Co-substituted ATS-type molecular sieves and films for cyclohexane oxidation

Pure CoAPO-36 crystal grains were synthesized by hydrothermal reaction. Porous α-Al₂O₃, stainless steel and K₂Ti₆O₁₃ supported CoAPO-36 films were fabricated using in situ crystallization for the first time. SEM images and XRD measurements demonstrate that a continuous CoAPO-36 film was obtained on the K₂Ti₆O₁₃ substrate. Diffuse reflectance UV-Vis spectra indicate that Co²⁺ has been incorporated into the ATS framework. Both CoAPO-36 crystal grains and the K₂Ti₆O₁₃ supported CoAPO-36 film exhibit satisfactory catalytic activities for the oxidation of cyclohexane.     

Electrochemical performance of high purity zinc and Zn-Al-Cd alloy as reference electrodes

The effects of Cl-concentration,temperature,pH,flow velocity,soluble oxygen content of seawater and anodic current on the potential of high purity zinc and Zn-Al-Cd reference electrodes were investigated. The results show that the investigated metal materials are liable to establish stable potential and act as reference electrodes in seawater,diluted seawater and urban tap water. Cl-concentration,temperature,seawater flow velocity and anodic current have an obvious effect on zinc potentials. However,seawate...     

Evidence from fluid inclusions for microbial methanogenesis in the early Archaean era

Methanogenic microbes may be one of the most primitive organisms, although it is uncertain when methanogens first appeared on Earth. During the Archaean era (before 2.5 Gyr ago), methanogens may have been important in regulating climate, because they could have provided sufficient amounts of the greenhouse gas methane to mitigate a severely frozen condition that could have resulted from lower solar luminosity during these times. Nevertheless, no direct geological evidence has hitherto been available in support of the existence of methanogens in the Archaean period, although circumstantial evidence is available in the form of approximately 2.8-Gyr-old carbon-isotope-depleted kerogen. Here we report crushing extraction and carbon isotope analysis of methane-bearing fluid inclusions in approximately 3.5-Gyr-old hydrothermal precipitates from Pilbara craton, Australia. Our results indicate that the extracted fluids contain microbial methane with carbon isotopic compositions of less than -56 per thousand included within original precipitates. This provides the oldest evidence of methanogen (> 3.46 Gyr ago), pre-dating previous geochemical evidence by about 700 million years.     

Medical entity and attributes extraction system based on relation annotation

The abundant entities and entity-attribute relations in medical websites are important data resources for medical research. However, the medical websites are usually characterized of storing entity and attribute values in different pages. To extract those data records efficiently, we propose an automatic extraction system which is related to entity and attribute relations (attributes and values) of separate storage. Our system includes following modules: (1) rich-information interactive annotation page rendering; (2) separate storage attribute relations annotating; (3) annotated relations for pattern generating and data records extracting. This paper presents the relations about the attributes which are stored in many pages by effective annotation, then generates rules for data records extraction. The experiments show that the system can not only complete attribute relations of separate storage extraction, but also be compatible with regular relation extraction, while maintaining high accuracy.     

A class of nonlinear nonlocal singularly perturbed reaction diffusion systems

The singularly perturbed initial boundary value problems for the reaction diffusion system are raised. Firstly, under suitable conditions, using a iteration technique, the differential inequalities theorem is constructed and introducing two auxiliary functions the existence and uniqueness theorem of solution for the basic reaction diffusion system is proved. Using the singularly perturbed method the formal asymptotic expressions of the solution are constructed with power series theory. By using the comparison theorem the existence and its asymptotic behavior of solution for the original problem are studied. Finally, using method of estimate inequalities, the structure of solutions for the problem is discussed thoroughly in three cases and asymptotic solution of the original problem is given. The asymptotic behavior of solution in the three cases is proved.