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光照强度和CO_2浓度间接调控对甘薯无糖组培苗光合特性的影响 被引量:13
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作者 徐志刚 崔瑾 +2 位作者 焦学磊 丁为民 李式军 《南京农业大学学报》 CAS CSCD 北大核心 2004年第1期11-14,共4页
以自行研制的组培苗光合速率测量系统检测了叶用甘薯无糖组培苗的光合速率 ,定量分析了外环境中CO2 浓度和光合光量子通量密度 (PPFD)对无糖组培苗光合特性的影响。结果表明 :采用透气封口材料和自然换气 ,间接合理调控PPFD和外环境CO2... 以自行研制的组培苗光合速率测量系统检测了叶用甘薯无糖组培苗的光合速率 ,定量分析了外环境中CO2 浓度和光合光量子通量密度 (PPFD)对无糖组培苗光合特性的影响。结果表明 :采用透气封口材料和自然换气 ,间接合理调控PPFD和外环境CO2 浓度对组培苗净光合作用产生积极促进作用 ;仅提高PPFD或外环境CO2 浓度不能有效促进光合作用。当使用透气率为 0 4的封口材料时 ,甘薯无糖组培苗的光合作用在光合光量子通量密度 2 5 0 μmol·m-2 ·s-1 和外环境CO2 浓度 8735 μmol·mol-1 展开更多
关键词 甘薯 无糖组培苗 光合特性 光照强度 二氧化碳浓度 间接调控 光合光量子通量密度
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新疆高产棉田光合特性研究 被引量:9
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作者 田立文 娄春恒 +2 位作者 文如镜 李蕾 谢迪佳 《西北农业学报》 CAS CSCD 1997年第3期41-43,共3页
高产棉田净光合效率日变化有1个明显的峰值,出现在14:00,它与光合光量子通量密度呈线性正相关。盛蕾期14:00后的净光合速率较14:00前小,高峰值多大于花铃期,而花铃期14:00前后净光合速率无明显差异。分析表明... 高产棉田净光合效率日变化有1个明显的峰值,出现在14:00,它与光合光量子通量密度呈线性正相关。盛蕾期14:00后的净光合速率较14:00前小,高峰值多大于花铃期,而花铃期14:00前后净光合速率无明显差异。分析表明,水分和光照仍是高产棉田光合作用的主要限制因子。 展开更多
关键词 光合速率 光合光量子 通量密度 棉花
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植物培养箱内LED光源均匀性的研究 被引量:6
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作者 武礼宾 曹立 +1 位作者 陈美香 刘银春 《照明工程学报》 2015年第2期104-109,共6页
比较了LED排列方式以及匀光板对植物培养箱内辐射照度分布均匀性的影响。在培养箱内安装了四种LED面光源:灯珠环形排列无匀光板(H0)、灯珠环形排列有匀光板(H1)、灯珠矩形排列无匀光板(J0)以及灯珠矩形排列有匀光板(J1)。然后采用太阳... 比较了LED排列方式以及匀光板对植物培养箱内辐射照度分布均匀性的影响。在培养箱内安装了四种LED面光源:灯珠环形排列无匀光板(H0)、灯珠环形排列有匀光板(H1)、灯珠矩形排列无匀光板(J0)以及灯珠矩形排列有匀光板(J1)。然后采用太阳分光辐射计(S-2441型)测量培养箱内72×6=432个测试点的辐射照度值,即每层受光面72个点,共6层。四个实验组各水平受光面的辐射照度均匀性采用标准差计算,其结果是:J1(1.004)<J0(1.308)<H1(2.149)<H0(2.608);四个实验组在垂直方向采用辐射照度梯度(斜率)来计算,其结果是:J1(1.066)<J0(1.353)<H1(1.737)<H0(1.783)。结果表明:(1)矩形排列均匀性优于环形排列,因为J1、J0在水平方向的辐射照度变化小,在垂直方向辐射照度变化梯度也小;(2)匀光板可以在一定程度提高均匀性,但也降低了辐射照度值。提供了一种将光合有效辐射照度转换成光合光量子通量密度的计算方法。 展开更多
关键词 辐射照度均匀性 LED照明 光合有效辐射 光合光量子通量密度 标准差
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InGaAsP/InP Double Quantum Well Intermixing Induced by Phosphorus Ion Implantation 被引量:2
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作者 CHEN Jie ZHAO Jie +1 位作者 WANG Yong-chen HAN De-jun 《Semiconductor Photonics and Technology》 CAS 2005年第4期217-220,共4页
A quantum well intermixing(QW1) investigation on double quantum well(DQW) structure with two different emitting wavelength caused by phosphorus ion implantation and following rapid thermal annealing (RTA) was ca... A quantum well intermixing(QW1) investigation on double quantum well(DQW) structure with two different emitting wavelength caused by phosphorus ion implantation and following rapid thermal annealing (RTA) was carried out by means of photoluminescence(PL). The ion implantation was performed at the energy of 120 keV with the dose ranging from 1 × 10^11cm^-2 to 1× 10^14cm^-2. The RTA was performed at the temperature of 700 ℃ for 30 s under pure nitrogen protection. The PL measurement implied that the band gap blue-shift from the upper well increases with the ion dose faster than that from lower well and the PL peaks from both QWs remained well separated under the lower dose implantation(-1 × 10^11cm^-2) indicating that the implant vacancy distribution affects the QWl. When the ion dose is over - 1 × 10^12cm^-2, the band gap blue-shift from both wells increases with the ion dose and finally the two peaks merge together as one peak indicating the ion implantation caused a total intermixing of both quantum wells. 展开更多
关键词 Ion implantation l InGaAsP/InP DOuble quantum well(DQW) Quantum well intermixing
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Ultraslow Optical Solitons in a Coupled Double Quantum-Well Nanostructure 被引量:1
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作者 HAO Xiang-Ying LIU Ji-Bing +2 位作者 LU Xin-You SONG Pei-Jun SI Liu-Gang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第3期519-523,共5页
We demonstrate the formation of ultraslow dark semiconductor double quantum well (SDQW) structure based optical solitons with a four-level scheme in an asymmetric on intersubband transitions by using only a low-inte... We demonstrate the formation of ultraslow dark semiconductor double quantum well (SDQW) structure based optical solitons with a four-level scheme in an asymmetric on intersubband transitions by using only a low-intensity pulsed laser radiation. With appropriate conditions we show numerically that the dark optical soliton can travel with a ultraslow group velocity Vg/c - -10^-3. Such a semiconductor system is much more practical than its atomic counterpart because of its flexible design and the controllable interference strength. This nonlinear optical process in the SDQW solid-state material may be used for the control technology of optical delay lines and optical buffers. 展开更多
关键词 optical solitons intersubband transitions semiconductor quantum well
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A Study on Photosynthetic Physiological Characteristics of Six Rare and Endangered Species 被引量:1
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作者 Tailin ZHONG Guangwu ZHAO +2 位作者 Jiamiao CHU Xiaomin GUO Genyou LI 《Agricultural Science & Technology》 CAS 2014年第8期1265-1270,共6页
The parameters of gas exchange and chlorophyl fluorescence in leaves of six rare and endangered species Neolitsea sericea, Cinnamomum japonicum var. cheni , Sinojackia microcarpa, Discocleidion glabrum var. trichocarp... The parameters of gas exchange and chlorophyl fluorescence in leaves of six rare and endangered species Neolitsea sericea, Cinnamomum japonicum var. cheni , Sinojackia microcarpa, Discocleidion glabrum var. trichocarpum, Parrotia sub-aequalis, Cercidiphyl um japonicum were measured in fields. The results showed that there were significant differences in photosynthetic capacity, intrinsic water use effi-ciency (WUEi ), the efficiency of primary conversion of light energy of PSⅡ and its potential activity, the quantum yield of PSⅡ electron transport, and the potential ca-pacity of heat dissipation among the six species. However, there was no significant difference in WUE. The highest values of net photosynthetic rate (Pn), transpiration rate (Tr) and stomatal conductance (gs) occurred in D. glabrum var. trichocarpum and the lowest in S. microcarpa. On the contrary, D. glabrum var. trichocarpum had the lowest WUE, intrinsic water use efficiency (WUEi ) and S. microcarpa had the highest. The results indicated that D. glabrum var. trichocarpum had higher photo-synthetic capacity and poorer WUE, while S. microcarpa had lower photosynthetic capacity and greater WUE. Furthermore, the mean values of maximal fluorescence (Fm), potential efficiency of primary conversion of light energy of PSⅡ (Fv/Fm),ΦPSⅡ, actual efficiency of primary conversion of light energy of PSⅡ (F′v/F′m) and non-photochemical quenching coefficient (NPQ) were the highest in S. micro-carpa, indicating that its PSⅡ had higher capacity of heat dissipation and could prevent photosynthetic apparatus from damage by excessive light energy. Correlation analysis showed that there were significant correlations among photosynthetic physi-ological parameters. However, the initial fluorescence (Fo) was not significantly cor-related with any other parameters. This study also revealed the extremely significant positive correlations between Pn and Tr, gs, apparent quantum yield (AQY), be-tween Tr and gs, between light saturation point (LSP) and AQY, between Fv/Fm and Fm, between ΦPSⅡ and photochemical quenching coefficient (qp), between Tr, gs and LSP, AQY. However, WUEi was significantly negatively correlated with Tr, gs, Pn, LSP and AQY. 展开更多
关键词 Gas exchange Chlorophyll fluorescence Water use efficiency Rare andendangered species
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Realization of Bipartite Positive-Operator-Value Measurements of Two-Photon Polarization States
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作者 LIN Qing 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第2期244-246,共3页
In this letter, we propose a scheme of a special quantum optical Fredkin gate assisted by optical manip- ulations and postselection from the coincidence measurements, and then modify it with cross-Kerr nonlinearities ... In this letter, we propose a scheme of a special quantum optical Fredkin gate assisted by optical manip- ulations and postselection from the coincidence measurements, and then modify it with cross-Kerr nonlinearities to be suitable for the realization of all possible positive operator-valued measurements of bipartite polarization states. This scheme is feasible in the lab with the current experimental technology. 展开更多
关键词 POVM linear optics cross-Kerr nonlinearity
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Study of the evanescent wave coupled semiconductor quantum dot amplifying fiber
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作者 WANG Ke-xin WANG Ting-yun PANG Fu-fei 《Optoelectronics Letters》 EI 2007年第1期14-17,共4页
Based on the character of semiconductors and the structure of optical fiber coupler, a new amplifying fiber, coupled semiconductor quantum dot amplifying fiber (CSQDAF), has been presented. A simplified model of PbS q... Based on the character of semiconductors and the structure of optical fiber coupler, a new amplifying fiber, coupled semiconductor quantum dot amplifying fiber (CSQDAF), has been presented. A simplified model of PbS quantum dot amplifying fiber is built on the energy band structure of semiconductor quantum dots, and a simple expression deduced from the two-level rate equations and light propagation equations is shown in this paper, by which the gain of quantum dot amplifying fiber can be calculated. A gain of approximately 4.5 dB has been measured in this coupled semiconductor quantum dot amplifying fiber at a wavelength of 1310 nm, when the fiber is pumped by a laser operating at a wavelength of 980 nm with power of 30 mW. 展开更多
关键词 衰逝波 耦合半导体量子点放大光纤 光纤放大器 光纤连接器 能带结构
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Black phosphorus quantum dot/g-C_3N_4 composites for enhanced CO_2 photoreduction to CO 被引量:21
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作者 Chunqiu Han Jue Li +4 位作者 Zhaoyu Ma Haiquan Xie Geoffrey I.N.Waterhouse Liqun Ye Tierui Zhang 《Science China Materials》 SCIE EI CSCD 2018年第9期1159-1166,共8页
The development of low cost, metal free semiconductor photocatalysts for CO2 reduction to fuels and valuable chemical feedstocks is a practically imperative for reducing anthropogenic CO2 emissions. In this work, blac... The development of low cost, metal free semiconductor photocatalysts for CO2 reduction to fuels and valuable chemical feedstocks is a practically imperative for reducing anthropogenic CO2 emissions. In this work, black phosphorus quantum dots(BPQDs) were successfully dispersed on a graphitic carbon nitride(g-C3N4) support via a simple electrostatic attraction approach, and the activities of BP@g-C3N4 composites were evaluated for photocatalytic CO2 reduction. The BP@g-C3N4 composites displayed improved carrier separation efficiency and higher activities for photocatalytic CO2 reduction to CO(6.54 μmol g^-1h^-1 at the optimum BPQDs loading of 1 wt%) compared with pure g-C3N4(2.65 μmol g^-1h^-1). This work thus identifies a novel approach towards metal free photocatalysts for CO2 photoreduction. 展开更多
关键词 black phosphorus quantum dots g-C3N4 PHOTO-CATALYSIS CO2 photoreduction
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Atom-atom entanglement characteristics in fiber-connected cavities system within the double-excitation space 被引量:4
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作者 YU XlangYang LI JianHong LI XiaoBin 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2012年第10期1813-1819,共7页
Starting from a rudimentary quantum-networks model that consists of two two-level confined atoms locating respectively in spatially-separated cavities coupled by fiber,we investigate the complex entanglement character... Starting from a rudimentary quantum-networks model that consists of two two-level confined atoms locating respectively in spatially-separated cavities coupled by fiber,we investigate the complex entanglement characteristics of the composite system analytically under the maximally initial entangled state that generates two excitations simultaneously during the temporal-evolution process.Our calculation clearly shows that,through mediating the atom-cavity coupling strength and photon-photon hopping rate appropriately,the entanglement dynamics displays some distinctive temporal properties differing from those obtained in one-excitation space,characterized partially by these newly quantum phenomena termed as entanglement sudden death and recurrence.Effectively,within the framework of two excitations,we suggest the purposeful manipulations of atomic entanglement communication for quantum networks. 展开更多
关键词 quantum entanglement cavity quantum electrodynamics fiber-connected cavities
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Simultaneous determination of Repaglinide and Irbesartan in biological plasmas using micellar enhanced excitation-emission matrix fluorescence coupled with ATLD method 被引量:1
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作者 Haiyan Fu Hedong Li +7 位作者 Mei Shao Tianming Yang Xu Zhang Rujing Xu Yujuan Wei Shuhua Chen Chuang Ni Hailong Wu 《Science China Chemistry》 SCIE EI CAS CSCD 2016年第7期816-823,共8页
A highly sensitive and selective 3D excitation-emission fluorescence method has been proposed to rapidly quantify the combined antidiabetics Repaglinide(Re) and Irbesartan(Ir) in rat and human plasmas with the aid of ... A highly sensitive and selective 3D excitation-emission fluorescence method has been proposed to rapidly quantify the combined antidiabetics Repaglinide(Re) and Irbesartan(Ir) in rat and human plasmas with the aid of second-order calibration method based on alternating trilinear decomposition(ATLD) method. Re and Ir with weak fluorescence can be endowed with strong fluorescent property by changing the microenvironment in samples and improving the fluorescence quantum yield by using an appropriate micellar enhanced surfactant. The enhanced excitation-emission matrix fluorescence of Re and Ir can be accurately resolved and can simultaneously attain the optimal concentration even in the presence of a potentially strong intrinsic fluorescence from complex biological matrices, such as rat and human plasmas, by using the ATLD method, which completely exploits the "second-order advantage". The average recoveries of Re and Ir obtained from ATLD with the factor number of 3(N=3) were 101.0%±4.3% and 99.1%±4.1% for rat plasma and 100.5%±5.4% and 97.1%±3.6% for human plasma. Several statistical methods, including Student's t-test, figures of merit, and elliptical joint confidence region, have been utilized to evaluate the accuracy of the proposed method. Results show that the developed method can maintain second-order advantage in simultaneous determinations of the weak fluorescent analytes of interest in different biological plasma matrices. 展开更多
关键词 REPAGLINIDE IRBESARTAN micellar enhanced fluorescence alternating trilinear decomposition
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Tunable ultraviolet to deep blue light emission from sulfur nanodots fabricated by a controllable fission-aggregation strategy
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作者 Lian Xiao Quanchao Du +5 位作者 Yi Huang Shijia Cheng Shuai Yin Teck Neng Wong Edwin Kok Lee Yeow Handong Sun 《Science China Materials》 SCIE EI CAS CSCD 2022年第10期2786-2792,共7页
Bright tunable light emission in the short wavelength range from sulfur nanodots was demonstrated with a photoluminescence quantum yield(PLQY)of up to 59.4%.A fission-aggregation mechanism was proposed for the formati... Bright tunable light emission in the short wavelength range from sulfur nanodots was demonstrated with a photoluminescence quantum yield(PLQY)of up to 59.4%.A fission-aggregation mechanism was proposed for the formation of sulfur nanodots with desired performances.This synthetic strategy allowed for simultaneous size control from 3.2 to 5.6 nm,thus tuning the emission color from ultraviolet(UV)to deep blue(342±430 nm),and for the suppression of unwanted nonradiative recombination centers and deep level emission.The luminescence mechanism and quantum confinement effect of the synthesized sulfur nanodots were investigated by optical spectroscopy and theoretical calculations.These results show promise toward the application of sulfur nanodots in UV optoelectronics,biomedical treatments,and sterilization. 展开更多
关键词 sulfur nanodots ULTRAVIOLET deep blue tunable photoluminescence heavy metal free high PLQY
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