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Transition metal oxides/hydroxides are important pseudocapacitive materials for supercapacitors, however, low electron transfer capability and poor long-term cycle stability limit their applications. Constructing transition metal oxide/hydroxide nanoarrays on conducting collectors is an effective way to solve the above problems. In this thesis, CuO nanowires based on carbon cloths (CuO–CCs) were firstly grown by chemical copper plating and thermal oxidation, and then Ni(OH)2@CuO–CCs and Fe2O3@CuO–CCs were constructed by chemical bath deposition and hydrothermal methods, respectively. The ASC device using Ni(OH)2@CuO–CCs as positive electrodes and Fe2O3@CuO–CCs as negative electrodes were assembled. The results demonstrate that the optimal specific capacities of Ni(OH)2@CuO–CCs and Fe2O3@CuO–CCs are 2.282 F cm−2 (at 1 mA cm−2) and 0.772 F cm−2 (at 2.5 mA cm−2), respectively. The ASC device reaches the energy density of 81.12 Wh kg−1 at a power density of 2.88 kW kg−1, and exhibit the capacitance maintenance of 97.9% after 10,000 cycles.

Aiming to lower the activation energy and expedite the oxygen reduction reaction (ORR) process of La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) cathodes for application in intermediate-temperature solid oxide fuel cells (IT-SOFCs), Er0.4Bi1.6O3 (ESB) modified LSCF was prepared by infiltrating using organic solvents. The infiltration of ESB dramatically reduces the polarization resistances of LSCF cathodes (from 0.27 to 0.11 Ω cm2 at 700 °C, from 0.58 to 0.25 Ω cm2 at 650 °C), and lowers their activation energy (from 100.28 to 97.15 kJ mol−1). Also, ESB makes the rate-limiting step of LSCF cathodes at high frequency change from the charge transfer process on the cathode to the adsorption and diffusion of oxygen on cathode surface. The single cell with ESB infiltrated LSCF cathodes shows a peak power density of 469 mW cm−2 at 700 °C using humid hydrogen and air as fuels and oxidants, respectively, as well as a good short-term stability for 50 h.

Ce0.8Sm0.1Bi0.1O2-δ-BaCe0.8Sm0.1Bi0.1O3-δ (BiSDC-BCSBi) composites are fabricated as novel electrolytes for intermediate-temperature solid oxide fuel cells (IT-SOFCs). Both dramatically enhanced sinterability and electrical performance are obtained due to the Bi doping. BiSDC-BCSBi composites are densified at as low as 1200 °C, allowing a decrease of 350 °C compared with Ce0.8Sm0.2O2-δ-BaCe0.8Sm0.2O3-δ (SDC-BCS) composites. The optimal electrical conductivity of BiSDC-BCSBi electrolytes measured at 600 °C in humid air reaches up to 27.97 mS cm−1, almost 6 times higher than that of SDC-BCS electrolytes (3.91 mS cm−1 in humid air), which is mainly attributed to their lower sintering temperature, more uniform microstructure, larger tensile strains, and higher concentrations of O–H groups and oxygen vacancies. The electrolyte-supported single cell with BiSDC-BCSBi electrolyte displays a peak power density of 397 mW cm−2 at 600 °C using humid hydrogen as fuel and ambient air as oxidant. These results imply that BiSDC-BCSBi composites have a great application prospect for IT-SOFCs.

Electrostatic spinning precursor fibers with presence of polysilazane and nano-Fe2O3 were herein derived by a thermally-induced polymerization at 1100 °C to prepare Fe-doped SiCN composite fibers. The phases and microstructures were characterized and their influences on properties of permittivity, permeability and electromagnetic waves absorption properties were systematically investigated at 2–18 GHz. During thermal carbonization, the additions of γ-Fe2O3 nanoparticles were in-situ reduced and transformed into core-shell structured Fe@Si3N4 particles, which were homogenously distributed in SiCN composite fibers. The RLmin of SiCN–Fe0.5 composite fibers reached −22.68 dB at 14.4 GHz with the thickness of 1.5 mm and showed a broad effective absorption bandwidth range (RL

The PDCs-SiCN(Fe) ceramics with negative permeability and permittivity (double-negative properties) were synthesized by polymer-derived method with ferric acetylacetonate as additive. The phase composition, microstructure, carbon crystalline state and electromagnetic properties of PDCs-SiCN(Fe) ceramics were analyzed. The results indicated that the double-negative properties of PDCs-SiCN(Fe) ceramics were controlled by the amount of Fe. The minimum reflectivity value (RLmin) of PDCs-SiCN(Fe) ceramics with 7 wt% Fe reached −54 dB in the double-negative frequency range (13.85–14.15 GHz) with 2 mm (thickness). In addition, the peak of the RLmin moved to the low frequency as the thickness increased, indicating the effective absorption band of PDCs-SiCN(Fe) ceramics can be broadened by adjusting the thickness.

Bi1-xSrxFeO3-δ (BSFO, x = 0, 0.1, 0.2, 0.3, 0.4) nanofibers were prepared by the electrospinning technology and evaluated as cathodes for intermediate temperature solid oxide fuel cells (IT-SOFCs). With the increase of Sr doping, the crystal structure changes from rhombohedral to cubic and the average diameter of the fibers decreased from 150 nm to 119 nm. When x = 0.3, BSFO nanofibers possess the lowest polarization resistance (0.137 Ω cm2 at 650 °C, 0.061 Ω cm2 at 700 °C), more than 75% smaller than that of BSFO nanopowders with the same composition (0.771 Ω cm2 at 650 °C, 0.282 Ω cm2 at 700 °C). The maximum power density of single cells with BSFO nanofiber cathode reaches up to 663.81 mW cm−2 at 700 °C using wet hydrogen (3 wt%) as fuels. The combination of element doping and microstructure optimizing is proven to be an effective approach for developing high-performance cathodes for IT-SOFCs.

High quality Er,Yb:CaGdAlO4 (Er,Yb:CALGO) single crystals with a diameter around 1 mm were successfully grown and investigated for the first time by the laser heated pedestal growth (LHPG) method. The cracking mechanism of (001) planes was studied via density functional theory (DFT). The doping concentration of Er3+ and Yb3+ was calculated by X-ray fluorescence analysis (XRF). The XRD pattern confirms that the phase of Er,Yb:CALGO is consistent with pure CALGO and the crystal quality was measured through Laue back-reflection measurements. The optical properties including absorption spectra, mid-infrared fluorescence spectra and fluorescence lifetime of the Er3+, Yb3+ co-doped CALGO crystal were measured at room temperature to assess its potential for improving absorption efficiency. Further research found that the disordered structure of the CALGO crystal could achieve wider absorption and emission bands accompanied with efficient energy transfer from the excited Yb3+ to Er3+. Our results indicated that the Er,Yb:CALGO crystal is a promising material for achieving tunable mid-infrared lasers.

Zeolitic imidazolate framework-8 (ZIF-8) nanoparticles with tunable diameters and a uniform morphology were constructed in dimethyl sulfoxide (DMSO)/H2O mixed solvents and were further decorated with dextran to improve their stability and biocompatibility. A series of reaction conditions, including the DMSO content in mixed solvents, molar ratio between precursors, growth time, and decoration of dextran, were systematically investigated. Most importantly, it was the union of DMSO and water that achieved the combined merits of both solvothermal and hydrothermal methods, namely, high uniformity and high efficiency, respectively. In addition, numerous properties of these ZIF-8 nanoparticles were subsequently studied, such as the crystal structure, surface properties, and porosity. Furthermore, composite ZIF-8 nanoparticles encapsulating various functional molecules were also successfully prepared in the same DMSO/H2O mixed solvents, thus laying the foundation for their application as nanocarriers in the biomedical field.

Single-crystal fiber (SCF) combines the advantages of bulk crystal and glass fiber gain media and shows broad application prospects in all-solid-state lasers. In this work, high-quality crack-free Nd:YAG SCFs with diameters of 0.8–1 mm were successfully grown by the micro-pulling-down (μ-PD) method. The as-grown SCFs showed homogeneous Nd3+ distribution, with a diameter fluctuation of less than 5%. The X-ray Laue patterns on the different crystal positions also revealed good crystalline consistency. Moreover, the core stress problems were investigated in terms of growth orientation to improve the crystal quality, and seed crystals with orientation of , and to 15° were used for crystal growth. Continuous-wave laser operations at 1064 nm were realized with the as-grown Nd:YAG SCFs. The maximum output of 8.32 W with a laser beam quality factor M2 = 1.08 was achieved.

Herein, bulk single crystals of Er:Y3Sc2Ga3O12 (Er:YSGG) with a maximum diameter of 35 mm or a maximum length of 100 mm were successfully grown by the Czochralski method using a 60 mm diameter crucible. The high-resolution X-ray diffraction and optical interferometry results indicated that the as-grown crystals were of high quality. The crystalline perfection of the as-grown crystal was evaluated to be 20.58′′ via the FWHM of the rocking curve, and the optical homogeneity RMS was in the order of 10−6. A continuous wave laser of the Er:YSGG crystal operating at 2798.7 nm has been demonstrated. Moreover, a maximum output power of 745 mW has been realized. The achieved maximum slope efficiency is 31.5%, which is, to date, the highest slope efficiency in the Er:YSGG crystal lasers operating at ∼2.8 μm.

Impressive developments have been achieved with the use of zeolitic imidazolate framework-8 (ZIF-8) as nanocarriers for tumor theranostics in recent decades by incorporating imaging agents and therapeutic drugs within ZIF-8. However, the simultaneous immobilization of hydrophilic and hydrophobic functional molecules into ZIF-8 nanoparticles in water or organic solvents still presents a daunting challenge. Herein, we developed a new synthesis/encapsulation two-in-one (denoted as one-pot) approach to synthesize uniform dextran-modified Cy5.5&ICG@ZIF-8-Dex nanoparticles in DMSO/H2O solvent mixtures, which enabled the simultaneous encapsulation of hydrophilic indocyanine green (ICG) and hydrophobic cyanine-5.5 (Cy5.5) during the same step. It was confirmed that the one-pot approach in this mixed solvents facilitated the loading of ICG and Cy5.5 molecules. Moreover, the encapsulation of Cy5.5 and ICG within ZIF-8 nanoparticles endowed them with fluorescence imaging capability and photothermal conversion capacity, respectively. The in vivo near-infrared (NIR) fluorescent images of A549-bearing mice injected with Cy5.5&ICG@ZIF-8-Dex demonstrated sufficient accumulations of Cy5.5 at tumor sites due to the enhanced permeability and retention effect. Most impressively, the fluorescent intensity of Cy5.5&ICG@ZIF-8-Dex at tumor site was approximately 40-fold higher than that of free Cy5.5. Additionally, the results of in vivo infrared imaging and photothermal therapy of Cy5.5&ICG@ZIF-8-Dex showed enhanced therapeutic efficiency in comparison with free ICG, further confirming its tumor-targeting capability and photothermal capacity. Therefore, this multifunctional system based on ZIF-8 nanocarriers offered a potential nanoplatform for tumor-targeting theranostics, thus broadening the synthesis and applications of ZIF-8 composite nanoparticles for NIR fluorescence imaging and photothermal therapy in the biomedical field. STATEMENT OF SIGNIFICANCE: Simultaneous immobilization of hydrophilic and hydrophobic molecules into ZIF-8 nanoparticles still remains a daunting challenge. Therefore, we have developed a new synthesis/encapsulation two-in-one approach to synthesize uniform Cy5.5&ICG@ZIF-8-Dex composite nanoparticles in DMSO/H2O solvent mixtures, which enabled the simultaneous encapsulation of hydrophilic indocyanine green (ICG) and hydrophobic cyanine-5.5 (Cy5.5) functional molecules during a single step. The results showed that the co-loading of Cy5.5 and ICG within the ZIF-8 nanoparticles endowed them with a remarkable fluorescence imaging capability and photothermal conversion capacity. Based on their enhanced convenience and efficacy to simultaneously encapsulate hydrophilic and hydrophobic molecules, the multifunctional nanocarriers that were prepared in the DMSO/H2O mixed solvents provide a potential nanoplatform toward fluorescence imaging and photothermal therapy for tumor theranostics.

Flow over a fish-like airfoil is numerically investigated to elaborate the hydrodynamics of the undulatory braking locomotion for an elongated eel-like body or long-based fin. For undulation with low frequency, we find that boundary layer separation occurs in a parameter region with wakes in which two vortex pairs are formed per undulatory period. The physical mechanism of separation is governed by the slip (the ratio of swimming-to-body-wave speed), and the critical value of the slip in an inertial flow regime is approximately 4/3 rather than 1, which is independent of steepness (or amplitude). The relationship between pressure drag and relative velocity (between phase speed and free stream velocity) changes from linear to quadratic, corresponding to two different flow structures; this happens due to boundary layer separation, and the piecewise scaling relationship between pressure drag and relative velocity is explicitly clarified. Considering the viscosity effects, the separation criterion and the scaling relationship in the case of an undulatory brake are both synthetically modified using the Reynolds number, with all the required parameters clearly expressed. The results of this study provide physical insight into understanding the flow structures and hydrodynamics of the undulatory braking locomotion, which has instructional significance to brake design.

The spontaneous assembly of nanoscale building blocks into continuous semipermeable membranes is a key requirement for the structuration of synthetic protocells. Engineering the functionality and programmability of these building units provides a step toward more complex cell-like entities with adaptive membrane properties. Inspired by the central role of protein (lectin)-carbohydrate interactions in cellular recognition and adhesion, we fabricate semipermeable polysaccharide-polymer microcapsules (polysaccharidosomes) with intrinsic lectin-binding properties. We employ amphiphilic polysaccharide-polymer membrane building blocks endowed with intrinsic bio-orthogonal lectin-glycan recognition sites to facilitate the reversible noncovalent docking of functionalized polymer or zeolitic nanoparticles on the polysaccharidosomes. We show that the programmed attachment of enzyme-loaded nanoparticles gives rise to a membrane-gated spatially localized cascade reaction within the protocells due to the thermoresponsiveness of the polysaccharidosome membrane, and we demonstrate that extended closely packed networks are produced via reversible lectin-mediated adhesion between the protocells. Our results provide a step toward nanoscale engineering of bioinspired cell-like materials and could have longer-term applications in synthetic virology, protobiology, and microbiosensor and microbioreactor technologies.

Polypyrroles have shown great potential in photoacoustic imaging and photothermal therapy owing to its excellent photothermal conversion capabilities. However, the synthesis of polypyrrole-based nano-assemblies which have colloidal stability in biological buffers requires a number of steps, including the polymerization of pyrrole monomers, self-assembly of polypyrrole-based copolymers, and even an additional step to increase the biocompatibility of the nano-assemblies. Herein, a "polymerization/assembly" two-in-one synthesis is proposed for the first time to achieve the one-step synthesis of a new family of polypyrrole-based nano-assemblies, dextran-polypyrrole nano-assemblies (Dex-PPy NAs), under ambient conditions and in aqueous media. In addition, the approach employs tetravalent cerium ions as initiators which can initiate the polymerization of pyrrole monomers through the initiation of free radicals from dextran molecular chains. The resultant Dex-PPy NAs have a photothermal conversion efficiency reaching as high as 41 % and an excellent photostability. More importantly, the NAs with controllable nanoscale dimensions display no signs of cytotoxicity in both in vitro and in vivo studies owing to their biocompatible dextran "shell". An in vivo study further confirmed that the Dex-PPy NAs have excellent real-time photoacoustic imaging and photothermal therapy capabilities for malignant tumors. Therefore, this study represents an important step towards the scalable synthesis of polypyrrole-based nano-assemblies with photothermal/photoacoustic dual capabilities and enhanced biocompatibility.

Highly efficient continuous-wave (CW) and passively Q-switching Er:YSGG lasers at around $2.8~\mu \text{m}$ were demonstrated. In the CW regime, a maximum output power was 514 mW with the dual-wavelength of 2795 and 2825 nm. The slope efficiency and optical-optical conversion efficiency were as high as 31% and 23%, respectively. Adopting black phosphorus as saturable absorber, a maximum output power of the passively Q-switched Er:YSGG laser was 240 mW, with a corresponding slope efficiency up to 15.8%. The shortest pulse duration was 293 ns, and the repetition rate was 109.1 kHz. The results indicated that Er:YSGG crystal would be a promising mid-infrared gain medium for high-efficiency laser operation.

Device-size Nd3+:(LuxGd1−x)3Ga5O12 (Nd:LGGG) single crystal plates have been grown by edge-defined film-fed growth (EFG) method for the first time. The problems encountered during the crystal growth have been discussed and solved, resulting in a single crystal plate with a length of 180 mm. In particular, the evaporation loss of Ga2O3 composition during the crystal growing has been depressed efficiently by using an Ir lid. The crystal perfection was confirmed by X-ray rocking curve with a FWHM of the 32 arcsec, meaning a high crystalline quality. It was very interesting to find that the distribution of Nd3+ in the crystal grown by EFG method was more homogeneous than that in Cz method, benefitting from the larger segregation coefficient of Nd3+ in EFG method. The thermal conductivity was measured to be 8.1 W m−1 K−1 at room temperature. All the properties showed that the Nd:LGGG crystal plates grown by EFG method were promising for high power laser application.

β-Ga2O3 is an ultra wide-bandgap semiconductor with promising applications in high voltage and temperature electronic devices and deep-ultraviolet optoelectronic devices, and has attracted lots of attention recently. However, there are still many unknowns about the basic properties needed to be explored urgently, which are very important and necessary for the devices design and application. In this work, bulk β-Ga2O3 single crystals with a width of 1 inch were grown by using an optimized edge-defined film-fed growth (EFG) method under Ar plus 50% CO2 atmosphere. High crystalline quality of the as grown crystal has been demonstrated by the high-resolution X-ray diffraction with 43.2 arcsec of the full width at half maximum (FWHM). The fundamental physical properties of different orientated samples, including thermal properties as a function of temperature up to 500 °C, electrical properties, refractive index and hardness were investigated systematically. Moreover, the measurement showed that aluminum turned out to be a good Ohimc electrode for n-type β-Ga2O3 single crystal.

High-quality bulk β-Ga2O3 single crystals have been grown by optimized edge-defined film-fed growth (EFG) method. The problems of cracking and polycrystals have been effectively solved by using a high-quality 1 inch-wide seed. The crystalline quality of the as-grown crystal has been confirmed by X-ray rocking curve with a full-width at half-maximum (FWHM) of 42.1 arcsec. Moreover, an economical and efficient one-step mechanical exfoliation method has been proposed to get epi-ready β-Ga2O3 wafers directly. The root mean square (RMS) roughness of the wafers is noted to be around 0.1 nm, which means they are comparable or even better than wafers processed by chemical mechanical polishing (CMP). The mechanism of the exfoliation method is analyzed from a crystallographic view. A photodetector is fabricated on the exfoliated wafer directly and the device is proved to show good performance in solar-blind band.

Considering their easy growth and doping in bulk crystal growth, and good crystalline quality, ?-Ga2O3 single crystals, a very important wide-bandgap semiconductor, are now also considered to be a promising optical crystal candidate. In this work, a Cr4+:?-Ga2O3 single crystal has been grown successfully by the edge-defined film-fed growth method. The thermal conductivity of Cr4+:?-Ga2O3 has been measured along the a* direction at room temperature obtaining 16.2 W m-1 K-1, and it was much larger than that of the usually used Cr4+-doped crystals, such as Y3Al5O12 (YAG) or YVO4. The Raman spectrum indicated that the cutoff phonon energy of the ?-Ga2O3 crystal was 767.8 cm-1. A passively Q-switched nanosecond pulsed Nd:YAG laser based on a Cr4+:?-Ga2O3 saturable absorber was experimentally demonstrated for the first time to our knowledge and its mechanism is explained by first-principles calculations. By inserting the Cr4+:?-Ga2O3 crystal into the Nd:YAG laser cavity, a Q-switched laser operation was obtained with a maximum average output power of 50 mW. The corresponding pulse repetition rate, pulse width, and pulse energy were determined to be of 421.5 kHz, 235.2 ns and 0.12 ?J, respectively.

CaGdAlO4 (CGA) single crystals have been grown in different oxygen concentration atmospheres by the Czochralski method. Crystals grown under an oxygen-containing atmosphere presented an inconsistent brown coloration. The origin of coloration was studied by density functional theory, and the simulated results show the oxygen defects and the absorption matched well with the experimental results. The brown coloration of CGA is due to the interstitial oxygen atoms. The fundamental properties of CGA crystals with different colors, including the crystal density, hardness, thermal and optical properties, were systematically investigated and compared when taking into account the effect of color center inside. The colorless CGA was grown under an inert gas atmosphere and exhibits a wide transparency range of 227–7140 nm. The maximum phonon energy was determined to be as low as 618 cm−1. The colorless CGA host crystal with a disordered structure, good thermal conductivity, low maximum phonon energy and wide transparency is promising for ultrafast ultraviolet and visible laser applications.

Single crystal fibers of 30% Er3+-doped compound of Y3(ScxGa1&minus, x)5O12 have been grown by using the micro-pulling down (&mu, PD) technique successfully. Our main purpose is to tune the fluorescence properties by adjusting the ratios of Sc3+ and Ga3+ ions inside the matrix crystals. The crystal structures of the series compounds were measured and analyzed through X-ray diffraction (XRD) measurements. The components and doping elements distributions were measured by the X-ray Fluorescence spectrometry and electron-probe microanalyzer. The absorption and mid-infrared fluorescence spectra, including the fluorescent lifetime of Er3+:4I13/2 and 4I11/2 levels were measured and compared systematically at room temperature. Spectral analysis indicated that the fluorescent lifetime of Er3+:4I13/2 tended to shorten and the emission spectra began to show a red shift when the proportion of YSG increased in the compound. Furthermore, the Raman spectra were measured to reveal the variations of lattice vibration and phonon energy.

Gehlenite crystal, Ca2Al2SiO7 (CAS) crystal is found to be appropriate material to high temperature piezoelectric sensors, for its high electrical resistivity and high temperature stability of piezoelectric coefficients. But the challenges of growing high quality single crystal and the fragile characteristics limited its broad application and mass production in future. In this paper, a new member of the melilite family, bulk Ca2Al2-xGaxSiO7 (CAGS) single crystal, was successfully grown by the Czochralski (Cz) method, without any bubble, inclusion and cracking. By a small fractional of gallium substitution, we obtained a new potential high temperature piezoelectric single crystal CAGS with larger pulling rate (more than twice that of CAS), and better quality of single crystal. Furthermore, the dielectric and piezoelectric properties of CAS and CAGS single crystals were measured and compared. The measured piezoelectric coefficient d14 of CAGS single crystal is 10.52 pC/N which is much higher than that of CAS (6.68 pC/N). The electrical resistivity of CAGS was found to be remarkably high, reaching a value of ∼2.3 × 109 Ω cm at 600 °C.

As we know, Ti3+:Al2O3 is a very famous crystal for ultrafast and tunable lasers. However, it also has disadvantages including small segregation coefficient and short fluorescence lifetime of Ti3+. For comparison, Ti-doped ?-Ga2O3 (Ti3+:?-Ga2O3) single crystals with good spectral properties have been designed and grown successfully by edge-defined film-fed growth method with larger segregation coefficient and longer fluorescence lifetime. The segregation coefficient of Ti3+ ions in the Ti3+:?-Ga2O3 crystal was calculated to be 0.49, which was much larger than that in Ti3+:Al2O3 (0.2). The thermal conductivity of Ti3+:?-Ga2O3 crystal was measured to be 24.7 W/mK along the ?010? direction at room temperature, which is very attractive as a laser crystal. Furthermore, the polarized absorption spectra and fluorescence spectra of Ti3+:?-Ga2O3 were measured and analyzed. The full width at half-maximum of the emission peak was as large as 140 nm. The fluorescence lifetime was up to 176 ± 5 ?s, which was about 50 times longer than that of Ti3+:Al2O3. All the properties indicate that Ti3+:?-Ga2O3 is a potential material for ultrafast and tunable laser applications.

Pr:CaGdAlO4 (Pr:CGA) crystals have been grown and investigated for the first time. A Na+ flux was designed to improve the crystal quality in the Czochralski growth process. The effect of the addition of the Na+ flux on crystal quality has been investigated, and its beneficial impact on the crystallinity, optical homogeneity and thermal properties of the grown crystals has been demonstrated. The optical spectra of Pr:CGA have been measured in order to assess its potential for photonics applications. The intensities of the absorption transitions have been analyzed by means of the Judd–Ofelt approach and the intensity parameters, the branching ratios and the radiative lifetimes of the emitting states have been evaluated. These have been compared with the experimental values obtained from pulsed light measurements. All the properties indicate that the Pr:CGA crystal has great prospects in the applications of visible lasers.

Yb:CaLuxGd1−xAlO4 (Yb:CLGA) crystals have been grown and studied for the first time. A more disordered structure than that of the Yb:CaGdAlO4 (Yb:CGA) crystal was designed by introducing Lu3+ ions into the crystal. The absorption spectra at 9.6 K provided clear evidence for the disordered structure of the Yb:CLGA crystal. Moreover, further spectral broadening was achieved compared to that of the Yb:CGA crystal. The crystal quality and spectroscopic properties of the Yb:CLGA crystal with the highest degree of disorder were investigated in detail. Improved ultrafast laser oscillators, in terms of narrower pulse width and higher peak power, are expected with this modified crystal.

Bulk TbCa4O(BO3)3 single crystals with diameter of 25 mm and length of 70 mm were successfully grown by the Czochralski (Cz) method for the first time to the best of our knowledge. The main problems of crystal growth were discussed and solved resulting in a high quality crystal. The crystalline perfection of the as-grown crystal was evaluated with full-width at half-maximum (FWHM) of the rocking curve being 35.05′′, and the optical homogeneity being 7.76 × 10−5. TbCa4O(BO3)3 crystallizes in the monoclinic space group Cm with unit cell parameters of a = 8.0715(7) A, b = 16.0000(15) A, c = 3.5454(3) A, and β = 101.2550(10)°. Several interesting phenomena of atom occupancy and structure distortion were observed and analysed. Furthermore, the hardness, density, absorption and transmission spectra were measured. The TbCOB crystal has a Mohs hardness value of 5.58, and it exhibits a high transparency ranging from 490 nm to 1500 nm.

Data synchronization technology is one of the key technologies of data storage in distributed database. At present, it is an effective method to achieve data synchronization between source database and target database by capturing incremental data and transferring incremental files. Based on the research of Oracle database and the analysis of commonly using incremental data capture methods, this paper designed DML trigger and incremental data identification table to store incremental identification data in the identification table, and generated incremental XML files for network transmission according to the identification table. Finally, the feasibility of this method was tested. Tests showed that the method was reliable and stable, and could be applied to data synchronization in distributed databases.

A systematical investigation of the spectroscopic and ultrafast performance of Yb:CaLu x Gd1−x AlO4 crystal (Yb:CLGA) was reported first in this work. A SESAM-based mode-locking laser was achieved by self-starting, generating reliable pulses as short as 69.6 fs. At a central wavelength of 1054 nm, a maximum average output power of 232 mW was obtained with the highest peak power of 63.7 kW. The same crystal was employed in wavelength tunable operation, and 65.7 nm of tuning range between 1023.1 nm and 1088.8 nm was obtained with a resolution of sub-0.1 nm.

In this Letter, a high-quality, few-layered black phosphorus (BP) saturable absorber (SA) was fabricated successfully, and a femtosecond solid-state laser modulated by BP-SA was experimentally demonstrated for the first time, to the best of our knowledge. Pulses as short as 272 fs were achieved with an average output power of 0.82 W, corresponding to the pulse energy of 6.48 nJ and peak power of 23.8 MW. So far, these represent the shortest pulse duration and highest output power ever obtained with a BP-based mode-locked solid-state laser. The results indicate the promising potential of few-layered BP-SA for applications in solid-state femtosecond mode-locked lasers.