土壤活性有机碳

土壤活性有机碳是土壤中活跃的化学组分,能显著影响土壤化学物质的溶解、吸附、解吸、吸收、迁移乃至生物毒性等行为,近年来土壤活性有机碳已成为土壤、环境和生态科学领域所关注的焦点和研究的热点。本文从土壤活性有机碳的来源、组成、含量、影响因素以及环境意义等方面做了简要的论述。一般认为,土壤活性有机碳来源于植物凋落物的分解、根系分泌物、土壤有机质的水解、土壤微生物本身及其代谢产物,因为来源的不同土壤活性有机碳含量也不同;影响土壤活性有机碳的因素有很多,研究表明,土壤活性有机碳随季节和湿度的变化呈现十分强烈的变异趋势;土地利用方式改变对土壤活性有机碳的影响在不同的研究中有不同的结果;土地管理措施如耕作、施有机肥和化肥、改变土壤pH值等对土壤活性有机碳也有很大的影响。土壤活性有机碳的生态环境效应主要表现在它对调节土壤养分流有很大影响,与土壤内在的生产力高度相关;它作为重金属的有机配体,对土壤溶液中的微量重金属的可移动性和迁移过程以及金属复合物的形成过程有着重要作用;它的存在影响农药在土壤中的截留、增加农药的水溶性,并影响农药在土壤中的运动;它对温室气体的排放、水体富营养化、岩石圈溶蚀都有很重要的作用。同时指出了未来的研究方向。

Investigation of the effect of branched structure on the performances of the copolymers synthesized from ethylene and alpha-olefin with rac-Et(Ind)(2)ZrCl2/MMAO catalyst system

The branched copolymers prepared from ethylene and alpha-olefins using rac-Et(Ind)(2)ZrCl2/MMAO catalyst system were studied. Both the absolute molecular weight ((M) over bar (W)) and the molecular size (radius of glyration, R-g) of the polymers eluting from gel permeation chromatography (GPC) columns were obtained simultaneously via a high temperature GPC coupled with a two-angle laser light scattering (TALLS) detector. The branched structures and performances of the copolymers display approximate molecular weight and molecular sizes were investigated. Wide angle X-ray diffraction analyses indicate that 16-carbon side branch could co-crystallize effectively with backbone chain at low alpha-olefin incorporation. The melt behaviors of the copolymers were studied by dynamic rheological measurements. Both branch length and comonomer content affect considerably the loss modulus, storage modulus and complex viscosity of the copolymers. The relationship between the dynamic-mechanical behavior and the comonomer content of the copolymers was also examined by dynamic-mechanical experiments.

Effect of rare earth element on the metabolism in rats by high resolution proton nuclear magnetic resonance spectroscopy

The high-field nuclear magnetic resonance (NMR) spectra can be used for the rapid multicomponent analysis in small amounts of biological fluids. In this paper, the effect of La (NO3)(3) on the rats' metabolism in urine was investigated by H-1 NMR analysis. The experimental groups of wistar rats were injected intraperitoneally with La(NO3)(3) at doses of 0.2, 2.0, 10 and 20mg/kg body weight. The remarkable variation of low molecular weight metabolites in urine has been identified by H-1 NMR spectra, in which dimethylamine, N, N-dimethylglycine, urea, alpha -ketoglutarate, trimethylamine N-oxide, succinate, citrate and amino acids have been suggested as NMR markers for renal damage and ethanol, lactate, taurine as the markers for liver damage. This work may assess its possible use in the early detection of biochemical changes associated with Rare Earth induced kidney and liver dysfunction.

稀土对大鼠代谢产物影响的核磁共振研究

以高场核磁共振技术为研究手段，通过分析腹腔注射０．２、２、１０、２０ｍｇ／ｋｇ体重剂量 的Ｌａ（ＮＯ３）。后大鼠尿液中代谢物浓度、物种的变化，研究了稀土化合物在动物体内的作用 情况，结果表明稀土的引入使动物肾脏和肝脏都受到一定程度的损伤。并在代谢物中挑选出 了合适的ＮＭＲ　ｍａｒｋｅｒｓ，其变化可以反映稀土离子作用后大鼠的异常代谢。

STUDIES ON THE SULFONATION OF POLY(PHENYLENE OXIDE) (PPO) AND PERMEATION BEHAVIOR OF CASES AND WATER-VAPOR THROUGH SULFONATED PPO MEMBRANES .1. SULFONATION OF PPO AND CHARACTERIZATION OF THE PRODUCTS

Poly(2,6-dimethylphenylene oxide) (PPO) was sulfonated to varying degrees using different sulfonating agents. Physical properties such as solubility, density, and thermal properties were studied for both PPO and sulfonated PPO (SPPO) with different degree

ENTANGLEMENT FLUCTUATION DURING PHASE-SEPARATION IN POLYMER BLENDS

For perhaps the first time, the dynamics of liquid-liquid phase separation was studied by time-resolved mechanical spectrometry in order to establish the relationship between blends' properties and the phase structures during spinodal decomposition (SD). The selected system was chlorinated polyethylene (CPE)/ethylene-vinyl acetate copolymer (EVA). It was found that in the early and intermediate stage of SD, the storage modulus (G') and the loss modulus (G'') increase with time after the initiation of the isothermal phase separation; in the later stage, G' and G'' decrease as phase separation proceeds. An entanglement fluctuation model was presented to manifest this phenomenon; it was found that the rheological behavior agrees well with the expections of the model in the early stage. For the later stage, the reduction of G' and G'' can be attributed to the increment of phase-domain size. (C) 1993 John Wiley & Sons, Inc.

胶州湾悬浮颗粒物中脂肪酸的时空分布及其在初级生产者到初级消费者食物传递中的作用

研究初级食物供给与初级消费之间数量与质量的关系在海洋浮游生态系统食物网研究中占有基础地位。悬浮颗粒物及浮游动物中脂肪酸的组成和含量可以很好地为食物关系研究提供信息。当悬浮颗粒物在时空上存在数量和质量差异时，这种差异就可能在浮游动物中体现出来，而且通过脂肪酸的信息可以追踪到这种差异。本研究旨在阐明脂肪酸在悬浮颗粒物组成中的生物标记作用和在悬浮颗粒物到浮游动物食物传递过程中的营养指示作用，同时应用这一标记物研究胶州湾海域悬浮颗粒物的大体分布及其与浮游动物间的食物关系。 文章首先依据2005年3月－2006年2月胶州湾颗粒有机碳及叶绿素a的数据估测碳生物量的转化系数，发现该系数受时空环境差异的影响，平均为56，从而推导出胶州湾浮游植物有机碳浓度，进而探讨浮游植物对颗粒有机碳的贡献。对各参数分析结果显示胶州湾颗粒有机碳、叶绿素a和浮游植物有机碳年平均浓度分别为为0.47 mg.L-1、4.16 μg.L-1及0.23 mg.L-1，三者表现出相似的时空变化动态，即湾内沿岸水域较高，湾外较低，夏季较高秋冬季较低。浮游植物对颗粒有机碳的贡献较高，年平均接近37%。 对悬浮颗粒物的脂肪酸组成分析后发现饱和脂肪酸（SSFA）16:0，14:0，18:0及单不饱和脂肪酸（MUFA）Σ16:1(ω7+ω5+ω9)所占比例较高，多不饱和脂肪酸（PUFA）中EPA和DHA也相对较高。总脂肪酸在水体中的绝对浓度及在颗粒有机碳中的相对含量均存在着时空变异，二者的平均变动范围分别在4.7－60.2 μg . L-1及20.1－86.7 μg . mg-1之间，夏季高于秋冬季，空间分布上二者均在湾东部相对较高，而在湾外较低。不同脂肪酸组合的时空变化可以反映出悬浮颗粒物组成的时空动态，其中16:1ω7/18:1ω9、Σ16:1/18:1ω9、Σ16:1/Σ18:1、Σ16/Σ18、Σ16/ΣFA及20:5ω3/22:6ω3等脂肪酸组合在研究海域可以较好的指示硅藻组成，而Σ18/ΣFA 及22:6ω3/ΣFA可以指示甲藻组成，BSFA/ΣFA、Σ(Br+St)/ΣFA 、Br/St (15:0)及 Br/St (15:0+17:0)可以较好的指示细菌，SSFA/ΣFA及(24:0+26:0)/ΣFA可以示踪碎屑组分及其中的陆源成份。ω3系列脂肪酸在有机碳中的含量及在总脂肪酸中的比例以及不饱和指数可以表征悬浮颗粒物的食物质量。通过标志脂肪酸对悬浮颗粒物组成的指示发现冬季2月悬浮颗粒物组成中硅藻所占比例较高，多数月份湾内近岸水域尤其是湾东部细菌组成相对较高，而湾口至湾外水域碎屑含量相对较高。 浮游动物总平均干重生物量为72.6 mg.m-3，平面分布表现为湾内北部及中心区域生物量普遍较高，湾东部水域较低，季节变化表现为总生物量在春季4月及冬季12月形成峰值，总体上在春季5月、夏季7月及秋冬大部分月份相对较低，但不同粒径组成其动态不尽相同。浮游动物的脂肪酸组成与悬浮颗粒物存在一定差别，表现为MUFA比例下降，PUFA比例升高；SSFA中14:0的比例下降，18:0及20:0比例提高，MUFA中20:1ω9比例升高，PUFA中，EPA及DHA所占比例也相对较高。8月份总脂肪酸含量较高，9月与10月相对较小，各粒级内差别不大。 利用主成份分析发现悬浮颗粒物的组分在浮游动物中能够用相应脂肪酸指标进行示踪，当食物数量充分满足需求时，浮游动物脂肪酸特征与悬浮颗粒物组成一致性较高，同时通过脂肪酸示踪发现当潜在食物数量较丰富时，浮游动物的摄食存在选择性，这种选择可能受食物质量的调控，而当食物数量较低时，其选择性也降低。 悬浮颗粒物中EPA含量及不饱和指数是相对重要的食物质量指示物，通过对其指示特征的分析发现胶州湾总体上浮游动物的摄食会影响其食物质量组成；但在8月，浮游动物的生物量受悬浮颗粒物质量的调控，而浮游动物生物量对食物数量的摄食压力较小，认为该时期是食物质量限制对浮游动物生物量影响相对重要的时期，可以用特征脂肪酸进行清晰的分析。

西太平洋特定海域沉积物的地磁场相对强度研究

沉积物可以提供连续的地磁场相对强度（RPI）记录，这些记录在全球范围内的对比具有一致性。目前RPI记录越来越多地在布容极性期内作为千年尺度高精度的地层对比手段，但由于构建RPI所需的岩石磁学标准较高，总体来说，RPI数据还相对缺乏，尤其是太平洋地区连续的RPI记录更是相对较少。本文以西太平洋特定海域沉积物为研究对象，进行了古地磁和岩石磁学方面等多个参数的综合测量，通过归一化天然剩磁得到了地磁场相对强度变化曲线，为RPI研究提供了新的记录，为研究区测年提供了新的手段。 西菲律宾海的Ph05孔沉积物的岩石磁学和古地磁研究表明，岩芯中的载磁矿物比较单一，以低矫顽力的磁铁矿为主，χ、ARM及SIRM等参数指示的磁性矿物的含量变化不大。磁性矿物的颗粒以准单畴为主，粒度指示参数χARM/χ具有冰期-间冰期旋回变化。通过交变退磁可得到稳定的特征剩磁，32-38 cm及108-110 cm处发现负倾角，并伴随着RPI的低值。谱分析检验后选择ARM作为归一化参数，通过ARM归一化天然剩磁获得了200 ka以来的地磁场相对强度记录。重建的RPI记录与综合曲线Sint-200有良好对比，可以反映全球性的信号。基于RPI建立的年代模型与氧碳同位素年代模型相似，可以作为独立的定年手段。 对东菲律宾海帕里西维拉海盆西侧F090102孔柱样沉积物进行了系统的古地磁和岩石磁学分析，结果表明样品适合进行相对强度研究。根据功率谱分析结果，选择非磁滞剩磁作为归一化的参数，得到约2 Ma以来的地球磁场相对强度变化曲线。该曲线与SINT-2000曲线可详细对比，比如呈比较典型的锯齿状特征，布容期内的记录与800 ka以来的SINT-800曲线相符。布容/松山极性转换期呈单强度降低的特征，在极性转换期和极性漂移期，相对强度曲线表现为显著低值。 对东海内陆架泥质区沉积物EC2005孔的磁学研究表明，岩芯在110 cm即受到还原成岩作用的影响；110-600 cm经历了铁氧化物还原阶段，样品中磁性矿物以PSD磁铁矿为主，随深度增加，其含量快速减少，其间随着硬磁矿物含量的波动，磁学参数也呈现出峰谷变化；600 cm向下岩芯经历硫酸盐还原阶段，各磁学参数都维持在很低的水平，顺磁性颗粒增加，并出现黄铁矿。早期成岩作用及重磁化作用使得古地磁信号被削弱和改造。

饱和链烷技术测定绵羊食性食量精确性研究

【目的】验证饱和链烷技术测定家畜食性和食量的精确性，确定绵羊粪便中链烷的回收率。【方法】于2004年秋季在中国科学院内蒙古草原生态系统定位研究站用不同放牧演替阶段的优势植物羊草（Lcymus chincnsis）、糙隐子草（Cleistogenes squarrosa）和冷蒿（Artemisia frigide）按一定比例混合组成日粮，饲喂9只2岁羯羊，每只羊投喂一粒QSM胶囊，试验期内每天记录绵羊实际牧草采食量、采食成分和排粪量，利用气相色谱分析牧草和粪样的链烷含量，应用链烷技术测定绵羊的排粪量、不同牧草呆食比例和总干物质采食量，并与实际值进行比较。【结果】3种牧草链烷模式存在种间差异；绵羊粪便中链烷的回收率随链烷长度的增加而线性增加；绵羊排粪量测定值与实际值存在极显著的正相关（P〈0．01，r=0．9994）；绵羊采食羊草、糙隐子草和冷蒿比例的测定值与实际值存在极显著（P〈0．01）正相关，相关系数分别为0．9913、0．9864和0．9999；绵羊干物质采食量用C33：C32和C31：C31比值测定的值分别比实际值低4％（±1．3％）和7％（±1．3％），但差异不显著（P〉0．05）。【结论】饱和链烷技术可以精确测定典型草原绵羊的排粪量、食物组成和采食量。

Influence of lanthanum on the uptake of trace elements in cucumber plant

The effects of La3+ on the uptake of trace elements (Se, Co, V, and Tc) in cucumber plants were studied by a radioactive multitracer technique. It was observed that the uptake and distribution of these trace elements in roots, stems, and leaves are different under different La3+, treatments. Furthermore, in the control, the plant accumulates Se-75, Co-56, and V-48 all in the order roots>leaves>stems, whereas Tc-95m was in the order leaves>stems>roots. The accumulations of Se-75 and Tc-95m in plants treated with different La3+ concentration were in the same order as those in the control, but the uptakes percentages of other kinds of element changed differently. The results indicate that lanthanum treatments to a growing cucumber lead to the change of uptake of trace elements, which suggest that a rare earth element is directly or indirectly involved in the ion transport of the plant and affects plant growth by regulating the uptake and distribution of elements that influence the plant cell physiology and biochemistry.

降压消脂保健组合物

本发明涉及一种降压消脂保健组合物，该组合物是由油菜花粉、决明子浸膏粉、山楂浸膏粉、黄芪浸膏粉、红花浸膏粉、山药浸膏粉制成，本发明具有调节血压，降低血脂，延缓高血压进展以及合并高脂血症，增强机体免疫力功能的作用，可达到预防和辅助治疗高血压症以及合并高脂血症的目的。

北大别黄土岭麻粒岩变质演化：对大别造山带演化进程的指示意义

Granulites from Huangtuling in the North Dabie metamorphic core complex in eastern China preserve rare mineralogical and mineral chemical evidence for multistage metamorphism related to Paleoproterozoic metamorphic processes, Triassic continental subduction-collision and Cretaceous collapse of the Dabieshan Orogen. Six stages of metamorphism are established, based on detailed mineralogical and petrological studies: (I) amphibolite facies (6.3–7.0 kbar, 520–550 °C); (II) high-pressure/high-temperature granulite facies (12–15.5 kbar, 920–980 °C); (III) cooling and decompression (4.8–6.0 kbar, 630-700 °C); (IV) medium-pressure granulite facies (7.7–9.0 kbar, 690–790 °C); (V) low-pressure/high-temperature granulite facies (4.0–4.7 kbar, 860–920 °C); (VI) retrograde greenschist facies overprint (1–2 kbar, 340–370 °C). The P–T history derived in this study and existing geochronological data indicate that the Huangtuling granulite records two cycles of orogenic crustal thickening events. The earlier three stages of metamorphism define a clockwise P–T path, implying crustal thickening and thinning events, possibly related to the assembly and breakup of the Columbia Supercontinent ca. 2000 Ma. Stage IV metamorphism indicates another crustal thickening event, which is attributed to the Triassic subduction/collision between the Yangtze and Sino–Korean Cratons. The dry lower crustal granulite persisted metastable during the Triassic subduction/collision due to lack of hydrous fluid and deformation. Stage V metamorphism records the Cretaceous collapse of the Dabieshan Orogen，possibly due to asthenosphere upwelling or removal of the lithospheric mantle resulting in heating of the granulite and partial melting of the North Dabie metamorphic core complex. Comparison of the Huangtuling granulite in North Dabie and the high-pressure (HP)–ultrahigh-pressure (UHP) metamorphic rocks in South Dabie indicates that the subducted upper (South Dabie) and lower (North Dabie) continental crusts underwent contrasting tectonometamorphic evolution during continental subduction–collision and orogenic collapse. High-pressure granulites are generally characterized by the absence of orthopyroxene. However, the Huangtuling felsic granulite rarely preserves the high-pressure granulite facies assemblage of garnet + orthopyroxene + biotite + plagioclase + K-feldspar + quartz. To investigate the effects of bulk rock composition on the stability of orthopyroxene-bearing, high-pressure granulite facies assemblages in the NCKFMASHTO (Na2O–CaO–K2O–FeO–MgO–Al2O3–SiO2–H2O–TiO2–Fe2O3) system, we constructed a series of P–T–X pseudosections based on the melt-reintegrated composition of the Huangtuling felsic high-pressure granulite. Our calculations demonstrate that the orthopyroxene-bearing, high-pressure granulite facies assemblages are restricted to low XAl [Al2O3/(Na2O + CaO + K2O + FeO + MgO + Al2O3) < 0.35, mole proportion] or high XMg [MgO/(MgO + FeO) > 0.85] felsic–metapelitic rock types. Our study also reveals that the XAl values in the residual felsic–metapelitic, high-pressure granulites could be significantly reduced by a high proportion of melt loss. We suggest that orthopyroxene-bearing high-pressure granulites occur in residual overthickened crustal basement under continental subduction–collision zones and arc–continent collision belts.