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The mixed-phase MoS2 (1T/2H MoS2) with heterostructure exhibited high catalytic activity. The specific ratios of 1T/2H could exhibit optimal performance in various applications. Therefore, more methods need be developed for synthesizing 1T/2H mixed-phase MoS2. Herein, a viable route was studied for the phase transition of 1T/2H MoS2 regulated by H+. Briefly, the commercially available bulk MoS2 was used to obtain 1T/2H MoS2 via chemical intercalation of Li+. Then the residual Li+ around 1T/2H MoS2 was replaced by H+ in acidic electrolytes, owing to the extremely higher charge-to-volume ratio of H+. Thus, the thermodynamically unstable 1T phase lost the protection of residual Li+ and could be re-transforming into the relatively stable 2H phase. The change of the 2H/(2H+1T) ratio was measured using novel extinction spectroscopy, which provides a rapid identification method in comparison with x-ray photoelectron spectroscopy (XPS). The experimental results revealed that the concentration of H+ influenced the phase transition velocity of MoS2. In particular, the phase transition from 1T to 2H phase in the H+ solution was faster at the beginning, and the higher the H+ concentration in an acidic solution, the faster the increase in 2H content. For an instant, the ratio of the 2H phase was increased by 7.08% in an acidic solution (CH + = 2.00 M) after 1 h, which was several times greater than the case in the distilled water. This finding provides a promising method to easily obtain different ratios of 1T/2H MoS2, which is beneficial for further development of catalytic performance especially in energy generation and storage.

Preservation properties of chitosan (CS) and sodium alginate (ALG) coatings are widely investigated, but their bilayer composite coating application to fish preservation is limited. The aim of present study was to evaluate the quality changes in 4°C turbot fillets treated with a bilayer coating based on lysozyme-CS (LZ-CS) coating layer and ALG coating layer. Changes in total viable counts (TVC), texture profiles, and physiochemical indexes including pH, total volatile basic nitrogen (TVB-N), and K value were examined. The results indicated that bilayer coating was more effective than LZ-CS and ALG monolayer coatings in preservation of turbot fillets. The bilayer coating significant inhibited the increase of TVC, pH, TVB-N, and K value, and maintained better texture characteristics of turbot fillets during storage. Therefore, the bilayer coating on the turbot is more superior to monolayer coatings, which would have potential applications on fish preservation.

Having a continuous mode of transportation, in the manufacturing and pharmaceutical industries, is desirable and this facilitated by the usage of dual transducer-type ultrasonic levitation-based transportation systems. It is well known that the structural and electrical parameters determine what can be transported continuously, but the relationships between these important parameters are still not clear. In this study, the vibrating plate length and the phase shift between the two transducers were investigated as both of these are key parameters for the transportation system, and affect the standing wave ratios (SWRs), the acoustic radiation forces, and consequently the way the transportation system operates. Through numerical analysis and experimental verification, it can be seen that when the sum or difference of the spatial phase difference (determined by the vibrating plate length) and the phase shift is equal to 180° × (1 + 2n) (where n is an integer), except for the spatial phase difference of 180°·m (where m is also an integer) and the SWRs approaches unity, all this implying that traveling waves (TWs) are dominantly excited on the vibrating plate. As a consequence, the TW-induced acoustic radiation force, which greatly exceeds the standing wave-induced force, causes the continuous transportation of the particle being moved in the sound field. This paper not only clarifies the requirements for generating this continuous transportation, but also provides valuable information on the practical design of such a transportation system.

A main way to investigate the biological effects of 50Hz electromagnetic field is to conduct animal experiments by using the simulating device of 50Hz electromagnetic field. In order to determine the exposure strength of experimental animals in rearing cages in simulating device more accurately, the distribution of electric field should be simulated. Based on ANSYS, a software of finite element analysis, we simulated two-dimensional (2D) electric field distribution of the proposed simulating device of high voltage 50Hz electric field for a case when there were no rearing cages, and we validated those simulation results by comparison with actual measurements. Additionally, we simulated three-dimensional (3D) electric field distribution in the rearing cages for the cases when there was one rearing cage and when there were 8 rearing cages in the simulating device respectively. The simulation results showed that distribution of 50Hz electric field in rearing cage was not uniform when there were rearing cages in the simulating device, and the maximum difference was about 9kV/m. Therefore, based on the movement tracking of animals and the distribution of 50Hz electric field in rearing cages, the cumulative exposure dose of experimental animals could be determined accurately through integral method in order to increase the accuracy of experiments.

Our goal is to find out how the passenger number, vehicle type and vehicle displacement influence the PM2.5 concentration in underground parking lots of large shopping centers. To this end, we collected data of PM2.5 concentration in several underground parking lots in CBDs of Changchun. We have some findings from the conducted experiments. First, PM2.5 concentration rises as the the number of passengers carried in the vehicle increases. As for vehicle type and displacement, high-displacement sedans and moderate-displacement SUVs contribute most to PM2.5 concentration inside the parking lots, among which vehicles of older age cause even greater pollution, with PM2.5 concentration averaging 208 μg/m³and 241μg/m³respectively. And high-displacement MPVs have greater influence on PM2.5 concentration than low-displacement ones.

High cycle fatigue experiments were conducted at 600°C to study the effect of manufacture defect on crack initiation behaviour of FGH96. The experiments were performed at different stress levels to considering the coupling effect of loading and defect. The stress ratio was selected at 0.05. The results revealed that the fatigue life behaviour are much different in different loading levels. In order to examine the crack initiation mechanism, Scanning electron microscopy (SEM) method was used to analyze the failure surfaces. Different failure modes including surface cracking, sub surface cracking as well as internal crack initiation were found. The tested fatigue lives were found to have a strong relation with the mode of the crack initiation.

The BESIII inner drift chamber is suffering from aging effect. Cylindrical Gas Electron Multiplier Inner Tracker (CGEM-IT) is considered as one of the upgrade candidates. A simulation study with Garfield++ program has been performed to understand the drift behaviour and to build a full digitization model. Parameters related to Lorentz angle, diffusion effect, drift time, multiplication and induction are obtained from the Garfield++ simulation. A preliminary digitization model is implemented in the BESIII Offline Software System (BOSS) based on those parameters.

Objective: To evaluate the efficacy of alginate oligosaccharides and sodium alginate (seaweed biological glue) after incision drainage for breast abscess. Methods: randomly selected 80 patients with breast abscess, observation group and control group 40 cases, observation group using alginate oligosaccharides, sodium alginate (seaweed biological glue) for postoperative patients with breast abscess incision drainage treatment disposal, the control group with saline treatment disposal, using t test to compare two groups of patients with postoperative incision healing time, switching frequency, the satisfaction degree of the patients of postoperative scar, using chi-square test to compare the postoperative recurrence rate. Results: the incisions of the two groups were completely healed, and the observation group had shorter healing time, fewer drug changes, lower recurrence rate and higher satisfaction to postoperative scars than the control group. Conclusion: the treatment of patients with breast abscess after open and drainage with algal oligosaccharide and sodium alginate (alginate biogel) after operation can significantly shorten the wound healing time of patients, reduce The Times of dressing changes, and improve patients’ satisfaction with scars and reduce recurrence.

Objective to explore the effect of Histoacyl tissue glue (hereinafter referred to as tissue glue) on incision healing in breast surgery. Method review during October 2017 to October 2018, 500 cases of breast surgery to surgical treatment of cases, including 200 cases of tissue glue closed incision, 200 cases of absorbable suture material, 100 cases by traditional suture, comparing three sets of closing time of incision, postoperative hospital stay, complications, patients on art mouth closed satisfaction. Results: the three groups were superior to the absorbable suture material, group and the traditional suture group in the closing-length glue group with statistically significant differences (P

In this paper, fabrication and surrounding refractive index response of a graphene oxide (GO) coated long period grating (LPG) is presented. An improved version of the Hummer's method was followed for the synthesis of GO used in this work and GO sheets were immobilized on the LPG fibre surface by using an electrostatic self-assembly technique. In this initial performance evaluation, intensity and wavelength variations of the transmission loss bands of the GO coated LPG were recorded at room temperature and this sensor probe is introduced as a good candidate for the further development of selective biosensors.

This paper presents the synthesis and characterization of a graphene oxide encapsulated gold nanorod (GNR) complex, where its stability was investigated over time by recording the absorption spectra obtained using a UV/Visible spectrometer over the wavelength region of 200 nm to 1000 nm. Poly Ethylene Glycol (PEG) stablized GNRs were found to be more stable in the presence of graphene oxide dispersions compared to Cetyl Timethyl Ammonium Bromide (CTAB) stabilized GNRs. These GNR complexes, prepared with an active graphene oxide coating on the surface, are presented as a well-suited platform for the development of localized plasmon resonance-based fibre optic biosensors due to the surface functional groups of graphene oxide that can form bio-composites with other biological nanomaterials.

This paper describes a thorough investigation of the NPL Vega BB3500 furnace to improve the quality and duration of the melt plateaux of a Re–C eutectic cell. The results of this investigation have shown that the position of the cell within the furnace is the most critical factor for optimizing fixed-point performance. It was found that better performance could be obtained from a furnace with uniform ring resistance than with highly non-uniform resistance profiles, but this effect was relatively small. When high resistance (hot) rings were deliberately introduced on either side of the cell, at a distance corresponding to several rings beyond the position of the cell, considerable improvement in the plateaux was observed. Nevertheless, the cell (or the cell performance or even plateaux) is very sensitive to the positioning of these hot rings. A new cell holder was designed and introduced. Raising the cell on supporting rings provided a radiative gap that increased the thermal uniformity of the cell itself. Carbon–carbon composite material (CC sheet) wrapped loosely around the cell further improved the uniformity of the cell wall and hence the plateau quality. Following these changes, the plateau duration was increased by a factor of 5. (Some figures in this article are in colour only in the electronic version)

Stochastic optimization is proposed for the pump absorption enhancement in double-clad fibres (DCFs). Monte Carlo forms of the Nelder–Mead (NM) method are proposed and benchmarked against a genetic algorithm (GA) and generalized pattern search (GPS) and mesh adaptive direct search (MADS) methods. A simple sampling NM variant offered the highest efficiency while MADS achieved global convergence with the highest probability in low dimensions. All algorithms examined are described within the pattern search frame while detailed pseudocode descriptions are given in structured functions. Smoothly perturbed patterns are proposed for implicitly constrained optimization in high dimensions. An improved Monte Carlo NM method, based on importance sampling and stochastically perturbed patterns, exhibited global convergence with higher efficiency than MADS in high dimensions. Many polymer and air outer cladding designs are optimized. A circular holey DCF with an optimally offset core and a single large solid-state hole with optimum offset, size and ellipticity offered 180% absorption enhancement over a conventional circular DCF with centred core.

The detection of moisture ingress in concrete is important for structural monitoring and in this work is realised by monitoring the shift in the characteristic wavelength of a fibre Bragg grating-based sensor. The sensor relies upon a moisture-sensitive polymer layer deposited on the fibre Bragg grating (FBG) and the strain induced on it as a result of polymer swelling is monitored. Moisture ingress experiments were carried out using two such optical fibre sensors, placed at varying distances from the edge of the face of standard concrete cubes to the inner part of the concrete sample and subjected to water at a constant temperature. Information on the properties of different types of concrete and thus potentially on the migration of dissolved salts and their effect on reinforcement bars within concrete can be obtained.

peer-reviewed A fluorescence-based temperature sensor system using a digital signal processing approach has been developed and evaluated in operation on a working automotive engine. The signal processing approach, using the least squares method, makes the system relatively insensitive to intensity variations in the probe and thus provides more precise measurements when compared to a previous system designed using analogue phase-locked detection. Experiments carried out to determine the emission temperatures of a running car engine have demonstrated the effectiveness of the sensor system in monitoring exhaust temperatures up to 250oC, and potentially higher PUBLISHED

We report a method to modify Si nanostructures on Si(100) by Ar+ ion sputtering, which we call post ion milling, or PIM. The effect of PIM on the nanodot modification was found to strongly depend on the value of ion flux utilized. For the ion flux of 80 µA cm−2 both the lateral and vertical dot sizes do not change significantly with the milling time, while for the ion flux of 15 µA cm−2 these sizes are dramatically reduced. The effect of PIM is attributed to a surface morphology transition process from a starting steady surface state to a target one. However, the final steady state surface morphology is not necessarily identical to the target one, but influenced by both the starting and target surface morphologies. Our results indicate that, given sufficiently low ion flux and low ion energy, very small nanostructures can be readily achieved via PIM.

We report an ion flux dependence study of the Si dot pattern formed on Si(100) by Ar+ ion sputtering with the ion energy being 1.5 keV, ion dose 5 × 1017 ions cm−2, and ion flux ranging from 280 to 1100 µA cm−2. Experimental results show that the lateral dot diameter d and the ion flux f basically follow the relationship of , and the surface roughness w decreases with increasing f in an exponential decay manner. Simulations based on a widely accepted continuum model, namely the noisy Kuramoto–Sivashinsky equation, reproduced the trend for d versus f but failed to explain that for w versus f. A redeposition consideration was then suggested. It is found that with this correction not only are the d–f and w–f relationships well explained, but the simulated surface morphology bears closer resemblance to the experimental one as well. The effect of redeposition becomes important for f> ~130 µA cm−2 as derived in this work.

A fibre-optic-based humidity sensor has been developed and used for the measurement of moisture absorption in concrete. The sensor was fabricated using a fibre Bragg grating (FBG) coated with a moisture sensitive polymer. To investigate the use of this sensing technique for the detection of moisture ingress in concrete, the sensor was embedded in various concrete samples of different water to cement ratios which were then immersed in a water bath. A direct indication of the humidity level within a sample is given by the shift of the Bragg wavelength caused by the expansion of the humidity-sensitive material coated on the fibre. The sensor itself exploits the inherent characteristics of the FBG, with its operation being based on the strain effect induced in the Bragg grating, through the swelling of the polymer coating. It was found that optical-fibre-based humidity sensors of this type form a basis for determining the changes in the moisture content in different concrete samples, indicating potential new applications of the sensor system to ensure the integrity of civil engineering structures in which they are used.

A computationally inexpensive method for the numerical calculation of the absorption efficiency in double-clad fibres (DCFs) for high power fibre lasers is presented. A three-dimensional (3D) ray tracing technique is used to record the network of ray spatial paths occurring inside the core finite volume elements. Each ray represents a beam of parallel photons that conveys a fraction of the launched pump power. The corresponding energy is space–time propagated along the established spatial path network inside the absorbing regions. Absorption spectra as well as illustrative 3D images of the beam's transverse overlapping strength are generated to help with the assessment and design of a practical optical fibre. As proven by a comparison with reported results, the method correctly describes the absorption trends inside DCFs of general geometry. Furthermore, it serves as a numerical simulation based tool for the optimization of the cross-sectional geometry and the corresponding refractive index profile. To demonstrate this, an all-solid-state holey DCF with superior absorption characteristics is designed and numerically evaluated.

The role of ion flux in Si(100) nanostructuring by normal-incidence Ar+ ion sputtering has been studied. The measured relationships of the Si lateral dot size versus ion flux, the surface roughness versus ion flux, and the surface roughness versus sample temperature with ion fluxes of 20 and 380 µA cm−2 all indicate that the value of the ion flux is decisive for the validity of the Bradley–Harper (BH) model in the nanostructuring of semiconductor single crystals. In this work, for Ar+ ion sputtering of Si(100) with ion energy of 1.5 keV, it is found that only beyond ~220 µA cm−2 is the BH model well applicable, while below that the Ehrlich–Schwoebel (ES) one tends to be involved. Our results suggest that the ES barrier effect is negligible under relatively high flux conditions, while it is substantial in the case of relatively low flux; for the BH model, the situation is just the reverse. Hence, caution should be exercised as regards the value of the ion flux when one tries to tune the semiconductor nanodot size following the BH model.

A fibre laser sensor has been developed to operate over a wide temperature range from room temperature to 440 °C, where the laser cavity has been formed using a combination of a chirped grating and a type IIA fibre Bragg grating (FBG), enclosing a length of erbium doped fibre as the active gain medium. A FBG stabilized 1480 nm laser diode was employed as the pump source to achieve laser oscillation associated with the type IIA Bragg grating wavelength on the wavelength band around 1550 nm. The broadband-chirped grating was used as one of the cavity end reflectors to achieve temperature-tunable laser action for sensing applications over a wide range. The sensitivity of the sensor was found to be 13.94 pm °C−1 with a root mean square error of 8.85 °C. The primary advantage of this laser-based sensor over passive optical fibre sensors is the significant improvement in both the signal-to-noise ratio and the narrow linewidth of the laser signal, making it especially well suited to multiplexing situations.

Fibre Bragg gratings (FBGs) of type I and IIA were fabricated in Ge-doped and B–Ge co-doped fibres using a 248 nm excimer laser and their performance characteristics were tested and compared with those of a chemical composition grating (CCG), written in a fluorine–germanium doped fibre, over a wide range of temperatures. Long-term testing (more than 600 h) involving a series of step-wise incremental temperature changes shows for the first time the potential of FBGs for high temperature measurement applications (up to and beyond 1100 °C), this depending on the type of FBG involved and the material and composition of the substrate fibre (the CCG was observed to be the most durable at very high temperatures). These gratings are likely to be useful for the simultaneous measurement of strain and temperature over these higher temperature ranges.

peer-reviewed A layer-by-layer assembly technique is used to coat layers of nano-thin-films of pH indicator on a U-bend optical fibre to create an effective sensor, using neutral red as the active element. The experimental results characterizing such a pH sensor shows a wide pH sensing range (from pH5 to pH10) fast response. PUBLISHED

peer-reviewed This paper reports on an optical fibre based sensor system to detect the occurrence of premature browning in ground beef. Premature browning (PMB) occurs when, at a temperature below the pasteurisation temperature of 71°C, there are no traces of pink meat left in the patty. PMB is more frequent if poorer quality beef or beef that has been stored under imperfect conditions. The experimental work pertaining to this paper involved cooking fresh meat and meat that has been stored in a freezer for, 1 week, 1 month and 3 months and recording the reflected spectra and temperature at the core of the product, during the cooking process, in order to develop a classifier based on the spectral response and using a Self-Organising Map (SOM) to classify the patties into one of four categories, based on their colour. Further tests were also carried out on developing an all-optical fibre sensor for measuring both the temperature and colour in a single integrated probe. The integrated probe contains two different sensor concepts, one to monitor temperature, based on Fibre Bragg Grating (FBG) technology and a second for meat quality, based on reflection spectroscopy in the visible wavelength range. PUBLISHED

This paper presents a novel design of an optical sensor platform, enabling effective integration of a number of optical fibre ('wired') sensors with wireless sensor networks (WSNs). In this work, a fibre Bragg grating-based temperature sensor with low power consumption is specially designed as a sensing module and integrated successfully into a WSN, making full use of the advantages arising from both the advanced optical sensor designs and the powerful network functionalities resident in WSNs. The platform is expected to make an important impact on many applications, where either the conventional optical sensor designs or WSNs alone cannot meet the requirements.

A high-Q and low threshold laser resonator, operating in the 2??m wavelength region, has been demonstrated by coupling a thulium-doped silica microsphere to a tapered fibre. Microspheres with diameters ranging from fifty to a few hundred micrometres were carefully fabricated for this purpose by melting an etched-clad thulium-doped silica fibre tip using a focused beam from a CO2 laser, while the tapered fibre with waist diameter in the desired range of 2??m was fabricated by using heating and stretching of standard single-mode telecommunication fibre. The tapered fibre served the dual purpose of transporting pump power into the sphere and allowing the extraction of the resulting laser emission. Under excitation at a wavelength of ?1.6??m, lasing occurred at wavelengths over the range from 1.9 to 2.0??m. Single-mode laser operation was obtained by exciting the fundamental whispering gallery mode resonance of the microsphere, while multi-mode lasing occurred for non-fundamental mode excitation. The threshold power of the laser was measured to be about 50??W delivered pump power, and a maximum laser power of 0.8?mW at around 1.94??m was observed for a 6?mW pump power, operating at wavelengths around 1.6??m. The laser was designed as a low threshold and compact source for miniaturized gas sensing devices operating over this important wavelength region.

In this work, two of surface plasmon resonance (SPR) and localized surface plasmon resonance (LSPR)-based optical fibre sensors have been successfully developed and cross-compared. With one SPR sensor being coated with a thin layer of gold film and the other gold-nanorods (GNRs), forming a LSPR sensor, both sensors are subjected to various refractive index changes. As a result their sensitivities are measured in the form of resonance wavelength shift as a function of refractive index variation. The results demonstrate that the thin-film coated SPR sensor has much higher sensitivity than that of GNRs coated LSPR sensor but with worse linearity.

This paper presents a novel sensor design and packaging, specifically developed to allow fibre grating-based sensors to be used in harsh, in-the-field measurement conditions for accurate strain measurement, with full temperature compensation. After these sensors are carefully packaged and calibrated in the laboratory, they are installed onto the paragrid of a set of flat-packed concrete units, created specifically for forming a small-scale, lightweight and inexpensive flexi-arch bridge. During the arch-bridge lifting process, the sensors are used for real-time strain measurements to ensure the quality of the construction. During the work done, the sensors have demonstrated enhanced resilience when embedded in concrete structures, providing accurate and consistent strain measurements during the whole installation process and beyond into monitoring the integrity and use of the structure.

A self-referenced optical fibre sensor for monitoring heavy metals, especially lead, has been developed and evaluated and the results obtained are discussed in detail in this paper. The sensor probe builds on concepts in prior work, creating a small, compact and portable device using an indicator immobilized at the fibre end. It functions in the visible part of the spectrum where the attenuation caused by fibre transmission is small and it offers a possible solution to the need for devices to be used in the field. This represents on-going research where the factors affecting the probe design and immobilization procedure used are considered and solutions offered.

The use of strain sensors is commonplace within civil engineering. Fibre optic strain sensors offer a number of advantages over the current electrical resistance type gauges. In this paper the use of fibre optic strain sensors and electrical resistance gauges to monitor the production of corrosion by-products has been investigated and reported.

The identification and quantification of compounds in the gas phase becomes of increasing interest in the context of environmental protection, as well as in the analytical field. In this respect, the high extinction coefficients of vapours and gases in the ultraviolet wavelength region allow a very sensitive measurement system. In addition, the increased performance of the components necessary for setting up a measurement system, such as fibres, light sources and detectors has been improved. In particular the light sources and detectors offer improved stability, and the deep UV performance and solarisation resistance of fused silica fibres allow have been significantly optimized in the past years. Therefore a compact and reliable detection system with high measuring accuracy is developed. Within this paper possible applications of the system under development and recent results will be discussed.

A novel approach to chloride ion monitoring in aqueous solutions using a long period grating (LPG) pair is reported, with the LPG pair used (LPGP) comprising two 2.5dB single LPGs and a physical centre-to-centre separation of around 30mm. An ultra-violet excimer laser was used to create the pair through a 250μm amplitude mask. The refractive index change due to the presence of the chloride ion (from an aqueous NaCl solution) was monitored, with the sensor having previously been calibrated using solutions of known refractive indices (RIs). A cross-comparison with the response of a single LPG (LPG1) under similar testing conditions was also carried out, and the results have shown that the LPGP could measure a RI change of ±0.003, achieving an improvement in the precision obtained (by ~ 6 times) using a single LPG. The focus of the work is on the underpinning technology for early stage corrosion monitoring (and indeed prevention) in structures, arising due to salt and water ingress.

peer-reviewed This paper describes the potential for the future development of comparatively low cost ultra-violet optical fibre ammonia gas detection systems. The potential for the construction of these systems using low-cost optoelectronic components is described. By experiment, it is shown that sub-ppm limits of detection that can be realised. PUBLISHED peer-reviewed

In this work, a 1600nm Er fibre laser, which demonstrates a high pumping efficiency, has been used to pump an efficient all-fibre Tm:Ho laser system using a 0.3 m length of optical fibre. A low threshold of 33 mW and a slope efficiency of 0.6% have been achieved with operation at a wavelength of ~1870 nm. A cross-comparison has been made with the output of a device pumped by a 785 nm laser diode. The focus of the work is better and more compact sources for gas sensing in the near infra red region of the spectrum.

This paper presents preliminary results obtained from research into the development of a microsphere fibre laser designed for use in a compact gas sensor system. In this paper the focus is on achieving the optimum coupling between the microsphere and the tapered fibre used and obtaining the potential ultra-low threshold of the laser system.

Fibre optic strain sensors offer a number of advantages over the current electrical resistance type gauges, yet are not widely used in civil engineering applications. The use of fibre optic strain sensors (with a cross comparison with the output of electrical resistance gauges) to monitor the production of corrosion by-products in civil engineering concrete structures containing reinforcement bars has been investigated and results reported.

We report a method to modulate the photoluminescence (PL) of SrTiO3(001) at room temperature by fluorhydric (HF) acid etching and Ar+ ion bombardment. The PL of the virgin sample is in the blue/green range, which can be enhanced in intensity by a factor of 7.2 after being fully etched in HF acid with the peak shape being unchanged. Ar+ ion bombardment of SrTiO3 can blueshift the overall PL, and the peak maximum becomes centred at 403 nm. After fully etching the ion-bombarded sample in HF, the PL peak stays in the blue light range, but its intensity increases to 17.5 times that of the virgin one. Oxygen vacancies assumed to be produced on the lateral sides of SrTiO3 nanograins are responsible for the PL emissions, and their variations in number and nature are attributed to the PL modulation.