不同成熟度烟叶在烘烤过程中主要挥发性香气成分的变化

采用卧式密集烤房,研究了不同成熟度条件下烟叶片中主要挥发性香气成分的变化。鲜烟叶中所含的香气物质经过烘烤大部分成份的含量下降,但在不同烘烤阶段,烟叶中香气物质的变化趋势不一致,多数成份在0小时至12小时或36小时至48小时含量增加,48小时后减少。因此在适熟烟叶条件下延长变黄时间,使烟叶充分变黄后再缓慢升温定色有利于提高烟叶香气物质含量。     

不同水分条件下施氮对小麦幼苗生长发育的影响

试验设4个处理:正常水分+不含N营养液、正常水分+全氮营养液、水分胁迫+不含N营养液、水分胁迫+全氮营养液,研究了不同水分、氮素水平对小麦苗高、根重、根冠比及叶绿素含量的影响。结果表明,水分胁迫使小麦根长缩短,株高降低,根冠比、叶绿素含量增加。除根长、根冠比外,全氮营养液使小麦苗高、叶绿素含量增加,根长和根冠比降低。     

施氮量与花期水分胁迫对不同氮效率油菜产量性能及氮肥利用效率的影响

为了明确花期水分胁迫下施氮对油菜产量形成、产量性能及氮肥利用效率的影响,以2个氮高效基因型(Monty和湘油15)和2个氮低效基因型(R210和Bin270)为供试材料,在不同氮水平(低氮0.05 g/kg,中氮0.2 g/kg,高氮0.4 g/kg),研究了花期水分胁迫下氮肥对不同氮效率基因型油菜产量、产量性能及氮肥利用效率的影响。结果表明,水分胁迫明显抑制了油菜的产量、产量性能和氮素吸收利用能力;就不同施氮量看,少量或过量施氮影响油菜产量及产量性能,所有供试材料的单株角果数、干物质量、收获指数和产量在中氮(0.2 g/kg)处理效果表现最好;水分对油菜生长发育的影响大于氮素养分,氮高效基因型对水分胁迫具有一定的减缓作用;适量供氮能够减轻水分胁迫对油菜生长发育的影响,氮高效基因型较氮低效基因型对水分和氮素胁迫具有更强的适应性。     

不同形态氮素营养及水分胁迫条件下赤霉酸对水稻生理特性的影响

以水稻品种金优402为研究材料,采用营养液培养,聚乙二醇模拟水分胁迫的方法,研究不同形态氮素营养和水分胁迫条件下,外源激素赤霉酸对水稻生理特性和生长的影响。试验设置3种水分条件和5种氮素营养(NH4+-N/NO3--N为0/100,25/75,50/50,75/25,100/0)条件,共15个处理:即正常水分处理,作为试验的对照;水分胁迫处理和水分胁迫加赤霉酸处理。结果表明,水分胁迫抑制水稻叶面积扩展,降低叶片相对含水量和叶绿素含量,增加脯氨酸的积累;添加赤霉酸则将除脯氨酸外的上述水稻的各项生理参数显著地提高到接近对照的水平。添加外源赤霉酸可以通过维持水稻膜渗透、增加叶面积、提高叶片相对含水量和叶绿素含量等生理机制,改善水稻幼苗对水分胁迫的适应能力。在水分胁迫下,NH4+-N/NO3--N为25/75的氮素营养最有利于缓解胁迫的影响,水分胁迫添加赤霉酸后,则以NH4+-N/NO3--N为50/50的氮素营养效果最佳。     

长白猪甘露聚糖结合凝集素-C基因的克隆与序列分析

摘 要：从长白猪肝脏组织中提取总RNA,经RT-PCR技术扩增pMBL-C基因,与pMD18-T载体连接,获得pMBL-C基因。序列测定结果显示该基因编码区为723bp,编码241个氨基酸残基。与已发表的猪MBL-C具有99%同源性;进化树分析显示与哺乳动物的MBL-C基因,尤其是牛的亲缘关系最近,而与MBL-A基因相差较大,与禽类的最远。本研究为进一步研究猪MBL分子的遗传特征提供了依据。     

缺氮条件下玉米自交系叶绿素含量与光合效率的变化

在低氮胁迫条件下,对25个玉米自交系穗三叶叶绿素含量、光合速率等进行了研究。结果表明：不同玉米自交系穗三叶叶绿素含量的降低呈现相似的规律性,光合速率也出现不同程度的降低,不同自交系间降低的幅度存在较大差异。穗位叶叶绿素含量的降低可作为氮素利用效率的次级选择指标,以穗位叶叶绿素含量降低的百分率为指标,将供试材料分成4类,其中许178、辽5114等自交系叶绿素含量降低幅度较小,具有较高的氮素利用效率。     

关中西部农业产业化的现状与对策

大力推进农业结构不断优化升级,实现产业化经营,是提高中国农业的整体素质、综合效益和国际竞争力的有效途径。在分析关中西部资源、产业现状、制约因素的同时,提出了促进关中西部农业产业化发展的对策和建议。     

缩合单宁与天然棕色棉纤维色素合成的关系

以白色棉为对照,采用香草醛法测定了4种天然棕色棉种皮细胞和棉纤维细胞发育过程中缩合单宁含量的变化规律.结果表明,各发育时期棕色棉纤维中缩合单宁的平均含量是白色棉的4.35倍,在4个棕色棉品种中,棕色棉成熟纤维色素与发育过程中棉纤维中缩合单宁的含量呈现正相关;各发育阶段棕色棉种皮中缩合单宁平均含量是白色棉的1.44倍,且在棕色棉品种中,颜色越深,种皮中缩合单宁的含量越高;不论是棕色棉还是白色棉,种皮中的缩合单宁含量都大于相应的棉纤维细胞中的缩合单宁的含量.成熟纤维中色素的含量与20-25 DPA棉纤维中缩合单宁的含量、棉纤维中缩合单宁总平均含量极显著相关.     

城市污泥堆肥及农用前后重金属形态变化的研究

笔者以城市污水处理厂污泥为研究对象,添加不同种类及不同比例的调理剂对A、B和C堆污泥进行高温堆肥试验,分析了堆肥成品的种子发芽指数和基本理化性质,用顺序提取法分析堆肥、种植小白菜前后重金属形态的变化,为城市污水厂污泥资源化利用及堆肥中重金属形态变化提供相关参考。结果表明,城市污水厂污泥经过堆肥处理,添加剂种类及添加比例对污泥的腐熟程度有一定影响,且堆料中重金属Cu、Zn的X-(KNO3+H2O)态均有所降低,其中Cu的X-(KNO3+H2O)态下降比例顺序是C堆(53.71%)＞A堆(24.64%)＞B堆(2.55%),Zn的X-(KNO3+H2O)态下降比例是A堆(80.58%)＞B堆(71.09%)＞C堆(66.34%);堆肥处理后的土壤中,Cu、Zn的X-(KNO3+H2O)态的比例则有所增加。试验结果对污水厂污泥堆肥土地利用及重金属形态在土壤中的形态转化具有实用价值。     

供氮形态和水分胁迫对水稻生长及氮素积累和分配的影响

为探讨不同形态氮素营养对水分胁迫条件下水稻生长及氮素积累和分配的影响,采用室内营养液培养及聚乙二醇(PEG6000)模拟水分胁迫处理的方法,在苗期设置5种供氮形态(NH_4~+/NO_3~-比为0/100,25/75,50/50,75/25,100/0)和2种水分条件(非水分胁迫和水分胁迫)的组合处理进行研究.结果表明,在水分胁迫条件下,NH_4~+/NO_3~-比为25/75处理的株高和叶面积最大,达到100/0处理的1.5和1.3倍.2种水分条件下,NH_4~+/NO_3~-为25/75处理的根长均为最大,其在非水分胁迫和水分胁迫下分别为100/0处理的6.8倍和3.3倍;非水分胁迫条件下植株不同部位氮积累量均高于水分胁迫条件.2种水分条件下,根系氮积累量均以0/100处理最大,茎部氮积累量以100/0处理最大,0/100处理最小;在非水分胁迫条件下,叶片的氮积累以100/0处理最大,水分胁迫下则是以75/25处理最大.在水分胁迫条件下,单一供应NO_3~--N可以提高水稻根系中氮素的积累,同时供应NH_4~+和NO_3~-( 75/25配比)可以促进氮在水稻叶片和茎中的积累和分配.     

污泥堆肥的应用及其在农业中的发展趋势

污泥是污水处理厂剩余物,随着社会的发展,资源的紧缺,污泥作为堆肥原料已逐渐成为人们处理污泥的主要方式,即把污泥经过堆肥化形成的生物固体应用于农田、林地、草地、市政绿化、果树及蔬菜地,使严重扰动的土地逐渐恢复植被并促进土壤熟化。污泥因其含有大量有机质和氮磷钾等营养成分,是非常值得利用的肥源。此文综述了污泥堆肥农用的历史及现状,污泥堆肥化的原理和过程;并对污泥堆肥在农业、林业、蔬菜、花卉、果树以及土地修复重建上的应用做了详细介绍,指出污泥堆肥在农业中的发展趋势以及存在的问题。     

Utilization of Mixed Compost from Sewage Sludge and Municipal Solid Wastes with Coke Breeze for Rice Fertilization

The composition and heavy metals content of sludge, solid wastes and coke breeze is detected in the test. Sludge, solid wastes and coke breeze compost the organic composite fertilizer. The experiments on it for rice fertilization were conducted. The results show that the contents of organic matter and N, P, K in wastewater sludge and solid wastes of Guilin are very abundant and heavy metals remain under the criteria. There is a significant efficiency for the organic composite fertilizer applied in raising rice yield, providing an extensive applicability.     

Research on Microbiological Method for Removing Heavy Metal from Sewage Sludge

A great quantity of heavy metal cause trouble when the sewage is used in agriculture as fertilizer. An experiment is carried out on green vitriol and sulfur as culture medium, different dosing ratio of the sewage sludge and inoculated or not the sewage sludge, the effect of heavy metal removal by microbe has been studied. It is shown that the microbes nursed under different environment have better effect on the heavy metal removal and the result of experiments is discussed.     

Carbon Emission and Low carbon Strategies of Sewage Sludge Treatment

The carbon emission during sewage sludge treatment is an important source of greenhouse gas. For the carbon reduction, the emissions from common treatment technologies are calculated with the mass balance model, then their low carbon degrees are evaluated, and finally the low carbon treatment strategies are put forward for different requirements. The results show that the technologies, such as digestion for methane recovery, incineration or co incineration for power production after drying with industrial waste heat, are the ones with the lowest carbon emission. Their low carbon degrees are 89.6%, 80.3% and 76.6% respectively. In the area where the above technologies cannot be applied, aerobic composting or landfill with aerobic stabilization pretreatment are the effective methods to reduce carbon emission. The low carbon treatment strategy, a new part of sludge treatment strategies, should be applied combining the local economy, technology and social conditions, so that it can meet the different requirements from sanitation to carbon emission reduction.     

Impacts of Microwave on Dewater Ability and Morphological Feature of Sewage Sludge

Firstly the impacts of heating temperature and rate of microwave on dewater ability and morphological feature of sewage sludge were investigated. Then CST, viscosity, SV, moisture content, COD, Zeta electric potential and morphological feature were tested. It is shown that the lowest CST of reclaimed water plant is 4.2s while the heating rate is 10℃/min and heating temperature is 80℃. SV, viscosity, moisture content of waste water plant sludge decrease and COD increases when heating temperature is higher. It is indicated that morphology of sludge changes under different heating conditions from fractal dimension and particle size data which is analyzed from image and calculated from cumulative weight percentage undersize of sludge particle. After 60~80℃ microwave pretreatment, dewater ability is proved.     

Thickening Properties and Utilization of Sewage Sludge Modified by Shale

It is beneficial for disposal and utilization to improve thickening and dehydration properties of sewage sludge.The influence of dosage and fineness of shale on sludge settlement were investigated experimentally.And It was shown that the addition of shale could improve the sludge thickening without volume increment when the shale dosage with fineness of 250～150 μm was less than 5%.The moisture content of thickened and dehydration sludge with 5%shale dosage were 80% and less than 60%, respectively.The addition of shale during the sludge settlement could improve the uniformity of the mixture of sludge and shale, which was favorite for producing building materials, and alleviate the smell of sludge in despite of increase in some extent in volume afterdehydration.The dehydrationsludge modified by shale could be used as raw materials to produce excellent expanded shale.     

污泥施用对4种绿化植物叶片性状和光合作用的影响

通过向种植土内添加不同比例的污泥用量,观测盆栽绿化植物叶片性状和光合生理的变化,筛选不同植物的适宜污泥用量。结果表明,‘金叶’梓树和‘红叶’石楠以25.0%浓度处理下,植物叶片性状和光合生理表现最强,可提高比叶面积、净光合速率和叶绿素含量;‘紫花’海棠也表现为相似的生理响应,改变各项生理指标以适应添加污泥的土壤,以12.5%含量处理效果佳。相反,乌桕的表现较差,随着浓度增加表现越差。建议在用封场土种植绿化植物时最多可添加25.0%的生污泥,绿化植物可选择‘金叶’梓树和‘红叶’石楠。     

Influence of Carbon-Rich Amendments on Nitrogen Losses During Sewage Sludge Composting

Different extra carbon sources(glucose, sucrose and straw powder）were added during sewage sludge composting. According to the results, separate add of the glucose(2.46 g/kg·ds）and sucrose(2.17 g/kg·ds）could reduce NH3 emission compared with the amount of NH3 emission(3.05 g/kg·ds). No significant reduction of nitrogen loss was found in the mixture of P3 amended with straw powder alone(3.1 g/kg·ds). Adding the mixture of sucrose and straw powder had significant effect on reducing ammonia emission(1.92 g/kg·ds). A good linear correlation between the carbon degradation rate and ammonia emission was found with correlation coefficients of -0.94(p<0.005). The combination of straw with glucose and sucrose could enhance the decomposition of organic carbon. The carbon source which has more readily degradable composition is helpful to nitrogen immobilization.     

施用生活污泥对滩涂土壤性质及重金属含量的影响

为了探讨应用生活污泥改良滩涂土壤的可行性,明确生活污泥对滩涂土壤理化性质及环境效应的影响,采用符合农用标准的城市生活污泥为材料,通过盆栽培养试验,研究了施用不同用量（0、2.5%、5%、10%、15%、20%,土壤、污泥均以干基计）的生活污泥对滩涂土壤性质及重金属含量的影响。结果表明,施用生活污泥可显著提高滩涂土壤的总氮、总磷、碱解氮、速效磷等养分含量,其中总氮、碱解氮增加的倍数很接近,速效磷增加的倍数远远高于全磷的增加倍数。施用生活污泥显著增加了滩涂土壤的有机质含量,降低了pH值,对土壤可溶性总盐含量无显著影响。施用生活污泥,增加了滩涂土壤Ni、Cd、Zn、Cu、Cr重金属的全量及有效态含量,在实际应用过程中应根据生活污泥重金属的含量确定施用量。     

城市污泥农用处置研究进展

城市污泥的处置方式主要有农业利用、陆地填埋、焚烧和排海。城市污泥中含有大量的植物营养元素,其土地利用能改善土壤的理化性质,提高作物产量,减少污泥对环境的二次污染,从而实现污泥的资源化、无害化、稳定化和减量化处置目标。虽然城市污泥中含有重金属等有害物质,但大量研究表明,经过无害化处理的城市污泥适量施用不会对土壤环境和作物品质造成影响。城市污泥的农林利用已成为最具潜力的污泥处置方式。