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31.
A new type of arc plasma reactor with 12-phase alternating current (AC) discharge for synthesis of carbon nanotubes (CNTs) is proposed. A couple of six discharge electrodes by which have mutually electrical connection between them to enlarge the high-temperature regions in the reactor are arranged to three-dimensional locations. A new method of CNTs fabrication by this reactor, which accomplishes to enlarge the suitable growth region in high purity and at high yield, was developed.  相似文献   
32.
We have developed a high temperature superconductor (HTS) micrometer-sized dc superconducting quantum interference device (SQUID) magnetometer for high field and high temperature operation. It was fabricated from YBa2Cu3O7-delta of 92 nm in thickness with photolithography techniques to have a hole of 4x9 microm2 and 2 microm wide grain boundary Josephson junctions. Combined with a three dimensional magnetic field coil system, the modulation patterns of critical current Ic were observed for three different field directions. They were successfully used to measure the magnetic properties of a molecular ferrimagnetic microcrystal (23x17x13 microm3), [Mn2(H2O)2(CH3COO)][W(CN)8]2H2O. The magnetization curve was obtained in magnetic field up to 0.12 T between 30 and 70 K. This is the first to measure the anisotropy of hysteresis curve in the field above 0.1 T with an accuracy of 10(-12) J T(-1) (10(-9) emu) with a HTS micro-SQUID magnetometer.  相似文献   
33.
Periodontal inflammation is a common inflammatory disease associated with chronic inflammation that can ultimately lead to alveolar attachment loss and bone destruction. Understanding autophagy and pyroptosis has suggested their significant roles in inflammation. In recent years, studies of differentiated embryo-chondrocyte expressed genes 1 and 2 (Dec1 and Dec2) have shown that they play important functions in autophagy and in pyroptosis, which contribute to the onset of periodontal inflammation. In this review, we summarize recent studies on the roles of clock genes, including Dec1 and Dec2, that are related to periodontal inflammation and other diseases.  相似文献   
34.
We conducted the welding experiment using three kinds of test piece, actual size, diaphragm and butt joint. Then, we examined the influence on strength, cooling time and carbon equivalent of weld metal by welding conditions on the different test pieces. We calculated an estimate of cooling time and chemical components. Consequently, we concluded that the strength of weld metal can be estimated by heat input, interpass temperature, carbon equivarent of welding wire and shape of test piece.  相似文献   
35.
Supposing a non-linear system is subjected to parametric uncertainties, the present paper aims at stabilizing its unstable steady states. A distinctive feature of the problem is that exact information about the steady state is unavailable. To cope with the difficulty, we have examined the applicability of the state difference feedback which uses the difference between the present state x(t) and the past state x(t-T). A rigorous stability analysis has been executed for the case where state deviations are controllable by a single input variable. The stability analysis has led to a favourable conclusion that if the number of unstable modes is just two, and if they are not associated with the origin in the complex plane, we are always able to find a controller which stabilizes the deviations from the unknown steady state. Design process is illustrated by using two kinds of pendulum systems.  相似文献   
36.
The extraction of oil from fungi (Mortierella ramanniana var.angulispora) was studied using carbon dioxide (CO2), nitrous oxide (N2O), trifluoromethane (CHF3) and sulfur hexafluoride (SF6) under supercritical conditions. The oil solubility was highest in SC-N2O followed by SC-CO2, while both SC-CHF3 and SC-SF6 showed poorer solvent power. The recorded oil solubilities at 333 K and 24.5 MPa were 2.3 wt% in N2O, 0.48 wt% in CO2, 0.0099 wt% in CHF3 and 0.0012 wt% in SF6. The oil solubilities in SC-N2O and SC-CO2 were measured over the pressure range 15.7–29.4 MPa and at temperatures ranging from 313–353 K. N2O always showed greater solvent power than did CO2 at the same temperature and pressure. The solvent power of a supercritical fluid increases with density at a given temperature, and increases with temperature at constant density. The change in neutral lipid composition of the extracted oil with the extraction ratio was measured. Free fatty acids or diglycerides were extracted more easily than triglycerides or sterol esters. The change in fatty acid composition was also measured. The proportion of γ-linolenic acid in the extract remained constant throughout the extraction.  相似文献   
37.
There has been a big challenge in structured peer-to-peer overlay network research area. Generally, a structured overlay network involves nodes evenly or based on their resource availabilities, and gathers nodes?? resources to achieve some bigger tasks. The challenge here is to gather resources based on nodes?? interests, and only interested nodes are involved in a certain task. Toward this challenge, we propose a new scheme to a peer-to-peer publish/subscribe network. Publish/subscribe represents a new paradigm for distributed content delivery. It provides an alternative to address-based communication due to its ability to decouple communication between the source and the destination. We propose a Bloom filter based mapping scheme to map IDs to nodes?? interests in addition to new interest proximity metric to forward events and to build nodes?? routing tables. We also propose a new approach called ??shared interest approach?? for network discovery. To evaluate the algorithms proposed in this work, we conducted simulations in both static and dynamic settings, and found a low false positive rate. We also discuss about a well-known application called Twitter, and show how our scheme would work in a real environment.  相似文献   
38.
A λ-type specific heat anomaly of U4O9?y, which occurs slightly above room temperature, was measured for the samples with different O/U ratios. The transition temperatures obtained from the peak of λ-type specific heat anomaly are in fairly good agreement with the data by X-ray diffraction and electrical conductivity measurements. The entropy increment for the transition was obtained to be 0.46 e.u. for UO2.250, 0.56 e.u. for UO2.240 and 0.70 e.u. for UO2.228, depending on O/U ratio. On the basis of the entropy change with O/U ratio, the mechanism of the phase transition is discussed. The entropy change due to the phase transition is mainly divided into two terms: one is due to the order-disorder rearrangement of U(IV) and U(V) ions,the other is associated with the displacement of oxygens ions. The former term is estimated to be rather smaller than the entropy change calculated by the Bragg-Williams approximation, and the latter is calculated using the X-ray diffraction data with the assumption of the Willis model.  相似文献   
39.
In this paper, a back propagation neural network (BPNN) has been applied to predict the corner wear of a high speed steel (HSS) drill bit for drilling on different workpiece materials. Specially defined static and dynamic features extracted by a wavelet packet transform (WPT) from the resultant force converted from thrust and torque together with the cutting conditions (workpiece material, spindle speed, drill diameter, feed rate) are used as inputs to train the network to obtain a better output, drill corner wear. Drilling experiments have been carried out over a wide range and, features newly defined and conventional ones, features extracted from different frequency bands are compared.  相似文献   
40.
A thrombus in a coronary artery causes ischemia, which eventually leads to myocardial infarction (MI) if not removed. However, removal generates reactive oxygen species (ROS), which causes ischemia–reperfusion (I/R) injury that damages the tissue and exacerbates the resulting MI. The mechanism of I/R injury is currently extensively understood. However, supplementation of exogenous antioxidants is ineffective against oxidative stress (OS). Enhancing the ability of endogenous antioxidants may be a more effective way to treat OS, and exosomes may play a role as targeted carriers. Exosomes are nanosized vesicles wrapped in biofilms which contain various complex RNAs and proteins. They are important intermediate carriers of intercellular communication and material exchange. In recent years, diagnosis and treatment with exosomes in cardiovascular diseases have gained considerable attention. Herein, we review the new findings of exosomes in the regulation of OS in coronary heart disease, discuss the possibility of exosomes as carriers for the targeted regulation of endogenous ROS generation, and compare the advantages of exosome therapy with those of stem-cell therapy. Finally, we explore several miRNAs found in exosomes against OS.  相似文献   
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