固氮菌与氮配施对生菜及油菜产量和品质的影响

采用盆栽试验研究了固氮菌(M)与氮(N)配施对生菜、油菜产量和品质的影响.结果表明:施加固氮菌(M2)后,生菜、油菜的鲜重和干重较之不加固氮菌(M1)有显著增加趋势,生菜、油菜的Vc含量分别提高4.2%~18.6%、17.6%~35.0%,还原糖含量分别提高17.6%~35.0%、6.7%~41.3%,硝酸盐含量分别降低40.5%~57.2%、22.8%~40.8%.在所有处理中,处理M2N3的两种蔬菜产量最高,品质最好.研究可为固氮菌肥的合理有效施用、氮肥的优化配比及叶菜类蔬菜高产优质的生物调控提供理论依据.图1表3参13     

乡镇企业可持续发展与小城镇建设

通过对乡镇企业的经济效益、环境效益和社会效益以及小城镇发展的优越性分析可知，乡镇企业不宜在农村发展，应该在小城镇中发展。     

Characteristics of dispersions and water-soluble extracts of crude and refined oils and their toxicity to estuarine crustaceans and fish

The quantitative hydrocarbon composition and behavior in seawater of water-soluble fractions (WSF) and oil-in-water dispersions (OWD) of 4 oils was investigated. Two crude oils, South Louisiana crude and Kuwait crude, and two refined oils, No. 2 fuel oil and bunker C residual oil, were used in these investigations. The WSFs of the crude oils had higher total oil-hydrocarbon concentrations and were richer in light aliphatics and single-ring aromatics than were the WSFs of the refined oils. The WSFs of the refined oils contained significantly higher concentrations of naphthalenes than did those of the crudes. The hydrocarbon composition of the aqueous phase of OWDs closely resembled that of the parent oils. Gentle aeration of the OWDs resulted in a loss of 80 to 90% of the aqueous hydrocarbons in 24 h. Alkanes disappeared from the dispersions more rapidly than aromatics. The WSFs and OWDs of the refined oils were considerably more toxic to the 6 test species than were those of the crude oils. The test species can be ranked according to increasing sensitivity to oil as follows: Cyprinodon variegatus, Menidia beryllina, Fundulus similus, Penaeus aztecus postlarvae, Palaemonetes pugio and Mysidopsis almyra. The results of this investigation are discussed in relation to the potential impacts of oil spills on the marine and estuarine environments.     

恩诺沙星与Cu复合污染对白菜和西红柿根及芽伸长的抑制作用

抗生素恩诺沙星和重金属Cu是当今我国土壤中较常见的污染物。本研究考察了恩诺沙星与Cu复合污染对砖红壤中白菜和西红柿种子的根及芽伸长的影响,以评估恩诺沙星和Cu复合污染潜在的生态风险。结果表明,加入不同浓度的Cu时,土壤中的恩诺沙星浓度与2种作物的根伸长和芽伸长的抑制率均显著相关(P0.05);白菜的敏感性均大于西红柿;白菜和西红柿的根伸长对复合污染的生态毒性的敏感性均较芽伸长更高;与单一恩诺沙星胁迫相比,在恩诺沙星与Cu(100 mg·kg~(-1))或Cu(300 mg·kg~(-1))复合污染下,二者对白菜和西红柿的根及芽伸长抑制效应均表现为协同作用。试验结果在揭示恩诺沙星与Cu复合污染的生态毒性效应的同时,也为重金属和抗生素复合污染的生态风险评价提供科学依据。     

投喂频率和饵料种类对黄颡鱼仔稚鱼生长和存活的影响

研究了以浮游动物为饵料日饱食投喂3次(F3)、2次(F2)、1次(F1)等不同投喂频率对3～32日龄黄颡鱼仔稚鱼生长和存活的影响,并比较了单独投喂浮游动物(Ⅰ组)、水蚯蚓(Ⅱ组)及两者混合投喂(Ⅲ组)对4～34日龄黄颡鱼生长和存活的影响.结果表明:(1)投喂频率对黄颡鱼仔稚鱼生长具有显著影响,F3组个体平均全长、体重显著高于F2、F1组;3～29日龄全长和体重特定生长率(SGR)与投喂频率间直线正相关(SGR1=1.0366D+3.2347,R2=0.9025;SGRW=3.00t3D+9.4829,R2=0.8833),投喂越多则生长越快.(2)17-25日龄时Ⅱ组生长显著低于Ⅰ、Ⅲ组;28日龄Ⅱ组生长仍显著低于Ⅲ组,但与Ⅰ组问没有显著差异;到34日龄,Ⅲ组生长最快,Ⅱ组生长超过Ⅰ组,3组间生长差异显著(P<0.05),表明28日龄后水蚯蚓为黄颡鱼更合适的饵料.(3)饵料种类对34日龄内的仔稚鱼成活率没有影响.试验表明,日饱食3次更有利于黄颡鱼仔稚鱼的生长;28日龄后投喂饵料应增加水蚯蚓;充足的适口饵料是影响黄颡鱼苗种生长的重要因素.图2表2参18     

Individual and combined effect of mercury and manganese on phenol and proline content in leaf and stem of mungbean seedlings

Mungbean (Vigna radiata L. Wilczelk cv. Pusa Baisakhi seedlings were raised in individual (0, 1, 10, 100 and 1000 ppm) and combined solutions (1 : 1, 10: 1, 1: 0 ppm Hg : Mn) of mercury and manganese for 6 days. Phenol and proline were found to accumulate in leaves in response to treatment with heavy metals. The magnitude of accumulation correlated with concentration of metals. However, a reverse trend was noticed in stem for phenol. Accumulation of phenol in response to heavy metal treatment was organ specific and occurred at higher rate in plant parts, which faced the stress mostly. However, accumulation of proline helped the plant to survive stress situation. In combined solutions, amelioration of mercurial toxicity by manganese was recorded.     

磷酸盐和石灰对污染红壤与黄泥土中重金属铜锌的钝化作用

采用外源加入重金属铜锌硝酸盐的方法,制成铜、锌单一及复合的三级污染红壤和黄泥土(Cu 200 mg·kg-1、Zn 400 mg·kg-1),平衡2个月;分别施入磷酸盐、石灰,稳定4个月后测定土壤中有效态铜、锌的含量,以阐明磷酸盐和石灰对重金属污染土壤中铜锌的钝化作用.结果表明,施入磷酸盐稳定120 d后,两种土壤中有效锌含量都显著降低,红壤中有效铜含量降低了8.3.6%,而黄泥土中有效铜含量变化不明显;施入石灰后,红壤中铜锌有效性含量降低了87.6?.3%,黄泥土中有效锌含量降低了90%,而有效铜含量最大降低幅度为47.4%.由此可见,磷酸盐对红壤中铜锌的钝化作用较强,对黄泥土中铜的钝化作用弱;石灰对两种土壤中铜锌的钝化作用都很强;磷酸盐和石灰对单一污染土壤铜锌的钝化固定作用要强于复合污染.     

费氏中华根瘤菌ntrBC基因突变株的构建及其特性

从费氏中华根瘤菌(Sinorhizobium fredii)HN01基因文库的重组质粒pGXHN300上获得ntrB、ntrC基因完整序列.通过自杀质粒pK18mob同源单交换的方法,分别获得了HN01菌株的ntrB和ntrC基因的突变株GXHNB、GXHNC.功能检测证明GXHNB、GXHNC能以硝酸盐为唯一氮源进行正常生长,但不能以铵源作为唯一氮源进行正常生长.图4表2参15     

高等数学教学与创新能力、实践能力的培养

高等教育的主要任务是培养具有创新精神和实践能力的高级人才,而高等数学在大学课程体系中占有十分特殊地位.在高等数学教学中培养学生的创新能力和实践能力的途经有:确定高等数学教学理念;重视知识过程教学;重视数学思想方法的渗透;加强数学建模教学;重建教学评价体系.参5.     

Plasmatic resistance and rate of respiration and photosynthesis of Zostera marina at different salinities and temperatures

Zostera marina L. was studied at the Izembek Lagoon, Alaska Peninsula. Two morphologically different forms, tidepool and subtidal, can be distinguished. Both show a high tolerance to different salinities and temperatures. The plasmatic resistance was found in a range of distilled H₂O up to 3.0 seawater (24 h) and between-6° and 34°C (12 h). Within these resistance limits, the photosynthesis, which has its maximum in normal (1.0) seawater, decreases nearly to zero not only in distilled H₂O but even in 2.0 seawater, and increases with the temperature in the tidepool form up to 35°C, but in the subtidal form up to 30°C only. At higher temperatures photosynthesis declines sharply in both forms. Respiration has its minimum in distilled H₂O and at 0°C and increases with increasing salinity and temperature.Dedicated to Prof. Dr. Dr. h. c. mult. K. Mothes, Halle, Germany (DDR) on the occasion of his 70th birthday.     

我院南校区学生体质和视力评价分析

目的:了解我院学生体质健康状况,为开展学校卫生和健康教育提供科学依据.方法:对我院南校区3个医科系学生采用整群分层随机方法抽取397人进行体格检查.结果:①男生身高和体质量评价均低于女生,药学系学生身高和体质量评价低于另2系.②男生正常体重比例低于女生,营养不良比例却高于女生,<16岁段正常体重人数比例较高,20~岁段正常体重人数大幅降低,营养不良人数却增多;肥胖率18~、19~岁段较高;男生高于女生.③视力低下率41.81%,随着年级的升高而增加;女生视力低下率高于男生.结论:南校区学生男生营养不良,女生视力低下,须加强学生膳食营养,加强体育锻炼和用眼卫生知识教育.表3,参5.     

有机无机肥配施比例对蔬菜产量和品质及土壤重金属含量的影响

关于蔬菜施有机肥和它与无机肥的合理配施比例,对蔬菜的产量和品质有重要影响,对土壤有机质和重金属含量也有影响。为控制施禽畜粪类有机肥对蔬菜的负面影响,探讨蔬菜的合理施用量和有机/无机肥配施比例,在不同质地的土壤上进行田间试验。结果表明,(1)施过量禽畜粪类有机肥对试验蔬菜产量和品质都会产生不良影响,小白菜(Brassica chinensis)和茄子(Eggplant)施禽畜粪超过22500kg/hm2、马铃薯(Solanum tuberosum L.)超过24000kg/hm2时,其产量不再增加,成活率下降,维生素C含量下降,多个试验均表现出有机肥用量增加而小白菜硝酸盐随之增加的典型特征;同时不论土壤的质地轻重,蔬菜重金属Pb有随禽畜粪用量增加而提高的趋势;在质地较轻的土壤上,蔬菜重金属Cd、As有随禽畜粪用量增加而提高的趋势;小白菜施禽畜粪肥超过7500kg/hm2、茄子和冬种马铃薯施禽畜粪肥超过75000kg/hm2,收获后土壤重金属含量高于对照和施无机肥的总Cr和As。(2)蔬菜单独施用有机肥的合适施用量,小白菜在较粘重的土壤上可施到22500kg/hm2,但有机肥与无机肥配合施用时有机肥用量可减量;茄子合适施用量应在22500kg/hm2左右;冬种马铃薯合适施用量应在24000kg/hm2左右。(3)蔬菜的有机/无机肥合理配比,小白菜、茄子、和冬种马铃薯施肥的有机氮与无机氮之比均为0.25∶1至0.5∶1时其产量和品质水平较佳。     

Bacterial degradation of monocrotophos and phyto- and cyto-toxicological evaluation of metabolites

The bacterium Serratia marsescens strain JAS16 was isolated from agricultural soil which had prior exposure to monocrotophos for three years. The strain JAS16 tolerated up to 1200 mg L^–1 monocrotophos and degraded the insecticide (1000 mg L^–1) at a degradation rate constant of 136 d^?1 (DT₅₀ = 3.7 d). In soil, the degradation rate constant was 105 d^?1 (DT₅₀ = 4.8 d). A schematic pathway is being proposed from the degraded products derived from gas chromatography--mass spectrometry (GC-MS). The phytotoxicity of degradation products to Vigna radiata, Vigna unguiculata, and Macrotyloma uniflorum and the genotoxicity to Allium cepa roots were found to be low. A cost-effective powder-based formulation was achieved with the isolate. The isolate remained viable during the storage and also multiplied with a higher colony forming units (CFU) load g^–1 for over a period of seven weeks of storage.     

甲胺磷和乙草胺对产甲烷菌种群数量及其活性的影响

采用厌氧培养箱、气相色谱技术和MPN计数法,研究了甲胺磷和乙草胺在4种浓度(0 1、0 2、0 5和1 0mg·L-1)下对水稻田土壤产甲烷菌种群数量及其活性的影响。加甲胺磷后7d内刺激产甲烷菌种群的生长,数量增加0.2～44.1倍,每管的产甲烷量增加0.8～2.1倍,且刺激作用随药剂浓度的增加而增强;加乙草胺后7d内,产甲烷菌的生长受到抑制,数量下降了50%～99%,每管的产甲烷量显著减少,且抑制作用随药剂浓度的增加而增强。随着加药时间的延长,甲胺磷和乙草胺逐渐降解,产甲烷菌数量又恢复至原有水平。     

Metals and organic components of sewage and sludges

Sewage and sludge samples were collected from rural areas of Vellore district. The metals like Cu, Zn, Cd, Pb, Fe, Ca and Mg were determined by Inductively coupled plasma atomic emission spectrophotometry (ICP-AES). For this determination HCl - HNO3 and 4N HNO3 extracts were used. The total organic carbon (TOC), chemical oxygen demand (COD) and organic matter (OM) have also been determined to evaluate the presence of organic and metallic contents in sewage and sludge environment.     

藻类有机质的组成结构对菲和壬基酚生物吸附的影响

对不同来源藻及其有机级分进行元素分析,利用高级核磁共振技术(multi/CP13C NMR)来准确地定量其有机官能团,并研究它们对菲和壬基酚的生物吸附行为和机理。结果表明游离脂和非水解有机碳级分对菲和壬基酚有最高的吸附能力,其吸附容量与脂肪结构呈极显著的正相关,而与极性官能团呈极显著的负相关;而且对壬基酚的吸附容量都大于对菲的吸附容量,可以用专性作用(如π-π键作用和氢键作用)来解释。     

Problems and prospectus of utilization of sewage and industrial wastewaters in agriculture

The basic objective of this study was to compile the available information on the composition of sewage and industrial wastewaters in India and their effect on soil–plant health upon their use in agricultural fields. The composition of sewage water is quite variable depending upon the contributing source, mode of collection, and treatment provided. The composition of sewage water varied from site to site which was in accordance with the type of industries present in that area. Continuous use of sewage and industrial wastewater irrigation recorded improvement in water retention, hydraulic conductivity, organic C and build-up of available N, P, K, micronutrient status, and soil microbial count. The electrical conductivity although increased due to sewage irrigation, it was within the tolerance limit to cause any soil salinity hazard. The toxic metals like Cd, Cr, Pb, and Ni were found to be accumulated in soil and plant due to long-term use of sewage and industrial wastewater irrigation. The concentration of these metals was higher in leafy vegetables than in grain crops. This warrants the potential hazard to soil–plant health suggesting necessity of their safe use after pretreatment as a cheap potential alternative source of plant nutrients in agriculture.     

氮磷营养盐因子对缘管浒苔生长、叶绿素荧光特性和氮磷富集的影响

为探讨大型海藻缘管浒苔(Ulva linza)对氮、磷加富的生理响应及其机制,分析了氮、磷浓度变化对藻体相对生长速率(Rr.g),氮、磷富集,叶绿素(Chl)含量,类胡萝卜素(Car)含量,色素比值(Chl a/Chl b、Chl/Car)以及叶绿素荧光参数的影响.结果表明,在30μmol·L-1P浓度不变条件下,随着N浓度的增加,藻体P含量持续降低,而其Rr、g、N含量、Chl含量、Car含量、色素比值(Chl a/Chl b、Chl/Car)和叶绿素荧光参数均逐渐上升,N3处理(500μmol· L-1 N)缘管浒苔Rr.g和叶绿素荧光参数均达到最大值,N4处理(1 000 μmol·L-1)缘管浒苔Chl含量、Car含量和Chl a/Chl b比值均达到最大值.在500 μmol·L-1N浓度不变条件下,依次增加P浓度,缘管浒苔Rr,g没有显著差异,N含量没有显著变化,而P含量则呈明显上升趋势,其他指标变化幅度小.综上所述,与P相比,N的变化对缘管浒苔生长、光合色素和光合作用的影响更明显,在N浓度为500 μmol·L-1、P浓度为30 μmol ·L-1、N/P比值为16.67条件下,藻体生长最佳.当水体富营养化加剧时,缘管浒苔富集氮、磷的能力持续上升.     

河岸缓冲带对氮磷的截留转化及其生态恢复研究进展

河岸缓冲带是河岸生态系统的重要组成部分,对农业非点源污染物起到有效的截留转化作用。对河岸缓冲带的定义、生态结构特性和功能,河岸缓冲带对氮和磷的截留转化作用以及河岸缓冲带的生态修复现状进行了综合评述。结果表明：草地和森林类型河岸缓冲带均能有效地控制氮和磷向水体中迁移;河岸缓冲带的宽度、水文特征、土壤性质、季节变化以及人为活动等是影响其截留效率的因素;加强退化河岸缓冲带的恢复重建工程,可以保证河岸生态系统的健康。针对目前研究中的不足,提出今后的研究方向,认为应进行长期的大尺度的野外实践研究,并从生态学的角度出发,建立合理的河岸缓冲带健康指标,为退化河岸缓冲带恢复重建提供科学依据。