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The main objective of this study was to examine the chemical composition of incident rainfall, throughfall, and stemflow from canopies of ‘Marsh’ grapefruit, and ‘Hamlin’ and ‘Temple’ orange trees. The concentrations of ammonium (NH4) and nitrate (NO3) were lower in the throughfall under the canopy or along the dripline as compared to those in the incident rainfall. This reduction is due to absorption of those nitrogen (N) forms by the tree foliage, thus, provides an evidence of contribution of (N) through wet deposition to N requirement of the trees. In contrast, concentrations of potassium (K), calcium (Ca), magnesium (Mg), and chloride (Cl) were greater in the throughfall or along the dripline compared to those in the incident rainfall. This is due to possible leaching of those elements from the foliage by the rainwater. Stemflow and throughfall also had greater pH and electrical conductivity (only in two out of three citrus varieties) as compared to the incident rainfall. Good correlation were found between concentrations of either K, Mg, or Ca, and Cl, phosphorus (P), or sulfur (S) in the incident rainfall for two storm events.  相似文献   
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小鼠血清抗磺胺二甲氧嘧啶抗体的研制   总被引:1,自引:0,他引:1  
将磺胺二甲氧嘧啶(SDM)与载体牛甲状腺球蛋白(BTG)偶联,构建SDM完全抗原SDM-BTG。用SDM-BTG免疫小鼠,诱导小鼠产生血清抗SDM抗体。ELISA检测表明:SDM-BTG免疫小鼠所产生的多克隆抗体与SDM-BSA包被抗原的结合有较强的特异性和较高的亲和力。  相似文献   
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Unconditional quantum teleportation   总被引:5,自引:0,他引:5  
Quantum teleportation of optical coherent states was demonstrated experimentally using squeezed-state entanglement. The quantum nature of the achieved teleportation was verified by the experimentally determined fidelity Fexp = 0.58 +/- 0.02, which describes the match between input and output states. A fidelity greater than 0.5 is not possible for coherent states without the use of entanglement. This is the first realization of unconditional quantum teleportation where every state entering the device is actually teleported.  相似文献   
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As part of a study of the processes involved in litter biodegradation following sewage sludge (SS) addition, the variations over 14 months of phosphatase activities in a cork oak litter (Quercus suber L.) were investigated. A field experimental design was carried out using the litter-bag method on both a fertilized plot receiving SS applications (twice ) and a control plot. Acid (APH) and alkaline (BPH) phosphatases were measured, along with several biotic and abiotic variables potentially involved in the regulation of these enzymes. These included moisture, temperature, pH, water-extractable inorganic P (PW), culturable heterotrophic bacteria and fungi. Sludge addition had significant effects on all the variables measured. Indeed, sludge increased significantly BPH activities, available PW, microbial densities (i.e. bacteria and fungi) and pH in the fertilized plot. In contrast, APH activities decreased significantly following sludge addition. As a consequence, the BPH/APH ratio increased markedly and immediately in the fertilized plot, but only after the 1st amendment. Following the 1st preconditioning SS amendment, the 2nd fertilization had fewer effects on biological variables, because of summer dryness. The different properties examined varied significantly with incubation time, and most were significantly related to the seasonal patterns of litter moisture in this Mediterranean forest ecosystem. Hence, sewage sludge application modified the intensity of microbial responses to environmental factors, but biological patterns regulating P turn-over were maintained.  相似文献   
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Pacemakers were implanted in 4 client-owned female dogs which had persistent atrial standstill. Three dogs were alive after 14 to 39 months and 1 dog was euthanized after 10.5 years. This report demonstrates that some dogs with persistent atrial standstill can survive for extended time periods.  相似文献   
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