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It is important yet challenging to perform accurate and interpretable time series forecasting. Though deep learning methods can boost forecasting accuracy, they often sacrifice interpretability. In this paper, we present a new scheme of series saliency to boost both accuracy and interpretability. By extracting series images from sliding windows of the time series, we design series saliency as a mixup strategy with a learnable mask between the series images and their perturbed versions. Series saliency is model agnostic and performs as an adaptive data augmentation method for training deep models. Moreover, by slightly changing the objective, we optimize series saliency to find a mask for interpretable forecasting in both feature and time dimensions. Experimental results on several real datasets demonstrate that series saliency is effective to produce accurate time-series forecasting results as well as generate temporal interpretations.

Independent travelers, especially professional independent travelers, tend to plan their trip schedules according to their interests, preferred hotels, landmarks they wish to visit, budgets, time availability and various other factors. Hence, travel schedule planning is valuable for satisfying the unique needs of each traveler. In this paper, we propose an algorithm for independent travel recommendation, consisting of three steps. Firstly, landmarks in the destination are selected under the specific constraints, which is modeled as a 0-1 knapsack problem. Then, the landmarks will be evaluated comprehensively using AHP (Analytic Hierarchy Process) model, and the greedy simulated annealing algorithm is adopted to select the best landmarks with high evaluation scores. Next, with AHP-decision model, a most reasonable free line to the tourist destination is selected from multiple candidates. Lastly, the path planning among the landmarks is abstracted as a TSP (Travelling Sales Problem) problem, and the simulated annealing algorithm based on roulette wheel selection is adopted to solve it. Through simulation experiments, by comparing with package tour from the aspects of landmark selection, valid sightseeing time ratio, valid sightseeing consumption ratio and the tourist satisfaction, the proposed algorithm is evaluated and analyzed. Simulation results illustrate the feasibility and rationality of our approach, which can be used as an effective reference deciding individualized travel schedules and trip planning.

The growing global demand for energy has challenged the use of data centers. The development and utilization of renewable energy, such as solar energy, has become a common choice for all countries in the world. To solve the problem, we propose a green data center task scheduling algorithm in the paper. Firstly, the energy is predicted by neural network. Next, the Analytic hierarchy process (AHP) is used to evaluate the load task, and the corresponding energy consumption is predicted. The proposed algorithm is evaluated and analyzed. Simulation results illustrate the feasibility and rationality of our approach, which can be used as an effective reference for deciding task schedule for green center.

With the popularization of opening community, it turns that the closed community is transformed into an open one, which has aroused wide attention and discussion. In this paper, we propose a model of influence on traffic after opening community. In model, dynamic weighting method is used to quantify the impact of traffic before opening community. Also, the ant colony algorithm is used to plan the route of vehicles in community. Though simulation experiments, the proposed algorithm is analyzed and evaluated. Simulation results illustrate the feasibility and rationality of our model.

The increase in massive data processing and computing in datacenters in recent years has resulted in the problem of severe energy consumption, which also leads to a significant carbon footprint and a negative impact on the environment. A growing number of IT companies with operating datacenters are adopting renewable energy as part of their energy supply to offset the consumption of brown energy. In this paper, we focused on a green datacenter using hybrid energy supply, leveraged the time flexibility of workloads in the datacenter, and proposed a thermal-aware workload management method to maximize the utilization of renewable energy sources, considering the power consumption of both computing devices and cooling devices at the same time. The critical knob of our approach was workload shifting, which scheduled more delay-tolerant workloads and allocated resources in the datacenter according to the availability of renewable energy supply and the variation of cooling temperature. In order to evaluate the performance of the proposed method, we conducted simulation experiments using the Cloudsim-plus tool. The results demonstrated that the proposed method could effectively reduce the consumption of brown energy while maximizing the utilization of green energy.

A novel mesoporous silica SBA-15 with monodisperse hexagonal lamelliform was prepared, and deposited on the quartz crystal microbalances (QCMs) to construct highly stable and sensitive humidity sensors. The humidity sensing characteristics of the sensors were investigated by measuring the resonant frequency shift of QCMs due to the additional mass loading caused by adsorption of water. X-ray diffraction, nitrogen adsorption/desorption, transmission electron microscopy and field emission scanning electron microscopy were employed to characterize these sensing materials. The results showed that the sensors had high sensitivity, good stability, short response/recovery time, well reproducibility and narrow hysteresis. Herein, not only a novel and low-cost humidity sensor material was exploited, but also a new application area for mesoporous materials was opened up.

Nanocrystalline tin dioxide (SnO2) materials with very interesting architectures (well-defined pores, hierarchical pores) were synthesized by a suitable heat treatment of SnO2/phenol formaldehyde resin (PFR) nanocomposite. The composite was obtained through a facile hydrothermal approach by using tin(IV) tetrachloride pentahydrate (SnCl4·5H2O) as a raw material, hexamethylenetetramine (HMT) as a pore-forming agent and monomer (HCHO) source for polymerization with phenol. Compared with the fine porous SnO2 sensor, the hierarchical porous SnO2 sensor showed a higher response. Owing to the hierarchical porous structure, the as-prepared materials exhibit satisfactory selectivity to chlorine along with high-sensitivity (249.3 at 10 ppm), fast response (7 s), very short recovery time (15 s), long-term stability as well as low power. The excellent sensing performance was discussed concerning the architectures of the materials.

A facile photochemical method was used to synthesize Ag nanoparticle (Ag NP) embedded-ZnO nanorods in this article. The as-synthesized Ag NP embedded-ZnO nanorod samples were characterized systematically by TEM, XPS, DSC, XRD and SEM. The characterization results confirmed that Ag NPs had been embedded in ZnO nanorods. The gas-sensing properties of Ag NP embedded-ZnO nanorods were also investigated. While the performances of the sensors can be enhanced by embedding Ag NPs onto the surfaces of ZnO nanorods, the response of Ag NP embedded-ZnO nanorod sensors to 50 ppm ethanol is almost three times as high as that of those made from pure-ZnO nanorods. The responses of the sensors have no apparent degradation after being exposed to ethanol of 30 ppm for 100 days. Our Ag NP embedded-ZnO nanorod sensors have long-term stability and exhibit highly enhanced gas-sensing performances in their response and selectivity for detecting ethanol vapor.

Molybdenum trioxide/polyaniline (MoO{sub 3}/PANI) composite was prepared first by ion-exchange reaction between aniline (ANI) and dodecylamine (DDA) which was intercalated precursor, and then was formed under the polymerization of ANI within the interlayer space of MoO{sub 3} at 120 deg. C for 3 d in air. According to powder X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, infrared spectroscopy and electrochemical testing, MoO{sub 3}/PANI composite has layered structure, and its interlayer spacing is 1.127 nm. Moreover, it has high thermal stability with the compound and completes its weight loss at 751.9 deg. C. Electrochemical investigation shows that MoO{sub 3} is the major active substance in the MoO{sub 3}/PANI electrode, and MoO{sub 3}/PANI electrode demonstrates better conductivity and electrochemical activity than pure MoO{sub 3} electrode, attributed to the promotion of Li{sup +} and/or electron transport. In addition, the alternating current impedance proves that if the resistance of MoO{sub 3}/PANI electrode reduces apparently, the electrochemical activity will increase correspondingly, the same as the relationship between the ohmic resistance and the electrical conductivity. - Graphical abstract: Aniline (ANI) monomer was intercalated into the interlayer space of molybdenum trioxide (MoO{sub 3}) and heat-treated at 120 deg. C for 3 d in air, and then polymerizedmore » to form layered structure of molybdenum trioxide/polyaniline (MoO{sub 3}/PANI) composite. Its interlayer spacing of MoO{sub 3}/PANI composite is 1.127 nm.« less

Indium oxide nanocrystals with mesoporous structure were successfully synthesized by using triblock copolymer as a template, and characterized by thermogravimetry-differential scanning calorimeter (TG-DSC), X-ray powder diffraction (XRD), high resolution transmission electron microscopy (HRTEM) and N2 adsorption. A high EO/PO ratio is thought to be the key point to prepare mesoporous In2O3. The results show that the average pore diameter of the products is 6 nm, the BET surface area is 54.78 m2/g, and the adsorbing pore volume is 0.345 cm3/g. After comparing with normal indium oxide nanoparticles by BET test, mesoporous indium oxide demonstrates a large difference in adsorbing pore volume and average pore diameters from normal ones.

Mesoporous SnO 2 is obtained through a simple hydrothermal process by using tin chloride as a raw material, urea as a pore-forming agent and pH regulator. X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Brunauer–Emmett–Teller (BET) nitrogen adsorption–desorption measurements are employed to characterize the obtained mesoporous structures. The results show that the as synthesized material after calcination can be well indexed to tetragonal phase SnO 2 with a mesoporous structure. The sensing properties of the sensor based on mesoporous SnO 2 are investigated. The results reveal that the response to dilute Cl 2 gas of the materials is very high and fast. The short recovery time mainly attributes to the bigger pore size of mesoporous SnO 2 . Finally, the reaction mechanism is proposed.

In this paper, a controlled synthesis of rod and hollow sphere SnO2 nanostructures has been realized via a solvothermal reaction, without employing any other toxic organic solvents. The well-defined morphologies are obtained by simply adding sodium hydroxide to aqueous ethanol solution. The products are characterized by XRD, TEM and SEM. Growth mechanisms for these two nanostructures were proposed. Gas sensors were fabricated and an investigation into the structure-based gas-sensing properties has been conducted. Compared with SnO2 hollow spheres, the nanorods display much better gas sensing properties, which is mainly due to their facile electrons transportation and excellent thermal stability.

In this work, mesoporous In2O3 nanorods composed of many small well-aligned crystal nanostructures have been fabricated by a simple sol−gel process, with block copolymer PE6800 as a soft template c...

Brush-like hierarchical ZnO nanostructures assembled from initial 1D ZnO nanostructures were prepared from sequential nucleation and growth following a hydrothermal process. The morphology, structu...

The LiV 3 O 8 samples with different morphologies have been successfully prepared by a mixed hydrothermal–sol–solid-state route via the reaction of vanadium pentoxide(V 2 O 5 ) and lithium hydrate(LiOH) at 200 °C in basic medium and subsequent gelation at 100 °C and thermal treatment at 300–550 °C. The crystal structure and morphology of the samples were characterized by X-ray diffraction (XRD), specific surface area measurements and scanning electron microscopy (SEM). Their electrochemical properties were investigated by means of constant charge/discharge cycling measurement. The results indicated that the calcination temperature has a significant effect on the crystal structure, morphology, and specific surface area of the LiV 3 O 8 samples, which consequently affects their electrochemical performance such as the initial capacity and the cycleability. The sample heat-treated at 300 °C shows the morphology of irregular blocks with low degree of crystallinity and high specific surface area, exhibiting high initial discharge capacity of 277.7 mAh g −1 but a fast capacity fade. In contrast, the samples annealed at higher temperature with perfectly uniform rod-like morphology show much better cycle performance.

A novel reversible photochromic nanocomposite film based on a hybrid inorganic-organic matrix in which heteropolyacid H4SiW12O40 (SiWA) was entrapped in Si-O-Ti network was prepared. Structure, photochromic behaviors and mechanism of the film were investigated by means of infrared spectroscopy (IR), ultraviolet-visible (UV-Vis) absorption spectra and electron spin resonance (ESR). The results showed that heteropolyanion i.e. SiW12O404− (SiW12), maintained a Keggin structure in the film and there was a strong interaction between anion SiW12 and cation R-NH3+ (R=link of hybrid composite). The photochromic properties of the composite film originated from reversible charge transfer between the anions and cations. Under UV irradiation, the anion would be reduced via one-electron step with simultaneous oxidation of the cation, accompanied by a color change from colorless to blue. Bleaching could occur when the film was in contact with ambient air or O2 in the dark.

A new organic ligand, 2-allyl-1,3-diphenyl-1,3-propanedione (ADP), and the corresponding quaternary Eu3+ complex, bi (ADP) (dibenzoyl methane) (1,10-phenanthroline) europium(III) [Eu(ADP)2(DBM)(Phen)] have been synthesized. Excellent red luminescence from the Eu3+ complex was observed excited at 419 nm, and the broad visible excitation band is attributed to excimer absorption. The luminescence quantum yield excited at 419 nm (34 ± 3%) was higher than that at 380 nm (30 ± 3%). This is the first time to find strong and high yield excimer excitation absorption for a europium complex at room temperature, therefore, the excimer absorption band located in visible region (400–500 nm). Moreover, very high yields of direct f–f excitation absorption of Eu3+ ions at 466 nm (104 ± 10%) and 536 nm (96 ± 10%) were firstly observed, and the excitation spectrum for the europium complex in solid state is extended in wide region from 220 nm to 580 nm.

Uniform ZnO nanorods were synthesized in high-yield by using metal zinc powder as zinc source via a one-step facile hydrothermal process under mild conditions, in which cetyltrimethylammonium bromide (CTAB) with ordered chain structures acted as the conversion of Zn powder into ZnO nanorods. The characterization results show that the as-synthesized products were structurally uniform and have diameters of 40–80 nm. Gas sensing properties studies show that ZnO nanorods exhibit more excellent response and stability to ethanol than that of ZnO nanoparticles. After working continuously for 50 days, the sensitivity of ZnO nanorods still retained 7.3, whereas, the ZnO nanoparticles showed only 1.0. The facile preparation method and the improved properties derived from typical rods-like nanostructure are significant for the future applications of gas sensing material.

A novel europium complex, Eu 2 (TDAP)(DBM) 6 (Phen) 2 (TDAP=terephthaloyl-diacetophenone, DBM=dibenzoyl methane, and Phen=1,10-phenanthroline), has been designed and synthesized. Excellent red luminescence from the Eu 3+ complex was observed excited at 434 nm, and the broad visible excitation band is attributed to excimer absorption. The luminescence quantum yield excited at 434 nm (54±5%) was great higher than that at 380 nm (35±3%). This is the first time to find strong and high-yield excimer excitation absorption for a europium complex at room temperature, therefore, the excimer absorption band located in visible region (400–500 nm).

Molybdenum oxide nanocomposites with layered structures were prepared directly from commercial bulk MoO 3 using alkylamines as the guests. By using molybdenum oxide-amines as the starting materials, novel molybdenum oxide–dye composite was synthesized. On the basis of X-ray diffraction, scanning electron microscopy and infrared results, a possible arrangement of alkylamines guests in the interlayer space of molybdenum oxide has been proposed. Moreover, the interactions between the inorganic host and the organic guests have been discussed. A linear relationship is observed between the interlayer distance and the number of carbon atoms in n -alkyl chains.

The PEG6000/nano- Ni ( OH )2 sol was prepared by modified sol–gel method. The effect of Ac - on Ni ( OH )2 colloidal particles and the structure of PEG6000/nano- Ni ( OH )2 was investigated. The results show that hydrogen bonds or other weak interaction forces between PEG6000 and Ni ( OH )2 can change the zeta potential of the Ni ( OH )2 surface and enhance the colloidal stability of Ni ( OH )2. The stable region of the PEG6000/ Ni ( OH )2 sol was determined by measuring the viscosity. The ratio of PEG6000 to Ni ( OH )2 is the principal factor that influences the flow patterns of the sol. Surfaces of the thin films prepared from Newtonian sol by sol–gel spin-coating method are smooth while those from pseudoplastic sol are rough. The results establish the theoretical foundation for preparing the nano- NiO thin films by spin-coating method.

In 2 O 3 nanorods were prepared by sol–gel technique with polyethylene octyl phenyl ther (OP-10) controlling their morphology and were characterized by TEM, TG-DSC and XRD. The results indicated that In 2 O 3 nanorods had the length of about 120 nm and the diameter of about 20 nm. The precursor was In 2 O(OH) 4 dry gelatin which was formed by partly dehydrating of In(OH) 3 molecules. The influencing factors and growth mechanism were discussed. The geometry arrangement parameter P of OP-10 was in 1/3–1/2 through calculating, which conformed the shape of claviform micelle.

Tungstosilicates (SiWA), acting as target molecules, were entrapped into MAAM/VTEOS/TEOS hybrid matrix by combining self-assembly technique and sol–gel process. The hybrid film was obtained by spin coating process and was characterized by IR, XRD and TG–DSC. Its photochromic behavior and mechanism were also studied by UV–vis and ESR spectrometries. The results show that SiWA still maintain Keggin structure in the matrix, interacted with –NH 2 group of matrix through hydrogen bond. After UV irradiation, W 6+ is reduced to W 5+ due to ligand-to-metal charge transfer (LMCT) and a free radical is formed at the same time. The decoloration process is closely related to the presence of O 2 . The hybrid film exhibits an excellent photochromism, mechanical strength and thermodynamic stability.

With InCl3·4H2O being used as raw materials, the precursor of nano-sized In2O3 powder was prepared by hydrolysis, peptization and gelation of InCl3·4H2O. After calcination, nano-sized In2O3 powder was obtained. The powder was characterized by thermo-gravimetric and differential thermal analysis (TG-DTA), X-ray diffractometry (XRD) and transmission electron microscopy (TEM), respectively. Calculation revealed that the mean crystalline size increased with increasing the calcination temperature, but crystal lattice distortion rate decreased with the increasing in the average crystalline size. This indicated that the smaller the particle size, the bigger the crystal lattice distortion, the worse the crystal growing. The activation energies for growth of nano-sized In2O3 were calculated to be 4.75 kJ·mol−1 at the calcination temperature up to 500°C; and 66.40 kJ·mol−1 at the calcination temperature over 600°C. TEM photos revealed that the addition of the chemical additive (OP-10) greatly influenced the morphology and size of In2O3 particles.

The dehydrating activation energies of the hematite with several doped ions used for the alcohol sensor were determinated by thermogravimetric differential thermal analyzer (TG-DTA) and the grain size of the samples were observed with TEM. The hematites with different doping amounts of Sn4+ were investigated by Mossbauer spectrometer. It shows that the different doped ion is of influence for grain growth of the hematite. The decrease of grain size stemmed from the doped ion causes gas sensitivity for alcohol to increase and the dehydrating activation energy to decrease correspondingly. When the different amounts of Sn4+ is doped in hematite, the microstructure of the hematite can be influenced.

Nanometer-sized SnO2 particles were prepared by a sol-gel method using inorganic salt as a precursor material. Its crystallization was investigated by means of TG-DTA, IR absorption spectra, X-ray diffractometry and TEM as well as its resistivity change and the gas sensitivity varied with temperature were measured in various reducing gas. The results indicate that well-crystallized nano-sized SnO2 with size around 15nm can be obtained at annealing temperature 600°C. The activation energy for the growth of nano-SnO2 was calculated to be 26. 55kJ. mol−1 when the annealing temperature was higher than 500°C. The measurements also show that there is a peculiar resistance change varied with temperature for nano-SnO2. It has relevance to the increase in surface adsorbed oxygen. The selective detectivities to C4H10 and petrol can be increased when ruthenium ion was doped in nano-SnO2 as a catalyst and so do the gas sensitivity to CO, CH4, H2etc. when rhodium ion was doped in. The detection to the several reducing gas can be realized when the temperature ranged from 260°C to 400°C.

Square-shaped single-crystalline SnO(2) nanowires and their sphere-like hierarchical structures were synthesized successfully with a template-free hydrothermal approach. It was found that an intermediate phase-Na(2)Sn(OH)(6)-is first produced because it is slow to dissolve in ethanol/water media. The intermediate phase gradually decomposes and converts into SnO(2) at temperatures higher than 200 °C. The reaction temperature also affects the microstructure of SnO(2) nanomaterials. Uniform square-shaped SnO(2) nanowires, which form sphere-like hierarchical structures in 100% structure yield, can be produced at 285 °C on a large scale. The diameter of the nanowires shows a decrease accompanying the increase of the reaction temperature. The temperature effect could be a result of the faster and oriented growth of SnO(2) nanowires along their [Formula: see text] direction at higher temperature. Chemical sensors constructed with square-shaped SnO(2) nanowires exhibit excellent stability, good sensitivity and selectivity, as well as a quick response and short recovery times under exposure to acetone gas in practical applications.

We present a semiconductor gas sensor based on mesoporous In2O3(m-In2O3). The m-In2O3was successfully fabricated by a simple sol-gel process, using block copolymer PE6800 as a soft template. The results of gas sensing reveal that the m-In2O3prepared at room temperature shows higher resistance, which plays the key role in its greater sensitivity. The pore structure of material has an influence on gas adsorption on the material surface, which further affects response-recovery time of gas sensor.

The stabilizing conditions of W/O microemulsion of Tx-6∼C4H9OH/c-C6H12/H2O system were studied by visual observation. The result shows that when the weight ratio of Tx-6 to C4H9OH is 4:1, the W/O microemulsion system has stabilizing and extensive regions, and the system is insensitive to the values of pH and in the range of room temperature. In accordance with the theoretical value of HLB.the suitable value of HLB for Tx-6 and C4H9OH to compose microemulsion is greater than 9, less than or equal to 10.

Nanometer ZnO gas sensing material with different particle size were made by chemical precipitation, emulsion and microemulsion, respectively. Crystal structure and ceramic microstructure of powders were determined by XRD and TEM. The mean grain size and lattice distortion of the materials were calculated with the Cauchy–Cauchy and Debye–Scherrer methods, respectively. Gas sensitivity of ZnO to H2, SF6, C4H10, gasoline, C2H5OH was measured. It can be shown from experimental results that grain size of ZnO gas-sensitive materials can be controlled by means of different processes or surfactants. The gas sensitivity of ZnO gas sensor depends upon its grain size.

Pure ZnO powder was made by chemical precipitation. ZnO-based gas sensing materials and Al 2 O 3 -based catalysts doped with a noble metal were prepared with impregnation. Gas sensitivity of ZnO single layer and double layer film gas sensors was measured in static state. It can be shown from experimental results that the gas sensitivity and selectivity of ZnO gas sensor can be improved by doping noble metal and using noble metal catalyst coating.

Nanometer-sized SnO 2 particles were prepared by a sol–gel method using inorganic salt as a precursor material. The investigated results indicate that well-crystallized nano-sized SnO 2 with size around 15 nm was obtained at annealing temperature 600°C. The activation energy for the growth of nano-SnO 2 was calculated to be 26.55 kJ mol −1 when the annealing temperature was higher than 500°C. The measurements also show that there is a peculiar resistance change as a function of temperature for nano-SnO 2 . It has relevance to the increase of surface adsorbed oxygen. The selective detection for C 4 H 10 and petrol can be increased when ruthenium ion was doped in nano-SnO 2 as a catalyst. The gas sensitivity to CO, CH 4 , H 2 , etc., can be increased when rhodium ion was doped in nano-SnO 2 as a catalyst and the detection to the several reducing gas can be realized ranging in temperature from 260°C to 400°C.

The LiV 3 O 8 samples with different morphologies have been successfully prepared by a mixed hydrothermal–sol–solid-state route via the reaction of vanadium pentoxide(V 2 O 5 ) and lithium hydrate(LiOH) at 200 °C in basic medium and subsequent gelation at 100 °C and thermal treatment at 300–550 °C. The crystal structure and morphology of the samples were characterized by X-ray diffraction (XRD), specific surface area measurements and scanning electron microscopy (SEM). Their electrochemical properties were investigated by means of constant charge/discharge cycling measurement. The results indicated that the calcination temperature has a significant effect on the crystal structure, morphology, and specific surface area of the LiV 3 O 8 samples, which consequently affects their electrochemical performance such as the initial capacity and the cycleability. The sample heat-treated at 300 °C shows the morphology of irregular blocks with low degree of crystallinity and high specific surface area, exhibiting high initial discharge capacity of 277.7 mAh g −1 but a fast capacity fade. In contrast, the samples annealed at higher temperature with perfectly uniform rod-like morphology show much better cycle performance.

Hollow SnO2 microspheres with diameters ranging from 300–500 nm have been prepared via a simple template-free hydrothermal method in ethanol–water mixed solution. X-ray powder diffraction (XRD), sc...

CdSnO3 micro-cubes with porous architecture were obtained exclusively via a simple co-precipitation method at 80 °C for 6 hours, with which a good response to ethanol vapor in ppb was observed.

Single-crystalline ZnO nanowires were synthesized, and further modified with Pd nanoparticles through self-assemblies. The self-assembly strategy shows advantages of tailoring the surface modification of ZnO nanowires with monodispersed Pd nanoparticles and further tuning of the functionalities of nano-architectures. It was found that poly(vinylpyrrolidone) (PVP) plays a key role in loading Pd nanoparticles onto the surfaces of ZnO nanowires. Having been turned into chemical sensors, the nano-architectures constructed from ZnO nanowires and Pd nanoparticles exhibit a highly enhanced response to H2S gas, compared to the devices from pure ZnO nanowires.

Corundum-type In2O3 nanorods were synthesized under ambient pressure by annealing, at 600 ◦ C, orthorhombic InOOH nanorods obtained by solvothermal reaction. The samples were characterized by x-ray diffraction (XRD) and transmission electronic microscopy (TEM), and their gas sensitivities were obtained. The results of XRD and TEM experiments show that solvent and surfactants have significant effects on the formation and morphology of the metastable phase during the synthesis of the precursor. The gas-sensitivity results show that hexagonal In2O3 nanorods are very sensitive to dilute ethanol and H2S. (Some figures in this article are in colour only in the electronic version)