Effect of Low Temperature and Sparse Light Conditions on Cold Tolerance of Different Rice Lines at Seedling Stage

Low temperature and sparse light in early spring is one of the factors causing reduction for rice production. So it is important to develop cold tolerance cultivars. In the present study, cold tolerance characters of 36 parents and 423 rice lines from 68 hybrid groups were investigated at seedling stage under low tempera- ture and sparse light conditions in field. There were 10 parent accessions with strong cold tolerance of level 1. Among them, 3 were common wild rice accessions; 4 were japonica rice cultivars; 2 were indica rice; 1 was offspring from hybrid be- tween indica and japonica.There were 33 lines with strong cold tolerance of level 1 from the hybrid groups of common wild rice,and 15 from the hybrid groups of IRBB5, and only 3 from the hybrid groups of BPHR96. There were abundant cold tolerance resources in rice germplasm. It was feasible to develop cold tolerance cul- tivars from the hybrids among common wild rice, japonica cultivars and indica culti- vars.

The Physiologic Reaction of Cucumber to Low Temperature and Low Light Intensity

The dynamics of chlorophyll content, leaf area and photosynthesis of cucumber seedlings were studied under sole stress of two low temperatures and low light intensity as well as combined stresses of low light intensity and the two low temperatures. The results showed that low light intensity reduced sensitivity of cucumber to low temperature and improved chlorophyll content, leaf area and chlorophyll fluorescence quantum yield. The photosynthesis rate was reduced under low light intensity. The intensity of light played the leading role in growth of cucumber under the low temperature condition, while the low temperature played the leading role under the critical low temperature condition. There were differences in reaction to light and temperature among different varieties. The tolerance to low temperature and low light intensity was not always synergetic for the same cucumber variety.

Photosynthetic Characteristics and Ultrastructure of Chloroplast of Cucumber Under Low Light Density in Solar-Greenhouse

The photosynthetic characteristics and ultrastructure of chloroplast of cucumber in solar-greenhouse were studied. The result showed that the photosynthetic rate (Pn), photosyntheticability (A350), carboxylation efficiency, light saturation point and light compensation pointall declined remarkably under low light density, indicating that the photosynthetic characteristicsof cucumber were closely related to light environment. Under low light density, the minimalfluorescence (Fo), alterable fluorescence (Fv), photochemical efficiency of PSⅡ(Fv/Fm), steadyfluorescence in light (Fs), maximal fluorescence (Fm) and actual efficiency of PSⅡ(φPSⅡ)etcincreased, indicating that the photochemical activity and efficiency for solar energy transformationenhanced, thus the light proportion used to electron transport also increased. The chlorophylla, b, a/b and carotenoid of shading leaves decreased. However, the depressed extent of Chl a andChl a/b were obviously larger than that of Chl b. The number of chloroplast and starch grainin cucumber leaves descended, but that of grana and lamella increased as a shaded result. Thesize of chloroplast and starch grain of shading leaves minished.

Effects of Acetylsalicylic Acid and Calcium Chloride on Photosynthetic Apparatus and Reactive Oxygen-Scavenging Enzymes in Chrysanthemum Under Low Temperature Stress with Low Light

The effects of acetylsalicylic acid （ASA）, CaCl2, and ASA ＋ CaCl2 on the photosynthetic apparatus and antioxidant enzyme activities were investigated in chrysanthemum Jinba （a cut flower cultivar） under low temperature stress with low light （TL stress） （16/12℃, day/night, PFD 100 μmol m^-2 s-1）. The results showed that under TL stress, the net photosynthesis rate （Pn）, carboxylation efficiency （CE）, apparent quantum yield （AQY）, maximal photochemical efficiency （Fv/Fm） of PSII, quantum yield of PSII electron transport （ФPSII）, and photochemical quenching （qP） of the chrysanthemum leaves in all treatments were significantly decreased, but the decreases were alleviated by ASA, CaCl2, and ASA ＋ CaCl2 treatments compared with the controls. The alleviating effect of ASA ＋ CaCI2 was better than either ASA or CaCl2 single treatment. Moreover, the ASA ＋ CaCl2 treatment highly improved the chlorophyll content, relatively improved the number and size of chloroplast and starch grain in the leaves of chrysanthemum plants compared with ASA and CaCl2 treatments. It was indicated that ASA and/or CaCI2 could regulate the photosynthetic functions in the leaves of chrysanthemum plants to enhance the resistance against TL stress. On the other hand, reduction in relative conductance rate implied that ASA and/ or CaCl2 could protect from membrane injury in leaves of chrysanthemum plants. The activities of SOD, POD, and CAT in the treated leaves of chrysanthemum were increased as compared with the controls. It was suggested that ASA and/or CaCl2 had positive regulation effects on the defence enzyme activities in chrysanthemum leaves which could protect the photosynthetic apparatus to a certain degree under the TL stress. In brief, the treatment of ASA together with CaCl2 was better for chrysanthemum plants to adapt TL stress than single ASA or CaCl2 treatments.

Determination of ion quantity by using low-temperature ion density theory and molecular dynamics simulation

In this paper, we report a method by which the ion quantity is estimated rapidly with an accuracy of 4%. This finding is based on the low-temperature ion density theory and combined with the ion crystal size obtained from experiment with the precision of a micrometer. The method is objective, straightforward, and independent of the molecular dynamics （MD） simulation. The result can be used as the reference for the MD simulation, and the method can improve the reliability and precision of MD simulation. This method is very helpful for intensively studying ion crystal, such as phase transition, spatial configuration, temporal evolution, dynamic character, cooling efficiency, and the temperature limit of the ions.

Studies on the oxidative modification of low density lipoprotein induced by ultraviolet light and the protective effect of green tea polyphenols

Uitraviolet（UV）light irradiation acting on human low density lipoprotein（LDL）couldgive rise to oxidative modification of LDL.Thiobarbituric acid reactive substances（TBARS）,rela-five electrophorefic mobility（REM）,relative fluorescence intensity at 420 nm（the excitation wavelength was 360nm）and lipid conjugated dienes of UV-irradiated LDL were all elevated withthe increase of irradiation time.Addition of 0.01％ EDTA into the irradiation system could inhi-bit this reaction,but the effect was not so potent as that induced in the Cu2+-PBS-LDLoxidative modification system China green tea polyphenols（CGTP）,on the other hand,had aneffective inhibitory effect with obvious dose-effect relationship.It was proposed that lipidperoxidation of LDL induced by free radicals which were generated from UV-irradiation andthe inhibitory effect of CGTP was attributed to its strong antioxidative action.

A low temperature processable tin oxide interlayer via aminemodification for efficient and stable organic solar cells

The exploitation of proper electron transport layers(ETLs)and interface optimization can play a pivotal role to promote the performance of organic solar cells(OSCs).In this work,low temperature processable tin oxide(SnO_(2))colloidal nanoparticles with ethanolamine(EA)treatment are successfully employed for efficient and stable OSCs with light soaking free.The EA is chemically bonded with SnO_(2),and the ethanolamine treated tin oxide(E-SnO_(2))layer delivers a suitable work function of 4.10 eV and a unique surface texture with suspended polar moieties.The enhanced performance of E-SnO_(2) based OSCs can be attributed to the improved charge transport and electron extraction,which is correlated with the regulated energy level alignment and contact quality of E-SnO_(2)/active layer.As a result,considerable power conversion efficiencies(PCEs)of 10.30%,13.93%and 15.38%for PTB7-Th/PC_(71) BM,PM7/ITC6-4 F and PM6/Y6 based OSCs have been realized with E-SnO_(2) as ETL,respectively.Compared with ZnO based devices,the E-SnO_(2) based OSCs exhibit an improved light aging stability,which can retain 94.3%of their initial PCE of 15.38%after 100 h light aging for E-SnO_(2)/PM6/Y6 based OSCs.This work demonstrates that the enormous potential of E-SnO_(2) to serve as ETL for high-efficiency and stable OSCs.

Low temperature-mediated repression and far-red light-mediated induction determine morning FLOWERING LOCUS T expression levels

In order to flower in the appropriate season,plants monitor light and temperature changes and alter downstream pathways that regulate florigen genes such as Arabidopsis(Arabidopsis thaliana)FLOWERING LOCUS T(FT).In Arabidopsis,FT messenger RNA levels peak in the morning and evening under natural long-day conditions(LDs).However,the regulatory mechanisms governing morning FT induction remain poorly understood.The morning FT peak is absent in typical laboratory LDs characterized by high red:far-red light(R:FR)ratios and constant temperatures.Here,we demonstrate that ZEITLUPE(ZTL)interacts with the FT repressors TARGET OF EATs(TOEs),thereby repressing morning FT expression in natural environments.Under LDs with simulated sunlight(R:FR=1.0)and daily temperature cycles,which are natural LD-mimicking environmental conditions,FT transcript levels in the ztl mutant were high specifically in the morning,a pattern that was mirrored in the toe1 toe2 double mutant.Low night-to-morning temperatures increased the inhibitory effect of ZTL on morning FT expression by increasing ZTL protein levels early in the morning.Far-red light counteracted ZTL activity by decreasing its abundance(possibly via phytochrome A(phyA))while increasing GIGANTEA(GI)levels and negatively affecting the formation of the ZTL-GI complex in the morning.Therefore,the phyA-mediated high-irradiance response and GI play pivotal roles in morning FT induction.Our findings suggest that the delicate balance between low temperature-mediated ZTL activity and the far-red light-mediated functions of phyA and GI offers plants flexibility in fine-tuning their flowering time by controlling FT expression in the morning.

Effect of high density pulse electric current on solidification structure of low temperature melt of A356 alloy

The effect of high density pulse electric current (HDPEC) on the solidification structure of the low temperature melt(LTM) of commercial A356 alloy was investigated. In the experiments, the HDPEC was discharged in the LTM (953?K, 903?K and 873?K). By the control experiments, the results showed that the solidification structure of the LTM of A356 alloy is refined apparently when the HDPEC is discharged in low temperature melt. However, the holding time of melt treated has an adverse effect on the solidification structure. The longer the holding time of the melt treated with HDPEC, the coarser the microstructure. With the same discharge voltage, the lower the temperature of LTM, the more obscure the refinement of solidification structure. Finally, the mechanism of microstructure refining by HDPEC was analyzed.

Low temperature doping of anatase nano TiO2

In this paper. Glucose, nitrate, and urea were respectively used as C, B, and N sources doped TiO2 at low temperature sol gel method, The obtained nano TiO2 was characterized by DRS, FIRT, TG-DTG. The photocatalytic properties and the optical response range of the natase nanocrystalline were analyzed and studied with the hybrid orbital theory. The results show that the band gap of the doped TiO2 was narrow, and the photocatalytic ability could be excited by the visible lighL and the doping of non metallic elements broadens the application range of TiO2, so that it could be excited under the visible light and obtained better use value.

Annealing Temperature-Dependent Luminescence Color Coordination in Eu-Doped AlN Thin Films

AlN was used as a host material and doped with Eu grown on Si substrate by pulsed laser deposition (PLD) with low substrate temperature. The X-ray diffraction (XRD) data revealed the orientation and the composition of the thin film. The surface morphology was studied by scanning electron microscope (SEM). While raising the annealing temperatures from 300˚C to 900˚C, the emission was observed from AlN: Eu under excitation of 260 nm excitation. The photoluminescence (PL) was integrated over the visible light wavelength shifted from the blue to the red zone in the CIE 1931 chromaticity coordinates. The luminescence color coordination of AlN: Eu depending on the annealing temperatures guides the further study of Eu-doped nitrides manufacturing on white light emitting diode (LED) and full color LED devices.

Ambient Light Alters Gene Expression Pattern of Enzymes and Transcription Factors Involved in Phenylpropanoid Metabolic Pathway in Potato under Chilling Stress

[Objective] Expressions of key enzymatic genes involved in phenyl-propanoid metabolic pathway in potato and StR2R3-MYB and StTGA transcripters were investigated in the present study. [Method] The primitive cultivar Yan was the materials for replicated trials and total RNA extracted from tissues of seedlings. Re-al-time florescent quantification PCR, multiple intervals of air temperature, light-il umi-nation and time-duration were factors of treatments in the experiment. Data on gene expressions were obtained and proceed to asses and compare effects based on statistical analysis. [Result] The results showed negative correlations between tem-perature degrees and expressions of StPAL, StDFR and StR2R3-MYB genes but not StTGA. Positive correlations, however, were derived between those of StCHS, StDFR and StR2R3-MYB and light-intensity. Significant interactive effects between expressions of StPAL and StDFR and treatments, light intensity and temperature degree, along the phenylpropanoid pathway were observed. Transcription regulator of StR2R3-MYB showed significant positive effect on the expression of StCHS of potato. StTGA transcription factor, on the other hand, gave significant negative ef-fects on the expression of StDFR. [Conclusion] Results from present study reveal the role of environmental factors and complicate interactions between such condi-tions as temperature-light il umination and mRNA function of target genes.

Bright light transmits through the brain: Measurement of photon emissions and frequency-dependent modulation of spectral electroencephalographic power

Photons are emitted during brain activity and when applied externally alter its functional connectivity during the resting state. In the present study we applied constant or time varying light (~10,000 lux) stimuli to one side of the skull and measured by photomultiplier tubes the photon density emitted from the opposite side of the skull along its two horizontal planes. Global quantitative electroencephalographic activity (QEEG) was recorded simultaneously. Reliable increases of ~2.5 × 10-11 W· m-2 during either constant or specific flash frequencies between 3 and 7 Hz as well as enhanced QEEG power in the theta and low beta range were measured. According to source localization by Low Resolution Electromagnetic Tomography (LORETA) the right parahippocampal region was particularly enhanced. Calculations employing known quantitative values for permeability and permittivity of brain tissue were consistent with this frequency band. Estimated concentrations of protons from hydronium ions indicated a Grotthuss chain-like process for moving photon energy through the cerebral medium may have mediated the distance-dependent latency. The results suggest that external light is transmitted through cerebral tissue, can be measured externally, and significantly affects functional connectivity. The findings support the conclusions of Starck et al. (World Journal Neuroscience, 2012).

低温弱光处理对茄子不同时期花青素含量及果实品质的影响

【目的】探究低温、弱光、低温弱光处理对茄子幼苗期、花期、果期花青素含量的影响,以及对茄子品质的影响,为茄子的优质培育以及高产栽培奠定理论基础。【方法】以紫黑茄秀娘为试验材料,分别在幼苗期、花期、果期进行低温(18℃/13℃,250μmol·m^(-2)·s^(-1))、弱光(25℃/20℃,120μmol·m^(-2)·s^(-1))、低温弱光(18℃/13℃,120μmol·m^(-2)·s^(-1))、CK(25℃/20℃,250μmol·m^(-2)·s^(-1))等4个处理,测定幼苗期形态及生理特性,不同时期、不同部位的花青素,以及果期果实的品质。【结果】低温弱光胁迫对幼苗生长存在显著影响,在幼苗期低温对幼苗生长及生理影响显著大于弱光及低温弱光,花青素含量均表现为根<叶片<叶脉<茎;在花期,花青素含量依次为花萼<花瓣;在果期,花青素含量依次为果肉<果柄<果皮。茄子不同时期受到胁迫后,不同部位的花青素含量均呈现弱光<CK<低温弱光<低温,各胁迫下果实色泽指数依次为弱光<CK<低温弱光<低温,可溶性糖含量、可溶性蛋白含量、类黄酮含量、总酚含量均呈现低温<低温弱光<弱光<CK。【结论】低温促进花青素合成;弱光抑制花青素合成;在低温弱光双因素互作下,低温因素对花青素含量的影响起主导作用,花青素的合成大于降解,花青素含量增加。低温、弱光、低温弱光胁迫下茄子品质均下降,其中,低温胁迫对茄子的品质影响最大。

50份加工型辣椒DH系苗期耐低温弱光综合评价

以前期利用花药培养技术创制的50份加工型辣椒DH系为试验材料,以SPAD值、F_(v)/F_(m)、根系直径、茎叶干质量、根系干质量、整株干质量和根冠比7个指标的耐低温弱光指数为评价指标,采用模糊隶属函数和聚类分析法对其进行耐低温弱光综合评价。结果表明:50份DH系的耐低温弱光模糊隶属函数综合指数范围在0.20~0.76之间,聚类分析可将其分为两大类,根据耐低温弱光指数特点和模糊隶属函数综合指数可确定第Ⅱ类有7份DH系为耐低温弱光材料,即H201605-8、H201604-4-1、H201612-4-1、H201605-7、H201612-4、H201605-34和H201604-18。50份加工型辣椒DH系间耐低温弱光性差异较大,可作为相关机理研究的试验材料;筛选出的7份耐低温弱光DH系为培育适合设施栽培的优良辣椒新品种提供了材料基础,也为定向培育抗非生物逆境辣椒种质新材料提供了参考。

防漏堵漏低密度水泥浆技术

跃进3-3XC井完钻井深达9432 m,水平钻进距离超过3400 m,刷新了亚洲最深和超深水平大位移井的纪录。该井地质结构复杂,施工难度大,对水泥浆性能要求高,除了高温、高压外,地层承压能力低,极易发生漏失。针对此类问题,通过研发新型功能性材料,构建了C-Lo PSD(1.30 g/cm^(3))、C-Lite STONE(1.60 g/cm^(3))与C-Hi PSD(1.40 g/cm^(3))三套低密度水泥浆体系,涵盖了中低温、高温等应用条件,并在跃进3-3XC井中成功应用,水泥浆性能满足固井需求。与之前用水泥浆体系相比,混浆效率、流变性、悬浮稳定性、水泥石抗压强度等明显提升。其中,C-Lite STONE(T_(BHC)=75℃/T_(TOC)=30℃)与C-Hi PSD(T_(BHC)=145℃/T_(TOC)=105℃)水泥浆体系在温差分别为45℃和40℃下,顶部48 h抗压强度达到8.1 MPa和14.3 MPa。跃进3-3XC井在施工期间多次遭遇漏失,通过使用自研的新型堵漏材料C-B62和C-B66,成功封堵裂缝,保证了固井施工的顺利进行。

基于PCA-SVM结合共聚焦拉曼光谱的特级初榨橄榄油掺伪压榨菜籽油定量分析

为了促进国内橄榄油市场的健康发展,对掺伪同样存在天然类胡萝卜素的低温压榨菜籽油的特级初榨橄榄油进行了定量鉴别研究。采用共聚焦拉曼光谱技术对不同掺伪浓度油样进行测试,基于密度泛函理论对油样的拉曼光谱峰的归属进行了理论分析,并对拉曼光谱数据进行主成分分析(PCA),然后利用支持向量机(SVM)构建PCA-SVM模型。另外,对PCA-SVM模型的检出限进行了研究。结果表明:特级初榨橄榄油与低温压榨菜籽油的拉曼光谱存在一定差异,最明显的光谱差异主要集中在谱峰1008、1161、1528 cm^(-1)和谱段2800~3000 cm^(-1)内,与密度泛函理论对不同油样拉曼光谱峰的分析一致;不考虑类胡萝卜素特征信号建立的PCA-SVM模型决定系数大于0.989,均方根误差小于2.990%,检出限为2%(低温压榨菜籽油体积分数);在特级初榨橄榄油掺伪定量分析中,考虑类胡萝卜素的特征信号有助于提高模型预测精度,但仅限于掺伪低价植物油中无类胡萝卜素存在的情况;PCA-SVM模型在不考虑类胡萝卜素特征信号的情况下依然具有良好的定量预测效果。综上,所建立的PCA-SVM模型可以用于掺伪2%以上低温压榨菜籽油的特级初榨橄榄油的定量鉴别。

多用途低温低密水泥浆体系室内研究及应用

多用途低温低密水泥浆体系,以G级油井水泥为基质,以人造玻璃微珠及火山灰活性胶凝材料为减轻材料,并辅其他功能性添加剂构建而成。体系以固相悬浮为基础模型,以紧密堆积技术为基本理论。通过优化颗粒级配提高单位体积水泥浆中的固相体积分数。减轻材料的使用进一步减少了固相颗粒间的游离水,降低水灰比,增强水泥石的致密性,降低渗透率,促进水泥石早期强度发展。现场应用结果表明,在不改变水泥浆体系材料种类的基础上,水泥浆配浆密度可实现1.4 g/cm^(3)与1.5 g/cm^(3)转换,同时可实现淡水配浆及海水配浆双液体作业;水泥浆适用温度范围为30~80℃;具有良好的浆体流动性,API失水可控,自由水为零,早期强度高,稠化时间可调。

PE-LLD散光膜氙灯加速老化行为及机制

农用聚乙烯散光棚膜可在较高透光率条件下提高雾度,将透过膜面的直射光转为散射光,促进膜内植株全维度获取有效光辐射。通过引入散光剂制备线型低密度聚乙烯(PE-LLD)散光膜,实现透光率90.99%、雾度62.29%,较空白对照膜透光率降低0.55%、雾度提高152.60%。耐老化性能是PE-LLD棚膜其他功效性能的基础保证,采用氙灯老化对PE-LLD散光膜进行加速降解,其宏观光学与力学性能变化趋势同空白膜一致,二者断裂伸长率分别在13d时降至初始值40.58%与47.01%(完全老化)。综合考察PE-LLD散光膜加速老化过程化学组成、结晶行为、晶粒尺寸及微观形貌变化规律,其老化过程随降解速度变化分3个阶段:老化前期分子链交联密度上升,二次结晶片段堆砌增大结晶度,降解缓慢;老化中期交联与降解并存,界面处散光剂脱落促使膜面破裂,片晶分布连续性降低,降解速度适中;老化后期分子主链降解加剧,膜面裂纹向纵深延展,力学性能快速降解至完全老化。研究表明,引入散光剂可在不影响PE-LLD棚膜宏观使用功能与老化降解性能的基础上有效提高雾度,实现散射光调控。

时效温度对Fe-30Mn-12Al-0.9C轻质高强钢组织和硬度的影响

针对高Al、高Mn含量的轻质高强钢Fe-30Mn-12Al-0.9C,研究了时效温度对该钢相组成、组织和硬度的影响,通过OM、XRD等分析了不同时效温度下其微观组织的演变规律。结果表明:在低温时效时,该钢的时效组织和固溶组织差异较小,主要为奥氏体+铁素体,晶内存在纳米级别κ-碳化物,硬度变化幅度较小;500℃时效时,组织中出现β-Mn,硬度开始升高;当时效温度为650℃时,组织发生明显改变,晶界出现大量β-Mn,硬度明显升高;当时效温度达到700℃时,奥氏体彻底分解为铁素体和κ-碳化物,伴随着晶界处β-Mn和κ-碳化物的聚集长大,材料的硬度达到最大值66.3 HRC。