、坡位和温度等无法改变的情况下,选择对压实的坡面进行整地翻耕处理,增加长条坑的数量并铺设无纺布等有效的工程改造措施,能显著增加植被盖度,促进植被恢复。     

海洋SOD抗疲劳作用动物实验方法初探

超氧化物歧化酶(SOD)具有防止细胞过度氧化的生理功能,从海洋生物中提取的SOD,可用于清除运动产生的自由基,起到抗疲劳作用.本文探讨了SOD抗疲劳作用的动物实验方法,为验证SOD抗疲劳效果建立技术平台.     

颗粒型燕麦牛乳饮品配方及工艺优化

从配方和工艺2 个角度研究颗粒型燕麦牛乳的稳定性,以离心沉淀率、黏度和感官评分作为评价指标。结果表明：对稳定剂进行优化后,得到最佳复配稳定剂配方为结冷胶添加量0.04%、卡拉胶添加量0.020%、羧甲基纤维素钠添加量0.020%、微晶纤维素添加量0.20%;对配料温度、水合时间、均质压力和灌装温度4 个影响体系稳定性的工艺点进行单因素试验,继而设计正交试验,得到最佳参数组合为配料温度50 ℃、水合时间40 min、均质压力30 MPa、灌装温度15 ℃,此条件下产品稳定性最佳,口感良好。     

Modelling land use strategies to optimise crop production and protection of ecologically important weed species

There is a need to develop farming systems that enable both a satisfactory level of crop production and suitable environmental conditions for natural species. Wildlife‐friendly cropping techniques, such as a reduced amount of applied herbicide or a lower crop density, might be adopted in order to maintain populations of weed species of biological interest. An alternative might be to adopt an intensive cropping system in a part of the field and spare the other part as set‐aside or field margins, available for the natural development of plant species. The objective of this study was to present a method to compare two strategies for maintaining a desirable level of abundance of a given species of interest in agricultural areas, specifically (i) a strategy based on a wildlife‐friendly cropping system in a large cultivated area and (ii) a strategy based on a more intensive cropping system in a reduced area of cultivation, i.e. with land‐sparing. The principle is to calculate the ratio of crop production obtained with strategy (i) to the production obtained with strategy (ii) for a given target density of natural species. We show that the value of this ratio, and thus the relative performance of the two strategies, depends on the density of the weed species that can be maintained in an uncultivated ecological area. The method is applied in case studies of two plant species with contrasting ecology and conservation goals. The numerical results show that the strategy based on a wildlife‐friendly cropping system is more profitable in most situations.     

Effect of co-cultivation and crop rotation on corm rot disease of Gladiolus

Field and pot experiments were conducted to evaluate the effect of co-cultivation and crop rotation on the growth and corm rot disease of gladiolus (Gladiolus grandiflorus sect. Blandus) cv. Aarti caused by Fusarium oxysporum f.sp. gladioli (Massey) Snyd. and Hans. In the field experiment, gladiolus was co-cultivated with 10 agricultural/horticultural crops viz. Allium cepa L., Brassica campestris L., Capsicum annuum L., Eruca sativa Mill., Helianthus annuus L., Tagetes erectus L., Zea mays L., Vinca rosea L. and Rosa indica L., in a soil infested with F. oxysporum. All the crops except V. rosea and R. indica reduced disease incidence. The effect of H. annuus and T. erectus was significant and more pronounced than other co-cultivated crops. In general, root and shoot dry biomass, corm fresh weight, number of cormlets and number of flowers per spike decreased as compared to the un-inoculated monoculture gladiolus treatment (negative control) but these parameters enhanced as compared to the F. oxysporum inoculated monoculture gladiolus treatment (positive control). In a pot experiment, all the crops of the field experiment except V. rosea and R. indica were sown in rotation with gladiolus. Pot grown plants of different species were harvested at maturity and the soil was inoculated with F. oxysporum. Gladiolus was cultivated 1 week after inoculation. Disease incidence was significantly suppressed in all the treatments ranging from 29% to 53%. The highest suppression of disease incidence was recorded in T. erectus (53%) followed by B. campestris (49%). The effect of preceding crops on various vegetative parameters was similar in the pot experiment to that of the field experiment. The present study suggests that corm rot disease of gladiolus can be managed by mixed cropping of H. annuus and T. erectus or cultivation of T. erectus and B. campestris in rotation.     

Effects of water‐misting sprays with forced ventilation on post mortem glycolysis,AMP‐activated protein kinase and meat quality of broilers after transport during summer

Effects of water‐misting sprays with forced ventilation on post mortem glycolysis, adenosine monophosphate‐activated protein kinase (AMPK) and meat quality of broilers after transport during summer were investigated in the present paper. A total of 105 mixed‐sex Arbor Acres broilers were divided into three treatment groups: (i) 45 min transport without rest (T); (ii) 45 min transport with 1 h rest (TR); and (iii) 45 min transport with 15 min water‐misting sprays with forced ventilation and 45 min rest (TWFR). Each treatment consisted of five replicates with seven birds each. The results indicated that the water‐misting sprays with forced ventilation could mitigate the stress caused by transport under high temperature conditions during summer, which reduced the energy depletion in post mortem Pectoralis major (PM) muscle. This resulted in a higher energy status compared to the T group, which would decrease the expression of phosphorylation of AMPK (p‐AMPK). Furthermore, decreased the expression of p‐AMPK then slowed down the rate of glycolysis in post mortem PM muscle during the early post mortem period, which in turn lessened the negative effects caused by transport on meat quality. In conclusion, water‐misting sprays with forced ventilation may be a better method to control the incidence of the pale, soft and exudative meat in broilers.     

设施番茄连作障碍土壤修复及其对青枯病害的防治效果

连作障碍的土壤修复是世界性难题。本研究利用土壤微生态修复剂结合青枯病植物疫苗菌剂来改良土壤和预防青枯病发生。在连作7年的番茄地,设3种处理,处理1为添加量60 t/hm²的土壤微生态修复剂和植物疫苗100倍稀释液,处理2为添加量30 t/hm²的土壤微生态修复剂和植物疫苗100倍稀释液,CK为不添加土壤微生态修复剂和植物疫苗,研究不同处理对连作番茄土壤养分、土壤酶活性、植株生长特性及病害防效的影响。结果表明,土壤微生态修复剂2种不同添加量处理的番茄土壤有机质、全氮、全磷和交换性钙含量均显著高于对照,而全钾含量显著低于对照;两种不同添加量处理的番茄土壤过氧化氢酶、脲酶、蔗糖酶和酸性磷酸酶活性均显著高于对照,添加量为30 t/hm²处理的土壤各酶活性（酸性磷酸酶除外）大于添加量为60 t/hm²处理的土壤;添加30 t/hm²处理的单果重量（113.82 g）显著高于添加量60 t/hm²处理（104.07 g）和对照处理（104.99 g）（P<0.05）,其对番茄青枯病防效达91.87%,大于添加量为60 t/hm²处理的防效（55.34%）。     

烯效唑浸种对干旱胁迫下工业大麻幼苗形态、渗透调节物质及内源激素的影响

选用0.4 mg·L^-1的烯效唑(S₃₃₀₇)浸种工业大麻"火麻一号"种子,采用盆栽试验方法,于大麻三叶期设置清水浸种后正常供水(CK)、清水浸种后干旱胁迫(D)和烯效唑浸种后干旱胁迫(D+S)3个处理,探讨烯效唑浸种对干旱胁迫下工业大麻幼苗形态、渗透调节物质及内源激素的影响。结果表明:与D处理的植株相比,D+S处理显著提高了根系干、鲜重,分别提高46.67%～61.54%和16.46%～25.53%;恢复了胁迫后期的地上部干、鲜重,复水4 d后地上部干、鲜重较D处理分别提高了4.38%和2.23%;促进了根系生长的能力,干旱胁迫8 d后,D+S处理较D处理根长、根表面积、根体积、根总投影面积、分枝数、交叉数和根尖数分别增加了34.48%、34.77%、69.10%、70.00%、29.62%、54.28%和33.07%;提高了幼苗叶片SPAD值,降低了细胞膜透性,增加了可溶性糖和可溶性蛋白含量,干旱胁迫8 d后D+S处理较D处理SPAD值增加了28.30%,细胞膜透性减少了17.22%,可溶性糖和可溶性蛋白含量分别增加了17.32%～36....     

A study of experimental autoimmune encephalomyelitis in dogs as a disease model for canine necrotizing encephalitis

In the present study, the use of dogs with experimental autoimmune encephalomyelitis (EAE) as a disease model for necrotizing encephalitis (NE) was assessed. Twelve healthy dogs were included in this study. Canine forebrain tissues (8 g), including white and grey matter, were homogenized with 4 mL of phosphate-buffered saline for 5 min in an ice bath. The suspension was emulsified with the same volume of Freund''s complete adjuvant containing 1 mg/mL of killed Mycobacterium tuberculosis H37Ra. Under sedation, each dog was injected subcutaneously with canine brain homogenate at four sites: two in the inguinal and two in the axillary regions. A second injection (booster) was administered to all the dogs using the same procedure 7 days after the first injection. Clinical assessment, magnetic resonance imaging, cerebrospinal fluid analyses, necropsies, and histopathological and immunohistochemical examinations were performed for the dogs with EAE. Out of the 12 animals, seven (58%) developed clinically manifest EAE at various times after immunization. Characteristics of canine EAE models were very similar to canine NE, suggesting that canine EAE can be a disease model for NE in dogs.     

早实核桃不同品种抗旱性综合评价

以12 个早实核桃品种苗木为试材,采用自然干旱胁迫及复水的方法,测定了复水后各品种与抗旱性有关的生长指标、生理生化指标、光合指标及叶绿素荧光指标。对复水后各指标进行主成分分析,筛选出影响抗旱性的5 个主要指标,利用隶属函数对早实核桃品种的抗旱性进行了综合评价。结果表明：12 个早实核桃品种抗旱性强弱依次为：辽核1 号 > 中林5 号 > 新早丰 > 温185 > 鲁光 > 中林1 号 > 辽核4 号 > 扎343 > 强特勒 > 香玲 > 西林2 号 > 西扶1 号。此评价结果与大田试验结果基本一致。