This paper investigates the FeCl₃- based few- layer graphene intercalation compound flakes based on the Raman spectroscopy. Different intercalated parts of the graphene flake and the corresponding doping level can be retrieved by the G band Raman mapping. The G band Raman spectrum consists of a single peak or double peaks for the bilayer and tetralayer graphenes, respectively. A surprising intrinsic G₀ peak appears at the edges of the intercalated graphene, which suggests that the doped graphene is partially undoped at the edges. Furthermore for the bilayer graphene intercalation compound flake, the 2D band peak can fit with four Lorenztian peaks with different full width half maxima (FWHM). This study provides a better understanding of the property of the electrically modified graphene.

The graphene, a single layer of carbon atoms in a hexagonal configuration, enjoys high carrier mobility, good biocompatibility and chemical stability. This paper briefly reviews the recent research progresses in the surface-enhanced Raman scattering (SERS) of graphene-metal nanoparticles (NPs) hybrid films, the excitation of graphene plasmons and the performance in sensing. In the visible region, the coupling between the graphene and the metal NPs allows the hybrid films to have enhanced absorption and much stronger electric field enhancement, and thus they can be used as highly sensitive SERS substrates. In the midinfrared region, the graphene plasmons can be excited by directly fabricating the graphene or fabricating the dielectric substrates with the help of guided-mode resonances, making them promising in refractive index sensing. In addition, the opportunities and challenges in this area are discussed.

The graphene is a single layer of carbon arranged in a honeycomb (hexagonal) lattice. The unique single layer structure endows this material with a series of extraordinary physicochemical properties, with promising applications in energy, environmental and biomedical sciences. The controllable production and assembly of the graphene is critical for practical applications. This review focuses on the assembly behavior of the graphene based on the colloid chemistry and the interface engineering. The graphene based multi-dimensional assemblies, from the 0D graphene based nanoparticles and the 1D fibers to the macro flexible 2D films and the 3D monoliths, are discussed in this review. The possibility of creating novel graphene assemblies is explored.

The graphene is an allotrope of carbon, a 2D thin film material with unique optical, electrical and mechanical properties. Recently, the optoelectronic devices using the graphene are extensively investigated. This paper reviews the applications of the graphene in solar cells, organic light-emitting diodes, and field emission devices. The graphene can serve as the flexible electrode for solar cells and organic light-emitting diodes due to its excellent conductivity and mechanical properties. The graphene can be used as an electron acceptor for organic solar cells for the honeycomb graphene can form a large donor acceptor interface with the organic polymer material, which might improve the exciton's diffusion rate and the electron's mobility. The graphene has a high charge mobility and sharp edges, and is endowed with the great field enhancement factor and can be used as electron conductive and electron emission materials.

The graphene is a new type of two-dimensional carbon nanomaterials with a single atomic layer, and it has an ultra high carrier mobility, a high thermal conductivity and other good properties. This paper reviews the current research progress of the graphene in enhanced heat transfer fields, including the measurement method for the thermal conductivity of the graphene, and the applications of the graphene in nanofluids, thermal interface materials, and polymer composites with high thermal conductivity. Some research directions in the future are suggested.

Pore structure of low permeability sandstones and characteristics of the corresponding low rate waterfloods have been investigated in virtue of CT scanning technology, nuclear magnetic resonance and rate-controlled mercury. The paper also addressed the effects of initial water and flow rate on characteristics of waterfloods. It was found that low rate can induce quasi-piston-like displacement where the saturations profile was steep and almost vertical to the forward direction and the water front was narrow and distinct. The reason for this flooding pattern may be the non-pronounced differences of flooding resistances. Notably, water passed directly through large pores and immediately blocked considerable oil in small and middle pores to be residue, though water was preferential to those pores. Moreover, once water breaks through, increasing flooding rate or flooding time hardly reduces the oil remaining inside the samples. It brings a low oil recovery probably due to the high pore-throat ratio which may result in enhancement of bypassing and snap-off. The results confirmed that the presence of initial water enhanced sweep efficiency substantially. On one hand, because water had previously occupied the small pores, the subsequent oil can only invade relatively large pores and became more movable. On the other hand, stable collars cannot form due to the steep front, which may suppress the snap-off.

Various problems exist in the development of Fuyang extra-low permeability oil layer using water flooding, including injection difficulty, recovery difficulty, low effectiveness, and low recovery rate. To solve these problems, a CO₂ flooding test was carried out at Shu101 well block in Daqing Yushulin Oilfield. Systematic evaluation of the displacement state, development characteristics and effects of CO₂ flooding was conducted. The results show that when the injection rate of CO₂ was 0.1 HCPV, through comparison of high pressure physical properties of two samplings, the light component increased by 5.7%, and the minimum miscibility pressure decreased from 32.2 MPa to 28.6 MPa, a drop of 3.6 MPa. Three kinds of displacement states existed in the test area: miscible, semi-miscible and immiscible phases, which account for 2/8, 1/8, and 5/8, respectively. Through research and oilfield practice, the development and adjustment technology of CO₂ flooding for different gas injection stages and different types of wells was developed. The oil recovery rate in the test area remained above 1% for four consecutive years. Numerical simulation predicted that the ultimate recovery using CO₂ flooding will be 10% higher than that using water flooding.

For the presence of the suspended spiral coil, the MEMS suspended inductor has unsatisfactory mechanical performance, and use of the inductor in shock environments is restricted. Aimed at this problem, this paper designed an on-chip integrated MEMS suspended spiral inductor with a novel step-shaped spiral coil. A simple cantilever beam was used to explain the design principle, and the radio frequency performance was considered together with the mechanical performance in the design to ensure the high-Q characteristic, which is the main and inherent advantage of the MEMS suspended inductor. The fabrication process of the inductor is briefly introduced. ANSYS and HFSS were used to study the mechanical performance and the radio performance of the inductor, respectively. To compare with simulation results of the introduced inductor (denoted by ‘Inductor- A’), a conventional MEMS suspended inductor with an equal cross-section area spiral coil (denoted by ‘Indcutor-B’) and a conventional MEMS suspended inductor with an additional support pillar (denoted by ‘Inductor-C’) were also analyzed by using ANSYS and HFSS at the same time. The results show that the anti-overload capacity of Inductor-A was improved by about three times that of the Inductor-B, while radio frequency performances of both inductors were almost the same, and accordingly, the quality factor of Inductor-A was much higher than that of Inductor-C, while mechanical performances of both inductors were almost the same. The results indicate that the inductor presented in this paper has excellent radio frequency performance and mechanical performance.

A new type of cantilever piezoelectric power generation device was designed to collect and use the energy generated by treading of the crowd on the stairs. The electricity generating circuit and mathematical model of the device were established based on resistance RLC. The equivalent circuit and the mathematical model were verified using the vibration experiment platform. The results show that in the condition of low frequency, the output electric power of the device increases with increasing displacement and decreasing frequency. The experimental output voltage of the device is the voltage of the equivalent resistance Z₂, and the ideal voltage calculated by the mathematical model was 2.64-2.88 times of the experimental output voltage. By analyzing and calculating the experimental data, the experimental source voltage that is consistent with theoretical calculation was obtained, and the maximum error was 7.1%, verifying the validity of the circuit and mathematical model for the piezoelectric power generation device and providing reference and guidance for its design.

Carbon/carbon (C/C) materials, heat-resistant rigid ceramic tiles and flexible felt were used for the leading edge, lower surface and upper surface of airbreathing hypersonic vehicles to meet thethermal protection requirement. The thermal analysis finite element model of hypersonic vehicles was established using Abaqus. The temperature distribution and the changes during the entire flight of the vehicle under typical aerodynamic heating were calculated. The peak temperature of the leading edge was 1637℃, and the peak temperatures for the upper and lower surfaces were 635 and 805℃, verifying the effectiveness of the proposed thermal protection structure. The temperature- time curve shows that the temperature of the leading edge and upper and lower surfaces increased significantly at 500 s with a largetemperature gradient. From 500 s to 1500 s, the temperature was continuously high. The temperature decreased rapidly after 1500 s. The heat transfer models were built for evaluating the efficiency of the three typical thermal protection structures. The optimum thicknesses for the materials were obtained as 57.6, 52.9, and 53.3 mm, which may provide references for the design of thermal protection systems.

In this paper, a dynamic fault tree model was first applied to evaluate safety of the engine lubrication system with faulttolerance and redundancy configuration. Using the dynamic fault tree and classical fault tree methods, a typical failure condition of the lubrication system was modeled and analyzed. The results show that the classical fault tree model cannot quantify the dynamic behavior aspect of system safety in a reasonable fashion, and prediction of failure probability deviates far from the actual situation (analytical errors up to 20 times). Meanwhile, the dynamic fault tree model not only correctly describes the sequence-based failure conditions, but also efficiently yields better quantitative failure probability calculation, demonstrating that dynamic fault tree model will have high potential in safety analysis of engine systems.

This paper aims to explore the influence of silt content on frost heaving properties of gravel soil, and provide theoretical basis for anti-freezing expansion design in practical engineering. A series of indoor frost heave tests were conducted to study the heaving properties of gravel soil under the same degree of saturation with different silt content, and under the same silt content with different moisture content using the improved experiment device. The test results show that the frost heaving ratio increased with the increase of silt content at unchanged degree of saturation in sealed environment, indicating high silt content can result in large frost heaving, so the control of silt content is an effective measure for prevention of gravel soil frost heaving. The frost heaving ratio increased with the increase of moisture content at unchanged silt content in sealed environment, indicating the frost heaving ratio is influenced by both the silt content and moisture content, so waterproof and drainage and control of the silt content are both important. It is conventionally believed that gravel soil does not have obvious frost heave due to large grain size; however, our research results indicate that gravel soil with a certain amount of silt and moisture can also generate obvious frost heave, which may exert considerable influence on the construction. Therefore, gravel soil frost heave in practical engineering cannot be ignored.

This paper compares differences in depression and quality of life between abnormal savda and non-abnormal savda type HIV/AIDS patients to investigate the influence of abnormal savda on depression and health-related quality of life of HIV/AIDS patients. According to abnormal body fluid classification criteria in traditional Uyghur medicine, 307 HIV/AIDS patients were differentiated, and their depression status and quality of life were assessed using HAMD and MOS- HIV scales. Syndrome differentiation results revealed that abnormal savda type patients accounted for 61.6%, while non- abnormal savda type patients (abnormal khan, sapara and belhem syndrome types) accounted for 38.4%. The proportion of patients with depression in total number of abnormal savda type HIV/AIDS patients was greater than that in non-abnormal savda patients (P<0.05). The average scores of mental health from MOS-HIV quality of life scale were lower in abnormal savda patients than that in non-abnormal savda patients (P< 0.05); however, the difference in average scores of physical health was not statistically significant (P>0.05). The average scores of physical function, cognitive function and role transition in abnormal savda patients were higher than that in non-abnormal savda syndrome patients (P<0.05), but the average scores of four subscales including social function, mental health, fatigue/energy, and health pressure were lower (P<0.05). The main syndrome type in HIV/AIDS patients was abnormal savda syndrome. Compared to nonabnormal savda syndrome patients, depression was more common in abnormal savda syndrome type patients, and has quite severe effects on quality of life, which should be noticed and intervened with traditional Uyghur medication to improve patient's healthrelated quality of life.

Artmisia ordosica was used as the experimental material for making biochar in this study. The effects of carbonization temperature on the pH and total K, Ca, and Mg of Artmisia ordosica biochar were investigated. The results showed that the concentrations of K, Ca, and Mg in the biochar increased with the increase of carbonization temperature. Compared with those at 300℃, the K, Ca, and Mg concentrations increased by 52.47%, 25.76%, and 86.32% at 900℃, respectively. The increase of element concentration is due to gradual removal of the volatile and decomposable components in Artmisia ordosica under different carbonization temperature. The heating process of carbonization enriches K, Ca, Mg, and other elements (relative enrichment coefficient RE>1). Low temperature contributes to the enrichment of K and Ca, while medium temperature is favorable for Mg. The RE of the three elements reached their maximum values at 300, 300 and 500℃, being 1.17, 1.15, and 1.22, respectively. The pH increased with the increase of carbonization temperature. The alkalinity of the biochar was correlated to the enrichment of the three elements, and the number and types of oxygen-containing functional groups at the biochar surface, and it had good correlation with the total alkaline functional groups at the surface of the biochar (with correlation coefficient of 0.8665).

Based on the technology of the protection against malicious web sites and the SDN (software defined networks), this paper puts forward a protection system against malicious web sites based on the SDN. Several experiments are conducted to verify the performance of each module of the system. The system is applied to a real campus network environment. And the testing results show that our system can effectively prevent malicious web sites and provide a good support against malicious attacks.

This paper presents a design of gateway system with ARM processor as the core based on LTE and ULP network to overcome the heterogeneous barrier between mobile communication and ULP Bluetooth network. ARM9 based control panel was used as the gateway control, which was connected to the EM3760 of LTE and ULP chip CC2540 through the serial port. The periphery circuit of the chip was designed, and μC/OS-II operating system was transplanted in the main control chip to realize data frame protocol conversion. The test result indicated that the gateway realized data protocol conversion between ULP and LTE and had satisfactory performance in practical applications in HDP well.

The medium frequency radar uses the circular polarization echoes to retrieve the wind fields and the electron density in the middle and upper atmosphere. To transmit and receive circular polarization echoes, a spaced antenna system, composed of a series of cross-dipoles, is used. Different demands are imposed for the circular characteristics in the echoes to retrieving the wind fields and the electron density, consequently, the receiver should be able to keep and remove the circular characteristics in the echoes. In most medium frequency radars, a hardware solution is adopted to remove the circular characteristics by making a phase adjustment to one of the two sets of signals associated with a cross dipole unit and then overlapping it with the other. Adjusting the phase at a medium frequency requires extra devices and a complicated system, what is more, the reliability of the device might be influenced by the environment. In this paper, the 4 I/Q components of a cross dipole unit are employed to compose the I/Q components of the signals associated with the circular polarization echoes. This method is very simple, and it only involves some basic calculations and judgments at each point. Theoretical analyses and numeral simulations show that this method is effective in removing the polarization characteristics.

With efficient and reliable torches for the thermal plasma generation becoming available in recent years, the thermal plasma as an energy source for pyrolysis/gasification has attracted much attention, and a special attention is paid to the waste treatment for the resource and the energy recovery. Plasma pyrolysis/gasification systems have unique features such as the extremely high reaction temperature and the ultra-fast reaction velocity as compared to the traditional pyrolysis/gasification systems. The plasma pyrolysis/gasification emerges, therefore, as a novel pyrolysis/gasification technology with a great potential in the solid waste disposal. This paper reviews the fundamental studies of plasma pyrolysis/gasification systems including the direct current (DC) arc plasma system and the radio frequency (RF) plasma system with an emphasis on the reactor design such as the plasma fixed/moving bed reactor system, the plasma entrained-flow bed reactor system and the plasma spout-fluid bed reactor system.

Airturbine is the main output device of a solar chimney power plant (SCPP). Its performance directly affects the effectiveness of the whole system. The influence of the type, structure, layout and parameters of the turbine on the overall effectiveness of SCPP will be the next research focus. This paper briefly summarizes research progress in this area at home and abroad,introducing the history, research methods, and achievements of studies on turbine performance and pointing out future research directions.