中美高校“马克思主义基本原理”课程教学的比较研究

通过对中美两国"马克思主义基本原理"课程的教学内容、教学方法、考核方式等方面的比较,从注重学习原著、开展讨论式教学、改革考核方式等三方面对中国高校"马克思主义基本原理"的课程教学改革提出了可行性建议。     

苏州古典园林垂直绿化造景探析

在苏州古典园林垂直绿化植物调查的基础上,介绍苏州古典园林中垂直绿化的植物种类,指出利用藤蔓植物造景是园林垂直绿化常用的手法之一,介绍了苏州古典园林中用于垂直绿化造景的23种植物,隶属于13科、19属,在垂直绿化造景的应用形式方面,结合苏州古典园林中网师园、拙政园、留园、怡园、狮子林、耦园中垂直绿化造景实例,强调粉墙为纸、植物为绘,廊架为亭、植物为荫,篱垣为支、植物为缀,山石为骨、植物为衣,驳岸为基、植物为缘,柱干为轴、植物为饰,桥壁为面、植物为点,坡地为丛、植物为铺。     

氮素形态对烟草生长及品质影响的研究进展

氮素是烟草生长和发育所必需的营养元素,在烟草生育期对烟株的化学物质合成、能量转换、信号传递等生理过程都有一定的影响。铵态氮和硝态氮是烟草吸收的主要氮素形态,对烟草不同时期、不同部位会产生不同的影响,合理的氮素比例有利于氮素的吸收以及烟叶品质的提高。本文从烟草对不同形态氮素的吸收利用的方式,不同氮素形态对烟草生长发育、品质形成、元素吸收、光合特性及碳氮代谢等方面的影响进行综述,以期为氮素形态对烟草生长影响的相关研究提供依据。     

Liming Influences Forms of Acidity in Soils Belonging to Different Orders under Subtropical India

A pot experiment was conducted to study the influence of liming on changes in different forms of acidity in relation to soil properties. Thirty-six surface (0–15 cm deep) soil samples were collected from different soil orders, namely Entisols, Inceptisols, Alfisols, and Entisols of coastal saline zone of West Bengal, India, and incubated for 21 days with three doses of lime [i.e., no lime (L₀), half lime (L_1/2), and full lime (L₁)]. Results of analysis of soil showed that there were significant increases in pH in water (pH_w) and pH in 0.02 M calcium chloride (CaCl₂) (pH_Ca) (1.3 and 1.5 units) and decrease in total acidity, hydrolytic acidity, exchange acidity, electrostatically bound aluminium (EBAl³⁺), and electrostatically bound hydrogen (EBH⁺) upon liming being from 1.53 to 0.57, 1.40 to 0.54, 0.13 to 0.03, 0.08 to 0.01, and 0.06 to 0.02 cmol (p⁺) kg^?1, respectively. The decrease in values of all the forms of acidity was greater in L₁ than in L_1/2 treatment under Entisols of the terai zone, followed by Entisols of coastal saline zone, Inceptisols, and Alfisols. The forms of acidity showed significant positive correlation with each other but negative correlation with pH_w and pH_Ca, except for EBH⁺.     

污水灌溉对林地土壤中磷的数量与形态影响

为避免城市生活污水携带的N、P进入水体,新西兰罗托鲁阿市处理后的污水直接喷灌至Whakarewarewa森林,同时建立污水灌溉林地处理系统长期定位试验地,以评价林地生态系统对污水携带营养物质的同化能力。为了解长期污水灌溉对土壤中P的数量、形态、环境的影响,对该灌溉系统中的土壤进行了剖面采样分析。结果表明:土壤TP(全磷)、Olsen P、M3P(Mehlich-3 P)在所有灌溉区的表层土壤(0～10 cm)均有显著(p<0.05)增加,部分指标的显著增加达深层土壤。随灌溉进入土壤的P大多被保存在上层土壤(0～40 cm)中。土壤中各形态的磷所占比例因长期污水灌溉而改变,灌溉前占优势的NaOH Po(以NaOH浸提得到的有机磷)经长期灌溉后被NaOH Pi(以NaOH浸提得到的无机磷)所取代,上层土壤WSP(水溶性磷,Wa-ter-soluble P)变化明显。以Olsen P 60 mg kg-1和M3P 150 mg kg-1为环境临界值可预测土壤剖面中P的淋失危机,WSP可望成为适用更广的土壤P淋失环境危机预测指标。     

黑龙江省西部草地土壤无机磷的形态

本文通过牧场试验，探讨了黑龙江省西部草地土壤无机磷形态，结果表明，四种草地土壤均以Ｃａ－Ｐ为主，约占无机磷总量的６０％左右，Ｏ－Ｐ含量少于Ｆｅ－Ｐ和Ａｌ－Ｐ．草甸黑钙土无机磷总量最高，Ｃａ２－Ｐ、Ｃａ８－Ｐ和Ａｌ－Ｐ都是草甸黑钙土重要的贮磷库；草甸风沙土无机磷总量最低，但Ｃａ８－Ｐ含量相对较高；草甸碱土无机磷总量、Ｃａ２－Ｐ和Ａｌ－Ｐ含量显著高于碱化草甸土．向草甸碱土和碱化草甸土施磷酸二铵能显著增加土壤无机磷的总量，尤其显著提高土壤中Ｃａ８－Ｐ和Ａｌ－Ｐ含量．     

襄垣县山羊球虫种类及感染情况调查

采用饱和盐水漂浮、重铬酸钾培养方法,对襄垣县112头山羊粪样进行了检查。结果发现,山羊球虫感染率为94.64%,共查获10种艾美耳球虫。当地山羊感染艾美耳球虫的优势种为雅氏艾美耳、阿氏艾美耳、浮氏艾美耳和小型艾美耳球虫。     

Distribution of potassium fractions in sweet potato (Ipomoea batatas) garden soils in the Central Highlands of Papua New Guinea and management implications

Previous studies indicated that potassium (K) deficiency is an important soil‐related factor for yield decline of the sweet potato gardens in the Central Highlands of Papua New Guinea, where sweet potato is an important staple food crop. An effort was made to characterize various fractions of K in the diverse soils of this region under sweet potato, to ascertain the probable reasons behind the observed K deficiency and its relationship to decreasing yield trends. Soils from two depths (0–10 cm) and (10–20 cm) in two types of gardens (old and new gardens) were assessed for different fractions of soil potassium in volcanic and non‐volcanic soil groups. Volcanic soils (Hydrandepts and Andaquepts) were significantly lower (P < 0.05) in exchangeable K than the non‐volcanic soils (Dystropepts, Tropoqualfs and Eutropepts). Mean exchangeable K content of the non‐volcanic soils was 95.5 mg/kg, whereas that of volcanic soils was 72.4 mg/kg. Similarly, new gardens had an average exchangeable K content of 94.1 mg/kg, which was significantly greater than 71.6 mg/kg soil of older gardens. Non‐exchangeable K content differed significantly (P < 0.001) between the soil types; mean K content was 85.9 mg/kg for the volcanic soils, whereas in non‐volcanic soils, it was 184.9 mg/kg. Garden types also differed significantly (P < 0.05) with respect to non‐exchangeable K content; new gardens registering higher average values (by almost 20%) than the older gardens. Multiple regression analysis showed that variability in the tuber yield was as a result of variability of water soluble and exchangeable K (up to 22%), non‐exchangeable K (2%), mineral K (4%) and leaf K concentrations (10%). Older gardens, which are in volcanic soil groupings, are more susceptible to the K depletion problem because of continuous sweet potato cultivation, possibly owing to their lower K reserves. Such gardens should be managed either with sufficient fallow periods for regeneration of soil fertility or with suitable application of mineral K fertilizers to enhance productivity.     

小麦大豆间套种植对磷素在土壤中的转化及有效性的影响

盆栽试验结果表明 ,不同作物间对土壤磷形态的影响差异较大 ,单作大豆形成Ca2 -P的比例显著提高 ,形成Ca8-P和Al-P、Fe-P的比例也比相应单作小麦少 ,说明大豆能减缓肥料磷在土壤中的转化和固定 ,减少磷素向无效的Ca10 -P和O -P方向转化     

不同咖啡园土壤磷素形态特征及其有效性研究

对不同咖啡园土壤磷素形态进行分析研究，结果表明：土壤磷素以无机磷为主，无机磷中以O-P居多，约占无机磷总量的54.63％；有机磷中以中活性有机磷居多，约占有机磷总量的70.14％；随种植年限增加，土壤全磷含量差异显著，但变化趋势不明显，有效磷、Al-P和Fe-P含量呈显著上升趋势，有机磷总量、中活性有机磷、中稳性有机磷、高稳性有机磷呈显著下降趋势；Ca-P、Fe-P、Al-P与有效磷呈显著或极显著正相关，磷素大量积累时主要以增加无机磷组分中有效性较高的Ca-P、Al-P和Fe-P为主。