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A high-durability and long-scale-distance fiber grating sensor and a manufacturing method therefor, which relate to the technical field of fiber grating sensors. A fiber grating is disposed on the middle segment of a commercial optical fiber. A bushing, a woven fiber jacket layer, and a packaging structure are disposed on the periphery of the commercial optical fiber. The commercial optical fiber and the bushing therebetween are fixed by using fixing points in the bushing. Anchoring segments are disposed between the fixing points in the, bushing and the woven fiber jacket layer. Two ends of the commercial optical fiber are sequentially connected to optical fibers on the anchoring segments and connecting optical fibers. Tail ends of the connecting optical fibers are connected to a transmission cable by using connecting flanges. By using the apparatus and the manufacturing method, the applicability and the durability of application of the fiber grating sensor in the civil traffic engineering field are improved, thereby providing a stable and reliable apparatus for long-time detection and sound monitoring of large engineering structures in the civil traffic engineering field.


A method of data transmission between power electronic devices without a communication line involves generation of a digital signal in a data transmission process. The digital signal enables PWM modulation of specific data information via a composite modulation method. The composite modulation superimposes PWM modulation waves after modulating the PWM carrier frequency or conducting high-frequency modulation on the data. The composite modulation generates a PWM drive pulse signal which is transmitted to a power circuit via a main power electronic circuit to complete the data transmission process. In the data receiving process, signals are extracted on the voltage and current of a power line via software or hardware, and data demodulated to obtain the data information to complete the data receiving process.


Hou J.-M.,Nanjing Southeast University
Physical Review Letters | Year: 2013

We study a two-dimensional fermionic square lattice, which supports the existence of a two-dimensional Weyl semimetal, quantum anomalous Hall effect, and 2π-flux topological semimetal in different parameter ranges. We show that the band degenerate points of the two-dimensional Weyl semimetal and 2π-flux topological semimetal are protected by two distinct novel hidden symmetries, which both correspond to antiunitary composite operations. When these hidden symmetries are broken, a gap opens between the conduction and valence bands, turning the system into a insulator. With appropriate parameters, a quantum anomalous Hall effect emerges. The degenerate point at the boundary between the quantum anomalous Hall insulator and trivial band insulator is also protected by the hidden symmetry. © 2013 American Physical Society.


Zhang W.,Nanjing Southeast University | Xiong R.-G.,Nanjing Southeast University
Chemical Reviews | Year: 2012

Practical synthetic strategies for construction of ferroelectric Metal-Organic Frameworks (MOF) are underway though the search for new ferroelectrics is now still an empirics-driven activity. Hydrogen bonds are widespread in MOFs, while aggregates linked by hydrogen bonds may undergo phase transitions due to proton transfers, which lead to structural polarizations. Dynamics of the guest molecules or ions may arouse complex structural phase transitions that reflect details of interactions between the host and the guest. In spite of great progress being made, research and applications of ferroelectric MOFs are still restricted by lack of basic understanding of ferroelectricity that needs extensive exploration. Coexistence or coupling between ferroelectricity and other physical properties such as magnetism, porosity, chirality, photoresponse, and optical properties may afford new types of materials and physical phenomena.


Qin Y.L.,Nanjing Southeast University
JACC. Cardiovascular interventions | Year: 2013

This study sought to evaluate the early and long-term effect of thoracic endovascular aortic repair (TEVAR) on type-B acute aortic dissection (AAD). Uncomplicated type-B AAD is generally treated with medical management; complicated dissections require surgery or TEVAR. Studies have demonstrated that long-term outcomes with medical management are suboptimal. Therefore, we sought to determine the long-term effect of TEVAR compared with medical management alone on type-B AAD. From January 2004 to May 2008, 193 consecutive patients in 2 hospitals were treated and retrospectively placed into 1 of 2 groups: 1) the TEVAR group-type-B AAD treated with TEVAR and antihypertensive medications (n = 152); and the 2) medicine group-uncomplicated type-B AAD treated medically alone (n = 41). All TEVAR procedures were performed in the acute phase. There were no significant differences in demographics, comorbidity profiles, or early events between groups. The cumulative freedom from all late adverse events at 1, 3, and 5 years was 97%, 89%, and 67% in the TEVAR group and 97%, 63%, and 34% in the medicine group. Log-rank tests showed that medically treated patients had more late adverse events than TEVAR-treated patients did (p = 0.003). The 5-year cumulative survival rate from all-cause death was not significantly different between the 2 groups. Patients with type-B AAD treated with TEVAR experienced fewer late adverse events than those treated with medical management, but there was no significant difference among the groups in 5-year mortality rates. Further studies of longer-term survival rates are needed to determine whether TEVAR could be an effective treatment for type-B AAD. Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.


Li M.,Nanjing Southeast University
Applied Energy | Year: 2013

Nano-graphite (NG)/paraffin composites were prepared as composite phase change materials. NG has the function of improving the thermal conductivity of the composite. The microstructure and thermal properties of the materials were examined with environmental scanning electron microscopy and differential scanning calorimetry. The results indicated that the NG layers were randomly dispersed in the paraffin, and the thermal conductivity increased gradually with the content of NG. Thermal conductivity of the material containing 10% NG were 0.9362. W/m. K. © 2013 Elsevier Ltd.


Ma H.F.,Nanjing Southeast University | Cui T.J.,Nanjing Southeast University
Nature Communications | Year: 2010

Luneburg lenses have superior performance compared with conventional lenses made of uniform materials with specially designed surfaces, but they are restricted by the difficulty of manufacturing the required gradient-index materials and their spherical focal surfaces. Recently, a new two-dimensional (2D) imaging lens was proposed and realized using transformation optics. Such a 2D lens overcomes the aberration problem, has a flattened focal surface and is valid for extremely large viewing angles. Here, we show the design, realization and measurement of a three-dimensional (3D) approximate transformation-optics lens in the microwave frequency band. The 3D lens is made of non-resonant metamaterials, which are fabricated with multilayered dielectric plates by drilling inhomogeneous holes. Simulation and experimental results demonstrate excellent performance of the 3D lens for different polarizations over a broad frequency band from 12.4 to 18 GHz. It can also be used as a high-gain antenna to radiate or receive narrow beams in large scanning angles. © 2010 Macmillan Publishers Limited. All rights reserved.


Ma H.F.,Nanjing Southeast University
Nature communications | Year: 2010

Since invisibility cloaks were first suggested by transformation optics theory, there has been much work on the theoretical analysis and design of various types and a few experimental verifications at microwave and optical frequencies within two-dimensional limits. Here, we realize the first practical implementation of a fully 3D broadband and low-loss ground-plane cloak at microwave frequencies. The cloak, realized by drilling inhomogeneous holes in multi-layered dielectric plates, can conceal a 3D object located under a curved conducting plane from all viewing angles by imitating the reflection of a flat conducting plane. We also designed and realized, using non-resonant metamaterials, a high-gain lens antenna that can produce narrow-beam plane waves in the near-field region in a broad frequency band. The antenna constitutes the transmitter of the measurement system and is essential for the measurement of cloaking behaviour.


Ma H.F.,Nanjing Southeast University | Cui T.J.,Nanjing Southeast University
Nature Communications | Year: 2010

Since invisibility cloaks were first suggested by transformation optics theory, there has been much work on the theoretical analysis and design of various types and a few experimental verifications at microwave and optical frequencies within two-dimensional limits. Here, we realize the first practical implementation of a fully 3D broadband and low-loss ground-plane cloak at microwave frequencies. The cloak, realized by drilling inhomogeneous holes in multi-layered dielectric plates, can conceal a 3D object located under a curved conducting plane from all viewing angles by imitating the reflection of a flat conducting plane. We also designed and realized, using non-resonant metamaterials, a high-gain lens antenna that can produce narrow-beam plane waves in the near-field region in a broad frequency band. The antenna constitutes the transmitter of the measurement system and is essential for the measurement of cloaking behaviour.


During typical microRNA (miRNA) biogenesis, one strand of a approximately 22 nt RNA duplex is preferentially selected for entry into a silencing complex, whereas the other strand, known as the passenger strand or miRNA* strand, is degraded. Recently, some miRNA* sequences were reported as guide miRNAs with abundant expression. Here, we intended to discover evolutionary implication of the fate of miRNA* strand by analyzing miRNA/miRNA* sequences across vertebrates. Mature miRNAs based on gene families were well conserved especially for their seed sequences across vertebrates, while their passenger strands always showed various divergence patterns. The divergence mainly resulted from divergence of different animal species, homologous miRNA genes and multicopy miRNA hairpin precursors. Some miRNA* sequences were phylogenetically conserved in seed and anchor sequences similar to mature miRNAs, while others revealed high levels of nucleotide divergence despite some of their partners were highly conserved. Most of those miRNA precursors that could generate abundant miRNAs from both strands always were well conserved in sequences of miR-#-5p and miR-#-3p, especially for their seed sequences. The final fate of miRNA* strand, either degraded as merely carrier strand or expressed abundantly as potential functional guide miRNA, may be destined across evolution. Well-conserved miRNA* strands, particularly conservation in seed sequences, maybe afford potential opportunities for contributing to regulation network. The study will broaden our understanding of potential functional miRNA* species.

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