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1.
A strain of thermophilic fungus Aspergillus fumigatus was cultured with K-bearing minerals to determine if microbe-mineral interactions enhance the release of mineralic potassium. Experiments were carried out in two settings, one with the mineral grains and the fungal cells in direct contact, and the other employing a membrane (pore size 0.22 μm) to separate the two. Measurements over a period of 30 days showed that, irrespective of the experimental setup, the concentration of free K in the culture was drastically higher than those in any of the control experiments where no living organism was present. Moreover, the occurrence of mineral-cell physical contact enhanced potassium release by an additional factor of 3 to 4 in comparison to the separation experiments. For contact experiments, Electron Probe Microanalysis revealed the formation of mycelium-mineral aggregates, and Atomic Force Microscopy imaging further indicated the possible ingestion of mineral particles by the fungus cells. Contrasting to what was observed and expected in control experiments, the potassium solubilization rate showed a positive dependence upon pH when fungi and minerals were mixed directly, and exhibited no correlations with solution acidity if cell-rock contact was restrained. These results appear to suggest that A. fumigatus promoted potassium release by means of at least three likely routes, one through the complexation of soluble organic ligands, another appealing to the immobile biopolymers such as the insoluble components of secretion, and the third related to the mechanical forces in association with the direct physical contact between cells and mineral particles.  相似文献   
2.
This paper describes the study of a single-column structure used as well-head platform. In order to check the reliability of computation theory and programme, model tests have been carried out. The paper introduces the conclusion of tests and the dynamic properties of single-column platform are obtained.  相似文献   
3.
本文介绍了海洋技术研究所质量管理处在维护质量体系运行方面的主要作法和经验体会,结合2000版ISO9201标准的新内容,提出适应新版标准的想法。  相似文献   
4.
The model QQC_(2-2) plankton net closing gear is a device designed to control the stratifiedsampling of the plankton net by means of a messenger. The device in its fie1d use has met with98% success in 766 times of strtified sampling of plankton at 157 stations during separatesurveys of Fujian coast zone, the Taiwan Strait, and the central section of the South China Sea,  相似文献   
5.
Diagnosis of iridovirus in large yellow croaker by PCR   总被引:1,自引:0,他引:1  
A rapid and sensitive PCR-based method for the detection of the large yellow croaker iridovirus(LYCIV) is described,which involves the amplification of a 295 bp fragment of the LYCIV ATPase gene from DNA isolated from naturally infected fish spleen.Sequencing of LYCIV ATPase gene fragment showed it shared 100% nucleotide sequence homology with the corresponding region of the ATPase gene of red sea bream iridovirus(RSIV) and sea bass iridovirus(SBIV),suggesting that LYCIV was homologous with RSIV and SBIV at least in part of the gemone.The specificity and sensitivity of the PCR procedure were tested on the iridovirus-infected fishes,the expected fragment was detected from spleen DNA samples of infected fishes,whereas no fragments were amplified from healthy fish spleen DNA,white spot syndrome baculoviruses(WSBV) DNA and pseudorabies virus(PRV) DNA.Detection limit of this method was 10-7 ng positive plasmid DNA containing target sequence,equal to about 100 virions.In the infected experiment,first positive detection(1/4) appeared at Day 3 post-infection,all fish(4/4) tested positive at Day 7,however obvious symptoms were observed at Day 8,so LYCIV infection could be detected prior to the appearance of obvious symptoms.These results indicate that this PCR method could be used for early,rapid and specific detection of LYCIV infection.  相似文献   
6.
INTRODUCTIONTheSMSRPSisstalledontheshipnavigatingovertheseaandreceivessatellitecloudmapsatanytimetoprovidereliablereal-timedataofmeteorologyandocean.Itisanimportantequipmentforsafeguardofshipnavigation.Chinahasthousandsofoceanicships.Butalmostallships,withonlyveryfewexception,arenotstalledbySMSRPS.Thecausesareasfollows:1.Thetechniqueisverycomplicated.2.Thedevelopmentcostisveryhigh.3.Ifweintroduceforeignequipment,thecostistooexpensive.4.Foreignequipmentanditssoftwarearecompletelyclo…  相似文献   
7.
The authors investigated the effect of Bacillus mucilaginosus on weathering of phosphorite. Analysis of different proteins was of significance in exploring the molecular biological mechanism in the bacterial weathering process. The concrete methods are described as follows: Mineral powder was put into liquid culture medium and B. mucilaginosus was incubated in the medium. The control (group) had no mineral powder in the medium. The treatments and controls were cultured simultaneously under the same condition. In a few days, the supernatant was filtrated, the main cations (Ca^2+, Mg^2+, Na^+, Mn^2+, Al^3+, Fe^3+, K^+) were measured by ICP-OES, and the contents of water soluble phosphorus (Pws) and silicon (Siws) were determined by colorimetry. The residual solid was weighed on the filter paper, followed by digestion with concentrated HNO3. The concentrations of the main cations and Pws, Siws in the digest liquid were measured by using the method mentioned above. After the supernatant was centrifuged, the precipitation was used to analyze the protein differences between the treatment groups and the control groups by 2-dimentional gel electrophoresis (2-DE). The experimental results showed that apatite and quartz were partially weathered, but kaolinite was dissolved completely. The population of bacteria increased when mineral powder was added in the liquid medium. Software analysis and comparison of the 2-DE pictures of bacterial proteins revealed 1134 visible protein spots in the treatment group, and 729 visible protein spots in the control group. To compare the bacterial protein expression contents of the treatment group with those of the control group, there were 496 different protein spots, including 214 protein spots which indicated that the protein contents increased, 75 protein spots were indicative of a decrease, and 207 proteins were newly synthesized. It is proposed that the increased bacterial contents may be related to some protein expression and activation after the  相似文献   
8.
因民铜矿发育两种金矿化类型:一是铜矿的伴生金;二是热液构造蚀变岩型。化探样品分析结果显示,金矿化主要赋存于金箔箐断层上、下盘的角砾状蚀变岩内,空间上受岩性和断裂构造的双重控制。邻区拖布卡金矿的成矿地质背景与本区相似,在成矿地质年代上作以类比推测,认为喜马拉雅期是主成矿期。另外通过对光片镜下和化探原生晕样聚类分析研究,发现构造蚀变岩型金矿化具明显的多期多阶段性及热液特征。  相似文献   
9.
结合车辆的运动轨迹只能被限制于道路网络上的事实约束,提出了一种基于道路特征的车辆监控数据存储管理方法,存储车辆在道路网特征点处的信息,通过将原始数据中存储的二维地理坐标转换为存储一维的沿道路网的线性参照坐标实现了监控数据和道路网的结合,可极大地节省GPS车辆跟踪数据的存储空间,有利于对车辆数据的进一步分析利用和交通信息的提取.  相似文献   
10.
A detrital zircon aged 4.1 Ga is discovered by the SHRIMP U-Pb method in a quartzite in Burang County, western Tibet. This is presently the oldest single-grain detrital zircon in China. The Th-U ratios of the two testing points of the 〉4.0 Ga zircon are between 0.76 and 0.86, indicating their magmatic origin. This discovery has offered an important age for investigating the geological evolution of the Qinghai-Tibet Plateau.  相似文献   
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