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Ultraviolet light-emitting diodes (UV LEDs) have been widely applied in various fields, such as sewage treatment, sterilization, and disinfection medical treatment. However, the remained problems of UV LEDs mainly concern poor photoelectric stability, low efficiency, safety protection, and among others. In order to evaluate and predict the stability and lifetime of UV LEDs safely and efficiently, a comprehensive UV LEDs two-step aging test system has been designed in this work. Two steps of different temperature stresses with total aging time up to 720 h are applied to UV LEDs. The junction temperature derived from spectroscopy has been taken under consideration during the test to evaluate lifetime accurately. A smartphone-based remote control and test scheme has been developed to monitor and control the online testing and therefore ensure the safety and convenience during the aging experiment. more...

We put forward a non-contact method for determining the transient two-dimensional (2D) temperature distribution of light emitting diodes (LEDs). A high-speed camera is employed to acquire the 2D reflective light of blue LED under test (468 nm) illuminated by a red LED (690 nm) as the incident light source to avoid the band-gap modulation effect. The 2D transient temperature distribution is derived in terms of temperature-dependent reflective light intensity relationship. Two cases are studied to test the system in this work under (1) 1980 fps frame rate with time resolution of $505~\mu \text{s}$ at 300 mA, and (2) 5600 fps with time resolution of $179~\mu \text{s}$ at 500 mA. Compared with the conventional infrared thermal imaging (TI) method, the spatial resolution and the time resolution of this proposed method increase up to one and two orders of magnitude, respectively. more...

The Western flower thrips (WFT), Frankliniella occidentalis, is a major threat to a wide range of agricultural crops and rapidly spreads throughout the world. Its international importance as a pest has led to tremendous growth in our knowledge of its biology, ecology, and novel approaches for its management. Unfortunately, the literature on WFT is widely dispersed and many researchers, extension specialists, and IPM practitioners are only now becoming aware of WFT, which has meant that management programs are still reliant on intense insecticide use, especially in recently invaded regions. Due to the current high demand in effective and sustainable control tactics for this pest, Journal of Pest Science dedicates a special issue to WFT. This special issue provides a consolidated review of WFT biology and ecology and helps to highlight alternative and novel management techniques to effectively controlling this pest in the future. more...

This letter proposes a multichannel optical fiber spectral and imaging system, aiming at evaluating the pixel-level optical properties of high definition display efficiently and precisely. The system makes use of 16-channel optical fibers to form a detecting array so that 16 points of a display under test can be measured cyclically by multiplexer and spectrometer and monitored by camera simultaneously. The optical path is reversible for both the light source and the laser positioning, and adjustable along a rail driven by a motor to enable the system to work in either magnification mode or reduction mode. The feasibility and accuracy of the system are verified by comparative experiments of standard light source, LED display, and OLED display, identifying both merits of a single-spot spectroradiometer and an imaging photometer/colorimeter and even more functions like pitch size and color gamut. more...

This paper presents the first report of the occurrence of the pinion-streaked snout Schrankia costaestrigalis (Stephens, 1834) in China and the first known record of this pest’s damage to potato (Solanum tuberosum L.) in the world. This discovery allowed us to alert entomologists and farmers, as well as agricultural agencies, and to provide a diagnostic tool to prevent potential establishment and spread of this newly introduced species in the potato-growing region of China and worldwide over the next few years. more...

We propose a non-contact method for determining phosphor/silicone temperature (phosphor temperature) in phosphor-coated light-emitting diode (pc-LED). The pc-LED with a surface mounted device (SMD) structure is primarily consisted of InGaN/GaN blue LED chip, (Sr,Ca)AlSiN3:Eu2+ red rare-earth phosphor, and transparent dimethyl silicone. This proposed method is basically based on a linear temperature dependence of divisional normalized emission power for phosphor/silicone mixture. Four types of pc-LED corresponding to four different phosphor concentrations are examined by proposed method. A comparison of measured results between micro-thermocouple device and proposed method has also been carried out, showing a fairly good agreement between them, except for pc-LED with 4.8 wt% phosphor concentration. We suggest that this proposed method can provide a useful tool for further study of optical and thermal characteristics in pc-LED. more...

To describe the perceived participation and assess its determinants among young and middle-aged stroke patients following acute care one month after discharge in mainland China.Two hundred and twenty-three patients were consecutively recruited from two tertiary hospitals and were followed up 1 month after discharge in the outpatient department or their communities to assess their participation by using the Impact on Participation and Autonomy Questionnaire, with 23 patients lost to follow-up. Determinants (i.e., sociodemographic, diseased-related, physical, psychological, and social factors) of participation were identified in four domains: indoor autonomy; outdoor autonomy; family role; and social life.The overall perceived participation of our respondents was good to fair. Forty-six (23.0%), 32 (16.0%), 13 (6.5%), and 19 (9.5%) perceived their participation as "very good" in the domains of indoor autonomy, family role, outdoor autonomy and social life, respectively. Stroke severity, depressive symptoms, and social support were the common determinants of participation for all the domains, with stroke severity being the strongest correlate. Activities of daily living was associated with indoor autonomy, family role, and outdoor autonomy, but not associated with social life.The perceived participation of our respondents is relatively optimistic. Physical health along with mental and social status can affect participation. Tailored strategies should be implemented early in the rehabilitation phase to promote stoke survivors' participation in all the domains.Implications for rehabilitationAlthough the overall perceived participation of young and middle-aged stroke patients was fair to good, attention should be paid to their family roles.The strategies should be mainly focused on reducing the stroke severity to improve patients' participation.Improving patients' depressive symptom and social support can also be helpful for improving their participation. more...

Aim To evaluate fatigue in chronic hepatitis B patients and its related independent factors, as well as the relationship between fatigue and health-related quality of life (HRQoL). Materials and methods The study enrolled 400 patients who met the selection criteria, and their sociodemographic information was collected. The 36-item Short-Form Health Survey (SF-36) and Multidimensional fatigue inventory 20 (MFI-20) were adopted to evaluate HRQoL and fatigue level. Results Significant differences between the fatigue group and non-fatigue group were observed for the female proportion (p=0.021), height (p=0.003), and weight (p=0.010), with or without regular exercise (p=0.001). We further determined the dimensions of fatigue that were affected by these factors and found that male patients showed significantly lower results than female patients in terms of physical fatigue (p=0.048), mental fatigue (p=0.017), and reduced motivation (p=0.025). In patients who exercised regularly, the fatigue scores for the three dimensions of general fatigue (p more...

In this letter, we propose an experimental method for determining two-dimensional (2D) junction temperature distribution of light-emitting diodes (LEDs) using microscopic hyperspectral-based centroid wavelength. The 2D centroid wavelength matrix is extracted from the hyperspectral data cube as temperature sensitive optical parameters (TSOP), which is linearly calibrated by short pulse voltage signal in order to eliminate the influence of self-heating effect. The 2D junction-temperature distributions of LEDs under working conditions are derived by TSOP matrix. The comparative experiments by micro-thermocouple ( $\mu $ -TC) and IR imaging reveal good coincidence in both averaged temperature and temperature distribution trends. more...

Every season over the past decade, efficacious thrips insecticides have been commonly applied for control of Thrips hawaiiensis on banana crops in China. For effective thrips control, some insecticides have been used extensively against the thrips in numerous banana plantations. This study aims to examine the current resistance status and the dynamics regarding the changing frequencies of resistance in the field T. hawaiiensis populations. A total of 13 field samples from banana orchards (Chengmai, Lingao, Dongfang and Ledong located in Hainan Province, China) were collected monthly in 2014 to 2017, and selected individuals were used in bioassays assessing insecticide resistance and metabolic enzyme activity compared to a laboratory-susceptible strain. In 2014, the initial resistance survey found that all sampled populations were susceptible to spirotetramat and cyantraniliprole, while Lingao and Chengmai population showed a moderate resistance to imidacloprid, acetamiprid, abamectin and spinetoram. Further, seasonal and annual analysis of resistance dynamics with imidacloprid, abamectin and spinetoram demonstrated that resistance in field populations of T. hawaiiensis developed quickly within a season (from April to August 2016), but resistance was unstable over subsequent seasons (April 2015, 2016 and 2017). Moreover, synergism experiments using enzyme inhibitors together with metabolic enzyme assays revealed that field-evolved insecticide resistance in T. hawaiiensis was closely associated with the elevated metabolic enzymes. The observed resistance increase within a season was attributed mainly to the intense use of these insecticides and short generation time of thrips. These findings suggest that a rotation system using efficacious thrips insecticides should be implemented for sustainable thrips control to reduce the potential of resistance development. more...

The non-visual effects of blue light in displays mean that excessive use of smartphones can disturb the human circadian rhythm. Thus, the impact of virtual reality (VR) headsets, which are worn closer to the human eye, may be even more serious. In this paper, based on non-visual parameters, such as the circadian action factor (CAF) and circadian illuminance, the circadian performance of smartphone-based VR displays is quantitatively evaluated by an evaluation system we designed. Moreover, we investigate the improvements in the circadian performance of VR headsets resulting from three practical methods for reducing the blue light content. Finally, a theoretical method of shifting the green-light wavelength of the screen close to 555 nm to optimize the CAF of VR headsets is proposed. Overall, the results of this paper are of significant value in quantifying the effects of VR displays on circadian rhythms and improving the safety of VR headsets with regard to human health. more...

Background Spinetoram, a new type of spinosyn with novel modes of action, has been used in effective thrips control programs, but resistance remains a threat. In the present study, a laboratory Thrips hawaiiensis population was subjected to spinetoram for resistance selection to investigate resistance development, stability, cross-resistance potential, biological fitness and underlying biochemical mechanisms. Results Resistance to spinetoram in T. hawaiiensis rapidly increased 103.56-fold (for 20 generations of selection with spinetoram) compared with a laboratory susceptible population, and the average realized heritability (h2 ) of resistance was calculated as 0.1317. Maintaining the resistant population for five generations without any further selection pressure resulted in a decline in the resistance ratio from 19.42- to 9.50-fold, suggesting that spinetoram resistance in T. hawaiiensis is unstable. Moreover, the spinetoram-resistant population exhibited a lack of cross-resistance to other classes of insecticides, and showed biological fitness costs. The results of synergism experiments using enzyme inhibitors and biochemical analyses revealed that metabolic mechanisms might not be responsible for the development of spinetoram resistance in T. hawaiiensis. Conclusion The current study expands understanding of spinosyn resistance in thrips species, providing a basis for proposing better integrated pest management strageties for thrips control programs and defining the most appropriate tools for such resistance management. © 2018 Society of Chemical Industry. more...

Entomogenous fungi have evolved many strategies for overcoming the defense systems that insects/mites, in turn, continue to evolve to fend off the fungi's attempt at infection. Although the host immune systems have garnered much attention, the importance of the cuticular defenses remains under-examined. The present study compared the mechanical properties – hardness and elastic modulus of the cuticles between a phytoseiid mite, Neoseiulus barkeri and a pest spider mite, Tetranychus urticae using nanoindentation techniques. We determined that the dorsal cuticle of N. barkeri possesses significantly greater hardness and stiffness, while the ventral cuticles of N. barkeri has mechanical properties similar to that of T. urticae. Exposure of the lateral abdomen region of N. barkeri after being distended by feeding, however, increased the susceptibility to fungal infection. It is found that the fungus can breach the exposed part of abdominal cuticle that is softer and less stiff, followed by conidial adhesion. This suggests mechanical properties of the dorsal cuticle of N. barkeri contribute substantially to withstand the mechanical force exerted by the attempted penetration of fungal hyphae. This study expand our knowledge of fungus–predator interactions and provide new insights into the feasibility of applying multiple biocontrol agents in pest control strategies. Keywords: Nanoindentation, Mite cuticle, Mechanical properties, Fungal defense, Phytoseiid mites, Spider mites more...

A majority of luminance measurement systems are currently focused on measuring the total luminance of light-emitting diodes (LEDs). It has largely limit its application on micro-LEDs, which require capturing the microscopic surface luminance. In order to study the microscopic characteristics of micro-LED displays, in this paper we propose a practical method that can accurately measure the luminance of a whole micro-LED array and even the surface luminance distribution of any single micro-led chip on the array. The essentials of this method are a high-precision complementary metal oxide semiconductor camera and a self-made data processing algorithm. Results show that the maximum error of the luminance measurement is less than 8%, which can prove the accuracy of the method. The metrical wavelength range and the accuracy of system can be dynamically set according to the camera and microscope. Endowed with ultrahigh dynamic ranges, this system proves its competency for evaluating the spatially resolved distribution of luminance for high brightness micro-LEDs. more...

With the emerging market for multichip module based high-power LED systems, the demand for advanced thermal management techniques has been steadily growing. This paper presents a model developed by the authors for thermal coupling matrix that can calculate temperature distribution at a given heat power of each chip. The model significantly simplifies the task of measuring thermal coupling effect on multichip light-emitting diodes with symmetrical structure, while simultaneously preserving temperature accuracy. The modeling technique was validated experimentally on three-, four-, and six-chip rectangular modules, and a ten-chip circular module, by infrared thermography and transient thermal measuring system, respectively. The modeling technique was found to be more efficient especially for large systems. The model offers a rapid way to predict thermal coupling behaviors of multichip LED systems. more...

Little is known about the perspectives of individuals with mental illness on community mental health services (CMHS) in China. The current study aimed to explore these perspectives. Semi-structured interviews were completed with a purposive sample of 25 individuals with mental illness recruited from three communities in Guangzhou City, China. The Colaizzi method was used for data analysis. Three main themes were identified: (a) patients' perceptions of CMHS , (b) patients' barriers to accessing CMHS , and (c) patients' expectations of CMHS . The identified issues should be taken into consideration in improving CMHS. CMHS staff, including nurses, should make patients more aware of CMHS. To increase CMHS use and make it more responsive to patients' expectations, staff should try to resolve patients' stigma and desire to return to society. [ Journal of Psychosocial Nursing and Mental Health Services , 55 (7), 30–37.] more...

Liriomyza trifolii (Burgess) is a highly invasive species that has become established in agricultural and ornamental crops throughout the world. L. trifolii was first recorded in China in 2005 in Guangdong Province. Subsequently, its known distribution in China has rapidly expanded to another 11 provinces (Zhejiang, Jiangsu, Shanghai, Fujian, Guangxi, Shandong, Hainan, Hebei, Henan, Hubei and Anhui), where it is currently causing considerable damage and economic losses. Experimental research and field surveys have contributed to our understanding of the ecology of L. trifolii and particularly the process of invasion and its interactions with other established, exotic Liriomyza leafminer species. A number of factors have contributed to the successful establishment of L. trifolii and displacement of interspecific competitors. In China, L. trifolii has become a particularly devastating pest in areas with intensive farming with extensive monocultures and a reliance on insecticide use. Integrated pest management incorporating judicious applications of insecticide combined with biological and cultural controls is likely to provide the best long-term management strategy for L. trifolii. We provide information regarding 10 years of L. trifolii invasion in China and discuss areas of future research to enhance our overall understanding of the biology and ecology of L. trifolii and to improve management programmes for this widespread invasive insect pest. © 2017 Society of Chemical Industry. more...

Fundamental to competitive displacement in biological invasion is that exotic species occupy the ecological niches of native species in novel environments. Contrasting outcomes of competitive displacement have occurred between Liriomyza trifolii and L. sativae in different geographical regions following their introduction. Various factors have been advanced in an attempt to explain these different competitive outcomes, although none of these explanations have addressed the effects of niche differences. We conducted field cage experiments to compare the feeding and habitat niches of the two leafminer species and their primary parasitoid, Opius biroi, when occurring together on kidney bean. A wider spatiotemporal niche breadth was found in L. trifolii (0.3670) than in L. sativae (0.3496). With respect to the parasitoid, the proportional niche similarity between L. sativae and the parasitoid was 0.3936 but only 0.0835 for L. trifolii, while similar results were found for niche overlap, indicating that stronger trailing behaviour and parasitic effects of O. biroi occurred in L. sativae. In conclusion, L. trifolii has outperformed L. sativae in occupying the ecological niche and is superior to L. sativae in avoiding parasitization by the pupal parasitoid, O. biroi. more...

Statin combined with ezetimibe demonstrates significant benefit in lowering low density lipid cholesterol (LDL-C) and cardiovascular events abroad, but whether intermediate intensity statins combined with ezetimibe is superior to high-intensity statin monotherapy in Chinese people is unknown.A total of 125 patients were randomly assigned to a intermediate intensity rosuvastatin group (rosuvastatin 10mg/d, n=42), high-dose rosuvastatin group (rosuvastatin 20mg/d, n=41) or combination therapy group (ezetimibe 10mg/d and rosuvastatin 10mg/d, n=42) with a 12-week follow-up. The primary end point was the proportion of patients who achieved the 2011 ESC/EAS LDL-C goal70mg/dL (1.8mmol/L) at week 12. Secondary end points included changes from baseline in lipids, the occurrence of all cardiovascular events, high-sensitivity C-reactive protein and safety markers.The combination therapy group in the primary end point was significantly higher than rosuvastatin (20mg) and rosuvastatin (10mg) at week 12 (81.0% vs 68.3% vs 33.3%, P0.001). And the similar change was observed in reducing LDL-C levels at week 12 (67.28% vs 52.80% vs 43.89%, P0.001). The incidence of drug-related adverse events was much higher in the rosuvastatin 20mg group than the rosuvastatin 10mg group and the combination therapy group (17.0% vs 2.4% vs 4.8%, P0.05).The combination of rosuvastatin 10mg/ezetimibe 10mg was an effectively alternative therapy superior to rosuvastatin 20mg or 10mg with a greater effect on lowering LDL-C and a lower incidence of drug-related adverse events in Chinese patients. more...

We introduce a new method for measuring the junction temperature of alternating current light-emitting diodes. This method employs a periodic bipolar voltage pulse signal as the input, and utilizes the amplitude of corresponding output current as the temperature sensitive parameter (TSP), of which a linear temperature dependence is proven in a prior experiment in this paper. On the basis of the TSP, we devise a detailed procedure—first, measure the thermal resistance of the package of ac-LEDs, which further contributes to the calculation of junction temperatures under various power inputs. Comparisons between values calculated by using this method and those obtained directly from a thermocouple indicate a decent accuracy of the former. The advantage of this method benefits from the stability of thermal resistance under different driving conditions that one could immediately obtain the junction temperature by measuring the electric and optical powers. more...

Relative reflected intensity of the incident exciting light is proposed to measure the junction temperature of light-emitting diodes (LEDs) under test. Reflectance spectra at a wide junction temperature range are acquired. Multichannel optical fibers greatly increase the collecting efficiency of the reflected light. Lock-in technique is utilized to exclude the interference of the emitting light from LEDs under test and to increase the dynamic range greatly. The results are in good agreement with those directly tested by a microthermocouple. To avoid extra carrier absorption and modulation effect, the incident exciting light should harbor smaller bandgap than that of LEDs under test. more...

Western flower thrips, Frankliniella occidentalis, first arose as an important invasive pest of many crops during the 1970s–1980s. The tremendous growth in international agricultural trade that developed then fostered the invasiveness of western flower thrips. We examine current knowledge regarding the biology of western flower thrips, with an emphasis on characteristics that contribute to its invasiveness and pest status. Efforts to control this pest and the tospoviruses that it vectors with intensive insecticide applications have been unsuccessful and have created significant problems because of the development of resistance to numerous insecticides and associated outbreaks of secondary pests. We synthesize information on effective integrated management approaches for western flower thrips that have developed through research on its biology, behavior, and ecology. We further highlight emerging topics regarding the species status of western flower thrips, as well as its genetics, biology, and ecology that facilitate its use as a model study organism and will guide development of appropriate management practices. more...

Agricultural pest catches on sticky traps can be used for the early detection and identification of hotspots, as well as for estimating relative abundances of adult pests, occurring in greenhouses. This study aimed to construct a detection model for whitefly and thrips from sticky trap images acquired in greenhouse conditions. An end-to-end model, based on the Faster regional-convolutional neural network (R-CNN), termed ‘TPest-RCNN’, was developed to improve the tiny pest detection accuracy. This architecture was trained using a transfer learning strategy on the Common Objects in Context dataset before training on the tiny pest training set to create the TPest-RCNN model. The new model achieved mean F1 score and average precision of 0.944 and 0.952, respectively, on a validation set. The TPest-RCNN model outperformed the Faster R-CNN architecture and other approaches using handcrafted features (color, shape and/or texture) in detecting multiple species from yellow sticky trap images. The test results also showed the model was robust to detect tiny pests on images of different pest densities and light reflections. Using a linear regression between the manual counts and an automatic detection results using the proposed method on images of 41 days, the determination coefficients reached 99.6% and 97.4% for whitefly and thrips, respectively. These results demonstrated that the proposed method could facilitate rapid gathering of information pertaining to numbers of the abundance of tiny pests in greenhouse agriculture and provide a technical reference for pest monitoring and population estimation. more...

Residual useful life (RUL) prediction is significant for condition-based maintenance. Traditional data-driven RUL prediction method can only predict fault trend of the system rather than RUL of a specific system component. Thus it cannot tell the operator which component should be maintained. The innovation of this paper is as follows: (1) Wavelet filtering based method is developed for early detection of slowly varying fault. (2) Designated component analysis is introduced as a feature extraction tool to define the fault precursor of a specific component. (3) Exponential life prediction model is established by nonlinear fitting of the historical RUL and the fault size characterized by the statistics used. Once online detection statistics is obtained, real-time RUL of the critical component can be predicted online. Simulation shows the effectiveness of this algorithm. more...

The accelerated life testing is a common tool to achieve lifetime prediction and reliability analysis for light-emitting diodes (LEDs). Currently, all popular accelerated methods, either offline or online, employ a large volume, energy-consuming temperature chamber, which will cause the instruments inside worse, and the methods are usually incapable of controlling the junction temperature online. In this paper, we propose a multifunctional online system that controls the temperature of heat sink directly by a heating plate integrated to electrical-current-stress fixture. The combinations of spectrometer with optical multiplexer and current source with electrical matrix switch are adopted to fulfill the comprehensive real-time testing of LEDs, including optical, electrical, colorimetric, and thermal properties. In particular, junction temperature is monitored and controlled online by pulse-voltage method, which raises the accuracy and reliability of lifetime analysis and prediction. A new file format–HDF5 is applied to process huge quantities of experimental data, which are helpful to analyze the failure mechanism. more...

Parents of children with ongoing cancer treatment are exposed to risks of developing posttraumatic stress symptoms (PTSS), but little is known about the prevalence and predictors of PTSS among Chinese parents of children with cancer. This study aimed to examine the predictors of PTSS, and explored the correlation of depression, resilience, and family functions with severe PTSS. This cross-sectional survey was conducted from May 2014 to September 2015 among the parents of cancer children treated in four general hospitals in South China. PTSS in the parents were measured using post-traumatic stress checklist-civilian version (PCL-C). Multiple regression analyses were performed to evaluate the predictive values of depression, resilience, family functioning, and the demographic variables for severe PTSS. A total of 279 parents (192 mothers and 87 fathers) participated in the survey. Severe PTSS, as defined by a PCL-C score ≥50, were reported in 32.97% (n = 92) of the total participants, 26.44% (23/87) in the fathers and 35.94% (69/192) in the mothers. The level of PTSS was positively correlated with depression (r = 0.782, P more...

Cooling is a critical process in the thermal designs of high-voltage light-emitting diodes (HV-LEDs), whose junction temperatures are in turn an essential criterion for evaluations of LED aging, light-color quality, and luminous efficacies. In the present work, both numerically and experimentally, we have identified two cooling-related parameters, namely thermal crowdedness and nonuniformity, that are related to the lowering of junction temperatures of 17 microchips. Based on these two parameters, we have further proposed three regimes that facilitate the optimization. In addition, great care must be taken to incorporate the difficulty of tackling the high voltage into electrical-resistance selections. The 3D transient conjugate heat transfer is simulated using the finite element package named COMSOL. Finally, we hope that the present study can provide the photonic and cooling industries with the guidance for optimizing cooling characteristics in HV-LEDs based on these two parameters and three reg... more...

The potato tuberworm, Phthorimaea operculella Zeller, is one of the most economically significant insect pests of potato in both field and storage worldwide. The biology of the pest and various management strategies such as cultural practices, biological, and chemical control and other control methods are reviewed. more...

A single-order diffraction transmission grating named spectroscopic photon sieve (SPS) for soft x-ray region is proposed and demonstrated in this paper. The SPS consists of many circular pinholes located randomly, and can realize both free-standing diffractions and the suppression of higher-order differations. In this paper, the basic concept, numerical simulations, and calibration results of a 1000-lines/mm SPS for soft x-ray synchrotron radiation are presented. As predicted by theoretical calculations, the calibration results of a 1000-lines/mm SPS verify that the higher-order diffractions can be significantly suppressed along the symmetry axis. With the current nanofabrication technique, the SPS can potentially have a higher line density, and can be widely used in synchrotron radiation, laser-induced plasma diagnostics, and astrophysics. more...

In this paper, we have proposed a transmission-type testing system for determining optical characteristics of remote-phosphor plates in white light-emitting diodes (WLEDs). A comparative analysis between the proposed system and a traditional reflection-type system has also been conducted. Results show that the measured optical efficiency of phosphors appears lower for the former than for the latter. Reasons lie in that, for the latter, during measurements, more blue leakage light enters the detector of the system, and more blue light is reabsorbed by phosphor plates and converted to yellow light. Both factors may lead to a slight increase in the light conversion efficiency of phosphors for the reflection-type system. However, in a real structure of WLEDs, the exciting light is mostly transmitting through the phosphor layer rather than being reflected. Finally, we propose that the transmission-type system is more suitable for determining optical properties for remote-phosphor WLEDs. more...

For humans, nonvisual biological effects, which can be parameterized by the circadian action factor (CAF), are important for their health and work performance. In this paper, an approach by adjusting electrical currents of three-primary light-emitting diodes (RGB-LEDs) to tune the CAF and color coordinates to be close to those of the standard light with various correlated color temperature (CCT) (2700 K–6500 K) has been reported. This approach is based on deriving an empirical formula between the optical power and the electrical current. In order to meet the requirement of both high color rendering index (CRI) and better CAF, we theoretically perform further spectral optimization on RGB-LEDs and have found that peak wavelengths of 466, 547, and 615 nm for the blue, green, and red color component, respectively, turn out to be the best peak wavelength combination for obtaining both high CRI and high luminous efficacy of radiation of RGB-LEDs, while the CAF, CCT, and color coordinates of RGB-LEDs approach those of the standard light. more...

Polyphagous thrips are among the most important economically pests that cause serious damage in various ornamental and vegetable crops throughout the world. Because of their small size and cryptic habits, a number of thrips species are easy to invade into new areas. For a long period, thrips control has mainly relied on frequent use of insecticides, which lead to a series of ecological problems. Although a number of alternative management tactics have been developed in many cropping systems, many invasive thrips continue to spread internationally and display vast damage potential. This chapter reviews microbial control of thrips with focus on the entomopathogenic fungi Beauveria bassiana, Metarhizium anisopliae, Isaria fumosorosea and Lecanicillium lecanii. The strains of fungal pathogens that were screened and proven to be effective for control of thrips should be developed worldwide and available for growers. We also discuss three areas of future research that will be necessary in improving management programs of thrips. more...

Background Aging is a known risk factor of idiopathic pulmonary fibrosis (IPF). However, the pathogenic mechanisms underlying the effects of advanced aging remain largely unknown. Telomeric repeat-containing RNA (TERRA) represents a type of long noncoding RNA. In this study, the regulatory roles of TERRA on human telomeres and mitochondria and IPF epithelial injury model were identified. Methods Blood samples were collected from patients with IPF (n = 24) and matched control individuals (n = 24). The significance of clinical research on the TERRA expression correlated with pulmonary fibrosis was assessed. The expression levels of TERRA in vivo and in vitro were determined through quantitative real-time polymerase chain reaction analysis. Telomerase activity was observed using a fluorescent quantitative TRAP assay kit. The functions of telomeres, mitochondria, and associated genes were analyzed through RNA interference on TERRA. Results TERRA expression levels significantly increased in the peripheral blood mononuclear cells of IPF patients. The expression levels also exhibited a direct and significantly inverse correlation with the percentage of predicted force vital capacity, which is a physiological indicator of fibrogenesis during IPF progression. This finding was confirmed in the epithelial injury model of IPF in vitro. RNA interference on TERRA expression can ameliorate the functions of telomeres; mitochondria; associated genes; components associated with telomeres, such as telomerase reverse transcriptase, telomerase, and cell nuclear antigen, cyclin D1; and mitochondria-associated cyclin E genes, including the MMP and Bcl-2 family. The RNA interference on TERRA expression can also improve the functions of oxidative-stress-associated genes, such as reactive oxygen species, superoxide dismutase, and catalase, and apoptosis-related genes, such as cytochrome c, caspase-9, and caspase-3. Conclusions In this study, the regulation of TERRA expression on telomeres and mitochondria during IPF pathogenesis was identified for the first time. The results may provide valuable insights for the discovery of a novel biomarker or therapeutic approach for IPF treatment. more...

We propose an experimental method that determines junction temperatures in light-emitting diodes by measuring currents while holding the low forward voltages constant. In this procedure, we first calibrate current-temperature-rela- tionship parameters under the condition of negligible thermal generation. With one of the two parametric values, we discover the existence of a forward voltage peak that yields most sensitive measurements of the junction temperature. Results show a nearly linear relationship between the algorithmic currents and temperature reciprocals with high testing precision. more...

We investigated the comparative structural and optical properties of semipolar InGaN/GaN multiple quantum wells (MQWs) grown on the (1101) facet GaN/sapphire substrate by metal-organic chemical vapor deposition using lateral epitaxial overgrowth. The scanning electron microscopy (SEM), photoluminescence (PL), and temperature-varying time-resolved photoluminescence measurement were performed to investigate the structure and optical properties. The cross-sectional SEM image shows that the stripe triangular structure of the QW with semipolar (1101) planes is obtained as sidewall facets with the mask stripes aligned along the GaN α-axis. The structural and optical advantages of semipolar orientations were confirmed by a modurate shift of the PL peak energy, higher internal quantum efficiency, and lower radiative recombination lifetime than the MQWs on (0001) GaN grown by conventional methods. The results were obtained because of the reduced polarization fields in semipolar InGaN/GaN MQWs comparing with that in polar (0001) MQWs. more...

Several strategies involving refuge have been proposed for delaying insect resistance to Bt crops. The report was focused on the unstructured 'natural' refuges that contain plants naturally presented as part of the cropping system in the form of non-Bt plants that differ from Bt plant species, or wild host plants of the target pests. The cases of natural refuges applied in different countries were analyzed, and the factors that favor their success are discussed. The results indicate that the effectiveness of a natural refuge strategy depends on the biological characteristics of the target pest, the spatial and temporal distribution and abundance of the host plants in the agricultural system and the quality of the host plants for the pest species. more...

Due to the problem of load varying or environment changing, machinery equipment often operates in multimode. The data feature involved in the observation often varies with mode changing. Mode partition is a fundamental step before fault classification. This paper proposes a multimode classification method based on deep learning by constructing a hierarchical DNN model with the first hierarchy specially devised for the purpose of mode partition. In the second hierarchy , different DNN classification models are constructed for each mode to get more accurate fault classification result. For the purpose of providing helpful information for predictive maintenance, an additional DNN is constructed in the third hierarchy to further classify a certain fault in a given mode into several classes with different fault severity. The application to multimode fault classification of rolling bearing fault shows the effectiveness of the proposed method. more...

A method is presented in this study to determine the junction temperature (Tj) of LED in terms of the relationship between the diode reverse current (IR) and Tj . A theoretical model for the dependence of IR on Tj is derived on the basis of the Shockley equation and is validated by our experimental results. The method is compared with the conventional forward voltage method, and its advantages have been identified. more...

It is well known that the antipsychotic drugs impact the health-related quality of life (HRQoL) of the bipolar patients. The side effects had been assessed only from the doctors’ perspective and neglected the patients’ subjective feeling. The aim of the study is to validate the specific instrument “tolerability and quality of life” (TOOL) into Chinese to describe and grade the impact of antipsychotic drugs on HRQoL from patients’ view. A psychometric study was conducted with euthymic bipolar disorder patients (N = 105) under antipsychotic treatment. The psychometric properties of the TOOL, including internal consistency, retest reliability, concurrent validity, content validity, discriminative validity, item analysis, confirmatory factor analysis and feasibility, were analyzed. The internal consistency and intraclass correlation coefficient (ICC) were adequate (Cronbach’s alpha = 0.80 and ICC = 0.81). A confirmatory factor analysis (CFA) validated the one-factor model. Significant Spearman’s rank correlations between the TOOL and both Bref QoL.BD (Brief version of Quality of Life in Bipolar Disorder) (r = −0.33, P more...

The electrical-thermal-optical characteristics of AlGaInP yellow and InGaN/GaN blue LEDs under electrical stresses were studied. Since the increase of effective acceptor concentration on p-type side, the forward voltages of AlGaInP decrease after 3155 h aging. And the operating voltage of high forward bias expansion for InGaN/GaN is due to the increase of the series resistance. Compared with InGaN/GaN, AlGaInP LEDs display different trend for the relationship between optical output and ideality factors. The relationship between ideality factor and radiative recombination is also studied and established. The characteristic of different intermediate adhesive is compared during aging period based on transient thermal test. more...

This paper reports the measurement of the junction temperature and the determination of the thermal resistance of the single-crystal-silicon solar cell under the dark and illuminating conditions, respectively. Under the dark condition, the solar cell is considered as a conventional p-n junction and is subject to a reverse current in order to measure its junction temperature and determine the thermal resistance. A white LED array is used as the light source to operate the solar cell in order to avoid the heating effect of the infrared light by the solar simulator. Furthermore, we thoroughly calculate the thermal dissipation power. The result demonstrates that the thermal resistance drops from 3.7 to 2.0 K/W with the increase of the irradiance from 89.6 to 194.3 $\hbox{W/m}^{2}$ . It is also found that the thermal resistance under the dark condition is much higher than that under the illuminating condition, which is attributed to the light effect on the thermal resistance. more...

The spotted asparagus beetle, Crioceris quatuordecimpunctata (Coleoptera: Chrysomelidae), is one of the most devastating pests of asparagus in China. Sprayed synthetic pesticides have been used to control C. quatuordecimpunctata damage, but they pose problems because of residues and harm to natural enemies. Neither the microbial coleopteran-specific toxin from Bacillus thuringiensistenebrionis, Cry3Aa, nor the fungal pathogen Beauveria bassiana have sufficient activity to effectively control C. quatuordecimpunctata damage to asparagus. However, second instar C. quatuordecimpunctata larvae exposed to a sublethal dose of Cry3Aa toxin demonstrated significantly higher larval mortality when exposed to B. bassiana. Our results suggest that a combination of Cry3Aa and B. bassiana may be effective in reducing damage by C. quatuordecimpunctata larvae to asparagus. more...

The thermal and infrared properties of a vertical-electrode gallium-nitride light-emitting diode (GaN LED) are studied. Because infrared emissivity is a critical parameter for temperature measurements, the relationship between temperature and emissivity for a vertical-electrode GaN LED is investigated using different heating mechanisms; the result indicates a strong dependence between them. The temperature variation across the chip surface of a LED with a Si substrate increases from 2.9 to 8.4°C when the current changes from 100 to 900 mA with heat sink temperature of 45°C. Temperature nonuniformity may occur as a consequence of nonuniform joule heating, which is due to nonuniform current flow through the vertical-electrode LED. Around the electrode pad the spreading current is especially crowded. more...

863 Solid-State Lighting Project of China [2006AA03A175]; project of Fujian Province of China [2008J0030]

We propose a non-contact measurement method for determining two-dimensional (2D) temperature distribution of light-emitting diodes (LEDs). This method is based on both micro-hyperspectral imaging technology and reflected light method, owning merits of both high efficiency and high spatial resolution. Blue and green bare LEDs are used as LED under test, while red and near-infrared LEDs provide incident light to avoid spectral overlapping so as to reduce measurement error. During data processing, the convolution linear filtering algorithm is employed to improve the measurement accuracy. This proposed method is compared with the micro-thermocouple and infrared thermal imaging, with their respective comparison results in fairly good agreements. For spatial resolution of 2D temperature distribution, this method increases at least one order of magnitude compared with the thermal imaging method. more...

Western flower thrips (WFT) is one of the most important pests of horticultural crops worldwide because it can damage many different crops and transmit various plant viruses. Given these significant impacts on plant production, novel methodologies are required to maximize regulation of WFT to minimize crop losses. One particular approach is to develop control strategies for the non-feeding, soil-dwelling stages of WFT. Control of these stages could be enhanced through the use of granules impregnated with entomopathogenic fungi mixed in the soil. The use of soil-applied fungi contrasts with existing approaches in which entomopathogenic fungi are formulated as oil-based suspensions or water-based wettable powders for foliar applications against the feeding stages of WFT. To examine the efficacy of this approach, we evaluated the effects of a granular formulation of Beauveria bassiana on the soil-dwelling, pupal phases of Frankliniella occidentalis in laboratory bioassays and greenhouse experiments. Based on micromorphological observations of fungal conidia during the infection process after treatment of WFT with a B. bassiana suspension, fungal conidia complete the process of surface attachment, germination, and penetration of the body wall of the WFT pupa and enter the host within 60 h of treatment. Given these results, we undertook a controlled greenhouse experiment and applied B. bassiana granules to soil used to cultivate eggplants. Populations of F. occidentalis on eggplants grown in treated soil were 70% lower than those on plants grown in the untreated soil after 8 weeks. Furthermore, when measuring the survival and growth of B. bassiana on granules under different soil moisture conditions, survival was greatest when the soil moisture content was kept at 20%. These results indicate that the application of B. bassiana-impregnated granules could prove to be an effective biological control strategy for use against F. occidentalis under greenhouse conditions. more...

We investigate the cryogenic external quantum efficiency (EQE) for some InGaN light-emitting diodes with different indium contents. We observe a monotonic decrease in EQE with the increasing forward current before the “U-turn” point, beyond which the thermal effect increases the EQE. We discover positive dependences among the droop rate (χ), differential electrical resistance (Rd), and indium content. Also, χ and Rd of individual green samples shift correspondingly during the aging test, when the Mg ions are activated at high injection density and diffuse into the active region. Considering the fact that both In and Mg ions would introduce point defects (PDs), we proposed a model that reveals the mechanism of interplay between PDs and carriers. PDs serve as both energy traps and non-radiative recombination centers. They attract and confine carriers, leading to an increase in Rd and a decrease in EQE. more...

Advances in the fundamentals and applications of diffraction gratings have received much attention. However, conventional diffraction gratings often suffer from higher-order diffraction contamination. Here, we introduce a simple and compact single optical element, named inclined rectangular aperture gratings (IRAG), for quasi suppression of higher-order diffractions. We show, both in the visible light and soft x-ray regions, that IRAG can significantly suppress higher-order diffractions with moderate diffraction efficiency. Especially, as no support strut is needed to maintain the free-standing patterns, the IRAG is highly advantageous to the extreme-ultraviolet and soft x-ray regions. The diffraction efficiency of the IRAG and the influences of fabrication constraints are also discussed. The unique quasi-single order diffraction properties of IRAG may open the door to a wide range of photonic applications. more...