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With ZnS nanoparticles as raw materials, two kinds of nanorods were fabricated. When ZnS nanoparticles were dispersed in Zn(NO 3 ) 2 solution and were treated in a sealed autoclave at 150 °C for 24 h, ZnO nanorods formed. ZnS nanoparticles work as a source of monomers for the growth of ZnO nanorods. With increase of concentration of Zn(NO 3 ) 2 solution, the products present long nanorods, short nanorods, star structure and bulk particle sequentially. When ZnS nanoparticles were kept in a solution at room temperature, ZnS nanorods formed after 21 days. ZnS nanoparticles work as assembly parts. They fit together spontaneously and present ZnS nanorods with many parallel stripes along the lengthways surface. To check the generality of self-assembling, PdS and Y 2 S 3 nanorods were also fabricated.

A pressure induced semiconductor-semimetal phase transition on tungsten diselenide has been studied using in situ electrical resistivity measurement and first-principles calculation under high pressure. The experimental results indicate that the phase transition takes place at 38.1 GPa. The first-principles calculations performed by CASTEP code based on the density functional theory illustrate that the indirect band gap of WSe2 vanishes at 35 GPa, which results in an isostructural phase transition from semiconductor to semimetal in WSe2. According to the pressure dependence of partial density of states, the semimetallic character of WSe2 is mainly caused by W−Se covalent bonding rather than van der Waals bonding.

Alkali metal azides can be used as starting materials for the synthesis of polymeric nitrogen, a potential material of high energy density. In this letter, we report the ionic transport behavior in sodium azide under high pressure by in situ impedance spectroscopy and density functional theory calculations. The ionic transportation consists of ion transfer and Warburg diffusion processes. The ionic migration channels and barrier energy were given for the high-pressure phases. The enhanced ionic conductivity of the γ phase with pressure is because of the formation of space charge regions in the grain boundaries. This ionic conduction and grain boundary effect in NaN3 under pressures could shed light on the better understanding of the conduction mechanism of alkali azides and open up an area of research for polymeric nitrogen in these compounds and other high-energy-density polynitrides.

The study on the thermal transport properties of matter under high pressure is important but is hard to fulfill in a diamond anvil cell (DAC) because the accurate measurement of the temperature gradient within the sample of DAC is very difficult. In most cases, the sample temperature can be read accurately from the thermocouples that are directly attached to the lateral edges of diamond anvils because both the sample and diamond anvils can be uniformly heated up to a given temperature. But for the thermal transport property studies in DAC, an artificial temperature distribution along the compression axis is a prerequisite. Obviously, the temperature of the top or bottom surface of the sample cannot be substituted by that of diamond anvils although diamond anvils can be considered as a good medium for heat conduction. With temperature field simulation by finite element analysis, it is found that big measurement errors can occur and are fatal to the correct analysis of thermal transport properties of materi...

The high-pressure transport behavior of CaF2 nanoparticles with 3 mol% Tb concentrations was studied by alternate-current impedance measurement. All of the electrical parameters vary abnormally at approximately 10.76 GPa, corresponding to the fluorite-cotunnite structural transition. The substitution of Ca2+ by Tb3+ leads to deformation in the lattice, and finally lowers the transition pressure. The F− ions diffusion, electronic transport, and charge-discharge process become more difficult with the rising pressure. In the electronic transport process, defects at grains play a dominant role. The charge carriers include both F− ions and electrons, and electrons are dominant in the transport process. The Tb doping improves the pressure effect on the transport behavior of CaF2 nanocrystals.

A simple method to prepare thermally reduced graphene oxide/polymer composites was developed to enhance the electrical conductivity of the polymer. Graphene oxide sheets were coated onto the surfaces of poly(vinylidene fluoride) powders and then hot pressed at 200 °C to form composites with a segregated structure. After hot-pressing, the thermally reduced graphene oxide sheets were located in the interstices among the polymer domains and formed a two-dimensional conductive network. The resulting composites exhibited excellent electrical conductivity and a low percolation threshold (0.105 vol.%).

Hybrid solar cells with organometal halide perovskites have already reached a power conversion efficiency exceeding 22.1%, but their toxic lead component remains a serious concern. Hence, the replacement of lead with nontoxic alternatives, such as tin, has attracted increasing interest. This study investigates the structural and optoelectronic properties of nontoxic perovskite methylammonium tin chloride (MASnCl3, MA: CH3NH3) under pressure. The synchrotron X-ray diffraction experiment shows that the sample transforms from the monoclinic to the triclinic phase and then amorphizes. The tilting and distortion of [SnCl6]4− octahedra are mainly responsible for the bandgap decreasing below 1.0 GPa. Upon further compression, an additional optical absorption peak appears, which is ascribed to the conduction band splitting of the triclinic MASnCl3. The high pressure behavior of MA cations indicates that the interaction between MA cations and [SnCl6]4− octahedra is strengthened. The pressure-induced electrical res...

The structural behavior of magnesium silicide (Mg2Si) was investigated in a diamond anvil cell (DAC) by energy dispersive synchrotron X-ray diffraction up to 41.3 GPa at room temperature. Two pressure-induced structural phase transitions for Mg2Si have been identified, at around 7.5 GPa and 21.3 GPa, respectively. The new structures of Mg2Si are in turn determined as orthorhombic phase with anti-cotunnite ( P n m a , Z = 4 ) structure and hexagonal phase with Ni2In-type ( P 6 3 / m m c , Z = 2 ) structure. Both the structural phase transitions are of first-order nature and are reversible.

A theoretical investigation on the structural stabilities and electronic properties of HgTe under high pressure was conducted using first principles based on density functional theory. Our results demonstrate that the sequence of the pressure-induced phase transitions of HgTe is from the zinc blende, to cinnabar, rocksalt, orthorhombic, and CsCl-type structures. The pressure effects on the optical properties were discussed and compared with previous calculations and experimental data whenever available.

Sol–gel thin film offers a number of advantages that makes it an attractive method for obtaining coatings on alloy. In this paper, an Al 2 O 3 film was deposited on a γ-TiAl-based alloy from aluminum isopropoxide (Al(OC 3 H 7 ) 3 ) as precursor. The thin film synthesized using a dip-coating process, was uniform and crack-free. Isothermal and cyclic oxidations of the coated and uncoated specimens at 1000 °C were performed to test its effect on the oxidation behavior of the alloy. The Al 2 O 3 film exhibited beneficial effects on the oxidation resistance of the alloy. The oxidation rate of the Al 2 O 3 coated specimens was much slower than that of the blank alloy. The oxide scales formed on the uncoated specimens were stratified. For the coated samples, beneath the Al 2 O 3 film, a mixture layer of rutile TiO 2 and α-Al 2 O 3 occurred, but more α-Al 2 O 3 formed on the coated specimens than that on the blank ones. The possible mechanism of the thin film on the oxidation behavior of the alloy was discussed.

The film-fabricating technology has been used to prepare the microcircuit on diamond anvil for resistivity measurement under extreme conditions. We chose molybdenum as the electrode material and alumina as the insulator and protective material. The sample thickness measurement was conducted and then the resistivity correction was performed under different thickness. The experimental error was proved to be less than 10%. By mounting alumina film between diamond anvil and microcircuit, high-temperature performance of a laser heating diamond anvil cell was improved obviously, which is available for in situ resistivity measurement under high pressure and high temperature. Meanwhile, the impedance spectroscopy of a powdered semiconductor sample was detected. Through the impedance arcs obtained, the grain boundary contribution to the resistivity can be well distinguished.

The interface effect is one of the most important factors that strongly affect the structural transformations and the properties of nano-/submicro-crystals under pressure. However, characterization of the granular boundary changes in materials is always challenging. Here, using tetrakaidecahedral Zn2SnO4 microcrystals as an example, we employed alternating current impedance, X-ray diffraction methods and transmission electron microscopy to elucidate the effect of the interface on the structure and electrical transport behavior of the Zn2SnO4 material under pressure. We clearly show that grain refinement of the initial microcrystals into nanocrystals (approximately 5 nm) occurs at above 12.5 GPa and is characterized by an anomalous resistance variation without a structural phase transition. A new phase transition pathway from the cubic to hexagonal structure occurs at approximately 29.8 GPa in Zn2SnO4. The unexpected grain refinement may explain the new structural transition in Zn2SnO4, which is different from the previous theoretical prediction. Our results provide new insights into the link between the structural transition, interface changes and electrical transport properties of Zn2SnO4.

Herein, we report on the intriguing electrical transport properties of compressed AlAs. The relative permittivity and the resistances of both the grain and bulk boundaries vary abnormally at ∼10.9 GPa, accompanied by the cubic-hexagonal structural transition of AlAs. With further compression, the boundary effect becomes undistinguished, and subsequently, the electrical transport mechanism converts from boundary- to bulk-dominated, which gives rise to a significant reduction in the total resistance of AlAs. After being quenched to ambient pressure, resistances recover to the initial values followed by the re-emergence of the boundary effect. Eg decreases with pressure and its pressure dependence changes at ∼14.0 GPa, which rationalizes the anomalous variation of the electrical transport properties. The experimental results indicate that the boundary effect can be modulated by compression and increases the resistance difference between the two states. This opens up a new possible basis for optimizing the performance of AlAs-based applications, including multilevel phase-change memories.

Two-dimensional tin selenide (SnSe) nanosheets were synthesized using a plasma-assisted direct current arc discharge method. The structural characterization indicates that the nanosheets are single-crystalline with an average thickness of ∼25 nm and a lateral dimension of ∼500 nm. The high pressure behaviors of the as-synthesized SnSe nanosheets were investigated by in situ high-pressure synchrotron angle-dispersive X-ray diffraction and Raman scattering up to ∼30 GPa in diamond anvil cells at room temperature. A second-order isostructural continuous phase transition (Pnma → Cmcm) was observed at ∼7 GPa, which is considerably lower than the transition pressure of bulk SnSe. The reduction of transition pressure is induced by the volumetric expansion with softening of the Poisson ratio and shear modulus. Moreover, the measured zero-pressure bulk modulus of the SnSe nanosheets coincides with bulk SnSe. This abnormal phenomenon is attributed to the unique intrinsic geometry in the nanosheets. The high-pressure bulk modulus is considerably higher than the theoretical value. The pressure-induced morphology change should be responsible for the improved bulk modulus.

A solid/mist reaction method is developed to produce well-crystallized light harvester layers without pinhole defects for perovskite solar cells. The reaction based on mist precursor can be facilely operated with low process temperature. And it can effectively control the volume of CH3NH3I solution and the reaction temperature, which affect the quality of perovskite harvester layers and the performance of perovskite solar cells remarkably. Under optimized condition, the efficiencies of devices reach 16.2% with the average efficiency of 14.9%. The solid/mist reaction is also used to fabricate planar junction solar cells and a PCE of 14.9% is obtained.

Path planning problem is one of the key contents in the research field of Geographic Information System (GIS), among which the finding of the shortest path is always a hot topic. When there is large quantity of data, the efficiency of traditional algorithms of Kth shortest paths is relatively low, and some path problems concerning big difference between the planned Kth paths under actual requirements cannot be solved. On the basis of Dijkstra algorithm, the concepts of favorability and repeatability are introduced to find Kth paths including the shortest in the current graph cyclically by determination of repeatability of path results and the change of graph caused by the change of favorability, thereby realizing the planning of multiple different paths. Compared with similar algorithms, this algorithm is faster, and the multiple path results obtained meet the requirement for certain repeatability while the lengths of paths are also quite reasonable.

High-quality ZnO thin films have been grown on single-crystal diamond substrates with (111) orientation, by low-pressure metal-organic chemical vapour deposition. X-ray diffraction spectra and photoluminescence (PL) spectra clearly showed that the quality of ZnO films was improved by the two-step growth method. Strong ultraviolet emissions and weak deep-level emissions with different intensity were both observed in the room-temperature PL spectrum. The change of surface morphology was also studied by atomic force microscopy. Zn and O elements in the deposited ZnO/diamond films were investigated by x-ray photoelectron spectroscopy, in which the statistical result of the ratio for O/Zn atoms of samples was about 1. Raman scattering was performed at room temperature. The E2, A1(TO) and E1(TO) mode peaks were seen at 437.46, 383 and 414.87 cm−1, which indicated a high crystalline quality for our samples.

Using a microcircuit fabricated on a diamond anvil cell, in situ conductivity measurements on nanophase (NP) γ-Fe2O3 are obtained under high pressure. For NP γ-Fe2O3, the abrupt increase in electrical conductivity occurs at a pressure of 21.3 GPa, corresponding to a transition from maghemite to hematite. Above 26.4 GPa, conductivity increases smoothly with increasing pressure. No distinct abnormal change is observed during decompression, indicating that transformation is irreversible. The temperature-dependence of the conductivity of NP γ-Fe2O3 was investigated at several pressures, indicating the electrical conductivity of the sample increases with increasing pressure and temperature, and that a remarkable phenomenon of discontinuity occurs at 400 K. The abnormal change is attributed to the electronic phase transitions of NP γ-Fe2O3 due to the variation of inherent cation vacancies. Besides, the temperature-dependence of the electrical conductivity displays semiconductor-like behavior before 33.0 GPa.

In situ electrical resistivity measurement of powdered Mg2Si has been performed in a diamond anvil cell up to 25.4 GPa. At about 22.2 GPa, Mg2Si underwent a pressure-induced semiconductor–metal phase transition that took place in the Ni2In-type structure rather than the anti-fluorite structure predicted theoretically. The other phases (anti-fluorite and anti-cotunnite) belong to the semiconductor phase.

Ohmic electrodes in the form of n-type (Si-doped) cubic boron nitride (c-BN) bulk crystals were fabricated by utilizing a covering technique, depositing Ti(10 nm)/Mo/(20 nm)/Pt–Au(200 nm) ohmic contact metal on both the sides of the c-BN substrate. The size of the specimen electrode was 100 × 100 μ m2 on one side and 300 × 300 μ m2 on the other side. Measurements on the specimen were made using a specially made device. Linear current–voltage characteristics were obtained. It is considered that the contact between the Ti-and Si-doped c-BN was ohmic.

An in situ energy dispersive x-ray diffraction study on nanocrystalline ZnS was carried out under high pressure up to 30.8 GPa by using a diamond anvil cell. The phase transition from the wurtzite to the zinc-blende structure occurred at 11.5 GPa, and another obvious transition to a new phase with rock-salt structure also appeared at 16.0 GPa-which was higher than the value for the bulk material. The bulk modulus and the pressure derivative of nanocrystalline ZnS were derived by fitting the Birch-Murnaghan equation. The resulting modulus was higher than that of the corresponding bulk material, indicating that the nanomaterial has higher hardness than the bulk material.

Iron carbide without any graphite was studied under high pressure and high temperature (HPHT); diamond layers were obtained both on diamond and on cubic boron nitride seeds at 5.5 GPa and 1700–1750 K. The results showed that transition-metal carbide was the main intermediate in the course of the transformation from graphite to diamond under HPHT.

Polycrystalline diamond films have been patterned on a polished Si substrate by means of selective seeding via hot-filament chemical vapour deposition. In addition to the process of selective seeding, the CH4/H2 concentration and the sizes of the patterns have effects on the selectivity. The mechanism of selective growth of diamond is also discussed in this paper.

Diamond films have been grown on polished Si substrates seeded with nanocrystalline diamond powder colloid using hot-filament chemical vapour deposition. Instead of using the conventional gaseous carbon source, a carbonized W filament was used as the carbon source. The only feeding gas was hydrogen. Compared with those produced by traditional methods, the polycrystalline diamond grown by this new method has smaller grain size. The growth mechanism is also discussed.

Boron-doped p-type diamond thin film was grown heteroepitaxially on silicon-doped n-type cubic boron nitride (c-BN) bulk crystal by the conventional hot-filament chemical vapour deposition method. A diamond thin-film/c-BN heterojunction p–n diode was fabricated by the covering technique for the first time. The rectification ratio of the diode reached five orders. The threshold value is 1 V; the reverse bias voltage is 6 V. The results indicate that the device is of great importance.

Highly ordered boron nanowire multiple nanojunctions; (see Figure) with unilateral feather-like morphology have been created via a simple magnetron sputtering method. These T- and Y-type nanojunctions stand freely in line to form uniform and well-oriented arrays on the substrate surface over areas of up to several tens of square centimeters.

The ionic transport and dielectric behaviors in NaNbO3 were studied under pressures up to 29.1 GPa by in situ impedance spectroscopy measurements. The transport process consists of the ionic transfer and the Warburg diffusion process between sample/electrode diffusion layers. A dielectric relaxation with a giant dielectric constant at low frequencies is observed, which is attributed to the “Maxwell-Wagner” interfacial polarization. In the Pbcm phase, the increase in the interaction between the Na+ ions and the NbO6 octahedra results in the enhancement of vibration resonance damping. In the high-pressure phases, the decrease in the relative permittivity with pressure indicates the existence of space charge polarization of the interface layer besides the ionic polarization.

In2S3 has been investigated under pressures up to 41.3 GPa at room temperature by in situ angle dispersive synchrotron x-ray diffraction in a diamond anvil cell. In the studied pressure range, the diffraction pattern can be indexed into the face centered tetragonal structure. No evident structural phase transition can be determined even with the emergence of some peaks, which can be considered as from impurity. The bulk modulus is determined to be K 0 = 37.8 ± 0.2 GPa with K' = 4.44 ± 0.05. In addition, we have documented a difference in the compressibility around two experiments associated with different pressure transmitting medium.

Ionic transport behaviors of silver chloride (AgCl) have been revealed with impedance spectra measurement under high pressures up to 20.4 GPa. AgCl always presented ionic conducting under experimental pressures, but electronic conduction can coexist with ionic conduction within the pressure range from 6.7 to 9.3 GPa. The ionic conductivity of AgCl decreases by three orders of magnitude under compression, indicating that Ag+ ion migrations are suppressed by high pressure. A parameter, fW, was defined as the starting frequency at which Ag+ ions begin to show obvious long-distance diffusion in AgCl. fW showed a similar trend with the ionic conductivity under high pressures, indicating that the speed of Ag+ ion diffusion slows down as the pressure increases. Unlike AgI, Ag+ ion diffusion in AgCl is controlled by the indirect-interstitial mechanism. Due to stronger ionic bonds and larger lattice deformation, Ag+ ion diffusion in the rigid Cl− lattice is more difficult than in the I− lattice under high pressures.

The four-point method is widely used to determine the electrical resistivity of materials. Using finite element analysis (FEA) to simulate the distribution of the steady current field in sample, we illuminate the electrode factor on accurate resistivity measurement under high pressure in a diamond anvil cell (DAC). The result reveals that the measurement error is close dependent on the size and the resistivity of electrode. In order to minimize the measurement errors and improve the measurement accuracy, reducing the electrode size and increasing the electrode resistivity is a better choice. (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Impedance spectroscopy of CdS nanocrystals (100 nm in diameter on average) was studied with the applied pressure up to 25 GPa using Solartron 1260 Impedance/Gain-Phase Analyzer in diamond anvil cell (DAC). The change in complex impedance related to the phase transition from wurtzite to rock salt was observed. Two distinct relaxation mechanisms were also identified. The effective scattering section of the grain boundary to charge carriers can be weakened under compression, which leads to the decrease of grain boundary resistance (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The electrical transport properties and phase transitions of CdS were investigated under high pressure and moderate temperature by a microcircuit fabricated on diamond anvil cell. Around 2.0 GPa the resistivity of CdS dropped two orders of magnitude sharply, implying a beginning of a phase transition from wurtzite phase to rock-salt phase. At about 4.0 GPa the resistivity appeared a local minimum indicating an end of the transition to rock-salt phase. A local maximum of the resistivity was observed at about 8.0 GPa, which was attributed to the changeover of indirect gap from ΣνXc to LνXc. Furthermore, two inflexions of resistivity were observed at about 16.0 GPa and 21.0 GPa, which predicting that the indirect band gap of CdS may further change at these pressures. In the range of experimental pressure and temperature CdS still showed the electrical transport property of a semiconductor. (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

In this paper, a tensile-strained layer is used to control the quantum dot arrangements. A 3 nm GaAs tensile-strained layer is grown on InP (001) substrate, and a four-monolayer InAs compressed layer is then grown on top by LP-MOVPE. Atomic force microscopy (AFM) measurements were performed. AFM images indicate that the InAs quantum dots are arranged along two orthogonal directions, their diameter is about 30 nm, the size fluctuation is only 10%, and their density is 8.8×109 cm−2, which is higher than that grown directly on InP or GaAs substrates. An identical structure, except for the presence of 30 nm of GaAs, was also grown. The islands on top of the 30 nm GaAs are mainly very big and rectangular in shape. We demonstrate that these characteristics originate from the modulated stress field of the GaAs tensile-strained layer.

The mechanical properties of poly(acrylic acid) (PAA) were investigated on the molecular scale by using AFM. PAA was adsorbed onto a glass substrate and then picked up at one point of the chain with the AFM tip and stretched. The deformation of single PAA chains under tension was measured and modeled by a modified freely-joint-chain model. The length distribution of loops and tails of adsorbed PAA on the glass substrate was also studied by analyzing the extension of the filaments.

In situ electrical resistivity measurement of CdSe was performed under high pressure and moderate temperature using a diamond anvil cell equipped with a microcircuit. With the pressure increasing, a sharp drop in resistivity of over two orders of magnitude was observed at about 2.6 GPa, it was caused by the transition to the rock-salt CdSe. After that, the resistivity decreased linearly with pressure. However, in different pressure range, the decreasing degree was obviously different. This attributed to the different electron structures. By fitting to the curve of pressure dependence of resistivity in different pressure range, the relationship of the band gap to pressure was given and the metallization pressure was speculated to be in the range of 70–100 GPa. The temperature dependence of resistivity showed that in the experimental temperature and pressure range the resistivity had a positive temperature coefficient.

The elastic properties of poly(vinyl alcohol) (PVA) were investigated on the nanoscale using the new technique of single molecule force spectroscopy by atomic force microscopy (AFM). It was found that the elastic properties of PVA molecules scale linearly with their contour lengths. This finding corroborates that the deformation of individual PVA chains is measured. The force spectra of PVA show a kink at around 200 pN and cannot be fitted by an extended Langevin function. The deviation of the elastic behavior of PVA from a freely jointed chain model may indicate the presence of a suprastructure of PVA in NaCl solution.

The Photoluminescence (PL) spectra of Gd2O3:Eu composed of cubic and monoclinic structure were collected on November 2003 and June 2006, respectively. The results show that a portion of cubic Gd2O3 transforms into monoclinic after the sample was left as it is for two years; and the 5D1–7FJ emission of Eu3+ in cubic host was enhanced in this released complex. Considering the high pressure behavior of Gd2O3, we think this structural transition is due to the sample that endures a process of press and release while the residual stress is released slowly.

In this paper, we present a method to control the nucleation sites of InAs self-assembled quantum dots (QDs). Tensile strained material, such as GaAs used here was grown on InP substrate before InAs deposition. This thin GaAs layer can provide a surface with gridded trenches which have the same function as atomic steps and are promising for the formation of QDs with nucleation sites controlled. Atomic-force microscopy measurement was performed and the AFM images indicate that the InAs islands grown with our technique is grid aligned and have good homogeneity and low-size fluctuation. In addition, another kind of three-dimensional structure with larger size would co-exist with normal QDs if 30 nm thick GaAs layer were deposited.

The quaternary Ga 0.16 In 0.84 As 0.80 Sb 0.20 epilayer was grown on GaSb substrate by metalorganic chemical vapour deposition (MOCVD). On the epitaxial surface smooth and perfect three-dimensional islands were observed by atomic force microscopy (AFM). A good crystalline quality was characterized by single-crystal X-ray diffraction pattern and double-crystal X-ray rocking curve. When the growth rate of the growth nucleus is larger than the growth rate of the high-index facet, the mode of island growth is isotropic.

The phase diagram of water near the ice VI–ice VII–liquid triple point and electrical transport properties of these ices have been studied by in situ electrical conductivity measurements in a diamond anvil cell. The obtained phase boundary between ices VI and VII and the melting curve for these ices are in accord with most previous results. The different properties and amount of orientational defects in ice VI and ice VII are associated with abrupt changes in conductivity when a phase transition from ice VI to ice VII occurs. The electrical transport mechanisms of these two ice polymorphs can be understood in terms of the conduction of the already existing ions and Bjerrum defects.

Real-time stitching is a research focus of UAV area. The speed and accuracy of stitching algorithm are both important for commanders to make right decisions in battlefield. In this paper, a real-time UAV aerial image stitching algorithm based on predicted region matching is proposed. A new matching strategy is applied to the feature matching step. The transformation matrix will be calculated by the matches between features in current image and features in a predicted region. Experimental results show that, comparing with traditional method, the new algorithm can reduce much stitching errors while keeping the process time almost the same. Keywordsreal-time stitching; predicted region; UAV; aerial image

Raman spectra of Na 0.5 Bi 4.5 Ti 4 O 15 have been investigated under hydrostatic pressure up to 10 GPa. Two pressure-induced phase transitions have been observed at about 1.94 GPa and 9.0 GPa, respectively.