Achieving Tunable Cold/Warm White‑Light Emission in a Single Perovskite Material with Near‑Unity Photoluminescence Quantum Yield

Single materials that exhibit efficient and stable white-light emission are highly desirable for lighting applications.This paper reports a novel zero-dimensional perovskite,Rb_(4)CdCl_(6):Sn^(2+),Mn^(2+),which demonstrates exceptional white-light properties including adjustable correlated color temperature,high color rendering index of up to 85,and near-unity photoluminescence quantum yield of 99%.Using a co-doping strategy involving Sn^(2+)and Mn^(2+),cyan-orange dual-band emission with complementary spectral ranges is activated by the self-trapped excitons and d-d transitions of the Sn^(2+)and Mn^(2+)centers in the Rb_(4)CdCl_(6)host,respectively.Intriguingly,although Mn^(2+)ions doped in Rb_(4)CdCl_(6)are difficult to excite,efficient Mn^(2+)emission can be realized through an ultra-high-efficient energy transfer between Sn^(2+)and Mn^(2+)via the formation of adjacent exchange-coupled Sn–Mn pairs.Benefiting from this efficient Dexter energy transfer process,the dual emission shares the same optimal excitation wavelengths of the Sn^(2+)centers and suppresses the non-radiative vibration relaxation significantly.Moreover,the relative intensities of the dual-emission components can be modulated flexibly by adjusting the fraction of the Sn^(2+)ions to the Sn–Mn pairs.This co-doping approach involving short-range energy transfer represents a promising avenue for achieving high-quality white light within a single material.

拟南芥光敏色素作用因子PIF3节水抗旱功能分析

光敏色素作用因子(PIFs)在植物生长发育和信号调控中发挥枢纽作用。为构建拟南芥PIFs转录因子PIF3的过表达载体,以蘸花法转化拟南芥,筛选获得过表达纯合株系,结合PIF3的突变体材料,对PIF3的节水抗旱功能进行分析。通过节水抗旱表型观察、离体叶片失水率测定、扫描电镜分析气孔等试验,发现拟南芥PIFs转录因子PIF3通过调节气孔开闭影响蒸腾,具有节水抗旱的功能。

几种生物菌剂防治烟草青枯病药效试验

为了筛选出高效防治烟草青枯病的生物菌剂,本试验选用3种复合生物菌剂进行了田间防效试验。结果表明,以每株烟塘施复合放线菌肥20 g作为基肥的效果最佳,不仅能够促进烟株的生长,且对青枯病的相对防效达81.34%,与烟草青枯病防控的常规农艺措施相比,相对防效显著提高。本研究结果为田间防治烟草青枯病提供了一种有效的生物防控措施,同时为烟草土传病害的绿色防治提供了一定的数据支撑。

草本植物-微生物联合修复低浓度含油污泥技术研究

【目的】探究4种新疆本土草本植物生物修复含油污泥的潜力,及其与微生物联合修复对低浓度含油污泥处理效果。【方法】以狗牙根(Cynodondactylon)、高羊茅(Festuca elata)、黑麦草(Lolium Perenne)和苏丹草(Sorghum sudanense)与解脂假丝酵母(Candida lipolytica,菌A)、2株枯草芽孢杆菌[菌B(Bacillus subtilis PL-2)和菌C(Bacillus subtilis XJ-16)]、混菌D(A+B+C)为研究对象,采用盆栽试验,分别设置微生物组、植物组、植物-微生物组及对照4组处理,分析不同处理对石油烃残留量、微生物数量、草种生物量和叶绿素含量的影响。【结果】120 d盆栽试验结表明,单独种植狗牙根、单独种植苏丹草、菌B、菌C处理对石油烃的降解效果较为相近,降解率分别为31.39%、34.19%、33.71%与33.39%,显著高于对照组(P<0.05);草本植物与微生物联合修复中,狗牙根中添加菌A、菌B和菌C效果显著,石油烃的降解率可达43.02%、40.20%和42.54%,且在联合修复后土壤中可培养细菌与真菌数量显著增加,分别为1.50×10^(5)~2.59×10^(5)cfu·g^(-1)和4.32×10^(4)~5.53×10^(4)cfu·g^(-1);此外,在添加降解菌后,狗牙根干重和叶绿素总含量均显著提高(P<0.05)。【结论】综合石油烃残留量、微生物数量、生物量以及叶绿素含量指标得出,新疆本地植物狗牙根与菌A(解脂菌假丝酵母)、菌B和菌C(均为枯草芽孢杆菌)的联合,可为当地低浓度含油污泥处理提供可行的技术方案。

Single-cell RNA sequencing of meiocytes and microspores reveals the involvement of the Rf4 gene in redox homeostasis of CMS-C maize

Normal microsporogenesis is determined by both nuclear and mitochondrial genes. In maize C-type cytoplasmic male sterility, it is unclear how the development of meiocytes and microspores is affected by the mitochondrial sterility gene and the nuclear restorer gene. In this study, we sequenced the transcriptomes of single meiocytes(tetrad stage) and early mononucleate microspores from sterile and restorer lines. The numbers of expressed genes varied in individual cells and fewer than half of the expressed genes were common to the same cell types. Four comparisons revealed 3379 differentially expressed genes(DEGs), with 277 putatively associated with mitochondria, 226 encoding transcription factors,and 467 possibly targeted by RF4. KEGG analysis indicated that the DEGs in the two lines at the tetrad stage were involved predominantly in carbon metabolism and in amino acid biosynthesis and metabolism, whereas the DEGs during the transition from the tetrad stage to the early mononucleate stage were associated mostly with regulation of protein metabolism, fatty acid metabolism, and anatomical structure morphogenesis. Thus, meiocyte and microspore development was affected by the surrounding cells and the restorer gene, and the restorer gene helped restore the redox homeostasis of microspores and the normal cellular reconstruction during the transition.

Numerical study of the dynamic characteristics of a single-layer graphite core in a thorium molten salt reactor

A reactor core in a thorium molten salt reactor uses graphite as a moderator and reflector. The graphite core is a multi-layered arrangement of graphite bricks that are loosely connected to each other using a system of keys and dowels. Consequently, the graphite core is a type of discrete stack structure with highly nonlinear dynamic behavior. Hence, it is important to investigate the dynamic characteristics of the graphite core. In this study, a threedimensional single-layer graphite core model, which is a part of the thorium molten salt reactor side reflector structure, was analyzed using the explicit method in ABAQUS 2016 to study the core dynamic behavior when subjected to different excitations. The design parameters,such as the diameter of the dowel, the gap between key and keyway and the bypass flow gap between two adjacent bricks, were also considered in this model. To reduce excessive demands on available computational resources considering the effect of molten salt, the spring–dashpot model was applied to model the interaction forces between the molten salt and graphite bricks. Numerical simulation results show that the effect of molten salt is a reduction inthe peak maximal principal stress, and a larger gap between two bricks is beneficial to maintain the integrity of the graphite core under earthquake loading. The results obtained by the simulation can be used as a reference for future designs of a molten salt graphite core.

Experimental animal models of pulmonary hypertension:Development and challenges

Pulmonary hypertension(PH) is clinically divided into 5 major types, characterized by elevation in pulmonary arterial pressure(PAP) and pulmonary vascular resistance(PVR), finally leading to right heart failure and death. The pathogenesis of this arteriopathy remains unclear, leaving it impossible to target pulmonary vascular remodeling and reverse the deterioration of right ventricular(RV) function. Different animal models have been designed to reflect the complex mechanistic origins and pathology of PH, roughly divided into 4 categories according to the modeling methods: noninvasive models in vivo, invasive models in vivo, gene editing models, and multi-means joint modeling. Though each model shares some molecular and pathological changes with different classes of human PH, in most cases the molecular etiology of human PH is poorly known. The appropriate use of classic and novel PH animal models is essential for the hunt of molecular targets to reverse severe phenotypes.

CEO继任、战略变革与动机——基于沪深两市2007-2013年公司数据的实证检验

本文选取沪深两市2007-2013年上市公司作为样本，检验了CEO继任对战略变革的影响以及实施战略变革的动机，同时进一步研究CEO继任和战略差异度对企业绩效的影响。结果显示：（1）继任CEO会实施更大幅度的战略变革，继任前企业绩效起到调节作用；（2）战略变革会降低CEO薪酬与任期，但是继任前较差的企业绩效会抑制战略变革对薪酬和任期的负向影响；（3）继任CEO战略变革幅度越大，企业绩效改善幅度越大。本文的贡献在于检验了CEO继任对战略变革的影响，并进一步检验了继任CEO实施战略变革的动机。

Zwitterionic monolayer grafted ceramic membrane with an antifouling performance for the efficient oil-water separation

Enormous demands on the separation of oil/water(O/W)emulsions in various industries,such as petrochemical,food and pharmaceutical industries,are looking for high performance and energy-efficient separation methods.Ceramic membranes have been used to deal with O/W emulsions,for its outstanding characteristics of easy-operation,high-flux,and long-term stability.However,membrane fouling is still a challenge in the industrial application of ceramic membranes.Herein,antifouling ceramic membranes were fabricated by grafting zwitterions on the membrane surface via an environment-friendly two-step grafting method,which improves the antifouling property and permeability.Successful grafting of such zwitterion on the ceramic surface was assessed by the combination of FTIR and XPS characterization.More importantly,the hydration can be formed by electrostatic interactions layer on the modified membrane,which was confirmed by TGA characterization.The antifouling performance of prepared zwitterionic ceramic membranes in the separation of O/W emulsions was systematically tested.The results suggested that zwitterion can significantly improve the flux of ceramic ultrafiltration membrane,and can also improve antifouling property dramatically by reducing the irreversible fouling in the separation of O/W emulsions.Therefore,zwitterionic ceramic membranes hold promising potentials as an antifouling,highly efficient and green method in the practical purification of the O/W emulsions.

Stress analysis of the TMSR graphite component under irradiation conditions

TMSR uses nuclear graphite as a neutron moderator, a reflector, and the structural material, and utilizes molten salt as a coolant. When running normally, the graphite components are immersed in the molten salt.Thus, the nuclear graphite comes into direct contact with the molten salt, which infiltrates the open pores of the nuclear graphite. This infiltration may influence the stress analysis of the graphite component. In this study, a User Material subroutine was used to analyze the stress distribution of the graphite component, both with and without molten salt infiltration. Many influence factors were taken into consideration, such as the dose gradient, the shape of the permeation zone, and the permeation area. The results show that the dose gradient, shape, and area of the permeation zone all significantly influence the stress distribution. Furthermore, the results of the stress analysis indicate that for a regular graphite component with a square cross section, the peak maximum principal stress value occurs at the center of the cross section, and the symmetry of the maximum principal stress distributions was modified by quarter circle and half ellipse permeation zones.

球磨辅助化学热洗处理含聚油泥的研究

采用球磨辅助化学热洗处理含聚油泥中的矿物油,考察球磨配合4种无机盐7种表面活性剂作用于含聚油泥的除油效果,通过调整复配药剂含量、反应液温度、料液比和球磨时间,最终确定了含聚油泥除油配方和除油条件。实验结果表明,碱性无机盐和非离子表面活性剂复配处理含聚油泥除油效果显著,阴离子表面活性剂其次,阳离子表面活性剂几乎无效果。以100 g含聚油泥(含油质量分数42.8%)为例,球磨辅助复配药剂处理含聚油泥除油率最高达97.5%。其中,复配药剂组成为NaOH、JFC-G和H-66,其复配比例6∶4∶1,复配药剂质量分数0.40%,含聚油泥除油温度75℃,料液比1∶5,球磨时间30~40 min。

Genome-wide analysis of OCT4 binding sites in glioblastoma cancer cells

OCT4,a member of the POU family of gene products,is an octamer motif-binding transcription factor.As it is known to play a crucial role in cancer processes including proliferation,invasion,and chemoradioresistance,it is important to identify the direct targets of OCT4 in living cancer cells.Here,chromatin immunoprecipitation-sequencing (ChIP-seq) was used to identify OCT4 binding sites in glioblastoma cancer cells.The results showed that 5438 OCT4 binding sites were localized in the glioblastoma cancer genome and that these sites contained a consensus sequence TTTkswTw (k=T or G,s=C or G,w=A or T),which occurred 3931 times in 2312 OCT4 binding regions.Furthermore,binding motifs of some other transcription factors were identified in OCT4 binding regions.Our results provide a valuable dataset for understanding gene regulation mechanisms underlying the function of OCT4 in glioblastoma cancer.

Improved cell performance and sulphur tolerance using A-site substituted Sr_(2)Fe_(1.4)Ni_(0.1)Mo_(0.5)O_(6-δ)anodes for solid-oxide fuel cells

Solid-oxide fuel cells(SOFCs)offer great promise for producing electricity using a wide variety of fuels such as natural gas,coal gas and gasified carbonaceous solids;however,conventional nickel-based anodes face great challenges due to contaminants in readily available fuels,especially sulphur-containing compounds.Thus,the development of new anode materials that can suppress sulphur poisoning is crucial to the realization of fuel-flexible and cost-effective SOFCs.In this work,La_(0.1)Sr_(1.9)Fe_(1.4)Ni_(0.1)Mo_(0.5)O_(6-δ)(LSFNM)and Pr_(0.1)Sr_(1.9)Fe_(1.4)Ni_(0.1)Mo_(0.5)O_(6-δ)(PSFNM)materials have been synthesized using a sol-gel method in air and investigated as anode mater-ials for SOFCs.Metallic nanoparticle-decorated ceramic anodes were obtained by the reduction of LSFNM and PSFNM in H_(2)at 850℃,forming a Ruddlesden-Popper oxide with exsolved FeNi3 bimetallic nanoparticles.The electrochemical performance of the Sr_(2)Fe_(1.4)Ni_(0.1)Mo_(0.5)O_(6-δ)ceramic anode was greatly enhanced by La doping of A-sites,resulting in a 44%decrease in the polarization resistance in reducing atmosphere.The maximum power densities of Sr-and Mg-doped LaGaO_(3)(LSGM)(300μm)electrolyte-supported single cells with LSFNM as the anode reached 1.371 W cm^(-2)in H_(2)and 1.306 W cm^(-2)in 50 ppm H_(2)S-H_(2)at 850℃.Meanwhile,PSFNM showed improved sulphur tolerance,which could be fully recovered after six cycles from H_(2)to 50 ppm H_(2)S-H_(2)operation.This study indicates that LSFNM and PSFNM are promising high-performance anodes for SOFCs.

厌氧(DUASB)+好氧(HTO)工艺处理玉米深加工废水

针对玉米深加工产业园来水种类多、水质复杂、有机物浓度高、可生化性较好、氨氮浓度高的特点,采用双层气箱式UASB(DUASB)+好氧高塔反应器(HTO)的工艺集中处理11 000m^3/d产业园综合废水,当进水COD为5 000～8 000 mg/L、NH_3-N为300～350 mg/L时,处理后COD、NH3-N分别降至200、20 mg/L以下,达到《污水排入城镇下水道水质标准》(GB/T 31962—2015)。

The chimeric gene atp6c confers cytoplasmic male sterility in maize by impairing the assembly of the mitochondrial ATP synthase complex

Cytoplasmic male sterility(CMS)is a powerful tool for the exploitation of hybrid heterosis and the study of signaling and interactions between the nucleus and the cytoplasm.C-type CMS(CMS-C)in maize has long been used in hybrid seed production,but the underlying sterility factor and its mechanism of action remain unclear.In this study,we demonstrate that the mitochondrial gene atp6c confers male sterility in CMS-C maize.The ATP6C protein shows stronger interactions with ATP8 and ATP9 than ATP6 during the assembly of F1F0-ATP synthase(F-type ATP synthase,ATPase),thereby reducing the quantity and activity of assem-bled F_(1)F_(o)-ATP synthase.By contrast,the quantity and activity of the F1'component are increased in CMS-C lines.Reduced F1F0-ATP synthase activity causes accumulation of excess protons in the inner membrane space of the mitochondria,triggering a burst of reactive oxygen species(ROS),premature programmed cell death of the tapetai cells,and pollen abortion.Collectively,our study identifies a chimeric mitochondrial gene(ATP6C)that causes CMS in maize and documents the contribution of ATP6C to F1F0-ATP synthase assembly,thereby providing novel insights into the molecular mechanisms of male sterility in plants.

Influence of contact layer on the sulphur corrosion of copper conductors in power transformers

Owing to the corrosive sulphides in the mineral insulating oil such as dibenzyl disul-phide(DBDS),copper windings in oil‐immersed transformers may suffer sulphur corrosion.This study investigates the influence of different contact conditions on the corrosion of copper conductors in transformers.Oil‐immersed accelerated corrosion experiment was conducted on copper conductors with various contact materials and different layers of insulating paper.The surface micromorphology,deposition compo-nent and the potentiodynamic polarization characteristics of copper conductors were explored.The results show that copper with different contact materials suffer sulphur corrosion;conversely,bare copper rarely does.It was also verified that the existence of a particular gap between copper and contact layer is a significant factor in sulphur corrosion by the formation of a concentration cell on the copper surface.The insu-lating paper wrapped around copper conductors does not increase the corrosion ten-dency of copper;however,it contributes to the formation of a region concentrated with DBDS,Cu^(2+),H^(+)by adsorption and impediment,which plays a key role in facilitating the sulphur corrosion of copper conductors.Moreover,sulphur corrosion can also occur on other metal parts in transformers when there is a particular gap on surfaces other than copper.

基于化学链的氨生产--一种有前途的非碳燃料生产途径

氨既是最基本的化工原料之一,也是一种很有前景的非碳燃料,可用于防止全球变暖.氨主要由1909年开发的曾获得两项诺贝尔奖的哈伯-博世工艺制成.然而该工艺过程有一些缺点,包括高碳足迹和需要苛刻的反应条件.有数据统计,用于全世界的合成氨上的能源占全球天然气产量的3%~5%和全球能源消耗的1%~2%.这使得开发替代的合成氨的方法很有必要.基于化学链的氨生产使用氮载体材料,可以在大气压下运行并实现高产品选择性和高能源效率.迄今为止,在这个关键领域还缺乏关于氮载体和基于化学链的氨生产系统的综述和展望.本文旨在全面回顾化学链的氨生产的最新进展,并总结性地展望了化学链的氨生产的未来发展.本文首先讨论了可持续的、基于化学链的氨生产的途径和氨的利用;然后,根据反应物和中间步骤将基于化学链的氨生产系统性地分为四类.此外,文章还全面回顾了每一类基于化学链的氨生产的氮载体的最新发展和所需的热力学性质;最后对基于化学链的氨生产技术的发展方向进行了展望.

六维生物样本银行的概念及其推动罕见病新药研发的作用

In 2001, Dr. Zhi-Cheng Jing encountered a pulmonary arterial hypertension (PAH) patient from a large pedigree. Dr. Jing collected the clinical information and blood samples from this pedigree and was the first to report the pedigree of familial PAH in China [1]. In2004, this pedigree was confirmed to carry a mutation in BMPR2(Arg491Trp), which was the first evidence of pathogenicity of BMPR2 mutation in the Chinese population [2].

Flexible Mg_(3)N_(2)layer regulates lithium plating-striping for stable and high capacity lithium metal anodes

Lithium metal is regarded as one of the most promising candidates for next-generation batteries.However,lithium dendrite formation and dead lithium accumulation are the critical problems which hinder its practical application.Herein,we constructed a flexible coating membrane layer which could effectively uniform the lithium deposition by isolating lithium metal from electrolyte and regulating the ion flux distribution.After modification,both the Li||Li symmetric cells(more than 1,400 h at 1 mA·cm^(−2)and 1 mAh·cm^(−2))and Li||Cu cells(more than 500 cycles at 0.5 mA·cm^(−2)and 0.5 mAh·cm^(−2),coulombic efficiency over 98%)deliver excellent long-cycle performance with high coulombic efficiency.The high performance is also proved in LiFePO4(capacity retention increases from 79%to 93%at 2 C after 400 cycles)and NCM811 full cells(capacity retention from 28.5%to 78%at 2 C after 500 cycles).High electro-performance in batteries demonstrates that the multifunctional layer plays a crucial role in stabilizing lithium anode.Moreover,in order to verify the universality of the method,we have extended this facile way to fabricate other types of flexible membranes.This work offers an insight into solving the current obstacles in the application of lithium metal batteries.

产生物表面活性剂菌株的筛选及发酵条件优化

[目的]筛选高产表面活性剂的菌株,并探究合适的培养条件。[方法]以被石油类物质污染的土壤为样品,通过排油圈和表面张力实验筛选出生物表面活性剂高产菌,结合单因素优化得出最佳发酵条件。[结果]通过初筛和复筛最终得到一株表面活性剂高产菌株FC-69,经16S rDNA鉴定为铜绿假单胞菌(Pseudomonas aeruginosa)。最终得出以20 g/L葡萄糖,3 g/L硝酸铵,NaCl 5 g/L,初始pH值8.0,培养温度30℃的培养条件更有利于FC-69菌株生物表面活性剂的合成。[结论]成功筛选出一株高产生物表面活性剂的菌种,结合优化后的发酵条件可使筛选菌株的生物表面活性剂产量达到31.61 g/L。