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41.
β-环糊精包合态三氟氯氰杀虫剂的制备 总被引:3,自引:0,他引:3
为了进一步提高三氟氯氰菊酯农药的防治效果。寻找适宜的农药新剂型,我们用液相法制备了三氟氯氰菊酯-β-环糊精包合物,并以水为基质进行了稳定性观察,同时又以差热分析法和气相色谱法确认了包合物的形成,以旋光度法证明两者间的包合比。结果表明,三氟氯氰菊酯与β-环糊精可形成1:1型包合物,该包合物稳定性高,具有一定的水溶性,而且在水中稳定,所以有望通过环糊 包合作用将三氟氯氰菊酯帛成水剂;当以气相法测试包合态三氟氯氰菊酯含量时,必须将其解络,使之成为游离状态,然后按常规方法进行含量测定。 相似文献
42.
红壤丘陵区农业开发中的生态环境效应及其调控 总被引:3,自引:0,他引:3
文章以江西余江县为例。通过实验研究,历史资料对比分析及邻近参照等方法。研究红壤区农业开发中的生态环境效应。农业开发引起的微观环境效应在于改变土壤水分及其运动状况,加速土壤物质迁移及降低土壤肥力质量;区域性效应是植被减少,农业面源污染,水土流失扩大及气候异常;全球性影响除区域集聚效应外,则是农业活动中产生的温室气体对全球气候的影响等,采取的调控对策主要是:保持合理开发,适当减轻土地压力,优化农业开发模式,更新农业耕作技术。强化环境整治与生态建设。 相似文献
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本文对松辽盆地东南部后五家户气田划分出22种沉积微相,建立7种相层序,分析了扇三角洲及三角洲沉积环境对天然气成藏的控制作用。指出了扇三角洲前缘砂体和三角洲前缘砂体较为发育,沉积物源来自气田东北部和东南部两个方向。后五家户气田多为构造—岩性气藏和岩性气藏。 相似文献
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Introduction The Western Kunlun Mountain Pass M=8.1 earthquake occurred on November 14, 2001 is the other M=8 earthquake occurred 50 years after Dangxiong, Tibet M=8.0 earthquake in Chinese mainland. The earthquake has caused the attention of the seismologists in the following aspects: 1) The fracture length is more than 400 km, which is far away from the estimated length by the statistic empirical function between the magnitude and the fracture length (WANG, et al, 2002); 2) The aftersh… 相似文献
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Application of dendrochronology and geomorphology to a recently emerged coastal area near Juneau, Alaska, has documented a Little Ice Age (LIA) sea-level transgression to 6.2 m above current sea level. The rise in relative sea level is attributed to regional subsidence and appears to have stabilized by the mid 16th century, based on a sea-cliff eroded into late-Pleistocene glaciomarine sediments. Land began emerging between A.D. 1770 and 1790, coincident with retreat of regional glaciers from their LIA maximums. This emergence has continued since then, paralleling regional glacier retreat. Total Juneau uplift since the late 18th century is estimated to be 3.2 m. The rate of downward colonization of newly emergent coastline by Sitka spruce during the 20th century closely parallels the rate of sea-level fall documented by analysis of local tide-gauge records (1.3 cm/yr). Regional and Glacier Bay LIA loading and unloading are inferred to be the primary mechanisms driving subsidence and uplift in the Juneau area. Climate change rather then regional tectonics has forced relative sea-level change over the last several hundred years. 相似文献
47.
Andesitic pillow lavas containing biogenic, solid bitumen (SB) are a constituent of a Neoproterozoic volcanosedimentary sequence (Teplá-Barrandian unit, Bohemian Massif) in the Mítov area of the Czech Republic. A black shale formation that is crosscut by these andesitic basalts is 565 Ma old. Carbon disulfide extracts of two powdered samples of SB contain 0.2 and 0.3 ppm of C60, respectively, as determined by high-pressure liquid chromatography. The peak assignment based on retention time is fully supported by high-resolution electron ionization mass spectrometry (EI-MS). No C70 was detected, nor was C60 found in two other SB samples from this locality. Other investigated carbonaceous samples from Bohemia (coals and anthracites of Upper Paleozoic age and anthraxolite, graphitoids, and graphite of Upper Proterozoic age) did not contain fullerenes at concentrations above the detection limit of 0.01 ppm. The absence of C60 in these samples was confirmed by EI-MS. The proposed mechanism of fullerene formation involves a primary algal phase, generation of a hydrocarbonaceous mixture in the course of thermal evolution of the sedimentary series, and their high-temperature transformation related to the extrusion of basalt. An important feature for fullerene conservation was the enclosure of fullerenes in SB with a structure similar to glasslike carbon, where the fullerene was protected against oxidation. 相似文献
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Dariusz Kucharczyk Miroslaw Luczynski Roman Kujawa Piotr Czerkies 《Aquatic Sciences - Research Across Boundaries》1997,59(3):214-224
Influence of water temperature on embryonic and larval development of bream (Abramis brama L.) was stdied. Eggs of bream were incubated at eight constant water temperatures between 13.2 and 26.8°C. The temperature
of 21.1°C gave highest hatching success, with no abnormalities in the eleutheroembryos and lowest mortality observed between
eyed egg stage and the time of hatching. Developmental rate increased with increasing temperature. Duration of embryonic development
(y; hours) decreased with increasing incubation temperature (x; °C) according to the formula: y=910.1−65.88 x+1.318 x2. Larvae were reared at eight constant temperatures ranging from 13.5 to 34.0°C. The instantaneous growth rate in wet weight
increased with increasing test temperature from 13.5 to 29.9°C, and then decreased at higher temperatures. Individual growth
of fish and biomass production rate were highest at 27.9°C. This temperature is considered optimal when food availability
and photoperiod are no limiting factors. 相似文献