缺钙对不同钙效率番茄幼苗钙吸收及幼茎解剖结构的影响

采用两个钙效率有较大差异的番茄品种(04,05)研究了缺钙胁迫对幼苗钙素吸收动力学特性、钙在体内的吸收和分配及幼茎解剖结构的影响。结果表明,正常供钙下不同钙效率番茄品种存在吸钙速率的基因型差异,钙低效品种04>钙高效品种05,经过缺钙胁迫后重新吸收钙的速率仍然以04>05。正常供钙下,钙低效品种04生长量、钙吸收量均显著高于钙高效品种05,而缺钙处理下植株生长量、钙吸收量、钙含量显著低于05。缺钙下两品种的根冠比增加,05增加程度高于04。正常供钙下两品种表皮细胞、薄壁细胞和形成层细胞形状大小匀称,排列紧密,04茎木质部导管数较多;缺钙使两品种幼茎形成层细胞发育受到影响,尤以04影响显著,表明缺钙胁迫对04品种结构的影响远远高于05。

土壤酸胁迫下不同花生品种(系)钙吸收、分配及钙效率差异

为明确不同花生品种(系)对土壤酸胁迫的响应差异及其机制,本试验在大田条件下,酸化土壤(pH值4.2)及正常土壤(pH值6.0,对照)中比较了19个花生品种(系)产量、主要农艺性状及钙吸收特征等指标的差异。结果表明,酸胁迫条件下,多数花生品种(系)植株钙含量显著下降,较对照平均降低0.18个百分点;酸胁迫降低了生殖体(果针、果壳、籽仁)中钙累积,而整株及营养体(根、茎、叶)钙累积量平均值与对照相差不大,表明酸胁迫主要抑制了果针和荚果对钙的吸收,对根系钙吸收影响较小;此外,酸胁迫显著降低了荚果、籽仁钙利用效率。酸胁迫导致花生徒长,胁迫处理植株干物重平均比对照增加31.2%,其中营养体及针壳增幅明显,籽仁干重下降显著。酸胁迫导致花生荚果性状变劣,酸胁迫下出仁率和空秕率平均值较对照分别降低45.5和55.5个百分点,百果重和荚果产量分别降低70.2%和60.4%。不同品种(系)耐酸系数变幅为0.002~0.548。按照耐酸系数,将供试品种(系)分成耐酸型、中间型及酸敏感型三类,其中L2010和花育32两品种(系)为耐酸型;酸胁迫下荚果产量、出仁率、籽仁钙累积量、荚果钙利用率及籽仁钙利用率等指标与耐酸系数呈极显著正相关,空秕率与耐酸系数呈极显著负相关。本研究为耐酸花生品种选育及酸化土壤花生高产栽培提供了理论依据。

花期减少施钙量对不同钙效率番茄果实钙形态和含量的影响

花期降低施钙量后 ,钙低效番茄品种Ｌ 40 2果实中钙含量显著降低 ,高效品种江蔬一号降低不显著 ,镁含量显著增加 ,钾含量有增加趋势。果实底端的钙含量高于顶端 ,降低施钙量后果实水溶性钙含量和比例显著提高 ,果胶酸钙含量和比例降低 ,磷酸钙含量也降低。钙低效品种Ｌ 40 2水溶性钙含量的增加 ,以及果胶酸钙和磷酸钙的降低程度 ,都大于高效品种江蔬一号 ,且降钙后果实顶端的草酸钙含量和比例增加。

花生荚果钙素吸收调控及其与钙素营养效率的关系国际合作课题

实验采用不同方法对花生荚果细胞钙素吸收进行调控，并探索其营养意义。结果表明，尼群地平可通过阻断钙通道而减少荚果钙素吸收；吲哚乙酸可促进外源钙内流，由此导致组织钙含量明显增加；尼群地平与吲哚乙酸混合作用下，吲哚乙酸不能活化为尼群地平所阻断的钙通道，组织钙含量减少，但由于其促进了细胞分裂与伸长，外果皮和中果皮胞壁相应结合钙增加，因而吸钙总量并不减少；细胞膜对Ｃａ２＋运输具有选择性，ＥＧＴＡ螯合钙不能通过细胞膜作跨膜运动，组织钙含量显著降低。

不同番茄品种苗期对缺钙胁迫的反应

正常供钙下 ,不同番茄品种幼苗的吸钙量有较大差异 ,白果强丰 >佳粉 2号 >合作 90 3>江蔬 1号。缺钙培养使番茄幼苗干物质积累和吸钙量下降 ,合作 90 3和白果强丰的干物质量下降程度高于江蔬 1号和佳粉 2号 ,白果强丰的吸钙量降为CK的 9% ,江蔬 1号降为CK的 33%。在CK和缺钙培养中 ,幼苗的老叶含钙量均高于根、茎、幼叶和中位叶 ,但在缺钙培养中 ,中位叶和幼叶的含钙量下降幅度高于根和茎 ;各部位吸钙量CK为中位叶>老叶 >茎 >根 >幼叶 ,缺钙培养后老叶 >中位叶 >茎 >根 >幼叶 ,各部位吸钙量占整株吸钙量之比的变化趋势与此相同。品种间对钙的敏感性比较表明 ,白果强丰对缺钙最敏感 ,合作 90 3次之 ,佳粉 2号和江蔬

脱硫技术中几个问题的探讨

本文给出了钙硫比的三个定义，考虑到灰渣中CaO的自脱硫作用，计算钙硫比时，根据所用的脱硫工艺不同以及脱硫装置在净化流程中的位置不同，应该选用不同的定义式。给出了脱硫效率的二个定义，考虑到脱硫系统漏风的影响，计算脱硫效率时，建议采用基于质量守恒的定义2。在其他条件相同时，存在一个最佳原始SO2浓度值，使脱硫效率达到最高，原始SO2浓度高于或低于这个值，都会导致脱硫效率降低。

Root Zone Microbial Populations, Urease Activities, and Purification Efficiency for a Constructed Wetland

In order to investigate the effects of microorganisms and their urease activities in macrophytic root zones on pollutant removal, four small-scale plots (SSPs) of vertical/reverse-vertical flow wetlands were set up to determine: a) the relationship between the abundance of microorganisms in the root zones and water purification efficiency; and b) the relationship between urease activities in the root zones and pollutant removal in a constructed wetland system. Total numbers of the microbial population (bacteria, fungi, and actinomyces) along with urease activities in the macrophytic root zones were determined. In addition, the relationships between microbial populations and urease activities as well as the wastewater purification efficiencies of total phosphorus (TP), total Kjeldahl nitrogen (TKN), biochemical oxygen demand in 5 days (BOD5), and chemical oxygen demand (COD) were also analyzed. The results showed that there was a highly significant positive correlation (r = 0.9772, P ＜ 0.01) between the number of bacteria in the root zones and BOD5 removal efficiency and a significant negative correlation (r = -0.9092, P ＜ 0.05) between the number of fungi and the removal efficiency of TKN. Meanwhile, there was a significant positive correlation (r -- 0.8830, P ＜ 0.05) between urease activities in the root zones and the removal efficiency of TKN. Thus, during wastewater treatment in a constructed wetland system,microorganism and urease activities in the root zones were very important factors.

Intensified solar thermochemical CO_(2) splitting over iron-based redox materials via perovskite-mediated dealloying-exsolution cycles

Solar thermochemical CO_(2)-splitting(STCS)is a promising solution for solar energy harvesting and storage.However,practical solar fuel production by utilizing earth-abundant iron/iron oxides remains a great challenge because of the formation of passivation layers,resulting in slow reaction kinetics and limited CO_(2)conversion.Here,we report a novel material consisting of an iron-nickel alloy embedded in a perovskite substrate for intensified CO production via a two-step STCS process.The novel material achieved an unprecedented CO production rate of 381 mL g^(-1)min^(-1)with 99%CO_(2)conversion at 850℃,outperforming state-of-the-art materials.In situ structural analyses and density functional theory calculations show that the alloy/substrate interface is the main active site for CO_(2)splitting.Preferential oxidation of the FeNi alloy at the interface(as opposed to forming an FeO_(x)passivation shell encapsulating bare metallic iron)and rapid stabilization of the iron oxide species by the robust perovskite matrix significantly promoted the conversion of CO_(2)to CO.Facile regeneration of the alloy/perovskite interfaces was realized by isothermal methane reduction with simultaneous production of syngas(H_(2)/CO=2,syngas yield>96%).Overall,the novel perovskite-mediated dealloying-exsolution redox system facilitates highly efficient solar fuel production,with a theoretical solar-to-fuel efficiency of up to 58%,in the absence of any heat integration.

Improvement of Propionic Acid Production for Antifungal Activity from Whey by Calcium Alginate Immobilization of Propionibacterium acidipropionici TISTR 442

The improvement of propionic acid production for antifungal activity, as fermenting by calcium alginate immobilized cells of Propionibacterium acidipropionici TISTR 442 was investigated by using whey as substrate. Optimal condition for immobilization was performed by adjusting tube distance to CaCI2 solution to be 4-6 cm and 7 mL/min flow rate of alginate gel. The production of propionic acid by immobilized cells in a 2 L fermentor using 1% CaCO3 and 5 N KOH to control the pH at 6.5 gave maximum propionic acid and they had consistent potential to recycle 2 rounds of fermentation and produced the total of 29.24 g/L propionic acid （15.85 ± 0.25 g/L and 13.39 ± 0.25 g/L propionic acid from Batch 1 and Batch 2 fermentation, respectively）. Compared to free-cell fermentation, propionic acid productivity increased 20% （0.083 g/h vs. 0.070 g/h） and fermentation time reduced 11% （192 h vs. 216 h） in 2 L fermentor with 40 g/L initial total sugar from whey. The fermented propionic acid as well as the commercial propionic acid from chemical process was able to inhibit the growth of the fungal tested.

Stable tin perovskite solar cells enabled by widening the time window for crystallization

Tin perovskite solar cells (TPSCs) are the most promising candidates for lead-free perovskite solar cells(PSCs).However,the poor crystallization and chemical stability of Sn perovskites are the two challenging issues for further application of TPSCs.Here,we present a strategy to stabilize CH(NH_(2))2SnI3(FASnI3) perovskite enabled by an amine complex,CH3NH3I·3CH3NH_(2),which can hinder the major degradation issue caused by the oxidation of Sn2+to Sn4+.The resulting Sn perovskite films exhibit enhanced crystallinity and stability in comparison with those made with conventional inorganic SnF2 additives.Finally,the device achieved a higher external quantum efficiency for charge extraction and a power conversion efficiency (PCE) of 9.53%,which maintained more than 90%of the initial efficiency after1000 h of light soaking under the standard AM 1.5 G solar illumination.

Facile synthesis of Ca-SiAlON:Eu^(2+) phosphor by the microwave sintering method and its photoluminescence properties

Pure Ca-SiAlON:Eu2+ was synthesized by microwave sintering method at a relatively low temperature of 1550℃.Photoluminescence intensity of the resultant phosphor was higher than those of the samples synthesized by conventional gas-pressure sintering technique at 1750℃.When it was excited at 450 nm,the as-prepared yellow Ca-SiAlON:Eu2+ sample had an external quantum efficiency of 42%,comparable to the sample synthesized at 1750℃ under 0.5 MPaN2 gas pressure by the GPS method reported in reference.The experimental results demonstrated that the microwave sintering method was also an interesting approach for synthesizing nitride phosphors,which promises lower firing temperature than those by carbothermal reduction and nitridation (CRN) methods,higher heating rate and shorter duration time compared with those by gas-pressure sintering.

Ambient stable FAPbI3-based perovskite solar cells with a 2D-EDAPbI4 thin capping layer

Two-dimensional(2D) lead halide perovskite materials are emerging as one of promising light-absorbing materials in perovskite solar cells(PSCs), which show outstanding stability and defect passivation. Unfortunately, the power conversion efficiency(PCE) of those stable 2D PSCs is still far behind that of 3D PSCs. Herein, we reported a simple in-situ growth technique for the ethylenediamine lead iodide(EDAPbI4) layer on the top of formamidinium lead iodide(FAPbI3) layer. The rationally designed layered architecture of2D-3 D perovskite film could improve the PCE of the PSCs. In addition, benefiting from the high moisture resistance and inhibited ion migration of EDAPbI4 layer, the 2D-3D-based devices showed obviously enhanced long-term stability,keeping the initial PCE value for 200 h and 90% of its initial PCE even after 500 h.

Boosting optoelectronic performance of MAPbI3 perovskite solar cells via ethylammonium chloride additive engineering

The quality of the perovskite light absorption layer plays a dynamic role in the photovoltaic properties of solar cells.The existing methods to prepare methylammonium lead iodide(MAPbI3)films render substantial structural defect density,particularly at the grain boundaries and film surface,constituting a challenge that hinders the further optoelectronic enhancement of perovskite solar cells.Herein,a unique approach was introduced:using a simple ethylammonium chloride(EACl)additive in perovskite precursor mixture to produce high-quality MAPbI3 thin films.The results indicated that EACl could encourage perovskite crystal growth without experiencing the intermediate phase formation and would evaporate from the perovskite after annealing.Additionally,a gradient perovskite structure was achieved using this technique,which impressively enhanced the performance of the perovskite films.A high power conversion efficiency(PCE)of 20.03%was achieved under the optimal amount of EACl,and the resultant efficient device could retain over 89%of the original PCE after aging for 1000 h at room temperature.This novel technique leads to a facile fabrication of highquality and less-defect perovskite thin films for competent and stable devices.

Organic-inorganic hybrid Sn-based perovskite photodetectors with high external quantum efficiencies and wide spectral responses from 300 to 1000 nm

Organic-inorganic hybrid perovskites are ideal materials for photodetection owing to their high charge carrier mobility, long charge carrier diffusion length, low dark current density and sharp absorption edge. However, a relatively small band gap(1.6 e V) limits their photonharvesting efficiency in the near-infrared region. In the present work, we demonstrate a hybrid methylamine iodide and Pb-Sn binary perovskite as the light absorption layer in photodetectors. Experimentally, the wavelength of photoresponse onset for the photodetectors can be extended to as great as 1,000 nm when the Sn content of the hybrid perovskite is increased to 30 mol%. In addition, the photodetectors exhibit a photoresponsivity of 0.39 A W^-1, a specific detectivity of 7×10^12 Jones, a fast photoresponse with rise and decay time constants and an external quantum efficiency greater than 50% in the wavelength range of350–900 nm, with a maximum value of about 80% at 550 nm.

Cementitious grain-boundary passivation for flexible perovskite solar cells with superior environmental stability and mechanical robustness

The power conversion effciency(PCE)of flexible perovskite solar cells(PSCs)has increased rapidly,while the mechanical flexibility and environmental stability are still far from satisfactory.Previous studies show the environmental degradation and ductile cracks of perovskite films usually begin at the grain boundaries(GBs).Herein,sulfonated graphene oxide(s-GO)is employed to construct a cementitious GBs by interacting with the[Pb I6]4–at GBs.The resultant s-GO-[Pb I6]4–complex can effectively passivate the defects of vacant iodine,and the devices with s-GO exhibit remarkable waterproofness and flexibility due to the tough and water-insoluble GBs.The champion PCE of 20.56%(1.01 cm^(2))in a device treated with s-GO is achieved.This device retains 90%of its original PCE after 180 d stored in the ambient condition,as well as over 80%retention after 10,000 bending cycles at a curvature radius of 3 mm.

Eliminating the electric field response in a perovskite heterojunction solar cell to improve operational stability

Intrinsic and extrinsic ion migration is a very large threat to the operational stability of perovskite solar cells and is difficult to completely eliminate due to the low activation energy of ion migration and the existence of internal electric field.We propose a heterojunction route to help suppress ion migration,thus improving the operational stability of the cell from the perspective of eliminating the electric field response in the perovskite absorber.A heavily doped p-type(p^(+))thin layer semiconductor is introduced between the electron transporting layer(ETL)and perovskite absorber.The heterojunction charge depletion and electric field are limited to the ETL and p^(+)layers,while the perovskite absorber and hole transporting layer remain neutral.The p^(+)layer has a variety of candidate materials and is tolerant of defect density and carrier mobility,which makes this heterojunction route highly feasible and promising for use in practical applications.

Thiamine additive engineering enables improved film formation towards high efficiency and moisture stability in perovskite solar cells

Perovskite solar cells(PSCs)attract widespread research interest due to their exceptional properties.However,the instability of the perovskite layer,especially the moisture instability,and existing defects seriously restrict the performance and limit the development of PSCs towards commercialization.Herein,we fabricate moisture-stable and efficient PSCs by incorporating a thiamine(THM)additive into a lead iodide(PbI_(2))precursor using a two-step spin-coating method.This strategy enables a better interaction between the THM additive and PbI_(2).Then,a higher energy barrier is produced when the material reacts with A-site cations to form perovskite crystals,resulting in larger grains and better-quality perovskite films.Through optimization of the concentration of the THM additive,the optimal perovskite achieves improved moisture stability and decreased trap states;thus,the corresponding unencapsulated devices achieve a remarkable power conversion efficiency(PCE)of 21.40%and maintain>92%of their initial PCE after 180 h in ambient air(~50%humidity).The excellent performance is mainly attributed to the fact that THM promotes crystal growth and passivates defects in perovskite films.

Effect of concomitant anti-solvent engineering on perovskite grain growth and its high efficiency solar cells

The grain boundaries and interface properties in the active layers of perovskite solar cells(PSCs)are important factors affecting the performances of the devices.In this work,a simple and fast concomitant annealing process is established by inducing the secondary growth of the grains using the anti-solvent o-dichlorobenzene(o-PhCl2)or chlorobenzene(PhCl)to suppress the volatilization of solvent molecules during the FA0.80MA0.15Cs0.05Pb(I0.85Br0.15)3(FA,CH5N2+,formamidine;MA,CH3NH3+,methylamine)film annealing procedure.The effects of anti-solvent molecules on the phase transformation,grain boundary fusion and morphology evolution of perovskite films are systematically investigated by X-ray diffraction(XRD)and scanning electron microscopy(SEM).The results indicate that anti-solvent molecules can inhibit solvent evaporation in the active layers and promote crystallite dissolution and ordered secondary growth along the surfaces of large grains.That can promote the formation of large grains and the passivation of surface defects,and can be favorable for the separation and transportation of photocarriers in the active layer.Consequently,the power conversion efficiency(PCE)of PSCs can be effectively improved,with a PCE of 20.72%being achieved by a secondary growth perovskite film optimized with o-PhCl2.Moreover,the efficiency remains at 85%of its initial value after 2400 h of treatment in a natural indoor environment with a relative humidity of 45±5%.

Large improvement of photovoltaic performance of flexible perovskite solar cells using a multifunctional phospho-ethanolamine-modified SnO_(2)layer

The non-radiative recombination loss caused by diverse defects within SnO_(2)electron transport layer(ETL),perovskite film,and their interface greatly hinders the further improvement of the performance and stability of flexible perovskite solar cells(PSCs).Therefore,it is urgent to develop an effective strategy to address these issues.Herein,a multifunctional material,phospho-ethanolamine(PE),is introduced into SnO_(2)aqueous colloids to suppress defects and prepare high-quality ETL.The results demonstrate that the incorporation of PE can significantly reduce the number of Sn dangling bonds due to the formation of new Sn–O–P bonds,which is beneficial to ameliorating the electrical properties of SnO_(2)and obtaining dense SnO_(2)film.Meanwhile,the amino group(NH_(2))of PE can interact with uncoordinated Pb^(2+)in perovskite,thereby suppressing SnO_(2)/perovskite interface defects and obtaining improved perovskite film quality.Consequently,the optimized flexible and rigid PSCs based on the SnO_(2)-PE composite ETL yield outstanding photoelectric conversion efficiency(PCE)of 18.48%and 21.61%,respectively.Moreover,flexible PSCs based on SnO_(2)-PE present excellent mechanical durability,and 90.6%of the original PCE is retained after 1000 bending cycles.

Stable tin perovskite solar cells developed via additive engineering

Tin perovskite solar cells(TPSCs)are promising for lead-free perovskite solar cells(PSCs)and have led to extensive research;however,the poor crystallinity and chemical stability of tin perovskites are two issues that prevent stable TPSCs.In this study,we outline a new process that addresses these issues by using tin(II)acetate(Sn(Ac)2)in place of the conventional SnF2 precursor additive.Compared with SnF2,Sn(Ac)2 improves the crystallinity and stability of tin perovskite with fewer defects and better charge extraction.Using this process,we developed a device that has a higher external quantum efficiency for charge extraction compared with the control devices and a power conversion efficiency of 9.93%,which maintained more than 90%of its initial efficiency after 1000 h operation at the maximum power point under standard AM 1.5G solar illumination.