马铃薯G6PDH基因家族鉴定及其在损伤块茎的表达分析

【目的】葡萄糖-6-磷酸脱氢酶(G6PDH)在植物响应非生物胁迫中发挥重要作用,鉴定马铃薯中G6PDH基因家族,并分析其在损伤块茎的表达模式,为深入研究马铃薯G6PDH基因在损伤胁迫中的作用提供参考。【方法】利用生物信息学对马铃薯G6PDH基因家族进行鉴定,并对该基因家族成员编码蛋白的染色体分布、蛋白理化性质和二级结构、进化关系、基因结构、保守基序和启动子顺式作用元件,以及在不同器官和损伤块茎中的表达模式进行分析。【结果】在马铃薯基因组中共鉴定到4个StG6PDHs家族成员,分别分布在4条染色体上,命名为StG6PDH1-StG6PDH4。根据亚细胞定位和系统进化分析,StG6PDH1、StG6PDH3和StG6PDH4位于叶绿体,属于质体型;StG6PDH2位于细胞质,属于胞质型。马铃薯G6PDH蛋白的氨基酸个数介于511-596 aa,分子量为58.48-66.65 kD,等电点为5.83-8.57,不稳定系数为39.79-47.53。蛋白二级结构以α-螺旋和无规则卷曲占比最多,β-转角最少。此外,StG6PDHs启动子含大量植物激素、光和胁迫响应元件。4个StG6PDHs在马铃薯根、茎、叶和块茎均有表达,且在叶片中的表达高于其他组织。StG6PDHs各成员共同参与马铃薯块茎对损伤胁迫的响应,其中,StG6PDH1、StG6PDH2和StG6PDH3在块茎损伤后36 h内上调表达,StG6PDH4在损伤后下调表达。【结论】在马铃薯中共鉴定出4个StG6PDHs基因家族成员,不均匀地分布于4条染色体上,其中,1个为胞质型,3个为质体型。StG6PDHs启动子区有光、激素和胁迫响应元件。损伤块茎中StG6PDHs的表达具有差异性,各成员协同调控了马铃薯块茎对损伤胁迫的应答。

Effect of valence and spin state on ethane dehydrogenation in Fe-S-1 catalyst

Light alkanes non-oxidative dehydrogenation is an attractive non-oil route for olefins production.The alkane dehydrogenation reaction is limited by thermodynamic equilibrium,and the C-H bond cleavage is commonly considered as the rate-determined step.The valence state of metal sites in catalysts will influence the stabilization of the vital intermediate(i.e.,C_(x)H_(y)...M^(δ+)...H)during the C-H bond cleavage process,which in turn affects the catalytic reactivity.Herein,we explicitly investigated the effect of different valence states of framework-Fe in silicate-1 zeolite on ethane dehydrogenation reaction through the combination of experimental and theoretical study.Fe(Ⅱ)-S-1 and Fe(Ⅲ)-S-1 catalysts are successfully synthesized by ligand-assisted in situ crystallization method,In-situ C_(2)H_6-FTIR shows the higher coverage of hydrocarbon intermediates on Fe(Ⅱ)-S-1,Under the same evaluation co nditio n,Fe(Ⅱ)-S-1 exhibits a higher space time yield of ethylene.Density functional theory(DFT)results reveal that the more coordinate-unsaturated and electron-enriched Fe(Ⅱ)sites boost the first C-H bond activation by slight deformation and efficient electron donation with C_(2)H_(5)^(*)species.Remarkably,the second C-H bond cleavage on Fe(Ⅱ)-S-1 undergoes a spin-crossing process from quintet state to triplet state,which involves a two-electro n-two-orbital interaction,further promoting the formation of ethylene.Microkinetic analysis is consistent with the experimental and DFT results.This work could provide methodology for elucidating the effect of metal valence states on catalytic performance as well as offer guidance for designing more efficient Fe-zeolite catalysts.

PDH产业发展现状及预测

全球约21%丙烷用于化工生产。由于北美等地C_(2)产业链利润高于C_(3),出口丙烷效益优于下游生产,北美和中东地区成为全球丙烷资源主要输出地。全球PDH装置产能的大幅增长也带动原料丙烷贸易增加,助力丙烷价格高位运行,同时需求增速保持低位。新增PDH装置主要来自中国,中国在2014—2016年经历了第一轮扩能高峰期,2019年开启第二轮PDH建设热潮。未来丙烯整体供应远超下游消费增速,过剩态势逐渐显现,直接影响PDH装置丙烯未来盈利水平。

Effect of Fe Addition on Dehydrogenation Performance of Methylcyclohexance over Pt/Al_(2)O_(3)

Catalysts with varying Fe contents were prepared using a sequential impregnation method to investigate the effects of Fe addition on the physicochemical properties of Pt/Al_(2)O_(3) and their performance in methylcyclohexane(MCH)dehydrogenation.The results demonstrated that the addition of Fe to Pt/Al_(2)O_(3) enhanced the electron density of Pt and improved catalytic activity,while exhibiting negligible influence on the catalytic selectivity for toluene.When the Fe content was 0.057%,the catalyst exhibited the highest MCH consumption rate,which was approximately two times higher than that of the catalyst without Fe.Additionally,the incorporation of Fe inhibited the formation of coke and reduced the quantity of coke deposits on the catalyst,thereby improving its catalytic durability.Overall,Fe shows promise as a prospective secondary element for Pt/Al_(2)O_(3) to enhance the MCH dehydrogenation performance.

Synthesizing active and durable cubic ceria catalysts(<6 nm)for fast dehydrogenation of bio-polyols to carboxylic acids coproducing green H_(2)

Dehydrogenation is considered as one of the most important industrial applications for renewable energy.Cubic ceria-based catalysts are known to display promising dehydrogenation performances in this area.Large particle size(>20 nm)and less surface defects,however,hinder further application of ceria materials.Herein,an alternative strategy involving lactic acid(LA)assisted hydrothermal method was developed to synthesize active,selective and durable cubic ceria of<6 nm for dehydrogenation reactions.Detailed studies of growth mechanism revealed that,the carboxyl and hydroxyl groups in LA molecule synergistically manipulate the morphological evolution of ceria precursors.Carboxyl groups determine the cubic shape and particle size,while hydroxyl groups promote compositional transformation of ceria precursors into CeO_(2) phases.Moreover,enhanced oxygen vacancies(Vo)on the surface of CeO_(2) were obtained owing to continuous removal of O species under reductive atmosphere.Cubic CeO_(2) catalysts synthesized by the LA-assisted method,immobilized with bimetallic PtCo clusters,exhibit a record high activity(TOF:29,241 h^(-1))and Vo-dependent synergism for dehydrogenation of bio-derived polyols at 200℃.We also found that quenching Vo defects at air atmosphere causes activity loss of PtCo/CeO_(2) catalysts.To regenerate Vo defects,a simple strategy was developed by irradiating deactivated catalysts using hernia lamp.The outcome of this work will provide new insights into manufacturing durable catalyst materials for aqueous phase dehydrogenation applications.

Mn-doped SrCoO_(3-δ) Perovskite Oxides for Ethylene Production via Chemical Looping Oxidative Dehydrogenation of Ethane

Chemical looping oxidative dehydrogenation (CL-ODH) is an economically promising method for convertingethane into higher value-added ethylene utilizing lattice oxygen in redox catalysts, also known as oxygen carriers. Inthis study, perovskite-type oxide SrCoO_(3-δ) and B-site Mn ion-doped oxygen carriers (SrCo_(1-x)MnxO_(3-δ), x=0.1, 0.2, 0.3)were prepared and tested for the CL-ODH of ethane. The oxygen-deficient perovskite SrCoO_(3-δ) exhibited high ethyleneselectivity of up to 96.7% due to its unique oxygen vacancies and lattice oxygen migration rates. However, its low ethyleneyield limits its application in the CL-ODH of ethane. Mn doping promoted the reducibility of SrCoO_(3-δ) oxygen carriers,thereby improving ethane conversion and ethylene yield, as demonstrated by characterization and evaluation experiments.X-ray diffraction results confirmed the doping of Mn into the lattice of SrCoO_(3-δ), while X-ray photoelectron spectroscopy(XPS) indicated an increase in lattice oxygen ratio upon incorporation of Mn into the SrCoO_(3-δ) lattice. Additionally, H2temperature-programmed reduction (H2-TPR) tests revealed more peaks at lower temperature reduction zones and a declinein peak positions at higher temperatures. Among the four tested oxygen carriers, SrCo0.8Mn0.2O_(3-δ) exhibited satisfactoryperformance with an ethylene yield of 50% at 710 °C and good stability over 20 redox cycles. The synergistic effect of Mnplays a key role in increasing ethylene yields of SrCoO_(3-δ) oxygen carriers. Accordingly, SrCo0.8Mn0.2O_(3-δ) shows promisingpotential for the efficient production of ethylene from ethane via CL-ODH.

Ethane Chemical Looping Oxidative Dehydrogenation to Ethylene over Co_(2)O_(3)(Fe_(2)O_(3),NiO)/LaCoO_(3) Oxygen Carriers

Ethane chemical looping oxidative dehydrogenation(CL-ODH)to ethylene is a new technology for converting ethane to ethylene.In the current study MeO/LaCoO_(3)(MeO=Fe_(2)O_(3),NiO or Co_(2)O_(3))composite metal oxides were prepared via citrate gel and impregnation methods,and used as oxygen carriers for CL-ODH.X-ray diffraction results indicated that all oxygen carriers had a perovskite structure even after eight redox cycles.Under a reaction temperature of 650°C,a reaction pressure of 0.1 MPa,and a weight hourly space velocity(WHSV)of 7500 mL/(g·h),ethane conversion over Co_(2)O_(3)/LaCoO_(3) reached 100%and ethylene selectivity reached 60%,both of which were better than corresponding values attained over Fe_(2)O_(3)/LaCoO_(3) and NiO/LaCoO_(3).Ethylene selectivity remained stable for 80 cycles over Co_(2)O_(3)/LaCoO_(3),then decreased gradually after 80 cycles.X-ray photoelectron spectroscopy results and evaluation results indicated that lattice oxygen and O_(2)2-had a direct relationship with ethane conversion and ethylene selectivity.Co_(2)O_(3)/LaCoO_(3) exhibited a strong capacity to release and absorb oxygen,mainly due to interaction between Co_(2)O_(3) and LaCoO_(3).

Thermal stable Pt clusters anchored by K/TiO_(2)—Al_(2)O_(3)for efficient cycloalkane dehydrogenation

Catalytic dehydrogenation of cycloalkanes is considered a valuable endothermic process for alleviating the thermal barrier issue of hypersonic vehicles.However,conventional Pt-based catalysts often face the severe problem of metal sintering under high-temperature conditions.Herein,we develop an efficient K_(2)CO_(3)-modified Pt/TiO_(2)—Al_(2)O_(3)(K—Pt/TA)for cycloalkane dehydrogenation.The optimized K—Pt/TA showed a high specific activity above 27.9 mol·mol^(-1)·s^(-1)(H_(2)/Pt),with toluene selectivity above 90.0%at 600℃with a high weight hourly space velocity of 266.4 h^(-1).The introduction of alkali metal ions could generate titanate layers after high-temperature hydrogen reduction treatment,which promotes the generation of oxygen vacancy defects to anchored Pt clusters.In addition,the titanate layers could weaken the surface acidity of catalysts and inhibit side reactions,including pyrolysis,polymerization,and isomerization reactions.Thus,this work provides a modification method to develop efficient and stable dehydrogenation catalysts under high-temperature conditions.

NiO-Doped Fe_(2)O_(3)/MgO Properties for the Chemical Looping Oxidative Dehydrogenation of Ethane

Ethane chemical looping oxidative dehydrogenation(CL-ODH)to ethylene is a new technology for ethylene preparation.Fe_(2)O_(3)/MgO oxygen carrier was prepared using the co-precipitation method.The influence of added NiO and its different loadings on Fe_(2)O_(3)/MgO were investigated.Then,a series of oxygen carriers were applied in the CL-ODH of the ethane cycle system.Brunauer-Emmett-Teller(BET),X-ray diffractometry(XRD),X-ray photoelection spectroscopy(XPS),and H2-temperature programmed reduction(TPR)were used to characterize the physicochemical properties of these oxygen carriers.It was confirmed that an interaction between NiO and Fe_(2)O_(3) occurred based on the XPS and H2-TPR results.Based on the CL-ODH activity performance tests conducted in a fixed-bed reactor,it was revealed that ethylene selectivity was significantly improved after NiO addition.Fe_(2)O_(3)-10%NiO/MgO showed the best activity performance with 93%ethane conversion and 50%ethylene selectivity at a reaction temperature of 650℃,atmospheric pressure,and space velocity of 7500 mL/(g·h).

基于PDH注入锁频的单频连续1064nm环形激光器(特邀)

单频连续激光器在光纤通信、激光雷达和光谱分析等领域有广泛应用,为了实现理想的单频连续输出,研究了一种基于PDH(Pound-Drever-Hall)注入锁频技术的单频连续1 064 nm的Nd:YVO_(4)环形激光器。实验采用线宽10 k Hz的单频光纤激光器作为种子源,从功率腔采用“8”字环形腔,通过PDH技术实现种子光的注入锁定。实验结果显示,在1.04 W的种子光注入条件下,当泵浦功率为38.12 W时,可实现13.46 W的稳定输出,对应线宽为37.26 kHz,功率稳定度为±0.55%。

Ca_(2)MnO_(4)-layered perovskite modified by NaNO_(3)for chemical-looping oxidative dehydrogenation of ethane to ethylene

Chemical-looping oxidative dehydrogenation(CL-ODH)is a process designed for the conversion of alkanes into olefins through cyclic redox reactions,eliminating the need for gaseous O_(2).In this work,we investigated the use of Ca_(2)MnO_(4)-layered perovskites modified with NaNO_(3) dopants,serving as redox catalysts(also known as oxygen carriers),for the CL-ODH of ethane within a temperature range of 700-780℃.Our findings revealed that the incorporation of NaNO_(3) as a modifier significantly-nhanced the selectivity for-thylene generation from Ca_(2)MnO_(4).At 750℃and a gas hourly space velocity of 1300 h^(-1),we achieved an-thane conversion up to 68.17%,accompanied by a corresponding-thylene yield of 57.39%.X-ray photoelectron spectroscopy analysis unveiled that the doping NaNO_(3) onto Ca_(2)MnO_(4) not only played a role in reducing the oxidation state of Mn ions but also increased the lattice oxygen content of the redox catalyst.Furthermore,formation of NaNO_(3) shell on the surface of Ca_(2)MnO_(4) led to a reduction in the concentration of manganese sites and modulated the oxygen-releasing behavior in a step-wise manner.This modulation contributed significantly to the enhanced selectivity for ethylene of the NaNO_(3)-doped Ca_(2)MnO_(4) catalyst.These findings provide compelling evidence for the potential of Ca_(2)MnO_(4)-layered perovskites as promising redox catalysts in the context of CL-ODH reactions.

基于超稳腔PDH锁频技术的852 nm超稳激光器

自上世纪80年代激光锁定技术发展以来,超稳激光器在光钟、引力波探测、腔量子电动力学、星地通讯等高精度光学量子时频计量领域发挥着重要作用。利用Pound-Drever-Hall(PDH)锁频技术,可以将自由运转激光器的频率锁定后获得极高频率稳定性的激光输出。这里,将852 nm波长激光锁定在超稳谐振腔的频率谐振点上,实现超稳频激光输出。试验中的超稳谐振腔品质因子达到1010,精细程度达到20万,输出激光的秒级频率稳定度达到5.2×10^(-15),线宽2.3 Hz。这一频率稳定度的连续激光器将为852 nm波长的钟激光器提供有力的技术支持,与Cs原子产生良好关联。

小麦G6PDH基因家族的鉴定与表达分析

葡萄糖-6-磷酸脱氢酶(G6PDH)是磷酸戊糖途径中的关键限速酶,在植物生长发育及非生物胁迫响应中发挥重要作用。本研究利用生物信息学对小麦G6PDH基因家族成员进行鉴定,并对该家族基因编码蛋白的理化性质、进化关系、亚细胞定位、基因复制事件以及在不同组织和不同胁迫下的表达模式进行分析。结果表明,在小麦基因组中共鉴定到14个G6PDH基因家族成员,分布在小麦2A、2B、2D、4A、4B、4D、6A、6B和6D染色体上,其中5个基因编码的蛋白为胞质型,9个为质体型。亚细胞定位预测表明,胞质型G6PDH蛋白主要定位于细胞质上,而质体型G6PDH蛋白主要定位于叶绿体上。根据系统进化和保守结构域特征,可将14个小麦G6PDH蛋白分为Cy、P0、P1和P2四个亚组。共线性分析表明,小麦G6PDH基因家族成员存在17对片段重复基因。RNA-seq分析结果表明,小麦G6PDH基因家族成员在不同组织中存在明显的表达差异,其中TaG6PDH1-2A/2B/2D基因在根中的表达量最高;TaG6PDH2-2A和TaG6PDH2-2B基因在干旱胁迫后1 h以及热胁迫后6 h均上调表达。进一步利用qRT-PCR检测6个小麦G6PDH基因在干旱和盐胁迫下的表达模式,发现分别有5个基因在小麦根中均上调表达,推测小麦G6PDH基因在非生物胁迫响应过程中发挥着重要功能。

大豆抗裂荚基因pdh1在长江中下游区域联合试验品种中的分布

大豆裂荚是导致大豆机收产量损失的重要原因之一,也是育种选择的重要指标之一。以抗裂荚基因pdh1为标记,对2021-2022年国家长江中下游区域联合鉴定品种进行分布鉴定。结果表明:105份试验品种中有56份品种含有pdh1基因,pdh1集中分布在粒用型中早熟组夏大豆品种中,占到夏大豆总数的91.4%。基因pdh1在参试品种中的分布具有明显的育成地域特点,由黄淮和东北地区(包含辽宁、安徽、河北、河南、江苏、山东)选育的大豆品种有82.3%含有pdh1,而在南方地区(包含福建、湖北、湖南、江西、四川、浙江)选育的品种中,pdh1含有率仅有11.6%。可以认为,抗裂荚基因pdh1在东北、黄淮地区育种中已得到有效利用,在南方地区尚未得到充分利用,该地区高温、高湿气候可能是影响田间抗裂荚选择的主要原因。采用分子鉴定辅助选择将有助于提高南方地区抗裂荚育种的效率。

Influence of carbonization temperature on cobalt-based nitrogendoped carbon nanopolyhedra derived from ZIF-67 for nonoxidative propane dehydrogenation

Propylene is a significant basic material for petrochemicals such as polypropylene,propylene oxide,etc.With abundant propane supply from shale gas,propane dehydrogenation(PDH)becomes extensively attractive as an on-purpose propylene production route in recent years.Nitrogen-doped carbon(NC)nanopolyhedra supported cobalt catalysts were synthesized in one-step of ZIF-67 pyrolysis and investigated further in PDH.XPS,TEM and N_(2) adsorption-desorption were used to study the influence of carbonization temperature on as-prepared NC supported cobalt catalysts.The temperature is found to affect the cobalt phase and nitrogen species of the catalysts.And the positive correlation was established between Co0 proportion and space time yield of propylene,indicating that the modulation of carbonization temperature could be important for catalytic performance.

PtSn/MgAl_(2)O_(4)-sheet催化剂的制备及其PDH反应性能

近年来,因为页岩气大规模开采的成功可以为丙烷脱氢制丙烯(PDH)工艺提供大量廉价的丙烷,丙烷脱氢制丙烯已成为最有前途和最具吸引力的丙烯生产技术。目前工业上丙烷脱氢主要采用的是负载型PtSn/Al_(2)O_(3)催化剂。然而在丙烷脱氢高温反应中,PtSn纳米粒子易烧结和积炭使催化剂遭受严重的失活。为了解决上述问题,本文合成了片状的MgAl_(2)O_(4)尖晶石载体负载PtSn金属纳米粒子,制备了PtSn/MgAl_(2)O_(4)-sheet催化剂。该催化剂具有较大的孔径,有利于PDH反应中反应物的吸附和产物的脱附,提高了催化剂的活性同时降低了积炭含量。同时片状的MgAl_(2)O_(4)尖晶石载体的(111)面与PtSn纳米颗粒存在着强的相互作用,阻止了PtSn纳米颗粒在高温反应中的烧结。在丙烷脱氢反应中,丙烷的转化率达到了43.2%,丙烯的选择性达到了95.0%,失活速率仅为0.008h^(-1),其性能优于商用的PtSn/Al_(2)O_(3)催化剂。

Anomalous metastable hcp Ni nanocatalyst induced by non-metal N doping enables promoted ammonia borane dehydrogenation

Developing high-performing non-noble transition metal catalysts for H_(2) evolution from chemical hydrogen storage materials is of great significance for the hydrogen economy system, yet challenging. Herein,we present for the first time that anomalous metastable hexagonal close-packed Ni nanoparticles induced by heteroatom N doping encapsulated in carbon(N-hcp-Ni/C) can exhibit admirable catalytic performance for ammonia borane(AB) dehydrogenation, prominently outperforming conventional fcc Ni counterpart with similar morphology and favorably presenting the state-of-the-art level.Comprehensive experimental and theoretical studies unravel that unusual hcp phase engineering of Ni together with N doping could induce charge redistribution and modulate electronic structure, thereby facilitating H_(2)O adsorption and expediting H_(2)O dissociation(rate-determining step). As a result, AB dehydrogenation can be substantially boosted with the assistance of N-hcp-Ni/C. Our proposed strategy highlights that unconventional crystal phase engineering coupled with non-metal heteroatom doping is a promising avenue to construct advanced transition metal catalysts for future renewable energy technologies.

轻烃转化生产丙烷技术配套PDH工艺的经济效益分析

分析了丙烷脱氢(PDH)行业发展现状,丙烷原料价格上涨是导致PDH行业目前陷入困局的主要原因;为寻找稳定且廉价的丙烷,提高PDH行业抵抗风险的能力,对轻烃转化生产丙烷这一新兴加工路线的技术特点和该技术与PDH工艺配套后的经济效益进行了分析。结果表明:该技术可将各类低价值轻烃高效转化为丙烷,可直接用作PDH原料,同时副产高价值的混合芳烃;在现有的能源价格体系下,轻烃转化生产丙烷技术与PDH工艺配套后可节约丙烷原料成本,帮助PDH企业摆脱对进口原料的依赖,并提高其抗风险能力和竞争力。轻烃转化生产丙烷技术为企业低价值轻烃的利用和PDH产业链的安全发展提供了良好的技术选择。

Effect of boron species on carbon surface on oxidative dehydrogenation of propane

Carbon catalysts for propane oxidative dehydrogenation(PODH)can potentially replace metal oxide catalysts due to their environmental friendliness(greenness)and excellent catalytic performance.Biomass carbon materials have the advantages of being abundant in variety,inexpensive,and easily available,but their catalytic selectivity is relatively poor in PODH.Therefore,we report here on a boron-doped sisal fiber carbon catalyst,which showed excellent selectivity of propylene in PODH,excluding the effect of surface-covered B2O3 on the catalytic performance by hot water washing.The carbon material exhibited the best catalytic performance with a load of 2%(mass)and a calcination temperature of 1100℃.At a reaction temperature of 400℃,the conversion rate of propane was 2.0%,and the selectivity toward propylene reached 88.6%.The new chemical bonds formed by boron on the surface of the carbon materials had an important effect on the catalytic performance,as determined by XPS characterization.The BAO groups affected the catalytic activity by inhibiting the generation of electrophilic oxygen species,while the BAC content improved the selectivity toward propylene by changing the electron cloud density.

A mini review on oxidative dehydrogenation of propane over boron nitride catalysts

Oxidative dehydrogenation of propane is an attractive route for the synthesis of propylene due to its favorable thermodynamic and kinetic characteristics, however, it is challenging to realize high selectivity towards propylene. Recently, it has been discovered that boron nitride (BN) is a promising catalyst that affords superior selectivity towards propylene in oxidative dehydrogenation of propane. Summarizing the progress and unravelling the reaction mechanism of BN in oxidative dehydrogenation of propane are of great significance for the rational design of efficient catalysts in the future. Herein, in this review, the underlying reaction mechanisms of oxidative dehydrogenation of propane over BN are extracted;the developed BN catalysts are classified into pristine BN, functionalized BN, supported BN and others, and the applications of each category of BN catalysts in oxidative dehydrogenation of propane are summarized;the challenges and opportunities on oxidative dehydrogenation of propane over BN are pointed out, aiming to inspire more studies and advance this research field.