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91.
The effect of treating algae-bearing water and induced odor by use of permanganate potassium composite (PPC) pre-oxidation was investigated, and was compared with the effect of treatments by pre-chlorination, permanganate petassium pre-oxidation and simple coagulation. The results showed that simple coagulation and pre-chlorination were less effective in removing algae and its odor, whereas PPC pre-oxidation was the most effective in algae removal and deodorization. Upon oxidation with PPC, the cells of Oscillatoria agardhic were inactivated and some intra-cellular and extra-cellular components were released into the water, which may help the coagulation by their bridging effect. The efficient removal of algae by PPC pre-oxidation is believed to be the joint contribution of several mechanisms.  相似文献   
92.
针对超二次曲面部件级关系特征抽取存在误差,以及在超二次曲面属性描述不具备唯一性条件下的部件级目标识别问题,利用最小结构误差关系匹配,结合部件特征属性约束的方法来对目标物体进行高效准确的识别;同时利用部件间相对姿态,设计了一种综合部件属性、关系属性和结构误差的最小误差评估函数,通过剪枝的解释树搜索,有效地实现了多物体场景下的目标物体识别.  相似文献   
93.
The DBSA-PANI-Fe composite powder with 50wt% of Fe nanoparticles was prepared by mechanically mixing the DBSA-doped polyaniline powder and Fe nanoparticles. The composite powder was compacted to pellets and the pellets were annealed in vacuum at 443,493,543, and 593 K for 60 and 120 min. The conductivity of the pellet increases markedly with increasing the annealing temperature up to 493 K, and then decreases with further increasing the annealing temperature. When the pellet was annealed at 493 K for 60 min, the increment of conductivity reaches a maximum value, and the conductivity is 2.6 times as large as that of the pellet unannealed. The conductivities of the pellets annealed under the conditions of 543 K/120 min, 593 K/60 min, and 593 K/120 min are lower than the conductivity of the pellet unannealed. For all the pellets, the variation in conductivity with temperature reveals that the charge transport mechanism can be considered to be 1-D variable-range-hopping (1-D VRH). The composite pellet shows a magnetic hysteresis loop independent of the annealing condition. The saturation magnetization is about 5.4×104 emu/kg. The saturation field and the coercivity are estimated to be 4.38×105 and 3.06×104 A/m, respectively. The crystalline structure ofFe nanoparticles in the composites does not change with the annealing condition. The annealing condition cannot destroy the polymer backbones.  相似文献   
94.
Single crystal Fe/Ag(001) superlattices with various periodicities were fabricated using ultrahigh vacuum evaporation deposition. It was found that single crystal bcc Fe layers and single crystal fcc Ag layers can epitaxially grow on a single crystal Ag buffer layer alternately, which was deposited on NaCl single crystal chips by ion beam assisted deposition. The magnetic measurements of the superlattices reveal an oscillation coupling between ferromagnetism and antiferromagnetism as a function of the Ag layer thickness. The oscillation period, which is 1 nm (5 Ag layers), is in good agreement with the calculated values when the Ag thickness is greater than 1.5 nm. While the thickness of the Ag spacer layer decreases to 1 nm, the oscillation coupling varies from calculations, which can be attributed to the intermixing of the interlayers according to the annealing results.  相似文献   
95.
Whole-genome sequence of Schistosoma haematobium   总被引:1,自引:0,他引:1  
Schistosomiasis is a neglected tropical disease caused by blood flukes (genus Schistosoma; schistosomes) and affecting 200 million people worldwide. No vaccines are available, and treatment relies on one drug, praziquantel. Schistosoma haematobium has come into the spotlight as a major cause of urogenital disease, as an agent linked to bladder cancer and as a predisposing factor for HIV/AIDS. The parasite is transmitted to humans from freshwater snails. Worms dwell in blood vessels and release eggs that become embedded in the bladder wall to elicit chronic immune-mediated disease and induce squamous cell carcinoma. Here we sequenced the 385-Mb genome of S. haematobium using Illumina-based technology at 74-fold coverage and compared it to sequences from related parasites. We included genome annotation based on function, gene ontology, networking and pathway mapping. This genome now provides an unprecedented resource for many fundamental research areas and shows great promise for the design of new disease interventions.  相似文献   
96.
Over the past decades, there have been many synthesis methods on producing well-defined crystals, due to their enormous application potentials in industrial field. Among them, high temperature gas-phase reactions (HTGR) approach may be one of the most promising processes for fabrication of well-defined crystals with controllable structure, size, shape, and composition. This review is focused on the recent progresses in synthesizing well-defined crystalline TiO2 dominated with, respectively, {001 } facets and { 105 } facets, one-dimensional ZnO and SnO2 nanorods/nanowires, MoS2 nanosheets as well as GaP, InP, and GaAs nanowires via HTGR approach. Although these research works were currently carried out on experimental scale, it is worth to note that the industrial importance of this HTGR approach for design and fabri- cation of well-defined crystals in the future owing to its advantages of continuous and scalable production with controlled dimensions and low cost.  相似文献   
97.
The bacterial diversity and abundance in snow of the summit (8201 m) of Cho Oyu mountain, Tibet, were analyzed by 16S rRNA gene sequencing followed by scanning electronic microscopy analysis. Most of bacteria were found to be of spherical or oval shape (〉95%). Bacterial 16S rDNA sequences were classified into 5 genera (Caulobacter, Ralstonia, Cupriavidus, Pelomonas and Pseudomonas). Gammaproteobacteria were the most abundant (91.25%) among the library that consists of 594 clones. The sequences found in this study are highly similar to those previously retrieved from other cold environments, such as ice core, sea ice, permafrost and snow. The results showed that the cold and barren environments strongly influence the survival of bacteria. The high similarity among sequences retrieved from snow sample and other places, such as ocean, soil and water, suggested that the bacteria in snow, soil and water environments have the same origin.  相似文献   
98.
Wang J  Wang W  Li R  Li Y  Tian G  Goodman L  Fan W  Zhang J  Li J  Zhang J  Guo Y  Feng B  Li H  Lu Y  Fang X  Liang H  Du Z  Li D  Zhao Y  Hu Y  Yang Z  Zheng H  Hellmann I  Inouye M  Pool J  Yi X  Zhao J  Duan J  Zhou Y  Qin J  Ma L  Li G  Yang Z  Zhang G  Yang B  Yu C  Liang F  Li W  Li S  Li D  Ni P  Ruan J  Li Q  Zhu H  Liu D  Lu Z  Li N  Guo G  Zhang J  Ye J  Fang L  Hao Q  Chen Q  Liang Y  Su Y  San A  Ping C  Yang S  Chen F  Li L  Zhou K  Zheng H  Ren Y  Yang L  Gao Y  Yang G  Li Z  Feng X  Kristiansen K  Wong GK  Nielsen R  Durbin R  Bolund L  Zhang X 《Nature》2008,456(7218):60-65
Here we present the first diploid genome sequence of an Asian individual. The genome was sequenced to 36-fold average coverage using massively parallel sequencing technology. We aligned the short reads onto the NCBI human reference genome to 99.97% coverage, and guided by the reference genome, we used uniquely mapped reads to assemble a high-quality consensus sequence for 92% of the Asian individual's genome. We identified approximately 3 million single-nucleotide polymorphisms (SNPs) inside this region, of which 13.6% were not in the dbSNP database. Genotyping analysis showed that SNP identification had high accuracy and consistency, indicating the high sequence quality of this assembly. We also carried out heterozygote phasing and haplotype prediction against HapMap CHB and JPT haplotypes (Chinese and Japanese, respectively), sequence comparison with the two available individual genomes (J. D. Watson and J. C. Venter), and structural variation identification. These variations were considered for their potential biological impact. Our sequence data and analyses demonstrate the potential usefulness of next-generation sequencing technologies for personal genomics.  相似文献   
99.
选取理雅各、威利和庞德的三种《论语》英译本中的两个句子——“学而时习之,不亦说乎?有朋自远方来,不亦乐乎?人不知而不愠,不亦君子乎?”、“君子坦荡荡,小人长戚戚。”的翻译,探讨译者身份、翻译目的和译者对原文的理解对译文的影响,在此基础上对三种译文进行比较。  相似文献   
100.
Recent cosmological measurements indicate that baryons comprise about four per cent of the total mass-energy density of the Universe, which is in accord with the predictions arising from studies of the production of the lightest elements. It is also in agreement with the actual number of baryons detected at early times (redshifts z > 2). Close to our own epoch (z < 2), however, the number of baryons detected add up to just over half (approximately 55 per cent) of the number seen at z > 2 (refs 6-11), meaning that about approximately 45 per cent are 'missing'. Here we report a determination of the mass-density of a previously undetected population of baryons, in the warm-hot phase of the intergalactic medium. We show that this mass density is consistent, within the uncertainties, with the mass density of the missing baryons.  相似文献   
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