Progress in Studies of Geomagnetic Navigation of Animals

The geomagnetic field may play a key role in orientation and navigation of many long-distance migratory animals. Taking homing and migrating birds as examples, this paper reviews recent progress in studies of geomagnetic ‘compass’ of animals. Moreover, we propose to address two aspects in future geomagnetic orientation research: (1) what are the true components of the ‘map’? (2) What are the magneto-receptors and which brain areas acquire and process the geomagnetic field information?     

In vivo imaging of specialized bone marrow endothelial microdomains for tumour engraftment

The organization of cellular niches is known to have a key role in regulating normal stem cell differentiation and regeneration, but relatively little is known about the architecture of microenvironments that support malignant metastasis. Using dynamic in vivo confocal imaging, here we show that murine bone marrow contains unique anatomic regions defined by specialized endothelium. This vasculature expresses the adhesion molecule E-selectin and the chemoattractant stromal-cell-derived factor 1 (SDF-1) in discrete, discontinuous areas that influence the homing of a variety of tumour cell lines. Disruption of the interactions between SDF-1 and its receptor CXCR4 inhibits the homing of Nalm-6 cells (an acute lymphoblastic leukaemia cell line) to these vessels. Further studies revealed that circulating leukaemic cells can engraft around these vessels, suggesting that this molecularly distinct vasculature demarcates a microenvironment for early metastatic tumour spread in bone marrow. Finally, purified haematopoietic stem/progenitor cells and lymphocytes also localize to the same microdomains, indicating that this vasculature might also function in benign states to demarcate specific portals for the entry of cells into the marrow space. Specialized vascular structures therefore appear to delineate a microenvironment with unique physiology that can be exploited by circulating malignant cells.     

Triboelectric nanogenerator as a new technology for effective PM2.5 removing with zero ozone emission

Particles matters (PMs) have raised serious concerns due to their great impact on human health. Coupling triboelectric effect and electrostatic induction, triboelectric nanogenerator (TENG) has demonstrated as a practical sustainable power source for portable devices. The characteristics of TENG, such as high electric field and high output power, make it a promising technology in air cleaning applications. Here, the mechanism of the TENG and its application in self-powered air cleaning technologies are reviewed. Using the TENG as a voltage source, a self-powered air cleaning system for removing SO₂ and PMs is developed; and the removal efficiency of nanofiber filters is greatly enhanced due to electrostatic attraction. More importantly, the technology is not only most effective for removing nano-scale particles that cannot be effectively filtered using conventional fiber-film filters, but also produces no ozone emission. Besides being an independent power supply, a vibration TENG based triboelectric filter is designed to effectively capture the PMs from automobile exhaust fumes. Hence, the TENG demonstrates its great potential in self-powered air cleaning applications.     

Bioleaching of vanadium from barren stone coal and its effect on the transition of vanadium speciation and mineral phase

This study determined the optimal conditions required to obtain maximum vanadium extraction and examined the transition of mineral phases and vanadium speciation during the bioleaching process. Parameters including the initial pH value, initial Fe2+ concentration, solid load, and inoculum quantity were examined. The results revealed that 48.92wt% of the vanadium was extracted through bioleaching under optimal conditions. Comparatively, the chemical leaching yield (H₂SO₄, pH 2.0) showed a slower and milder increase in vanadium yield. The vanadium bioleaching yield was 35.11wt% greater than the chemical leaching yield. The Community Bureau of Reference (BCR) sequential extraction results revealed that 88.62wt% of vanadium existed in the residual fraction. The bacteria substantially changed the distribution of the vanadium speciation during the leaching process, and the residual fraction decreased to 48.44wt%. The X-ray diffraction (XRD) and Fourier transform infrared (FTIR) results provided evidence that the crystal lattice structure of muscovite was destroyed by the bacteria.     

Effects of friction stir processing on the microstructure and superplasticity of in situ nano-ZrB2/2024Al composite

In this study, in situ nano-ZrB_2/2024 Al composites fabricated from 2024Al–K_2ZrF_6–KBF_4 system were processed by friction stir processing(FSP) to achieve superplasticity of the composites. And the effects of particle contents(1 wt%, 3 wt%, 5 wt%), matrix grain size(micron or submicron), strain rates(5×10~(-3)s~(-1), 1×10~(-2)s~(-1), 2×10~(-2)s~(-1) and deformation temperatures(400 K, 480 K, 600 K, 700 K, 750 K) on the superplasticity of the composites were investigated. After the friction stir processing, the coarse grains of the cast composites with matrix grain size of about 80–100 μm and nano-Zr B2 reinforcement size of 30–100 nm were crushed into small grains about 1 μm in size, and the uniformity of the nano-Zr B_2 reinforcements was also improved. And under the same superplastic tensile testing condition at the temperature of 750 K and strain rate of 5×10~(-3)s~(-1), the FSP nano 3 wt%Zr B_2/2024 Al composite exhibited an superplastic elongation of 292.5%, while the elongation of the corresponding cast composite was only less than 100%. Meanwhile, the m values of the FSP composites were always higher than the cast composites, especially the FSP composites with 3 wt% particles has the m value of 0.5321 i.e., the FSP composites should had better superplastic properties than cast ones. Furthermore, the FSP composites had higher apparent deformation activation energy(Q) than that of the lattice diffusion of pure aluminium, indicating that the deformation mechanisms of the FSP composites should be grain boundary sliding mechanisms.     

实现PS光学互连的一种新方法

提出应用散斑调制和在４ｆ系统傅里叶平面引入适当的相移实现Ｐｅｒｆｅｃｔ－Ｓｈｕｆｌｅ（ＰＳ）的一种方法，并进行了实验验证．结果表明，应用该方法可得到满意的光互连，且简单易行．     

核事故早期场外应急决策优化系统

介绍在１９９７年初研制完成的核电站事故早期场外应急决策优化系统，讨论了应急防护决策及其优化的主要模式、参数和某些特点。     

Biocompatibility of Mg-Nd-Zn-Zr alloy with rabbit blood

In this study, in vitro blood biocompatibility of Mg-Nd-Zn-Zr (JDBM) alloy was investigated to determine its suitability as a degradable medical biomaterial. Blood biocompatibility was assessed by blood cell aggregation, platelet adhesion, and protein adsorption. A titanium alloy was used as control. The results showed that the JDBM alloy did not induce significant blood cell aggregation, platelet adhesion, and protein adsorption comparison with the titanium alloy (P>0.05). Our data indicate that the JDBM alloy has excellent in vitro blood compatibility, and thus can be considered as a potential degradable biomaterial for medical applications with respect to hemocompatibility.     

Off-line Programming Technology Based on RPC Communication Method and its Application

This paper puts forward a communication programming method between robot and external computer based on RPC (Remote Produce Call) communication method, which realizes robot distributed controlling network system model. And a new Robot off line programming method is built based on this communication method and network model. Further more, as an example, robot automarking and autocutting of shipbuilding profile system is developed, which proves the ideas of author's offline programming and development methods of robot flexible automation system.     

Preparation of calcium carbonate particles coated with titanium dioxide

The preparation of a new mineral composite material, calcium carbonate particles coated with titanium dioxide, was studied. The mechanism of the preparation process was proposed. The new mineral composite material was made by the mechanoehemieal method under the optimum condition that the mass ratio of calcium carbonate particles to titanium dioxide was 6.5:3.5. The mass ratios of two different types of titanium dioxide (anatase to rutile) and grinding media to grinded materials were 8:2 and 4:1 respectively, and the modified density was 60%. Under this condition, the new material was capable of forming after 120-min modification. The hiding power and oil absorption of this new material were 29.12 g/m2 and 23.30%, respectively. The results show that the modification is based on surface hydroxylation. After coating with titanium dioxide, the hiding power of calcium carbonate can be improved greatly. The new mineral composite materials can be used as the substitute for titanium dioxide.