144 resultados para TC


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The hyphenated technique of high performance liquid chromatography coupled with inductively coupled plasma mass spectrometry(HPLC-ICP-MS) was applied to the simultaneous determination of five organotin compounds in the shellfish samples. Agilent TC-C-18 column was selected, mobile phase of the HPLC was CH3CN:H2O: CH3COOH = 65:23:12 (V/V), 0. 05% TEA, pH = 3.0 at flow rate 0.4 mL/min. Five mixed organotin standards from 100 mu g/L to 0. 5 mu g/L was used for the method evaluation. The experimental results indicate that the linearity (R-2) for each compound was over 0.998. The shellfish samples were treated by supersonic extraction with mobile phase for 30min. Four organotin compounds including dibutyltin (DBT), tributyltin (TBT), diphenyltin (DphT) and triphenyltin (TPhT) in shellfish samples were detected with method mentioned above. It was found that the domain compounds in the samples were tributyltin (TBT) and triphenyltin (TPhT). The recoveries test from the standard addition for trimethyltin (TMT tributyltin (TBT), and triphenyltin (TPhT) were, over 80%. However, the recoveries for diphenyltin (DPhT) and dibutyltin (DBT) were relatively low, 37.3% and 75.2% respectively. The reason might be attributed to the decomposition of those compounds during the extraction procedure. The further study on this subject is under the progress.

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对柴达木唐古特白刺种籽油的安全性和降血脂作用进行了研究。以超临界CO2萃取技术提取白刺种籽油,采用小白鼠进行急性毒性实验和安全性评价,以高脂例料诱导建立大鼠高脂动物模型,灌胃种籽油4w,测定动物血清血脂水平。结果表明,小鼠每日给予白刺籽油40ml/kg,连续观察14d,无毒性表现,服用安全;种籽油5g/kg和10g/kg剂量对高脂饲料诱导的大鼠血清TC、TG及LDL具有显著的抑制作用,可显著升高高血脂大鼠HDL/TC和HDL/LDL的比值,表明高剂量白刺种籽油具有显著的降血脂作用。

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为了研究柴达木盆地唐古特白刺果实的降血脂、抗氧化作用,本文采用高脂饲料诱导小鼠和大鼠 建立高脂动物模型,灌胃给药4周,测定各组实验动物的血清血脂水平,并测定大鼠红细胞SOD活性和血清脂质过氧化物(LPO)分解产物丙二醛(MDA)的含量变化。结果显示唐古特白刺果实1.8g/kg和3.6g/kg剂量对高脂饲料诱导的小鼠和大鼠血清TC、TG及大鼠的LDL具有显著的抑制作用;同时可显著升高高血脂大鼠HDL/TC和HDL/LDL的比值,提高高血脂大鼠SOD活力和降低高血脂大鼠MDA含量;对大鼠体重和正常小鼠血脂水平无明显影响。表明唐古特白刺果实具有降血脂、防治动脉粥样硬化和抗氧化作用。

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Influence of La3+ on the accumulation of trace elements (Se-75, Co-56, Rb-83, V-48, (95)mTc, and Ga-67) in chloroplasts of cucumber seedling leaves was studied by a radioactive multitracer technique. At the same time, chloroplast contents of different concentrations of La3+ treatment were calculated. It was observed that chloroplast contents peaked at 0.02 mM La3+ treatment and that the uptake and distribution of these trace elements in chloroplasts of cucumber seedling leaves are different under different La3+, treatments. With the increase of lanthanum concentrations from 0.002 to 2 mM, the uptake percentages of Se-75, Co-56, and Rb-83 presented an obvious increase and then sharply decreased in contrast to the nonlanthanum treatment, whereas there appeared a sharp decrease and then restored control level in the uptake of V-48. The other two trace elements, namely Tc-95m and Ga-67, were accumulated only in the presence of 0.02 mM La3+. The results indicate that lanthanum treatments to growing the cucumber lead to the change of trace element uptake in the chloroplasts of leaves, which suggest that lanthanum might influence the accumulation of trace elements in chloroplasts of cucumber seedling leaves by regulation of various ion transport mechanisms, thus affecting the photosystem of leaves.

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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.

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随着FPGA的发展,FPGA测试技术也得到了很快地发展。因为FPGA的结构和传统专用集成电路有着本质的区别,在FPGA中不能形成可测性设计电路,但它的可编程能力决定了其测试电路可以通过编程的方法来实现。本文讨论了XilinxXC4000系列FPGA中互连资源的自动测试方法。提出了一种新的测试资源坐标定位方法,使得测试软件能够将测试配置转换成器件配置,并搭建了硬件测试平台,实现实体FPGA芯片测试。

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Using the popular CERCHAR testing to measure the abrasiveness of rock which is CERCHAR abrasiveness index(CAI). The digital imagine processing program IPP is used to quantify the rock texture such as the grain size, the shape of grain and the index of grain homogeneity. And the rock mechanical testing machine are used to measure the strength, hardness and elastic modulus. Basic on these three experiments, this paper finds the relationship between the CAI and physical and mechanical properties of rock. They are both the mesostructure and macroscopical properties of rock. According to the theory of tribology and wear, this paper finds the disc cutter wear mechanism during the machine and rock interaction process. The detail research results are as follows: (1) The size and form of the mineral grains constituting the rocks affect the abrasiveness of the rock. The rock abrasiveness CAI is a function of the product of the texture coefficient(TC) multiplying equivalent quarts content(Q%). (2) There is no obvious relationship between the rock abrasiveness CAI and the single macroscopical property of rock such as hardness, unconfined compressive strength, tensile strength and elastic modulus. But when taking the texture coefficient(TC) and the mineral composition in consideration, it shows that the rock abrasiveness CAI is relative to the combination of the rock mechanical property, the texture coefficient(TC) and the mineral composition. That is to say various factors which are from the mesostructure feature to the macroscopical property of rock control the rock abrasiveness. (3) The disc cutter penetrating into rock is a machine/rock interaction process. During this interaction, the wear of disc cutter is mainly coming from the abrasive of abrasiveness matters. First, the surface of the cutter ring is hunched, and then the material of the cutter ring is being wiped off during the iterative interaction. Second, the hard mineral in the rock and the muck will microcosmic cutting the surface material of cutter ring. (4) The disc cutters consumption is determined by the machine parameters and the geology condition. The machine parameters include the thrust and the revolution rate of the cutterhead. The geology condition include two aspects: the macroscopical properties which are the strength and/or hardness of rock, the presence of discontinuities in rock mass, the hardness, sharp, edge and size of the muck and so on. And the mesostructure features which are the hard mineral composition, the sharp and size of the grain of the rock.

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The Eastern Himalayan Syntaxis (EHS) is one of the strongest deformation area along the Himalayan belt resulted from the collision between Indian plate and the Eurasian Plate since the 50~60Ma, and has sensitivity tracked and preserved the whole collisional processes. It should depend on the detail geological investigations to establish the deformational accommodate mode, and the uplift history, to elucidate the deep structure and the crust-mantle interaction of the Tibet Plateau of the EHS. The deep-seated (Main Mantle Thrusts) structures were exhumed in the EHS. The MMT juxtapose the Gangdese metamorphic basement and some relic of Gangdese mantle on the high Himalayan crystalline series. The Namjagbawa group which is 1200~1500Ma dated by U/Pb age of zircon and the Namla group which is 550Ma dated by U/Pb age of zircon is belong to High Himalayan crystalline series and Gangdese basement respectively. There is some ophiolitic relic along the MMT, such as metamorphic ocean mantle peridotite and metamorphic tholeiite of the upper part of ocean-crust. The metamorphic ocean mantle peridotites (spinel-orthopyroxene peridotite) show U type REE patterns. The ~(87)Sr/~(86)Sr ratios were, 0.709314~0.720788, and the ~(143)Nd/~(144)Nd ratios were 0.512073~0.512395, plotting in the forth quadrant on the ~(87)Sr/~(86)Sr-~(143)Nd/~(144)Nd isotope diagram. Some metamorphic basalt (garnet amphibolite) enclosures have been found in the HP garnet-kynite granulite. The garnet amphibolites can be divided two groups, the first group is deplete of LREE, and the second group is flat or rich LREE, and their ~(87)Sr/~(86)Sr, ~(143)Nd/~(144)Nd ratios were 0.70563~0.705381 and 0.512468~0.51263 respectively. Trace element and isotopic characteristics of the garnet amphibolites display that they formed in the E-MORB environment. Some phlogolite amphibole harzburgites, which exhibit extensive replacement by Phl, Amp, Tc and Dol etc, were exhumed along the MMT. The Phl-Amp harzburgites are rich in LREE and LILE, such as Rb, K etc, and depletes Eu (Eu~* = 0.36 ~ 0.68) and HFSE, such as Nb, Ta, Zr, Hf, P, Ti etc. The trace element indicate that the Phl-Amp harzburgites have island arc signature. Their ~(87)Sr/~(86)Sr are varied from 0.708912 to 0.879839, ~(143)Nd/~(144)Nd from 0.511993 to 0.512164, ε Nd from- 9.2 to - 12.6. Rb/Sr isochrone age of the phlogolite amphibole harzburgite shows the metasomatism took place at 41Ma, and the Amp ~(40)Ar/~(39)Ar cooling age indcate the Phl-Amp harzburgite raising at 16Ma. There is an intense crust shortening resulted from the thrust faults and folds in the Cayu block which is shortened more 120km than that of the Lasha block in 35~90Ma. With the NE corner of the India plate squash into the Gangdese arc, the sinistral Pai shear fault and the dextral Aniqiao shear fault on the both sides of the Great bent of Yalun Zangbu river come into active in 21~26Ma. On the other hand, the right-lateral Gongrigabu strike-slip faults come into activity at the same period, a lower age bound for the Gongrigabu strike-slip fault is estimated to be 23~24Ma from zircon of ion-probe U/Pb thermochronology. The Gongrigabu strike-slip faults connect with the Lhari strike-slip fault in the northwestern direction and with the Saganing strike-slip at the southeastern direction. Another important structure in the EHS is the Gangdese detachment fault system (GDS) which occurs between the sedimental cover and the metamorphic basement. The lower age of the GDS is to be 16Ma from the preliminary 40Ar/39Ar thermochronology of white mica. The GDS is thought to be related to the reverse of the subducted Indian crust and the fast uplift of the EHS. Structural and thermochronology investigation of the EHS suggest that the eastern Tibet and the western Yunnan rotated clockwise around the EHS in the period of 35~60Ma. Later, the large-scale strike-slip faults (RRD, Gaoligong and Saganing fault) prolongate into the EHS, and connect with the Guyu fault and Gongrigabu fault, which suggest that the Indianchia block escape along these faults. Two kind of magmatic rocks in the EHS have been investigated, one is the mantle-derived amphibole gabbro, dioposide diorite and amphibole diorite, another is crust origin biotit-garnet adamellite, biotit-garnet granodiorite and garnet-amphibole-biotite granite. The amphibole gabbro dioposite diorite and amphibole diorite are rich in LREE, and LILE, such as Ba, Rb, Th, K, Sr etc, depleted in HFSE, such as Nb, Ta, Zr, Hf, Ti etc. The ratio of ~(87)Sr/~(86)Sr are from 0.7044 to 0.7048, ~(143)Nd/~(144)Nd are from 0.5126 to 0.5127. The age of the mantle origin magamatic rocks, which result from the partial melt of the raising and decompression anthenosphere, is 8Ma by ~(40)Ar/~(39)Ar dating of amphibole from the diorite. The later crust origin biotite-garnet adamellite, biotite-garnet granodiorite and garnet-amphibole-biotite granite are characterized by aboudance in LREE, and strong depletion of Eu. The ratios of ~(87)Sr-~(86)Sr are from 0.795035 to 0.812028, ~(143)Nd/~(144)Nd from 0.51187 to 0.511901. The ~(40)Ar/~(39)Ar plateau age of the amphibole from the garnet-amphibole-biotite granite is 17.5±0.3Ma, and the isochrone age is 16.8±0.6Ma. Their geochemical characteristics show that the crust-derived magmatic rocks formed from partial melting of the lower curst in the post-collisional environment. A group of high-pressure kaynite-garnet granulites and enclave of high-pressure garnet-clinopyroxene grnulites and calc-silicate grnulites are outcroped along the MMT. The peak metamorphic condition of the high-pressure granulites yields T=800~960 ℃, P=1.4~1.8Gpa, corresponding the condition of 60km depth. The retrograde assemblages of the high-pressure grnulites occur at the condition of T=772.3~803.3 ℃, P=0.63~0.64Gpa. The age of the peak metamorphic assemblages are 45 ~ 69Ma indicated by the zircon U/Pb ion-plobe thermochronology, and the retrograde assemblage ages are 13~26Ma by U/Pb, ~(40)Ar/~(39)Ar thermochronology. The ITD paths of the high-pressure granulites show that they were generated during the tectonic thickening and more rapid tectonic exhumation caused by the subducting of the Indian plate and subsequent break-off of the subducted slab. A great deal of apatite, zircon and sphene fission-track ages, isotopic thermochronology of the rocks in the EHS show that its rapid raising processes of the EHS can be divided into three main periods. There are 35~60Ma, 13~25Ma, 0~3Ma. 3Ma is a turn in the course of raising in the EHS which is characterized by abruptly acceleration of uplifting. The uplift ratios are lower than 1mm .a~(-1) before 3Ma, and higher than 1mm .a~(-1) with a maximum ratio of 30mm .a~(-1) since 3Ma. The bottom (knick point) of the partial anneal belt is 3.8km above sea level in the EHS, and correspond to age of 3Ma determined by fission-track age of apatite. The average uplift ratio is about 1.4 mm .a~(-1) below the knick point. The EHS has raised 4.3km from the surface of 2.36km above sea level since 3Ma estimated by the fossil partial anneal belt of the EHS. We propose a two-stage subduction model (B+A model) basing on Structural, thermochronological, magmatical, metamorphic and geophysical investigations of the EHS. The first stage is the subduction of the Indian continental margin following after the subduction of the Tethys Ocean crust and subsequent collision with the Gangdese arc, and the second stage is the Indian crust injecting into the lower crust and upper mantle of the Tibet plateau. Slab break-off seems to be occurred between these two stages.

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抗生素是广泛应用于人类和动物疾病治疗的药物,近年来在养殖业中抗生素更是常常作为动物催长剂。这些抗生素会通过人畜排泄物、药品的丢弃、污水排放、农业废物堆积等途径进入到环境中。环境中抗生素的残留会导致细菌耐药性的产生、微生态平衡的破坏,以及对生态环境和人类难以预知的影响。抗生素污染是近十年来才在国际上引起注意的新型环境问题,目前研究非常薄弱,要深入认识抗生素的环境影响特征就迫切需要对抗生素在环境中的迁移、归宿等地球化学行为进行针对性的研究。本文研究了贵阳城市污水、南明河及乌江渡水库中氯霉素(CAP)、土霉素(OTC)、四环素(TC)和金霉素(CTC)的环境地球化学特征,包括抗生素的分布、迁移特征及影响因素,并分析了贵阳市动物源性食品中抗生素的残留特征,探讨了环境因素对抗生素稳定性及吸附/解吸的影响,以期了解抗生素在环境中的降解、迁移等环境行为的特征,并据此评价抗生素的环境影响特点,为认识抗生素的污染特点、发展相应的控制、治理措施提供科学依据。主要内容包括: 1. 对环境样品中CAP和TCs的前处理过程和检测方法进行了优化。对水样的前处理采用固相萃取的方法,对土壤和沉积物的前处理采用EDTA-McIlvaine振荡萃取、SAX-HLB净化富集的方法;选择HPLC-UV作为分析的手段,对样品中的4种抗生素进行了检测,各化合物得到了很好的分离,该方法简便、快捷、重现性好。 2. 证实了抗生素在城市污水中的普遍存在。贵阳城市污水中以CAP的污染最为突出,其含量明显高于广州地区的城市污水;污水中四环素类药物(TCs)的含量和大多数欧美国家及地区城市污水中TCs的含量相当。这一结果证明,污水中抗生素的污染非常严重,对地表水环境形成严重的威胁。污水中抗生素的来源包括:人服用抗生素药物以及食用含有抗生素残留的食品之后的排泄物;食品中残留的抗生素随剩余食品的丢弃而进入污水。污水中抗生素的含量都具有明显的季节变化规律,冬春季含量明显高于夏秋季,我们认为这与各季节用水量和疾病特点有关。污水中抗生素的大量存在说明:1)抗生素存在滥用的现象,特别是CAP可能存在严重的违法使用,这一现象应当重视;2)污水中的抗生素会威胁水环境质量,应加强处理和控制技术。 3. 证明了城市河流受到多种来源的抗生素影响,其中城市污水是最重要的源,而且抗生素在河流中呈现一定的持久性。南明河上游河段中抗生素的来源包括郊区城镇污水、养鱼场、制药厂污水排放及地表垃圾。城市污水是抗生素的一大排放源,受其影响,排污口下游的河段受到的抗生素污染尤为严重,此外还有来自下游郊区城镇和农业污水的影响。对南明河中抗生素的来源及行为特点的剖析表明:1)抗生素在南明河的水和沉积物中具有不同的分布特征:河水中以CAP的污染最为严重,各水样中CAP的含量基本都高于TCs;而大部分沉积物中TCs的含量都高于CAP。CAP和TCs在水-沉积物之间的分布特征表明,它们在水环境中的地球化学行为明显受到吸附/解吸特点的影响,CAP的亲水性强,而TCs的亲粒性强。2)虽然在养殖业中已禁止使用CAP,但河水和污水中CAP的大量存在,这一结果揭露了CAP仍然存在大量违法使用的事实。3)河水中抗生素含量的季节差异明显,冬春季抗生素的含量高于夏秋季,其原因主要是夏秋季河水流量大,对河水中抗生素的稀释作用强。沉积物中抗生素的含量没有明显的季节变化规律,各季节抗生素的平均含量差异较小。4)受污水影响,各季节排污口下游的南明河水受到的抗生素污染尤为严重,污水口上下游之间的含量差异明显。沉积物在冬季受城市污水的影响大,在排污口下游的抗生素的含量明显高于上游,而春、夏、秋季受污水影响不明显。这可能是因为在春、夏和秋季其它污染源的影响较大,因此污水的影响强度减弱。夏季上游沉积物中CAP的含量甚至高于下游,原因一方面是因为夏季城市污水中抗生素含量低,对南明河的影响减小,另一方面可能因为夏季雨水多、水量大,将上游的地表垃圾以及积累在小河沟中的垃圾冲刷到南明河中,而这些工业及生活垃圾通常是抗生素的一大来源。 抗生素在河流中呈现了一定的持久性,在20 km的范围内水和沉积物显示了明显的污染水平,可能会对水生生态以及流域的环境造成一定的影响。此外,贵阳市南明河两岸的农田通常是用河水进行灌溉的,从而可能使抗生素的污染危及到食物链,对人体的健康有潜在的威胁。 4. 由于食品(如鱼肉、猪肉等)中残留的抗生素是污水中抗生素的重要来源,因此我们研究了养殖业(水产养殖区)中抗生素的环境行为特点,还研究了常见动物源性食品中抗生素的残留特点。对养鱼区的研究表明,养鱼饲料中含有大量的抗生素,是养鱼区水环境中抗生素的来源。由于饲料的颗粒大,且河水流速快,因此饲料中的抗生素不会对水体造成很大的影响,但是在网箱区的沉积物中形成了高含量的残留,除此以外,在乌江渡主航道的河心沉积物中抗生素的含量也相当可观。这说明该区水产养殖的抗生素主要影响沉积物,且相应的污染不是局部的,而会影响到整个养鱼区。从沉积物中抗生素平均含量的季节差异来看,各季TCs的用药量可能不同,秋季的用量可能最大,而其它季节用量相当;CAP在每个季节的用量可能相当。尽管分析的饲料中CAP的含量高于TCs,但在各季节乌江渡水库主航道沉积物中TCs的含量几乎都远高于CAP,这是由于TCs比CAP更易存在于沉积物中。乌江渡水库上下游主航道沉积物中抗生素的含量差异日益减小,说明了乌江渡水库的污染已日益严重。这些抗生素虽然暂时被固定在了沉积物中,活性相对较小,但是在外界条件的影响下,它们的吸附/解吸作用是可以改变的。因此,乌江渡沉积物中高含量的抗生素残留对水生生态环境具有潜在的威胁。 对贵阳市动物源性食品(鱼肉、猪肉和牛奶)中抗生素的残留特征的分析表明,这些食品中普遍残留有高含量的抗生素,被人食用后,其中的抗生素也会被人体摄入,一部分抗生素会随着人的排泄物而进入到污水中,并最终进入环境中;另一部分抗生素会积蓄在人体中,到一定浓度后就会对人体造成伤害。鲩鱼、鲫鱼、鲤鱼、鳙鱼和鲢鱼中CAP、OTCTC和CTC的平均含量范围分别在57.1~365.5 µg/kg、37.0~60.7µg/kg、34.3~72.4 µg/kg和22.3~68.0 µg/kg之间。秋季的长吻鲍、团头鲂、鲈鱼、长江洄鱼、对虾、黄鳝、泥鳅和猪肉中CAP、OTCTC和CTC的平均含量分别为88.1 µg/kg、76.8 µg/kg、343.7 µg/kg和34.2 µg/kg;牛奶中的含量分别为4.2 µg/L、1.6 µg/L和2.5 µg/L和22.0 µg/L。 5. 确定了抗生素的稳定性、吸附/解吸作用与各因素的关系,据此可以探讨环境中抗生素的行为特点及机理,并为环境中抗生素的污染防治提供依据。在短时的加热中,TCs发生了部分降解,而CAP却几乎没有发生分解,说明烹饪过程中的加热不能去除食品中的抗生素,这些抗生素则会进入到人体和污水中。当pH在2~8之间时,TCs的性质较稳定;CAP在pH=1~10的范围内性质都比较稳定。地表和地下水体的pH一般为7左右,说明了水环境中TCs受pH的影响小,而CAP几乎不受影响。在6个月的时间内,TCs在3种介质中都发生了不同程度的降解,但仍有大部分残留;CAP几乎没有发生明显的降解,这说明CAP和TCs的污染具有一定的持久性。TCs的吸附/解吸受颗粒物粒径的影响大,粒径越小,吸附越强;CAP不受影响。这证明了在环境中CAP更易以水溶态的形式存在,而TCs更易吸附在沉积物中。颗粒物中CaCO3含量越高,TC和CTC的吸附越强,证明CaCO3可以用来增强TC、CTC的吸附,这为环境中抗生素的治理提供了一条思路。