大豆泛基因组研究进展

人工驯化为农业发展提供了原始驱动力,也深刻地改变了许多动植物的遗传背景。伴随组学大数据理论和技术体系的发展,作物基因组研究已迈入泛基因组时代。借助泛基因组的研究思路,通过多基因组间的比较和整合,能够评估物种遗传信息上界和下界,认知物种的遗传多样性全貌。此外,将泛基因组与染色体大尺度结构变异、群体高通量测序及多层次组学数据相结合,可以进行更为深入的性状-遗传机制解析。大豆(Glycine max(L.)Merr.)是重要的粮油经济作物,大豆产能关乎国家粮食安全。对大豆遗传背景形成、重要农艺性状关键位点的解析,是实现更高效的大豆育种改良的前提。本文首先对泛基因组学的核心问题进行了阐述,解释了从头组装/比对组装、迭代式组装和图基因组等泛基因组研究策略的演变历程和各自特征;接着对作物泛基因组研究的热点问题进行了概括,并且以大豆为例详细阐释了包括类群选择、泛基因组构建、数据挖掘等方面在内的泛基因组研究的开展思路,着重说明染色体结构变异在大豆演化/驯化历程中的贡献及其在农艺性状遗传基础挖掘上的价值;最后讨论了图泛基因组在数据整合、结构变异计算方面的应用前景。本文对作物泛基因组未来的发展趋势进行了展望,以期为作物基因组学及数据科学研究提供参考。

基于镍铁层状双氢氧化物的氧析出催化剂:催化机制、电极设计和稳定性

近几十年来,氧析出反应因其在能量储存和转换技术中的关键作用而受到了广泛关注。然而,它需要高效的催化剂例如IrO2和RuO2,来加速其缓慢的反应动力学。在所开发的低成本材料中,镍铁层状双氢氧化物(NiFe LDH)较为有前景,其在碱性电解质中表现出出色的氧析出性能,过电位很低,在10 mA·cm^(-2)处仅需200-300 mV。虽然人们在开发基于NiFe LDH的高效电催化剂方面做出了巨大努力并取得了一些成果,但是要进一步降低其过电位具有相当的挑战性。为了克服这个瓶颈,就需要明确识别其活性位点和催化机理,从根本出发来探究新的解决方案,以获得具有超低过电位的催化剂。本综述首先回顾了NiFe LDH的结构、组成和发展历史。虽然人们在研究催化活性位点和机制方面付出了巨大努力,但其真正的催化位点和机制仍然是模棱两可并存在争议的。我们对催化位点研究的代表性工作进行了全面分析,希望对催化机理和活性位点能提供一些深入认识和理解。此外,我们还就增强其催化活性的各种策略,如杂原子掺杂和引入空位等,进行了总结并基于电子和几何结构对其活性提高原理进行了分类,为开发高性能的NiFe LDH基催化剂提供新的见解和方向。此外,催化剂的稳定性,尤其是在高电流密度等技术条件下的稳定性至关重要,但常常被人们忽视。最新的研究表明,NiFe LDH基催化剂在高电流密度下运行一段时间就会出现严重的活性衰减。因此,本综述强调了稳定性问题的重要性,以引起更多研究者对此问题的关注,并分析了NiFe LDH基催化剂的衰减机理,总结和讨论了基于这些衰减机理开发的改善稳定性问题的最新策略。最后,本综述讨论了制备兼具优异催化活性和稳定性的NiFe LDH基的高效催化剂的可能发展方向。

Method to measure tree-ring width,density,elemental composition,and stable carbon and oxygen isotopes using one sample

Tree-ring width(RW),density,elemental com-position,and stable carbon and oxygen isotope(δ^(13)C,δ^(18)O)are widely used as proxies to assess climate change,ecology,and environmental pollution;however,a specific pretreat-ment has been needed for each proxy.Here,we developed a method by which each proxy can be measured in the same sample.First,the sample is polished for ring width meas-urement.After obtaining the ring width data,the sample is cut to form a 1-mm-thick wood plate.The sample is then mounted in a vertical sample holder,and gradually scanned by an X-ray beam.Simultaneously,the count rates of the fluorescent photons of elements(for chemical characteriza-tion)and a radiographic grayscale image(for wood density)are obtained,i.e.the density and the element content are obtained.Then,cellulose is isolated from the 1-mm wood plate by removal of lignin,and hemicellulose.After producing this cellulose plate,cellulose subsamples are separated by knife under the microscope for inter-annual and intra-annual stable carbon and oxygen isotope(δ^(13)C,δ^(18)O)analysis.Based on this method,RW,density,elemental composition,δ^(13)C,and δ^(18)O can be measured from the same sample,which reduces sample amount and treatment time,and is helpful for multi-proxy comparison and combination research.

Constitutive modeling of viscoelastic-viscoplastic behavior of short fiber reinforced polymers coupled with anisotropic damage and moisture effects

In this paper, a combined viscoelasticity-viscoplasticity model, coupled with anisotropic damage and moisture effects, is developed for short fiber reinforced polymers (SFRPs) with different fiber contents and subjected to a variety of strain rates. In our model, a rate-dependent yield surface for the matrix phase is employed to identify initial yielding of the material. When an SFRP is loaded at small deformation before yielding, its viscoelastic behavior can be described using the generalized Maxwell model, while when plasticity occurs, a scalar internal state variable (ISV) is used to capture the hardening behavior caused by the polymeric constituent of the composite. The material degradation due to the moisture absorption of the composite is modeled by employing another type of ISV with different evolution equations. The complicated damage state of the SFRPs is captured by a second rank tensor, which is further decomposed to model the subscale damage mechanisms of micro-voids/cracks nucleation, growth and coalescence. It is concluded that the proposed constitutive model can be used to accurately describe complicated behaviors of SFRPs because the results predicted from the model are in good agreement with the experimental data.

Two dimensional metal halide perovskites: Promising candidates for light-emitting diodes

Two dimensional halide perovskites are emerging as attractive electroluminescent materials for developing high-performance light-emitting devices owing to their unique structures and/or superior optoelectronic properties.This review begins with an introduction to the working principles of and the key figures for evaluating the performance of LEDs.Secondly,the structure and optoelectronic properties of two dimensional perovskites are summarized and discussed. Their advantages in LED application over their 3D counterparts are systematically analyzed.Following the theoretically discussion,the progresses on the preparation of two dimensional perovskite materials as well as their performances in LEDs have been summarized. At last,several challenges and prospects are presented for achieving high performance 2D perovskite-based LEDs.

Improved perovskite solar cell efficiency by tuning the colloidal size and free ion concentration in precursor solution using formic acid additive

Improving the quality of the perovskite active layer is crucial to obtaining high performance perovskite solar cells(PSCs). In this work, by introducing formic acid into the formamidinium lead iodide(FAPbI3)precursor solution, we managed to achieve reduced colloidal size in the solution, leading to more uniform deposition of FAPbI3 film with lower trap state density and higher carrier mobility. The solar cells based on the FAPbI3 absorber layer modified with formic acid show significantly better photovoltaic performance than that on the reference FAPbI3 film without formic acid. The device performance shows a close correlation with the colloidal size. Within the range studied from 6.7 to 1.0 nm, the smaller the colloidal size is, the higher the solar cell efficiency. More specifically, the cell efficiency is improved from17.82% for the control cell without formic acid to 19.81% when 0.764 M formic acid was used. Formic acid has also been added into a CH3NH3PbI3(MAPbI3) precursor solution, which exhibits a similar effect on the resulting MAPb I3 films and solar cells, with efficiency improved from 16.07% to 17.00%.

Post-treatment by an ionic tetrabutylammonium hexafluorophosphate for improved efficiency and stability of perovskite solar cells

Interface engineering is an effective way to improve efficiency and long-term stability of perovskite solar cells(PSCs).Herein,an ionic compound tetrabutylammonium hexafluorophosphate(TP6)is adopted to passivate surface defects of the perovskite film.It is found that TP6 effectively reduced the surface defects,especially at the grain boundaries where the defects are abundant.Meanwhile,the exposed long alkyl chains and fluorine atoms in the TP6 enhanced the moisture stability of the perovskite film due to its strong hydrophobicity.In addition,the driving force of charge carrier separation and transport is increased by enlarged built-in potential.Consequently,the power conversion efficiency(PCE)of PSCs is significantly improved from 20.59% to 22.41%by increased open-circuit voltage(V_(oc))and fill factor(FF).The unencapsulated device with TP6 treatment exhibits better stability than the control device,and the PCE retains-80%of its initial PCE after 30 days under 15%-25%relative humidity in storage,while the PCE of the control device declines by more than 50%.

High-quality perovskite MAPbI_3 single crystals for broad-spectrum and rapid response integrate photodetector

Organic–inorganic single-crystalline perovskites have attracted significant attentions due to their exceptional progress in intrinsic properties＇ investigation and applications in photovoltaics and optoelectronics. In this study, the large perovskite CH3NH3PbI3 single crystal with the largest length of 80 mm was prepared through the method of inverse-temperature crystallization. Meanwhile, the mass production of integrate photodetectors have been fabricated on the single-crystalline wafer and the photoresponse performances were investigated. The results show that the single-crystalline photodetectors have broad spectrum response to 900 nm, rapid response speed（〈40 μs） and excellent stability. These findings are of great importance for future promising perovskite single crystalline for integrated photoelectronic application.

Catalytic Pyrolysis of Soybean Oil with CaO/Bio-Char Based Catalyst to Produce High Quality Biofuel

In this paper,CaO/bio-char was synthesized by directly co-pyrolysis of Ca(OH)_(2) and rice straw,and used as catalyst to catalytic pyrolysis of soybean oil to produce high quality biofuel.In this co-pyrolysis process,CaO particles has been successfully embedded on the bio-char surface.During the catalytic pyrolysis process,CaO/biochar showed a good catalytic performance on the deoxygenation of soybean oil.Pyrolysis temperature affected the pyrolysis reactions and pyrolytic products distributions dramatically,higher pyrolysis temperature lead to seriously cracking reactions,lower bio-oil yield and higher gases yield,and lower pyrolysis temperature lead to higher bio-oil yield with higher oxygenated compounds content and lower hydrocarbons contents,the suitable pyrolysis temperature was around 650℃.Under the optimal conditions(650℃ with WHSV at 6.4 h^(−1) and carrier gas flow rate at 100 ml/min),the selectivity(%)of hydrocarbons in the bio-oil was more than 90%.CaO/bio-char catalyst still shows good catalytic deoxygenation activity after 4 cycles.1 g of CaO/bio-char catalyst can catalyze pyrolysis of 32 g of soybean oil to produce high-quality liquid fuel.Bio-char based catalyst has been proved to be a promising catalyst for catalytic conversion of triglyceride-based lipids into high quality liquid biofuel.

Evaluation of the Power Generation Capacity of Hydrokinetic Generator Device Using Computational Analysis and Hydrodynamic Similitude

This paper presents a similitude and computational analysis of the performance of a scaled-down model of a paddle wheel style hydrokinetic generator device used for generating power from the flow of a river. The paddle wheel dimensions used in this work are one-thirtieth scale of the full-size paddle wheel. The reason for simulating the scaled-down model was to prepare for the testing of a scaled-down physical prototype. Computational Fluid Dynamics using ANSYS Fluent 14.0 software was used for the computational analysis. The scaled-down dimensions were used in the simulations to predict the power that can be generated from the scaled size model of the paddle wheel, having carried out similitude analysis between the scaled down size and its full-size. The dimensionless parameters employed in achieving similitude are the Strouhal number, power coefficient, and pressure coefficient. The power estimation of the full-size was predicted from the scaled size of the paddle wheel based on the similitude analysis.

Continuous-Time and Discrete-Time Singular Value Decomposition of an Impulse Response Function

This paper proposes the continuous-time singular value decomposition (SVD) for the impulse response function, a special kind of Green’s functions, in order to find a set of singular functions and singular values so that the convolutions of such function with the set of singular functions on a specified domain are the solutions to the inhomogeneous differential equations for those singular functions. A numerical example was illustrated to verify the proposed method. Besides the continuous-time SVD, a discrete-time SVD is also presented for the impulse response function, which is modeled using a Toeplitz matrix in the discrete system. The proposed method has broad applications in signal processing, dynamic system analysis, acoustic analysis, thermal analysis, as well as macroeconomic modeling.

Comparison of Spatial Forms between Villages under Different Cultures in Jiangxi Province

Taking Meipi Village and Zhuqiao Village as the research objects,the external space,internal space and architecture form of the ancient villages were compared,and the law and essence of village pattern under different cultures were summarized in this article,so as to provide ideas for the preservation and continuation of Jiangxi's history and culture and innovative rural development.

穿支位置与穿支穿深筋膜后走行方式对股前外侧皮瓣发生部分坏死的影响初探

目的探讨穿支位置与穿支穿深筋膜后走行方式对股前外侧皮瓣发生部分坏死的影响。方法回顾性研究苏州瑞华骨科医院手外科2018年10月至2021年6月采用游离股前外侧皮瓣修复四肢创面术后皮瓣发生部分坏死的25例患者资料,同时在同一时期内随机选择25例采用股前外侧皮瓣修复创面皮瓣完全成活患者。对比分析两组年龄、性别、穿支类型、穿支距皮缘距离、穿支位置设计与穿支穿深筋膜后走行方式的一致性、皮瓣切取时间、皮瓣大小的差异,探索股前外侧皮瓣发生部分坏死的原因。结果皮瓣部分坏死组和皮瓣完全成活组年龄、性别、穿支类型、穿支距皮缘距离、皮瓣切取时间、皮瓣大小差异无统计学意义(P>0.05),两组穿支位置设计是否与穿支深筋膜后走行一致的例数差异有统计学意义(P=0.001)。将其进行logistic回归分析显示,穿支位置设计与穿支穿深筋膜后走行方式是否一致为皮瓣部分坏死的影响因素(OR=38.812,P<0.001)。结论穿支位置设计与穿支穿深筋膜后走行方式是否一致是影响皮瓣发生部分坏死的原因。根据穿支穿深筋膜后走行方式及穿支位置设计皮瓣,可降低皮瓣发生部分坏死的概率。

Duplication and sub-functionalization of flavonoid biosynthesis genes plays important role in Leguminosae root nodule symbiosis evolution

Gene innovation plays an essential role in trait evolution.Rhizobial symbioses,the most important N2-fixing agent in agricultural systems that exists mainly in Leguminosae,is one of the most attractive evolution events.However,the gene innovations underlying Leguminosae root nodule symbiosis(RNS)remain largely unknown.Here,we investigated the gene gain event in Leguminosae RNS evolution through comprehensive phylogenomic analyses.We revealed that Leguminosae-gain genes were acquired by gene duplication and underwent a strong purifying selection.Kyoto Encyclopedia of Genes and Genomes analyses showed that the innovated genes were enriched in flavonoid biosynthesis pathways,particular downstream of chalcone synthase(CHS).Among them,Leguminosae-gain typeⅡchalcone isomerase(CHI)could be further divided into CHI1A and CHI1B clades,which resulted from the products of tandem duplication.Furthermore,the duplicated CHI genes exhibited exon–intron structural divergences evolved through exon/intron gain/loss and insertion/deletion.Knocking down CHI1B significantly reduced nodulation in Glycine max(soybean)and Medicago truncatula;whereas,knocking down its duplication gene CHI1A had no effect on nodulation.Therefore,Leguminosae-gain typeⅡCHI participated in RNS and the duplicated CHI1A and CHI1B genes exhibited RNS functional divergence.This study provides functional insights into Leguminosae-gain genetic innovation and sub-functionalization after gene duplication that contribute to the evolution and adaptation of RNS in Leguminosae.

The MADS-box transcription factor GmFULc promotes GmZTL4 gene transcription to modulate maturity in soybean

Flowering time and maturity are crucial agronomic traits that affect the regional adaptability of soybean plants.The development of soybean cultivars with early maturity adapted to longer days and colder climates of high latitudes is very important for ensuring normal ripening before frost begins.FUL belongs to the MADS-box transcription factor family and has several duplicated members in soybeans.In this study,we observed that overexpression of GmFULc in the Dongnong 50 cultivar promoted soybean maturity,while GmFULc knockout mutants exhibited late maturity.Chromatin immunoprecipitation sequencing(ChIP-seq)and RNA sequencing(RNA-seq)revealed that GmFULc could bind to the CArG,bHLH and homeobox motifs.Further investigation revealed that GmFULc could directly bind to the CArG motif in the promoters of the GmZTL3 and GmZTL4 genes.Overexpression of GmZTL4 promoted soybean maturity,whereas the ztl4 mutants exhibited delayed maturity.Moreover,we found that the cis element box 4 motif of the GmZTL4 promoter,a motif of light response elements,played an important role in controlling the growth period.Deletion of this motif shortened the growth period by increasing the expression levels of GmZTL4.Functional investigations revealed that short-day treatment promoted the binding of GmFULc to the promoter of GmZTL4 and inhibited the expression of E1 and E1Lb,ultimately resulting in the promotion of flowering and early maturation.Taken together,these findings suggest a novel photoperiod regulatory pathway in which GmFULc directly activates GmZTL4 to promote earlier maturity in soybean.

Natural GmACO1 allelic variations confer drought tolerance and influence nodule formation in soybean

Soybean[Glycine max(L.)Merr.]is one of the most important,but a drought-sensitive,crops.Identifying the genes controlling drought tolerance is important in soybean breeding.Here,through a genome-wide association study,we identified one significant association locus,located on chromosome 8,which conferred drought tolerance variations in a natural soybean population.Allelic analysis and genetic validation demonstrated that GmACO1,encoding for a 1-aminocyclopropane-1-carboxylate oxidase,was the causal gene in this association locus,and positively regulated drought tolerance in soybean.Meanwhile,we determined that GmACO1 expression was reduced after rhizobial infection,and that GmACO1 negatively regulated soybean nodule formation.Overall,our findings provide insights into soybean cultivars for future breeding.

The issues on the commercialization of perovskite solar cells

Perovskite solar cells have aroused a worldwide research upsurge in recent years due to their soaring photovoltaic performance,ease of solution processing,and low cost.The power conversion efficiency record is constantly being broken and has recently reached 26.1%in the lab,which is comparable to the established photovoltaic technologies such as crystalline silicon,copper indium gallium selenide and cadmium telluride(CdTe)solar cells.Currently,perovskite solar cells are standing at the entrance of industrialization,where huge opportunities and risks coexist.However,towards commercialization,challenges of up-scaling,stability and lead toxicity still remain,the proper handling of which could potentially lead to the widespread adoption of perovskite solar cells as a low-cost and efficient source of renewable energy.This review gives a holistic analysis of the path towards commercialization for perovskite solar cells.A comprehensive overview of the current state-of-the-art level for perovskite solar cells and modules will be introduced first,with respect to the module efficiency,stability and current status of industrialization.We will then discuss the challenges that get in the way of commercialization and the corresponding strategies to address them,involving the upscaling,the stability and the lead toxicity issue.Insights into the future direction of commercialization of perovskite photovoltaics was also provided,including the flexible perovskite cells and modules and perovskite indoor photovoltaics.Finally,the future perspectives towards commercialization are put forward.

双侧股前外侧皮瓣修复全足皮肤脱套伤创面的血供重建方式及疗效分析

目的:探讨双侧股前外侧皮瓣组合修复全足皮肤脱套伤创面的血供重建方式及临床疗效。方法:回顾性分析2020年3月至2022年12月苏州瑞华骨科医院创面修复科应用双侧股前外侧皮瓣串联组合修复全足脱套伤创面患者18例(36块皮瓣)资料,单块皮瓣面积24 cm×7 cm~42 cm×11 cm,采用直接串联、内增压后串联或串联后混合内增压3种不同血供重建方式组合2块皮瓣。术后观察记录皮瓣张力、皮色、皮温、毛细血管反应、皮瓣存活情况、伤口愈合时间,如有血管危象等异常表现需及时处理。随访时观察皮瓣外形及功能恢复情况,供瓣区瘢痕及功能影响等。术后末次随访时,采用综合评价量表评定皮瓣修复效果,采用英国医学研究会(BMRC)感觉功能评定标准评定皮瓣感觉功能。结果:18例(36块皮瓣)皮瓣均成功切取。8例(16块皮瓣)皮瓣内穿支均共干,双侧股前外侧皮瓣直接行串联修复足部创面;6例(12块皮瓣)皮瓣内部分穿支不共干,进行内增压后串联修复足部创面;4例(8块皮瓣)皮瓣部分穿支不共干,行串联混合内增压后修复足部创面。术后3例(3块皮瓣)出现张力高、皮色暗、皮温凉、毛细血管反应快等静脉危象表现,通过手术探查后危象解除。供受区伤口2~3周愈合,皮瓣全部存活。术后随访11.3(10~27)个月。11例皮瓣外形臃肿,影响穿鞋,于皮瓣修复术后6~9个月行Ⅱ期皮瓣修薄整形术。末次随访,大腿供区遗留线状瘢痕,膝关节、髋关节运动功能无明显不良影响;18例(36块皮瓣)皮瓣修复效果评定为优者13例(26块皮瓣)、良者5例(10块皮瓣),皮瓣感觉功能评定为S2~S3级。结论:双侧股前外侧皮瓣串联组合,穿支增压方式灵活,血供可靠,覆盖创面面积大,供区损伤小,可获得较为满意的皮瓣修复效果及感觉功能,是修复足脱套伤创面的理想方法之一。

High-accuracy primary and transfer standards for radiometric calibration

The first research and experimental results obtained in China of high-accuracy radiometric calibration based on cryogenic radiometer are reported. Uncertainties of cryogenic radiometer and trap detectors at 7 wavelengths in the visible spectrum (488-786 nm) were less than 0.023% and 0.035% respectively, which proved the reasonability and possibility of establishing and transferring high-accuracy radiometric standards based on detectors.

De novo assembly of a Chinese soybean genome

Soybean was domesticated in China and has become one of the most important oilseed crops. Due to bottlenecks in their introduction and dissemination, soybeans from different geographic areas exhibit extensive genetic diversity. Asia is the largest soybean market; therefore, a high-quality soybean reference genome from this area is critical for soybean research and breeding.Here, we report the de novo assembly and sequence analysis of a Chinese soybean genome for "Zhonghuang 13" by a combination of SMRT, Hi-C and optical mapping data. The assembled genome size is 1.025 Gb with a contig N50 of 3.46 Mb and a scaffold N50 of 51.87 Mb. Comparisons between this genome and the previously reported reference genome(cv. Williams82) uncovered more than 250,000 structure variations. A total of 52,051 protein coding genes and 36,429 transposable elements were annotated for this genome, and a gene co-expression network including 39,967 genes was also established. This high quality Chinese soybean genome and its sequence analysis will provide valuable information for soybean improvement in the future.