标定低浓度高锰酸钾溶液的方法比较

比较以高锰酸钾本身和邻菲哕啉-Fe^2＋作指示剂，对低浓度高锰酸钾溶液进行标定发现，以邻菲啰啉-Fe^2＋作指示剂的标定，结果更为准确。     

钾素营养对烤烟烟叶品质影响的研究进展

烟草是喜钾作物,增施钾肥可提高烟叶含钾量,提高烟叶的生理活性,提高烟叶内在品质,增加烤烟的抗逆性,提高产量及其质量,烟叶的含钾量直接影响烟叶的香气质、香气量、燃烧性和持火力等.     

钾素营养对浅海沉积土桉树生长的影响

研究了浅海沉积物发育的砂壤土上种植桉树(EucalyptusU6),N60g/株、P2O590g/株作基肥,钾肥的多次施用对桉树的生长影响,结果表明:只是在造林前配合NP作基肥或当年追施钾肥才能发挥理想的钾肥使用效果。在NP作基肥的基础上添加氯化钾50g/株,一年生树高增长24.6%,当年再追施氯化钾50g/株的处理,一年生树高增长52.5%,二年生胸径则分别增长22.1%、42.8%;而后钾肥的追施效果不显著;这些差异一直保持到伐龄6a,但随林龄的增长,差异有所减少。由于材积由树高和胸径来决定,使处理间材积上的差异更加明显,并由此带来明显不同的经济效益。桉树对肥料的“相互作用效应”是明显的,造成以上结果的最大可能是桉树对元素的平衡需求。因此,建议桉树施肥以多元素的复合肥为主,并添加适量的微量元素,对其提供完全的营养,才能获得理想的产量,同时,应尽早进行施肥,以免错过桉树敏感期对肥料的大量需要而造成难以弥补的损失。     

钾肥对小麦根际土壤镉的吸收及其植物毒性的影响

研究不同钾肥对Cd在根际土壤-植物系统中转移及植物有效性的影响可为农业生产提供依据。以潮褐土为供试土样,采用盆栽方法研究了氯化钾、硝酸钾、硫酸钾对小麦(Triticum aestivum L)根际环境镉的吸收转移及植物有效性的影响。结果表明,(1)KCl提高根际土中有效态Cd质量分数(wCd),K2SO4和KNO3降低根际土壤有效态wCd。(2)K2SO4处理下,小麦根wCd显著大于对照;随KNO3和KCl施入量的增加,小麦根中Cd含量逐渐升高。(3)相同处理三种钾肥比较小麦地上部干物重表现为:KNO3>KCL>K2SO4,根干物质量均低于对照。(4)钾肥的施入提高小麦体内CAT,POD酶活性。建议Cd污染土施用KNO3,尽量避免施用KCl和K2SO4。     

Effects of chlorine content and position of chlorinated phenols on their oxidation kinetics by potassium permanganate

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｍｏｌｅｃｕｌａｒｓｔｒｕｃｔｕｒｅｓｏｆｐｈｅｎｏｌｓｓｈｏｗｃｈａｒａｃｔｅｒｉｓｔｉｃｏｆｈｉｇｈｌｙｒｅｓｏｎａｎｃｅ .Ｓｉｎｃｅｃｈｌｏｒｉｎｅｉｓａｗｉｔｈｄｒａｗｉｎｇｅｌｅｃｔｒｏｎａｔｏｍ ,ｓｕｂｓｔｉｔｕｔｉｏｎｏｆｃｈｌｏｒｉｎｅｏｎａｒｏｍａｔｉｃｒｉｎｇｃａｎｃａｕｓｅｍａｎｙｓｉｇｎｉｆｉｃａｎｔｅｆｆｅｃｔｓｏｎｔｈｅｒｅａｃｔｉｖｉｔｙｏｆｐｈｅｎｏｌｓ(Ｆｏｌｋｅ,1986;Ｂａｒｂｅｎｉ,1987;Ａｉｔｋｅｎ ,1994 ) .Ｆｏｒｅｘａｍｐｌｅ ,…     

Cr6+对人血红细胞膜的损伤及茶多酚对其保护作用的分子机理研究

采用TBA(thiobatbrturic acid)法和ESR自旅标记技术,测定了无机致癌物重铬酸钾(Cr~(6+))对红细胞膜的蛋白巯基和磷脂的作用,结果表明,Cr~(6+)引发红细胞膜产生脂质过氧化的同时,膜上蛋白巯基构象和磷脂的流动性发生改变.而茶多酚对Cr~(6+)引起红细胞膜上的这些变化均有明显抑制作用.     

Chemical Changes in Agricultural Soils of Korea: Data Review and Suggested Countermeasures

The monitoring of chemical properties, including heavy metals, in soils is necessary if better management and remediation practices are to be established for polluted soils. The National Institute of Agricultural Science and Technology initiated a monitoring study that investigated fertility and heavy metal contents of the benchmarked soils. The study covered paddy soils, upland soils, and horticultural soils in the plastic film houses, and orchard soils throughout the Korea from 1990 to 1998. Likewise,4047 samples of paddy and 2534 samples of plastic house in 1999 and 2000 were analyzed through the Soil Environment Conservation Act. Soil chemical properties such as pH, organic matter, availablephosphate and extractable calcium, magnesium and potassium contents, and heavy metal contentssuch as cadmium, copper, lead, zinc, arsenic, mercury, and cobalt contents were analyzed. The studyshowed that the average contents of organic matter, available phosphate, and extractable potassiumrapidly increased in plastic house soils than in upland or paddy soils. Two kinds of fertilizer recommendation systems were established for the study: the standard levels by national soil average data for 77 crops and the recommendation by soil test for 70 crops. Standard nitrogen fertilizer application levels for cereal crops changed from 94 kg/ha in 1960s, 99 kg/ha in 1970s, 110 kg/ha in 1980s to 90 kg/ha in 1990s. The K₂O-fertilizer also changed from 67 kg/ha in 1960s, 76 kg/ha in 1970s, 92 kg/ha in 1980s, andonly 44 kg/ha in 1990s. In rice paddy fields, the average contents of Cd, Cu, Pb, and Zn in surface soils(0–15 cm depth) were 0.11 mg kg^–1(ranged from 0 to 1.01), 4.70 mg kg^–1(0–41.59), 4.84 mg kg^–1(0–66.44), and 4.47 mg kg^–1(0–96.70), respectively. In the uplands, the average contents of Cd, Cu, Pb, Zn,and As in surface soils (0–15 cm depth) were 0.135 mg kg^–1(ranged from 0 to 0.660), 2.77 mg kg^–1(0.07–78.24), 3.47 mg kg^–1(0–43.00), 10.70 mg kg^–1(0.30–65.10), and 0.57 mg kg^–1(0.21–2.90), respectively. In plastic film houses, the average contents of Cd, Cu, Pb, Zn, and As in surface soil were 0.12 mg kg^–1(ranging from 0 to 1.28), 4.82 mg kg^–1(0–46.50), 2.68 mg kg^–1(0–46.50), 31.19 mg kg^–1(0.19–252.0), and 0.36 mg kg^–1(0–4.98), respectively. In orchard fields, the averagecontents of Cd, Cu, Pb, Zn, As, and Hg in surface soils (0–20 cm depth) were 0.11 mg kg^–1(ranged from 0–0.49), 3.62 mg kg^–1(0.03–45.30), 2.30 mg kg^–1(0–27.80), 16.60 mg kg^–1(0.33–105.50),0.44 mg kg^–1(0–4.14), and 0.05 mg kg^–1(0.01–0.54), respectively. For polluted soils with over thewarning content levels of heavy metals, fine red earth application, land reconsolidation and soilamelioration such as lime, phosphate, organic manure, and submerging were recommended. For the countermeasure areas, cultivation of non-edible crops such as garden trees, flowers, and fiber crops; landreformation; and heavy application of finered earth (up to 30 cm) were strongly recommended. Landuse techniques should be changed to beharmonious with the environment to increase yield andincome. Soil function characteristics should betaken into account.     

几种耕作土壤钾交换特性的研究

本文研究了三组不同粘土矿物组成的耕作土壤钾素的交换特性,结果表明,供试土壤的钾交换选择性系数(K_c)与交换性钾比率(EPR)呈极显著的负相关,相关系数变化于-0.86至-0.95之间,且K_c因EPR的增加而趋于恒值。以伊利石、蛭石占优势的第一组土壤和以伊利石为主、高岭石为次的第二组土壤的K_c趋于恒值时的EPR明显高于以高岭石为主、伊利石为次的第三组土壤。三组土壤的钾吸附比率(PAR)与EPR均呈极显著的正相关,相关系数变化于0.94至0.98之间。土壤钾交换选择性的强弱因粘土矿物组成、粘粒含量和初始交换性钾饱和度的不同而表现出如下趋势:第一组土壤>第二组土壤>第三组土壤。     

长期定位施肥对土壤磷、钾素动态变化的影响

23年定位施肥试验的结果表明，不施肥和单施氮肥的土壤，其有效磷质量分数迅速下降，前3年比播前降低约50％，自第7年开始比播前降低2／3左右，降至4-5μg／g之后处于稳定状态。土壤全磷质量分数始终保持在0．40-0．50g／kg的水平，有机磷略有增加。施有机肥以及有机肥与氮肥配施的土壤，其有效磷和有机磷质量分数增加显著。单施氮肥的土壤，其速效钾、缓效钾质量分数均降低，全钾质量分数变化不明显。在每年每公顷单施含钾150．0kg、300．0kg的有机肥或与138kg、276kg氮素配施的土壤中，以单施含钾300．0kg的有机肥的土壤的钾素盈余量最多，并随配施氮量的增加而盈余量减少。试验23年后的土壤，其钾素盈余量与土壤速效钾、缓效钾质量分数均有极显著的相关性，而与全钾质量分数的相关性小大。     

高碘酸钾氧化甲基红催化光度法测定超痕量锰

拟定了测定超痕量锰的新催化光度法。方法基于存在氨三乙酸为活化剂,以高碘酸钾催化氧化甲基红。方法的检出限为4×10~(-11)g/ml,表观摩尔吸光系数为2×10~7L·mol~(-1)·cm~(-1),测定锰量的线性范围为2—28ng/25ml,可直接分析水样和谷物制品中锰。