Decomposition and nutrient release patterns of Phyllostachys bambusoides and Arundinaria racemosa, India

We investigated decomposition and nutrient release patterns of leaf and sheath litter of two important highland bamboo species (viz. Phyllostachys bambusoides Sieb. (Zucc.) and Arundinaria racemosa Munro) by using a litter bag technique. Our objective was to improve understanding of the addition of organic matter and nutrients to soil from the litter of two abundant highland bamboo species, species that support the local population of the region in many ways. N concentration and N/P ratio were significantly higher (p<0.01) in leaf litter of P. bambusoides. Significantly, larger values of lignin concentration, C/N ratio, and lignin/N ratio were found in the sheath litter of A racemosa. Weight loss of both leaf and sheath litter was strongly positively correlated with N and N/P ratio, and significantly negatively correlated (p<0.01) with C/N ratio. Lignin/N had a negative correlation with decay rate. In both species, only lignin concentration of the litter showed strong positive correlation with N release. Litter decomposition and N release patterns were similar for the two bamboo species, whereas, P release rate from leaf litter was higher in P. bambusoides and differed significantly between sheath and leaf litter for both species. The complex pattern of nutrient release through mineralization and immobilization during litter decomposition ensures nutrient availability in both managed and natural bamboo stands subjected to anthropogenic disturbances.     

利用肿腿蜂防治松墨天牛最佳时段分析与建议

针对目前众多防治单位在松墨天牛羽化盛期利用肿腿蜂进行防治的现状,根据肿腿蜂寄生行为对寄主的要求和松墨天牛发生的特点,初步分析了最适放蜂期的确定因素,提出最适放蜂期为松墨天牛羽化盛期后约1个半月。     

不同有机物料对土壤碳氮含量及紫甘蓝产量的影响

设计不施肥(CK)、常规施肥(CM)、施玉米秸秆+鸡粪(SM)、施草炭+鸡粪(PM)、施蘑菇渣(MM)和施高量鸡粪(HM)6个处理的大田试验,探讨不同有机物料对新建蔬菜大棚土壤碳氮含量及紫甘蓝产量的影响。结果表明:各处理碳、氮分解残留率的大小顺序为MMPMCMHMSM。各处理均能提高土壤有机碳、活性有机碳、全氮和铵态氮的含量。其中MM、PM处理土壤有机碳和活性有机碳含量显著高于CK处理和常规施肥处理,有机碳含量比空白处理提高36.64%以上,活性有机碳含量提高31.90%以上;HM、PM、MM处理土壤全氮、铵态氮含量显著高于CK处理,全氮含量比空白处理提高18.89%以上,铵态氮含量提高92.74%以上;土壤硝态氮含量仅HM、PM处理高于CK处理,而CM、SM、MM处理都低于CK处理。施用有机物料也能提高紫甘蓝的产量,其中以HM、MM处理产量最高,增产20%以上。综合考虑紫甘蓝产量及土壤碳、氮等指标以MM处理效果最好,因此注重粪肥与菇渣等有机物料的配合施用能提高新建大棚土壤碳素和氮素含量,改善土壤肥力,有利于紫甘蓝增产。     

控释BB肥在苹果苗圃育苗上的经济效益

[目的]研究了控释BB肥对苹果嫁接苗生长和经济效益的影响。[方法]通过大田试验,比较控释BB肥与普通肥料的施用效果。[结果]施肥量相同的SF与CRF1处理相比较,CRF1处理嫁接苗质量、经济效益在0.05水平显著高于SF处理;即使减少肥料的施用量,CRF2、CRF3处理嫁接苗质量和经济效益仍不低于SF处理。因此,从培育优良的苹果嫁接苗的角度考虑,控释肥推荐施肥量为630-150-480 kg/hm2;从减少肥料投入、增加经济效益的角度考虑,控释肥推荐施肥量为504-120-384 kg/hm2。[结论]该研究可为控释肥在苹果苗圃育苗上的合理施用提供技术指导。     

我国缓/控释肥料的应用进展

缓/控释肥料是近年来的一个研究热点。它对作物产量、性状、品质以及肥料利用率等的影响是其应用研究的主要方向。笔者总结了近年来我国缓/控释肥料的应用进展。     

聚羟基脂肪酸酯的生物合成与废弃物的资源化利用

针对如何降低聚羟基脂肪酸酯的生产成本问题,对利用各种废弃物和剩余材料作为原料生产聚羟基脂肪酸酯的研究进行了综述,并对其中存在问题进行了分析总结。分析表明,利用废弃物生产聚羟基脂肪酸酯,不仅能降低聚羟基脂肪酸酯生产成本,也为废弃物处理问题提供了一条可行的途径。     

再论中国古建筑的木构选择

立足于中国古建筑的木框架结构的建筑体系,认为中国古人之所以选择木材作为建筑材料有其自身存在的特点和必然性。分析了传统聚落的建筑特点,藉以透视出中国古建筑就地取材的特点,进而分析了中国木构建筑形制在广度、高度上的适应性,以及其所彰显的平面布局的灵活性和复杂性。结合中国人的生命观,从精神与物质双重层面解析了中国木构建筑中所蕴涵的永恒意义。试图通过自然选择、技术进步、空间优势、精神价值、审美需求等方面的阐述,为中国传统建筑最终使用木材作为建筑材料的成因理出一条脉络,旨在比较客观地对待中国古人在人类文明进步史上所做的努力。     

氮气进气量对粮堆中氮气浓度的影响

通过在密闭的模拟仓中采用上充下排和下充上排的充氮方式进行试验,一次性充气让粮堆内氮气浓度达到98%,玉米中氮气的进气量需要达到粮堆密闭体积的0.806倍,稻谷是0.861倍,而小麦是0.774倍,相应地所需要耗电量为玉米0.3kW.h/t,稻谷0.4kW.h/t,小麦0.25kW.h/t。让粮堆内一次性充气达到95%的氮气浓度,玉米耗电为0.25kW.h/t,稻谷0.24kW.h/t,小麦015kW.h/t。     

恩诺沙星聚合物胶束的制备及体外释放

通过比较3种不同质量比的两嵌段共聚物制备的聚合物胶束,优化恩诺沙星聚合物胶束的制备工艺,并考察该胶束的理化性质和体外释药特性。以自乳化溶剂挥发法制备恩诺沙星聚合物胶束,并采用单因素法优化处方;HPLC法测定其载药量、包封率、体外释药特性,激光粒度仪测定其粒径及分布,红外分光光度法（IR）确证含药胶束特征。结果显示,采用PLA16000-mPEG2000（聚乳酸-聚乙二醇单甲醚）共聚物为载体,以丙酮为有机溶剂,所制备胶束平均粒径为（117.2±8.2）nm,载药量为（3.3±0.17）%,包封率为（32.3±1.70）%;相对于另外2种材料制备的胶束有较好的载药量,且IR确证药物已被包封在胶束中。恩诺沙星胶束体外释药试验表明其具有一定的缓释特性。     

Comparative Evaluation of Three In Situ Castration Techniques for Sterilizing Donkeys: Incision–Ligation (a Novel Technique), Section–Ligation–Release,and Pinhole

Castration is one of the most common surgical procedures performed in equines and is associated with various complications, such as severe hemorrhage and evisceration. Using clinical, hormonal, and histopathological findings, this study aimed to evaluate a novel in situ castration technique and compare it with two other in situ techniques, namely, “section–ligation–release” (SLR) and “pinhole” (PH), to choose the most compatible and safe technique for sterilizing donkeys. Fifteen adult male donkeys were divided into three groups (five animals each). The vascular and the nonvascular parts of the spermatic cord were double ligated separately after opening the skin and the tunica vaginalis at the scrotal neck in the first group (incision–ligation [IL] technique, IL group). In the second group, donkeys were subjected to in situ castration using SLR technique, where both parts of the spermatic cord were triple clamped, ligated, and transected (SLR group). In the third group, percutaneous ligation of the spermatic vessels was performed without opening the skin (PH technique, PH group). The PH technique was less effective and failed to induce necrosis in the testes in situ. Also, Testosterone hormone levels remained elevated 60 days after this procedure. Although the IL and SLR techniques result in convincing reductions in resting and human chorionic gonadotropin–stimulated testosterone levels in treated donkeys, IL and SLR techniques were conducted under narcosis and strict asepsis. We concluded that the PH technique should not be recommended for sterilizing donkeys. Meanwhile, the IL and SLR techniques can be considered as an alternative to other conventional methods used for sterilizing donkeys.