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In this study, piezoelectric zinc oxide (ZnO) thin film was deposited on the Pt/Ti/SiNx/Si substrate to construct the FBAR device. The Pt/Ti multilayers were deposited on SiNx/Si as the bottom electrode and the Al thin film was deposited on the ZnO piezoelectric layer as the top electrode by a DC sputtering system. The ZnO thin film was deposited onto the Pt thin film by a radio frequency (RF) magnetron sputtering system. The cavity on back side for acoustic reflection of the FBAR device was achieved by KOH solution and reactive ion etching (RIE) processes. The crystalline structures and surface morphologies of the films were analyzed by X-ray diffraction (XRD) and field emission scanning electron microscope (FE-SEM). The optimized as-deposited ZnO thin films with preferred (002)-orientation were obtained under the sputtering power of 80 W and sputtering pressure of 20 mTorr. The crystalline characteristics of ZnO thin films and the frequency responses of the FBAR devices can be improved by using the rapid thermal annealing (RTA) process. The optimized annealing temperature and annealing time are 400 °C and 10 min, respectively. Finally, the FBAR devices with structure of Al/ZnO/Pt/Ti/SiNx/Si were fabricated. The frequency responses showed that the return loss of the FBAR device with RTA annealing was improved from −24.07 to −34.66 dB, and the electromechanical coupling coefficient (kt2) was improved from 1.73% to 3.02% with the resonance frequency of around 3.4 GHz.

Commercial TiO2 photocatalyst P25 was first used as a support to prepare Ag-deposited catalysts by adsorbed-layer nanoreactor synthesis (ANS). Characterizations were performed by UV–vis diffuse reflectance spectroscopy, TEM, XRD, XPS, PL spectroscopy, and photo-electrochemical analysis. Results showed that Ag nanoparticles with size of less than 10 nm distributed very homogeneously on the TiO2 surface. The adsorption layer on the TiO2 surface acting as a nanoreactor led to tight interaction between quantum-size Ag particles and the TiO2 surface, thereby introducing staggered heterojunction structures into the catalysts. The heterojunction between quantum-sized Ag particles (less than 10 nm) and TiO2 led to the surface plasmon resonance effect and strong visible-light response of catalysts. Ag deposition further caused distortions in TiO2 crystal lattices. Both the heterojunction and TiO2 lattice distortions enhanced the separation efficiency of charge carriers, which improved the photocatalytic activity for phenol in seawater under visible-light irradiation. The catalyst exhibited high stability and reusability after six cycles because of its morphological stability.

The seawater system is a typical salt water system. A catalyst should overcome the disturbance from the salt ions for an efficient photodegradation of organic pollutants in the seawater system. Commercial photocatalysts (P25) and La3+-doped SiO2–TiO2 prepared using adsorbed-layer nanoreactor synthesis (ALNS) were first used for photodegrading different initial concentrations of phenol in seawater under weak UV light irradiation. The weak adsorption capacities for phenol and the hydrophilic surfaces of the two photocatalysts could not overcome the disturbance of salt ions and thus showed low photocatalytic activities. Based on this, graphene oxide (GO) was used as a support to prepare TiO2 and La3+-doped TiO2 using ALNS. The solvothermal treatment with alcohol was used as a solvent for both TiO2 crystallization and GO reduction. Results showed that TiO2 nanoparticles with sizes

Systematic studies on noncovalent functionalization of multiwalled carbon nanotubes (MWNTs) were assisted by a series of aromatic dye molecules with different structural characteristics. The effects of molecular structure on the affinities of different dyes to the MWNTs were evaluated. Two main factors have been found to play the key roles for the dye–MWNTs interactions, which are molecular geometry and charge. It was found that molecules with planar structures and high charge load are favored for the adsorption. This work not only demonstrates a simple and effective method to functionalize the sidewalls of carbon nanotubes but also give insight to the adsorption mechanism between the carbon nanotubes and aromatic molecules.

The mechanism of thiophene cracking catalyzed by Bronsted acidic zeolites was computed at the level of B3LYP density functional theory. It was found that this catalytic reaction involves two major steps: (1) protonation of thiophene associated with an electrophilic aromatic substitution to another thiophene in a concerted way to form 2-(2,5-dihydrothiophen-2-yl) thiophene, and (2) C S bond dissociation in 2,5-dihydrothiophene promoted by further protonation. The intermediate, 4-mercapto-1-(thiophen-2-yl)but-2-en-1-ylium, was found to have a CH 2 group close to a C C bond and a SH group, in agreement with the experimental findings. A strong stabilization effect of the zeolite framework on the transition states was found by embedding the 5T cluster into the larger 34T and 56T clusters. The rate-determining step is the electrophilic aromatic substitution.

The first examples of novel bowl-shaped tribenzotriquinacenes (TBTQs) bearing three dithiametacyclophane units within their arene peripheries are reported. The synthesis is based on a C-3v-symmetrical hexakis(chloromethyl)tribenzotriquinacene as the key intermediate and yields the inter-ring metacyclophane-type macrocyclization instead of the intra-ring orthocyclophane-type cyclocondensation. Multiple nucleophilic substitution of the same key intermediate leads to a number of other new 6-fold functionalized tribenzotriquinacenes, some of which may be of interest as readily accessible building blocks for the construction of novel bowl-shaped organic networks. The molecular structures of the novel tris(dithiametacyclophanes) and of the hexakis(chloromethyl)- and hexakis(hydroxymethyl)tribenzotriquinacenes have been determined by X-ray analysis and interesting host/guest aggregation and torsional effects in the solid state are discussed.

An airflow distribution in an ventilation network is changed when an airway resistance in the network is changed by an airflow regulator damaging or an airway collapsing. The occurrence of an abnormal airway will be found by analysing the airflow changes created in the network, if airflows are monitored in several airways. This paper describes the newly developed methods to locate an abnormal airway and estimate the changed value of resistance by means of analysis of the measured airflow data.In the first method the ventilation network is analyzed, measured airflow data being introduced, and the pressure distribution thereby obtained are examined, which enables us to detect the place creating an abnormal airflow resistance and to evaluate the change.The second method utilises a data base of airflow distributions which are calculated in advance for various combination of network resistances.In the case of the occurence of an abnormal airway, it is generally impossible to get the accurate airflow distribution by an ordinary method for ventilation analysis method, because the value of the changed resistance there is unknown. However, it is proved that the correct airflow distribution can be obtained, if measured airflow data are introduced in the ventilation network analysis method proposed in this paper.