As energy gradually becomes a more valuable commodity, the desire for reduced energy losses strengthens. Lighting is a critical field on this matter, as it accounts for a large percentage of the global electricity con...As energy gradually becomes a more valuable commodity, the desire for reduced energy losses strengthens. Lighting is a critical field on this matter, as it accounts for a large percentage of the global electricity consumption and modern lighting systems are greatly more efficient than incandescent, discharge, and fluorescent lights. Previous research has proven that plants do not require the entire visible spectrum but react only to specific wavelengths, making it possible to control their growth and yield via artificial lighting. The flexibility of control of Light Emitting Diode (LED) lights allows for the combination of great energy losses reduction and controlled plant growth, achieving the improvement of two major parameters in a single action. This review paper summarizes the current research on the effect different light wavelengths have on specific plant species and discusses the applications of LED lighting for horticulture, yield storage, and disease protection.展开更多
In the context of promoting green energy transition and addressing climate change globally,solar energy,as a clean and renewable energy source,has gradually become a hot topic for research.Solar streetlight systems re...In the context of promoting green energy transition and addressing climate change globally,solar energy,as a clean and renewable energy source,has gradually become a hot topic for research.Solar streetlight systems realize energy self-sufficiency and environment-friendly lighting by integrating photovoltaic power generation technology and efficient LED lighting technology.By comprehensively analyzing the current status of the application of solar streetlights at home and abroad,this paper discusses its technical advantages,market penetration,and challenges in its development.In terms of technical characteristics,this paper focuses on analyzing the key technologies such as energy conversion efficiency and intelligent control systems of solar streetlights.展开更多
The paper summarizes the research on the development of standards for tunnels and roads LED lighiing application in Shanghai. analyzes the existing problems on LED road lamps and lighting design, introduces the experi...The paper summarizes the research on the development of standards for tunnels and roads LED lighiing application in Shanghai. analyzes the existing problems on LED road lamps and lighting design, introduces the experiments and testing results, and summarizes current problems of LED street lighting, proposing that LED lighting energy conservation should he ＂systematic energy saving＂ throughout the full life cycle based on the integration of products and applications.展开更多
As the quality of power LED improves and the cost of power LED reduces, semiconductor lighting will replace incandescent and fluorescent lighting gradually, causing another revolution on the lighting history. And its ...As the quality of power LED improves and the cost of power LED reduces, semiconductor lighting will replace incandescent and fluorescent lighting gradually, causing another revolution on the lighting history. And its driving solution has been greatly accelerated. Based on the white power LED I-V characteristics and the application ambiance, proposed is a new LED lighting solution, suiting indoor and outdoor illumination. According to the test results, the design is optimized, and the electrical efficiency is 95% and the output current deviation is 13.0%.展开更多
Storage and transportation of vegetable commercial seedlings becomes an important link along with the continuous expansion of planting areas of facility vegetables and vegetable seedling culture industry. In this stud...Storage and transportation of vegetable commercial seedlings becomes an important link along with the continuous expansion of planting areas of facility vegetables and vegetable seedling culture industry. In this study,pepper variety‘Nongda 24' was as the experimental material,and changes in the morphological and physiological indicators of plug seedlings in different low temperature( 6 and 11℃) and poor light environments were studied to find suitable storage environmental conditions. The results showed that pepper seedlings could be stored and transported for 14 days when storage temperature was 11℃ and light conditions such as light intensity and photoperiod were 30 μmol/( m^2·s)and 12 h/d by using a fluorescent lamp with R∶ B ratio of 1. 9,and 15 μmol/( m^2·s) and 24 h/d by using LED with R∶ B ratio of 1. 3,respectively. Moreover,the quality of pepper seedlings could be protected effectively. Compared to the fluorescent lamp,LED with high luminous efficiency and low energy consumption was suitable for the storage or long-distance transportation of pepper seedlings in low temperature and poor light environments.展开更多
With the application of energy-saving, environmental and durable LED lighting products, the reliability testing has become a pivot point for the large scale industrialization and popularization. The paper briefly intr...With the application of energy-saving, environmental and durable LED lighting products, the reliability testing has become a pivot point for the large scale industrialization and popularization. The paper briefly introduces two methods to be respectively applied in the accelerated depreciatinn lesting for the luminous flex of LED lighting products and the life of outdoor LED-driving power, which can sharply shorten the time for lifetime lest. providing references for the LED lighting products＇ reliability evaluation.展开更多
Objectives: Peripheral neuropathy (PN) is a significant contributor to disability in the elderly. It is also one of the most prevalent complications of type 2 diabetes, prediabetes and metabolic syndrome. PN is common...Objectives: Peripheral neuropathy (PN) is a significant contributor to disability in the elderly. It is also one of the most prevalent complications of type 2 diabetes, prediabetes and metabolic syndrome. PN is commonly associated with pain, numbness, tingling, burning, and cramping in the feet and legs. Current treatment options are limited to controlling pain, seizures and use of antidepressant medications. These treatments have undesirable side effects and don’t stop PN progression. Here we utilized a combination of individual-specific modalities to improve local circulation and relieve PN symptoms. Methods: We conducted an open-label, multicenter pilot trial with 34 subjects (19 males and 15 females ranging from 40 - 85 years of age). All of the participants were diagnosed with peripheral neuropathy and had bilateral symptoms in their feet, and many reported the same symptoms (pain, numbness, tingling, burning, and cramping) in their lower legs. The duration of symptoms ranged from four months to over six years. On Day 0, subjects were given a 90-day supply of the oral supplement with dosing instructions and a LED light therapy device. They also received three platelet-rich plasma (PRP) injections in their lower extremities. Subjects also received an extracorporeal shockwave therapy (ESWT) treatment for each foot and subsequently twice per week for the first six weeks, then once weekly for the duration of the study. Subjects filled out the Brief Pain Index (BPI) at weekly intervals. On Day 90, subjects completed the Patient Global Impression of Change (PGIC) survey. Results: There were significant responses to pain, as evidenced by BPI scores at weeks 8, 9, 10 and 11 (p = 0.02, 0.01, 0.02, and 0.003, respectively). Analysis of the final day PGIC survey showed a favorable outcome for 73% of participants (p = 0.003), with the majority reporting Very Much Improved. Conclusions: By utilizing a multi-modality treatment protocol that includes PRP, LED light therapy, ESWT and an oral dietary supplement, we observed significant reductions in BPI scores. Quality of life and their overall impression of change (PGIC) were significantly improved, and there were no significant side effects.展开更多
Light spectrum plays an important role in regulating the growth and development of in vitro cultured potato(Solanum tuberosum L.) plantlets. The status of potato plantlets at the end of in vitro stage influences the m...Light spectrum plays an important role in regulating the growth and development of in vitro cultured potato(Solanum tuberosum L.) plantlets. The status of potato plantlets at the end of in vitro stage influences the minituber production after transplanting. With 100 μmol m^-2s^-1 total photosynthetic photon flux density(PPFD), a light spectrum study of 100% red light emitting diodes(LEDs) light spectrum(RR), 100% blue LEDs light spectrum(BB), 65% red+35% blue LEDs light spectrum(RB), and 45% red+35% blue+20% green LEDs light spectrum(RBG) providing illumination at the in vitro cultured stage of potato plantlets for 4 weeks using fluorescent lamp as control(CK) was performed to investigate the effects of LEDs light spectrum on the growth, leaf anatomy, and chloroplast ultrastructure of potato plantlets in vitro as well as the minituber yield after 2 months transplanting in the greenhouse. Compared to CK, RB and RBG promoted the growth of potato plantlets in vitro with increased stem diameter, plantlet fresh weight, plantlet dry weight, and health index. Furthermore, BB induced the greatest stem diameter as well as the highest health index in potato plantlets in vitro. Root activity, soluble protein, and free amino acid were also significantly enhanced by BB, whereas carbohydrates were improved by RR. In addition, thickness of leaf, palisade parenchyma and spongy parenchyma was significantly increased by BB and RBG. Chloroplasts under BB and RBG showed well-developed grana thylakoid and stroma thylakoid. Unexpectedly, distinct upper epidermis with greatest thickness was induced and palisade parenchyma and spongy parenchyma were arranged neatly in RR. After transplanting in the greenhouse for 2 months, potato plantlets in vitro from BB, RB, and RBG produced high percentage of large size tuber. BB improved fresh and dry weights of the biggest tuber but decreased tuber number per plantlet. In addition, RBG increased tuber number as well as tuber fresh and dry weight slightly. Our results suggested monochromatic blue LEDs as well as combined red, blue or/and green LEDs light spectrum were superior to fluorescent lamp spectrum in micro-propagation of potato plantlets. Therefore, the application of RBG was suitable;BB and RB could be used as alternatives.展开更多
Diamond reinforced copper （Cu/diamond） composites were prepared by a pressure infilla＇ation technique. The composites show a super high conductivity of 713 W.m-1.K-1 in combination with an extremely low coefficient...Diamond reinforced copper （Cu/diamond） composites were prepared by a pressure infilla＇ation technique. The composites show a super high conductivity of 713 W.m-1.K-1 in combination with an extremely low coefficient of thermal expansion （CTE） of 7.72 × 10-6 K-1 （25-100℃）, which are achieved by modifying the copper matrix with adding 0.3 wt.% of boron to get a good thermal contact between the matrix and the diamond particles. By adopting a series of postmachining techniques the composites were made into near-net-shape parts, and an electroless silver coating was also successfully plated on the composites. Finally, their potential applications in the thermal management of fight emitting diodes （LED） were illustrated via prototype examples.展开更多
Red and blue light illumination has been reported to significantly affect plantlet growth.Potato is an important food and feed crop in the world and potato plantlet cultured in vitro plays an important role in potato ...Red and blue light illumination has been reported to significantly affect plantlet growth.Potato is an important food and feed crop in the world and potato plantlet cultured in vitro plays an important role in potato production.However,few studies have documented the effects of red and blue light on the growth of potato plantlets revealed at the transcriptome level.The objective of this study was to determine the growth and physiological responses of potato plantlets cultured in vitro under monochromatic red(RR),monochromatic blue(BB)as well as combined red and blue(RB)LEDs using the RNA-Seq technique.In total,3150 and 814 differentially expressed genes(DEGs)were detected in potato plantlets under RR and BB,respectively,compared to RB(used as control).Compared to the control,the DEGs enriched in"photosynthesis"and"photosynthesis-antenna proteins"metabolic pathways were up-regulated and down-regulated by BB and RR,respectively,which might be responsible for the increases and decreases of maximum quantum yield(F_(v)/F_(m)),photochemical quantum yield(φ_(PSII)),photochemical quenching(q_(P))and electron transfer rate(ETR)in BB and RR,respectively.Potato plantlets exhibited dwarfed stems and extended leaves under BB,whereas elongated stems and small leaves were induced under RR.These dramatically altered plantlet phenotypes were associated with variable levels of endogenous plant hormones gibberellin(GAs),indoleacetic acid(IAA)and cytokinins(CKs),as assessed in stems and leaves of potato plantlets.In addition,monochromatic red and blue LEDs trigged the opposite expression profiles of DEGs identified in the"plant hormone signal transduction"metabolic pathway,which were closely related to the endogenous plant hormone levels in potato plantlets.Our results provide insights into the responses of potato plantlets cultured in vitro to red and blue LEDs at the transcriptomic level and may contribute to improvements in the micro-propagation of potato plantlets cultured in vitro from the light spectrum aspect.展开更多
Phosphor SrGa2 S4 ：Eu^2＋ was synthesized with a high temperature solid state reaction. Its absorption spectrum, photolumineseence spectra, and fluorescence lifetime were studied in details. The excitation spectrum e...Phosphor SrGa2 S4 ：Eu^2＋ was synthesized with a high temperature solid state reaction. Its absorption spectrum, photolumineseence spectra, and fluorescence lifetime were studied in details. The excitation spectrum extended from UV to visible light region, and matched the emission of GaN chip. （Sr1- xEUx）Ga2S4 emits strong green light and the concentration quenching did not occur; while the thermal quenching was evident. The emission peak shifted to long wavelength with inereasing Eu^2＋ concentration because of the changing of the crystal field strength. The lifetime of Eu^2＋ ion was in the order of microsecond, which was reasonable for d→f transition. The electroluminescence spectrum of as-fabricated PC-LED at IF=20 mA was measured and most of the blue light of blue-LED chip at 460 nm was absorbed by the phosphor and simultaneously down-converted into an intensive green light at 540 nm. The color coordinate was （0.32, 0.63）. SrGa2S4：Eu^2＋ was a promising phosphor for GaN-based green LEDs.展开更多
In order to accurately and automatically measure the light emitting diode(LED) colorimetric parameters,the design of a measurement system by adopting a high-performance spectrometer and looking-up table method was pre...In order to accurately and automatically measure the light emitting diode(LED) colorimetric parameters,the design of a measurement system by adopting a high-performance spectrometer and looking-up table method was presented based on the LabVIEW.First,the data of the LED relative spectral power distribution(SPD) were read by the spectrometer to measure LED chromaticity coordinate,and the slopes table were formed by the LED chromaticity coordinate and the equal stimulus point.Then,the CIE1931 chromaticity diagram was divided into 4 different regions to ensure the slopes table that had the character of monotonic decreasing.Finally,the LED dominant wavelength and purity were automatically calculated using the LabVIEW programs.The data of LEDs' colorimetric parameters have demonstrated that the measurement method in this paper can achieve higher precision result.展开更多
This paper describes the development of a timer based voltage to frequency converter(V FC).Timer LM555is used in astable multivibrator mode with two OPTO-LDRs(light dependent resistors)in the circuitry.The frequency o...This paper describes the development of a timer based voltage to frequency converter(V FC).Timer LM555is used in astable multivibrator mode with two OPTO-LDRs(light dependent resistors)in the circuitry.The frequency of timer output waveform which is measured using a digital storage oscillator(DSO)is almost linearly proportional to the applied input voltage.Hence we obtain a linear relationship between the frequency of timer output waveform and the input voltage.Because of its quasi-digital output,the main advantages of this developed converter are linear input-output relationship,small size,easy portabilityand high cost performance.In addition,the timer output waveform can be directly interfaced with personal computer or microprocessor/microcontroller for further processing of the input voltage signal without intervening any analog-to-digital converter(ADC).展开更多
A system with uniform light reflection in the inner surface within a horizontal 2/3 cylindrical structure for line-scan CCD of the print testing was designed. The design was based on diffuse reflection uniformity of t...A system with uniform light reflection in the inner surface within a horizontal 2/3 cylindrical structure for line-scan CCD of the print testing was designed. The design was based on diffuse reflection uniformity of the integrating sphere and requirement of the strip uniform illumination region. This system was called dome light. White light LED array light sources were used for uniform illumi- nation. The LEDs were filtrated to composite array light source based on coefficient of variation of a single LED. The standard white board and SG color checkers were used in the line-scan CCD imaging experiments under the dome light and ordinary illumination light source. The average color difference （AE） of SG color checkers in CIELAB space was 2. 091 under the dome light and 2. 286 under ordinary illumination light source respectively. Experimental results indicate that the dome light can satisfy illumination uniformity and color rendering consistency for line-scan CCD and provide a standard light source for uniform calibration of different cameras.展开更多
Progress with GaN-based light emitting diodes （LEDs） that incorporate nanostructures is reviewed, especially the re- cent achievements in our research group. Nano-patterned sapphire substrates have been used to grow...Progress with GaN-based light emitting diodes （LEDs） that incorporate nanostructures is reviewed, especially the re- cent achievements in our research group. Nano-patterned sapphire substrates have been used to grow an A1N template layer for deep-ultraviolet （DUV） LEDs. One efficient surface nano-texturing technology, hemisphere-cones-hybrid nanostruc- tures, was employed to enhance the extraction efficiency of InGaN flip-chip LEDs. Hexagonal nanopyramid GaN-based LEDs have been fabricated and show electrically driven color modification and phosphor-free white light emission because of the linearly increased quantum well width and indium incorporation from the shell to the core. Based on the nanostruc- tures, we have also fabricated surface plasmon-enhanced nanoporous GaN-based green LEDs using AAO membrane as a mask. Benefitting from the strong lateral SP coupling as well as good electrical protection by a passivation layer, the EL intensity of an SP-enhanced nanoporous LED was significantly enhanced by 380%. Furthermore, nanostructures have been used for the growth of GaN LEDs on amorphous substrates, the fabrication of stretchable LEDs, and for increasing the 3-dB modulation bandwidth for visible light communication.展开更多
A new optical wireless network based on white LED lights in home area is proposed. It is a duplex channel communication system utilizing signal emitters of white LED lights in the downlink and infrared devices in the ...A new optical wireless network based on white LED lights in home area is proposed. It is a duplex channel communication system utilizing signal emitters of white LED lights in the downlink and infrared devices in the uplink. Strategies for the system construction are given. Performance for users＇ mobile access of different kinds of optical concentrators is investigated. Indoor channel band-width is analyzed considering white LED light distribution, wall reflection, and receivers field of view （FOV）. Various modulation methods are discussed. A demo point-to-point system for surfing the net is constructed using a new line code of 4B6B which is developed to stabilize the optical output, and a peak data rate of 1 Mbps is achieved. This system is built into the lighting infrastructure, therefore decreasing the cost and offering a solution for wireless access in places which are sensitive to radio frequency like hospitals.展开更多
Carotenoids are an important component of the human diet, and fruit is a primary source of carotenoids. The synthesis and regulation of carotenoids in fruit are important contributors to the formation of fruit quality...Carotenoids are an important component of the human diet, and fruit is a primary source of carotenoids. The synthesis and regulation of carotenoids in fruit are important contributors to the formation of fruit quality. In China, strawberry is one of the main seasonal fruits grown in the winter. Previous studies have shown that light has a significant effect on the metabolism of anthocyanins, sugars, and polyphenols in strawberry. However, the understanding of the role of light in regulating the metabolism of carotenoids in strawberry remains limited. This study investigated the effects of blue, red, yellow-green, and white light on carotenoid metabolism in strawberry.Blue light treatment promoted the synthesis of multiple carotenoids, including lutein, compared with the other three treatment groups. The RNA sequencing data revealed that blue light treatment promoted the expression of lycopene ε-cyclase(LCYE), and the transient overexpression of LCYE in strawberry fruit promoted lutein accumulation in strawberry. Overall, the results suggest that blue light can promote the synthesis of lutein in strawberry by inducing the expression of LCYE.展开更多
Carotenoids are involved in the formation of plant leaf color as well as photosystem photoprotection. This study showed that blue light significantly induced up-regulation of the total carotenoid content in the inner ...Carotenoids are involved in the formation of plant leaf color as well as photosystem photoprotection. This study showed that blue light significantly induced up-regulation of the total carotenoid content in the inner leaves of orange-head Chinese cabbage(OHCC). Furthermore, the transcriptomic analysis revealed that blue light treatment induced upregulation of genes in photosynthesis(BrHY5-2, BrCOP1 and BrDET1) and the methylerythritol 4-phosphate pathways(BrGGPS, BrDXS and BrHDR) upstream of the carotenoid metabolic pathway. Carotenoid metabolomic analysis revealed that the accumulation of several orange and red carotenoids(lycopene, zeaxanthin, β-carotene, lutein, and β-cryptoxanthin) after blue light treatment contributed to the deepening of the leaf coloration, suggesting that short-term blue light treatment could be used to boost nutritional quality. The light signal gene BrHY5-2 participated in the blue light-induced transcriptional regulation of carotenoid biosynthesis in OHCC. Overexpression of BrHY5-2 in Arabidopsis significantly increased the total carotenoid content and the sensitivity to blue light. The above findings revealed new insights about blue-light-induced carotenoid synthesis and accumulation in OHCC lines. They suggested a new engineering approach to increase the nutritional value of vegetables.展开更多
文摘As energy gradually becomes a more valuable commodity, the desire for reduced energy losses strengthens. Lighting is a critical field on this matter, as it accounts for a large percentage of the global electricity consumption and modern lighting systems are greatly more efficient than incandescent, discharge, and fluorescent lights. Previous research has proven that plants do not require the entire visible spectrum but react only to specific wavelengths, making it possible to control their growth and yield via artificial lighting. The flexibility of control of Light Emitting Diode (LED) lights allows for the combination of great energy losses reduction and controlled plant growth, achieving the improvement of two major parameters in a single action. This review paper summarizes the current research on the effect different light wavelengths have on specific plant species and discusses the applications of LED lighting for horticulture, yield storage, and disease protection.
文摘In the context of promoting green energy transition and addressing climate change globally,solar energy,as a clean and renewable energy source,has gradually become a hot topic for research.Solar streetlight systems realize energy self-sufficiency and environment-friendly lighting by integrating photovoltaic power generation technology and efficient LED lighting technology.By comprehensively analyzing the current status of the application of solar streetlights at home and abroad,this paper discusses its technical advantages,market penetration,and challenges in its development.In terms of technical characteristics,this paper focuses on analyzing the key technologies such as energy conversion efficiency and intelligent control systems of solar streetlights.
文摘The paper summarizes the research on the development of standards for tunnels and roads LED lighiing application in Shanghai. analyzes the existing problems on LED road lamps and lighting design, introduces the experiments and testing results, and summarizes current problems of LED street lighting, proposing that LED lighting energy conservation should he ＂systematic energy saving＂ throughout the full life cycle based on the integration of products and applications.
文摘As the quality of power LED improves and the cost of power LED reduces, semiconductor lighting will replace incandescent and fluorescent lighting gradually, causing another revolution on the lighting history. And its driving solution has been greatly accelerated. Based on the white power LED I-V characteristics and the application ambiance, proposed is a new LED lighting solution, suiting indoor and outdoor illumination. According to the test results, the design is optimized, and the electrical efficiency is 95% and the output current deviation is 13.0%.
基金Supported by National Key Research and Development Program of China(2017YFB0403901)
文摘Storage and transportation of vegetable commercial seedlings becomes an important link along with the continuous expansion of planting areas of facility vegetables and vegetable seedling culture industry. In this study,pepper variety‘Nongda 24' was as the experimental material,and changes in the morphological and physiological indicators of plug seedlings in different low temperature( 6 and 11℃) and poor light environments were studied to find suitable storage environmental conditions. The results showed that pepper seedlings could be stored and transported for 14 days when storage temperature was 11℃ and light conditions such as light intensity and photoperiod were 30 μmol/( m^2·s)and 12 h/d by using a fluorescent lamp with R∶ B ratio of 1. 9,and 15 μmol/( m^2·s) and 24 h/d by using LED with R∶ B ratio of 1. 3,respectively. Moreover,the quality of pepper seedlings could be protected effectively. Compared to the fluorescent lamp,LED with high luminous efficiency and low energy consumption was suitable for the storage or long-distance transportation of pepper seedlings in low temperature and poor light environments.
文摘With the application of energy-saving, environmental and durable LED lighting products, the reliability testing has become a pivot point for the large scale industrialization and popularization. The paper briefly introduces two methods to be respectively applied in the accelerated depreciatinn lesting for the luminous flex of LED lighting products and the life of outdoor LED-driving power, which can sharply shorten the time for lifetime lest. providing references for the LED lighting products＇ reliability evaluation.
文摘Objectives: Peripheral neuropathy (PN) is a significant contributor to disability in the elderly. It is also one of the most prevalent complications of type 2 diabetes, prediabetes and metabolic syndrome. PN is commonly associated with pain, numbness, tingling, burning, and cramping in the feet and legs. Current treatment options are limited to controlling pain, seizures and use of antidepressant medications. These treatments have undesirable side effects and don’t stop PN progression. Here we utilized a combination of individual-specific modalities to improve local circulation and relieve PN symptoms. Methods: We conducted an open-label, multicenter pilot trial with 34 subjects (19 males and 15 females ranging from 40 - 85 years of age). All of the participants were diagnosed with peripheral neuropathy and had bilateral symptoms in their feet, and many reported the same symptoms (pain, numbness, tingling, burning, and cramping) in their lower legs. The duration of symptoms ranged from four months to over six years. On Day 0, subjects were given a 90-day supply of the oral supplement with dosing instructions and a LED light therapy device. They also received three platelet-rich plasma (PRP) injections in their lower extremities. Subjects also received an extracorporeal shockwave therapy (ESWT) treatment for each foot and subsequently twice per week for the first six weeks, then once weekly for the duration of the study. Subjects filled out the Brief Pain Index (BPI) at weekly intervals. On Day 90, subjects completed the Patient Global Impression of Change (PGIC) survey. Results: There were significant responses to pain, as evidenced by BPI scores at weeks 8, 9, 10 and 11 (p = 0.02, 0.01, 0.02, and 0.003, respectively). Analysis of the final day PGIC survey showed a favorable outcome for 73% of participants (p = 0.003), with the majority reporting Very Much Improved. Conclusions: By utilizing a multi-modality treatment protocol that includes PRP, LED light therapy, ESWT and an oral dietary supplement, we observed significant reductions in BPI scores. Quality of life and their overall impression of change (PGIC) were significantly improved, and there were no significant side effects.
基金supported by the National High-Tech R&D Program of China (2013 AA 103005)
文摘Light spectrum plays an important role in regulating the growth and development of in vitro cultured potato(Solanum tuberosum L.) plantlets. The status of potato plantlets at the end of in vitro stage influences the minituber production after transplanting. With 100 μmol m^-2s^-1 total photosynthetic photon flux density(PPFD), a light spectrum study of 100% red light emitting diodes(LEDs) light spectrum(RR), 100% blue LEDs light spectrum(BB), 65% red+35% blue LEDs light spectrum(RB), and 45% red+35% blue+20% green LEDs light spectrum(RBG) providing illumination at the in vitro cultured stage of potato plantlets for 4 weeks using fluorescent lamp as control(CK) was performed to investigate the effects of LEDs light spectrum on the growth, leaf anatomy, and chloroplast ultrastructure of potato plantlets in vitro as well as the minituber yield after 2 months transplanting in the greenhouse. Compared to CK, RB and RBG promoted the growth of potato plantlets in vitro with increased stem diameter, plantlet fresh weight, plantlet dry weight, and health index. Furthermore, BB induced the greatest stem diameter as well as the highest health index in potato plantlets in vitro. Root activity, soluble protein, and free amino acid were also significantly enhanced by BB, whereas carbohydrates were improved by RR. In addition, thickness of leaf, palisade parenchyma and spongy parenchyma was significantly increased by BB and RBG. Chloroplasts under BB and RBG showed well-developed grana thylakoid and stroma thylakoid. Unexpectedly, distinct upper epidermis with greatest thickness was induced and palisade parenchyma and spongy parenchyma were arranged neatly in RR. After transplanting in the greenhouse for 2 months, potato plantlets in vitro from BB, RB, and RBG produced high percentage of large size tuber. BB improved fresh and dry weights of the biggest tuber but decreased tuber number per plantlet. In addition, RBG increased tuber number as well as tuber fresh and dry weight slightly. Our results suggested monochromatic blue LEDs as well as combined red, blue or/and green LEDs light spectrum were superior to fluorescent lamp spectrum in micro-propagation of potato plantlets. Therefore, the application of RBG was suitable;BB and RB could be used as alternatives.
基金supported by the National Natural Science Foundation of China (No. 50971020)the National High-Tech Research and Development Program of China (No. 2008AA03Z505)
文摘Diamond reinforced copper （Cu/diamond） composites were prepared by a pressure infilla＇ation technique. The composites show a super high conductivity of 713 W.m-1.K-1 in combination with an extremely low coefficient of thermal expansion （CTE） of 7.72 × 10-6 K-1 （25-100℃）, which are achieved by modifying the copper matrix with adding 0.3 wt.% of boron to get a good thermal contact between the matrix and the diamond particles. By adopting a series of postmachining techniques the composites were made into near-net-shape parts, and an electroless silver coating was also successfully plated on the composites. Finally, their potential applications in the thermal management of fight emitting diodes （LED） were illustrated via prototype examples.
基金funded by the Scientific Research Fund of College of Science&Technology,Ningbo University for the Introduction of High-level Talents,China(RC190006)。
文摘Red and blue light illumination has been reported to significantly affect plantlet growth.Potato is an important food and feed crop in the world and potato plantlet cultured in vitro plays an important role in potato production.However,few studies have documented the effects of red and blue light on the growth of potato plantlets revealed at the transcriptome level.The objective of this study was to determine the growth and physiological responses of potato plantlets cultured in vitro under monochromatic red(RR),monochromatic blue(BB)as well as combined red and blue(RB)LEDs using the RNA-Seq technique.In total,3150 and 814 differentially expressed genes(DEGs)were detected in potato plantlets under RR and BB,respectively,compared to RB(used as control).Compared to the control,the DEGs enriched in"photosynthesis"and"photosynthesis-antenna proteins"metabolic pathways were up-regulated and down-regulated by BB and RR,respectively,which might be responsible for the increases and decreases of maximum quantum yield(F_(v)/F_(m)),photochemical quantum yield(φ_(PSII)),photochemical quenching(q_(P))and electron transfer rate(ETR)in BB and RR,respectively.Potato plantlets exhibited dwarfed stems and extended leaves under BB,whereas elongated stems and small leaves were induced under RR.These dramatically altered plantlet phenotypes were associated with variable levels of endogenous plant hormones gibberellin(GAs),indoleacetic acid(IAA)and cytokinins(CKs),as assessed in stems and leaves of potato plantlets.In addition,monochromatic red and blue LEDs trigged the opposite expression profiles of DEGs identified in the"plant hormone signal transduction"metabolic pathway,which were closely related to the endogenous plant hormone levels in potato plantlets.Our results provide insights into the responses of potato plantlets cultured in vitro to red and blue LEDs at the transcriptomic level and may contribute to improvements in the micro-propagation of potato plantlets cultured in vitro from the light spectrum aspect.
基金Project supported by the National Natural Science Foundation of China (20171046)
文摘Phosphor SrGa2 S4 ：Eu^2＋ was synthesized with a high temperature solid state reaction. Its absorption spectrum, photolumineseence spectra, and fluorescence lifetime were studied in details. The excitation spectrum extended from UV to visible light region, and matched the emission of GaN chip. （Sr1- xEUx）Ga2S4 emits strong green light and the concentration quenching did not occur; while the thermal quenching was evident. The emission peak shifted to long wavelength with inereasing Eu^2＋ concentration because of the changing of the crystal field strength. The lifetime of Eu^2＋ ion was in the order of microsecond, which was reasonable for d→f transition. The electroluminescence spectrum of as-fabricated PC-LED at IF=20 mA was measured and most of the blue light of blue-LED chip at 460 nm was absorbed by the phosphor and simultaneously down-converted into an intensive green light at 540 nm. The color coordinate was （0.32, 0.63）. SrGa2S4：Eu^2＋ was a promising phosphor for GaN-based green LEDs.
基金National Natural Science Foundation of China (No. 51105289)Doctoral Program Foundation of Self-determined and Innovative Research Funds of WUT,China (No. 2010-ZY-JD-034)
文摘In order to accurately and automatically measure the light emitting diode(LED) colorimetric parameters,the design of a measurement system by adopting a high-performance spectrometer and looking-up table method was presented based on the LabVIEW.First,the data of the LED relative spectral power distribution(SPD) were read by the spectrometer to measure LED chromaticity coordinate,and the slopes table were formed by the LED chromaticity coordinate and the equal stimulus point.Then,the CIE1931 chromaticity diagram was divided into 4 different regions to ensure the slopes table that had the character of monotonic decreasing.Finally,the LED dominant wavelength and purity were automatically calculated using the LabVIEW programs.The data of LEDs' colorimetric parameters have demonstrated that the measurement method in this paper can achieve higher precision result.
文摘This paper describes the development of a timer based voltage to frequency converter(V FC).Timer LM555is used in astable multivibrator mode with two OPTO-LDRs(light dependent resistors)in the circuitry.The frequency of timer output waveform which is measured using a digital storage oscillator(DSO)is almost linearly proportional to the applied input voltage.Hence we obtain a linear relationship between the frequency of timer output waveform and the input voltage.Because of its quasi-digital output,the main advantages of this developed converter are linear input-output relationship,small size,easy portabilityand high cost performance.In addition,the timer output waveform can be directly interfaced with personal computer or microprocessor/microcontroller for further processing of the input voltage signal without intervening any analog-to-digital converter(ADC).
基金Supported by the National Natural Science Foundation of China(61078048)
文摘A system with uniform light reflection in the inner surface within a horizontal 2/3 cylindrical structure for line-scan CCD of the print testing was designed. The design was based on diffuse reflection uniformity of the integrating sphere and requirement of the strip uniform illumination region. This system was called dome light. White light LED array light sources were used for uniform illumi- nation. The LEDs were filtrated to composite array light source based on coefficient of variation of a single LED. The standard white board and SG color checkers were used in the line-scan CCD imaging experiments under the dome light and ordinary illumination light source. The average color difference （AE） of SG color checkers in CIELAB space was 2. 091 under the dome light and 2. 286 under ordinary illumination light source respectively. Experimental results indicate that the dome light can satisfy illumination uniformity and color rendering consistency for line-scan CCD and provide a standard light source for uniform calibration of different cameras.
基金Project supported by the National Natural Science Foundation of China(Grant No.61334009)the National High Technology Research and Development Program of China(Grant Nos.2015AA03A101 and 2014BAK02B08)+1 种基金China International Science and Technology Cooperation Program(Grant No.2014DFG62280)the"Import Outstanding Technical Talent Plan"and"Youth Innovation Promotion Association Program"of the Chinese Academy of Sciences
文摘Progress with GaN-based light emitting diodes （LEDs） that incorporate nanostructures is reviewed, especially the re- cent achievements in our research group. Nano-patterned sapphire substrates have been used to grow an A1N template layer for deep-ultraviolet （DUV） LEDs. One efficient surface nano-texturing technology, hemisphere-cones-hybrid nanostruc- tures, was employed to enhance the extraction efficiency of InGaN flip-chip LEDs. Hexagonal nanopyramid GaN-based LEDs have been fabricated and show electrically driven color modification and phosphor-free white light emission because of the linearly increased quantum well width and indium incorporation from the shell to the core. Based on the nanostruc- tures, we have also fabricated surface plasmon-enhanced nanoporous GaN-based green LEDs using AAO membrane as a mask. Benefitting from the strong lateral SP coupling as well as good electrical protection by a passivation layer, the EL intensity of an SP-enhanced nanoporous LED was significantly enhanced by 380%. Furthermore, nanostructures have been used for the growth of GaN LEDs on amorphous substrates, the fabrication of stretchable LEDs, and for increasing the 3-dB modulation bandwidth for visible light communication.
文摘A new optical wireless network based on white LED lights in home area is proposed. It is a duplex channel communication system utilizing signal emitters of white LED lights in the downlink and infrared devices in the uplink. Strategies for the system construction are given. Performance for users＇ mobile access of different kinds of optical concentrators is investigated. Indoor channel band-width is analyzed considering white LED light distribution, wall reflection, and receivers field of view （FOV）. Various modulation methods are discussed. A demo point-to-point system for surfing the net is constructed using a new line code of 4B6B which is developed to stabilize the optical output, and a peak data rate of 1 Mbps is achieved. This system is built into the lighting infrastructure, therefore decreasing the cost and offering a solution for wireless access in places which are sensitive to radio frequency like hospitals.
基金supported by the National Natural Science Foundation of China (31901996)the Natural Science Foundation of Jiangsu Province,China (BK20190264)the Major Agricultural New Varieties Creation Project of Jiangsu Province,China (PZCZ201721)。
文摘Carotenoids are an important component of the human diet, and fruit is a primary source of carotenoids. The synthesis and regulation of carotenoids in fruit are important contributors to the formation of fruit quality. In China, strawberry is one of the main seasonal fruits grown in the winter. Previous studies have shown that light has a significant effect on the metabolism of anthocyanins, sugars, and polyphenols in strawberry. However, the understanding of the role of light in regulating the metabolism of carotenoids in strawberry remains limited. This study investigated the effects of blue, red, yellow-green, and white light on carotenoid metabolism in strawberry.Blue light treatment promoted the synthesis of multiple carotenoids, including lutein, compared with the other three treatment groups. The RNA sequencing data revealed that blue light treatment promoted the expression of lycopene ε-cyclase(LCYE), and the transient overexpression of LCYE in strawberry fruit promoted lutein accumulation in strawberry. Overall, the results suggest that blue light can promote the synthesis of lutein in strawberry by inducing the expression of LCYE.
基金supported by the National Key Research and Development Program of China (2017YFD0101802 and 2016YFD0101701 )the Key Research and Development Program of Yangling Seed Innovative Center, China (Ylzy-sc-04)the Key Research and Development Program of Shaanxi Province, China (2023YBNY-078)。
文摘Carotenoids are involved in the formation of plant leaf color as well as photosystem photoprotection. This study showed that blue light significantly induced up-regulation of the total carotenoid content in the inner leaves of orange-head Chinese cabbage(OHCC). Furthermore, the transcriptomic analysis revealed that blue light treatment induced upregulation of genes in photosynthesis(BrHY5-2, BrCOP1 and BrDET1) and the methylerythritol 4-phosphate pathways(BrGGPS, BrDXS and BrHDR) upstream of the carotenoid metabolic pathway. Carotenoid metabolomic analysis revealed that the accumulation of several orange and red carotenoids(lycopene, zeaxanthin, β-carotene, lutein, and β-cryptoxanthin) after blue light treatment contributed to the deepening of the leaf coloration, suggesting that short-term blue light treatment could be used to boost nutritional quality. The light signal gene BrHY5-2 participated in the blue light-induced transcriptional regulation of carotenoid biosynthesis in OHCC. Overexpression of BrHY5-2 in Arabidopsis significantly increased the total carotenoid content and the sensitivity to blue light. The above findings revealed new insights about blue-light-induced carotenoid synthesis and accumulation in OHCC lines. They suggested a new engineering approach to increase the nutritional value of vegetables.
