淹水还原条件对不同土壤中镧形态分布的影响

以旱作条件为参照,研究淹水还原条件对镧形态分布的影响。结果表明:淹水还原条件对内源镧B1态:水溶态、可交换态与碳酸盐结合,B2态:铁锰氧化物结合态,B3态:有机质及硫化物结合态的分布没有显著影响;对于外源镧,B1和B3态受淹水条件影响较大,相对于旱作条件,其浓度有增加的现象,淹水条件下B2态在中性土壤中含量稳定,酸性土壤中含量下降,而碱性土壤中含量则上升,产生变化的具体机制还有待进一步研究。两种模拟条件下外源镧3种形态的分布未达到显著性差异。不论在旱作还是淹水条件下,3种土壤中外源镧各形态浓度顺序相同,B1和B2态为:黄红壤黄褐土砂姜黑土,B3态为:砂姜黑土黄褐土黄红壤;两种模拟条件下,3种土壤中的外源镧有进入残渣态的趋势,但并不明显,且不同土壤的各形态对残渣态的贡献不同。     

全波长扫描式多功能读数仪-分光光度法测定土壤中无机氮

快速准确测定土壤中铵态氮、硝态氮含量对监测土壤肥力水平和生态环境,指导作物氮肥施用非常重要。选择30份土样,利用全波长扫描式多功能读数仪(酶标仪)结合靛酚蓝分光光度法、硫酸肼还原法测定土壤中铵态氮和硝态氮含量,探讨利用酶标仪测定土壤无机氮含量的可行性。结果显示,利用酶标仪测定土壤铵态氮、硝态氮含量与连续流动分析仪测定结果之间无明显差异,彼此间呈显著线性相关。铵态氮回归直线方程为Y(连续流动分析仪-NH_4~+-N)=0.997 6 X(酶标仪-NH_4~+-N)-0.012 3,相关系数R=0.961 9(n=30,P<0.01);硝态氮回归方程为Y(连续流动分析仪-NO_3~--N)=0.959 3 X(酶标仪-NO_3~--N)+0.021 9,相关系数R=0.964 0(n=30,P<0.01)。酶标仪测定铵态氮回收率在96.2%～108%,相对标准偏差在10%以内;硝态氮测定回收率为94.9%～110%,且相对标准偏差在5%以内,酶标仪测定土壤铵态氮和硝态氮方法检出限分别为0.068mg/L和0.028mg/L。酶标仪测定土壤无机氮速度快,精密度、准确度较高,消耗试剂少,可用于大批量土壤浸提液中铵态氮和硝态氮含量的快速分析。     

全波长扫描式多功能读数仪-分光光度法测定土壤中的无机氮

快速准确测定土壤中铵态氮、硝态氮含量对监测土壤肥力水平和生态环境,指导作物氮肥施用非常重要。选择30份土样,利用全波长扫描式多功能读数仪(酶标仪)结合靛酚蓝分光光度法、硫酸肼还原法测定土壤中铵态氮和硝态氮含量,探讨利用酶标仪测定土壤无机氮含量的可行性。结果显示,利用酶标仪测定土壤铵态氮、硝态氮含量与连续流动分析仪测定结果之间无明显差异,彼此间呈显著线性相关。铵态氮回归直线方程为Y(连续流动分析仪-NH_4~+-N)=0.997 6 X(酶标仪-NH_4~+-N)-0.012 3,相关系数R=0.961 9(n=30,P0.01);硝态氮回归方程为Y(连续流动分析仪-NO_3~--N)=0.959 3 X(酶标仪-NO_3~--N)+0.021 9,相关系数R=0.964 0(n=30,P0.01)。酶标仪测定铵态氮回收率在96.2%～108%,相对标准偏差在10%以内;硝态氮测定回收率为94.9%～110%,且相对标准偏差在5%以内,酶标仪测定土壤铵态氮和硝态氮方法检出限分别为0.068mg/L和0.028mg/L。酶标仪测定土壤无机氮速度快,精密度、准确度较高,消耗试剂少,可用于大批量土壤浸提液中铵态氮和硝态氮含量的快速分析。     

全波长扫描式多功能读数仪-分光光度法测定土壤中无机氮

快速准确测定土壤中铵态氮、硝态氮含量对监测土壤肥力水平和生态环境,指导作物氮肥施用非常重要。选择30份土样,利用全波长扫描式多功能读数仪(酶标仪)结合靛酚蓝分光光度法、硫酸肼还原法测定土壤中铵态氮和硝态氮含量,探讨利用酶标仪测定土壤无机氮含量的可行性。结果显示,利用酶标仪测定土壤铵态氮、硝态氮含量与连续流动分析仪测定结果之间无明显差异,彼此间呈显著线性相关。铵态氮回归直线方程为Y(连续流动分析仪-NH_4~+-N)=0.997 6 X(酶标仪-NH_4~+-N)-0.012 3,相关系数R=0.961 9(n=30,P0.01);硝态氮回归方程为Y(连续流动分析仪-NO_3~--N)=0.959 3 X(酶标仪-NO_3~--N)+0.021 9,相关系数R=0.964 0(n=30,P0.01)。酶标仪测定铵态氮回收率在96.2%～108%,相对标准偏差在10%以内;硝态氮测定回收率为94.9%～110%,且相对标准偏差在5%以内,酶标仪测定土壤铵态氮和硝态氮方法检出限分别为0.068mg/L和0.028mg/L。酶标仪测定土壤无机氮速度快,精密度、准确度较高,消耗试剂少,可用于大批量土壤浸提液中铵态氮和硝态氮含量的快速分析。     

保存、分析方法等因素对土壤中硝态氮测定的影响

为探明土壤中硝态氮测定的影响因素,采用黑土、潮土、红壤为材料,研究样品的保存方法、浸提剂种类、分析方法、实验用水及试剂纯度对土壤中硝态氮测定的影响。结果表明,测定土壤硝态氮时,土样在冷冻条件下保存优于冷藏条件。冷冻条件下保存可在45 d内完成测试,而冷藏保存则需在7 d内完成测试。采用0.01 mol/L CaCl2和2 mol/L KCl为浸提剂时,对土壤中硝态氮的测定结果无显著差异。紫外比色法的测定结果与林业标准法(LY/T1230-1999)相比无显著差异,但显著高于流动注射法,且紫外比色法与流动注射法之间有显著相关性。流动注射法的测定结果与林业标准法相比也无显著差异。实验用水的杂质可使土壤中硝态氮的测定结果显著偏高,对其进行加热煮沸、蒸馏及无氨化蒸馏后可显著降低水中杂质的含量。     

贡嘎山东坡森林土壤有效微量元素分布特征

对青藏高原东缘贡嘎山东坡森林土壤有效微量元素的含量、分布及影响因子进行了研究。结果表明,四种典型土壤土层中有机质、水解氮、有效磷和速效钾的含量基本表现为由上而下逐渐降低的趋势;且在不同林型条件下,土壤养分含量分布也有差异;位于不同海拔高度的土层中,有机质等常量养分的分布表现出两头高、中间低的态势。土壤中B、Zn、Mn三种元素的含量均低于或远远低于各自的临界值;除Mn以外,有效态微量元素B、Cu、Zn、Fe含量均呈现出自上而下逐渐减少的趋势,即为表层富集型。     

农用稀土施用量、宽窄行配置对鲜食糯玉米产量构成因素及品质的影响

通过田间小区试验,研究了不同稀土施用量、不同宽窄行配置对鲜食糯玉米产量、产量构成要素和品质的影响。结果表明:农用稀土施用量为200 mg.kg-1时,宽窄行配置为70+50 cm时,吐丝进程最快;皮渣比率、可溶性糖含量、籽粒粗淀粉含量、植株全氮含量均比较小;蒸煮品质即风味、气味,糯性等表现最佳。小花总数、受精小花数、结粒数随着农用稀土施用量增加而减少,且宽窄行配置70+50 cm时,为最大。在农用稀土施用量为600 mg.kg-1时,宽窄行配置60+60 cm时,鲜穗产量为最高,达11883.9 kg.hm-2,在农用稀土施用量为800 mg.kg-1时,宽窄行配置70+50 cm时,鲜穗产量为最低,为9355.8 kg.hm-2。     

贵州红枫湖溶解态稀土元素地球化学研究

以中国西南碳酸岩盐地区的红枫湖及环湖河流水体为研究对象,采用液-液萃取和ICP-MS测试方法,对水中溶解态稀土元素浓度进行了测定,借以探讨碳酸盐岩水体环境下稀土元素的地球化学行为和环境效应。研究结果表明,红枫湖湖水溶解态稀土含量相对较低,∑REE总浓度分布于14.3～27.2 ng.kg-1之间,平均含量为18.24 ng.kg-1,明显低于地表水体浓度平均值。环湖河水溶解态∑REE浓度分布于4.07～102.28 ng.kg-1,平均为24.12 ng.kg-1。湖水和河水的页岩(PAAS)标准化的溶解态稀土元素配分模式都显示了显著的重稀土富集特征以及Ce元素负异常,而水化学络合计算结果显示,水体中溶解态稀土几乎以占绝对优势的碳酸盐无机络合形态存在,其他络合方式所占比例非常微小。这些都显示与相对偏碱性的水化学环境有关。     

低剂量硝酸镧对小鼠肾脏自由基防御机能的影响

通过采用肾组织匀浆生化测定法, 观察不同剂量硝酸镧灌胃一个月后, 小鼠肾组织中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、脂质过氧化物(LPO)、谷胱甘肽过氧化物酶(GSH-PX)含量的变化, 探讨了低剂量硝酸镧的抗氧化作用; 结果表明 雌性、雄性小鼠20.0, 10.0 mg*kg-1 Cu-ZnSOD和CAT的含量均较对照组明显降低; 而GSH-Px和LPO的含量均较对照组显著升高. 雌性、雄性小鼠0.1, 0.2, 2.0 mg*kg-1组Cu-ZnSOD, CAT, GSH-Px和LPO的含量与对照组无显著性差异. 较高剂量(20.0, 10.0 mg*kg-1)的硝酸镧的直接损伤可使小鼠肾脏脂质过氧化反应增强, 清除自由基的能力下降. 较低剂量(0.1, 0.2, 2.0 mg*kg-1)的硝酸镧对小鼠肾脏自由基的生成和清除无影响.     

微流池多光程土壤有效态氮磷测定方法研究

农业面源氮磷污染是当前地表水体污染主要来源,而土壤有效态氮磷测试大都依赖于流动分析仪在实验室完成,无法满足个性化土壤有效态氮磷现场测定需求。建立了一种微流池多光程的土壤有效态氮磷测定技术,通过柔性化参数设置,实现不同土壤有效态氮磷测试规范和现场测试。以广东省韶关市农业科学研究所和北京市农林科学院提供的26个样品为例进行有效态铵态氮、硝态氮和磷测定验证。实验结果表明,微流池多光程土壤有效态氮磷测定方法中有效态铵态氮、硝态氮和磷的检出限(LOD)分别为0.0086、0.0094和0.0078 mg/L,相对标准偏差(RSD)分别为0.80%、5.7%和0.90%,加标回收率在92.0%~103%,平均单样品测试时间6 min。测试过程自动化,极大地提升了土壤有效态氮磷测定效率和测试结果准确性,为农业面源污染防治提供技术支撑。     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

恶臭嗅辨实验室建设探讨

针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。     

Summary of development of the theory of stability of colloids and thin films

In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.     

Study of hydration of two cements of different strengths

Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, M_o, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700^oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.     

解决能源问题的新途径——光解水制氢的研究

面对日益枯竭的能源危机,氢能是一种洁净、最有前景的替代能源。目前在各种制氢的方法中光催化分解水制氢的研究最多,光解水过程中催化剂最关键,本文对利用太阳能光解水的途径、提高光催化反应效率以及光催化剂的开发研究进行了综述。     

黄酮化合物的合成研究进展

黄酮化合物是一类具有多种生物活性的天然产物,其经典的合成方法主要为查耳酮路线和β-丙二酮路线.近年来出现了许多新技术、新方法.本文介绍了2'-羟基查尔酮的氧化关环法、黄烷酮氧化法、改进的Baker-Venkataraman法及其他合成黄酮化合物的方法.