时效处理对2195 Al-Li合金挤压型材腐蚀行为的影响

对2195铝锂合金分别进行欠时效(UA)、峰时效(PA)、双级时效(DA)和回归再时效(RRA)处理,观察并讨论其显微组织、晶间腐蚀(IGC)、剥落腐蚀(EXCO)和应力腐蚀开裂(SCC)行为。结果表明,合金经不同时效处理后,其IGC和EXCO耐蚀性顺序为:RRA>UA>DA>PA。PA和UA态的低耐蚀性主要是T_(1)相在晶界处连续析出形成连续的腐蚀通道引起的,而粗大不连续析出的T_(1)相以及较宽的无析出带导致的腐蚀通道中断是RRA态具有最佳耐蚀性的原因。RRA态合金表现出最好的抗应力腐蚀性能,抗应力腐蚀顺序为:RRA>DA>UA>PA。晶间T_(1)相的不连续析出促进了腐蚀裂纹穿过晶界进行扩展,从而提高了2195铝锂合金的抗应力腐蚀性能。

Modification and refinement effects of Sb and Sr on Mg_(17)Al_(12) and Mg_2Si phases in Mg-12Al-0.7Si alloy

The effects of Sb and Sr on the modification and refinement of Mg_(17)Al_(12)and Mg_2Si phases in Mg-12Al-0.7Si alloy were investigated and compared. The microstructure and mechanical properties of Mg-12Al-0.7Si alloy and its modification mechanism by Sb and Sr were investigated using a scanning electron microscope(SEM), an energy dispersive spectrometer(EDS), X-ray diffraction(XRD) and differential thermal analysis(DTA). The results indicate that by adding 0.5wt.% Sb to the Mg-12Al-0.7Si alloy, the Mg_(17)Al_(12)phase was refined and broken into some discontinuous island structures. However, some network Mg_(17)Al_(12)phases still can be detected in Mg-12Al-0.7Si-0.09 Sr alloy. Therefore, Sb performs better in modification and refinement of Mg_(17)Al_(12)phase than does Sr. Small amounts of fine polygonal shaped Mg_2Si phases were found in Mg-12Al-0.7Si-0.5Sb alloy, while the morphology of Mg_2Si phases in Mg-12Al-0.7Si-0.09 Sr alloy changed from the coarse Chinese script shapes to fine granule and irregular polygonal shapes, indicating that the effects of modification and refinement on Mg_2Si phase are more significant by adding 0.09 wt.% Sr than 0.5wt.% Sb. The ultimate tensile strengths of the Sb and Sr modified Mg-12Al-0.7Si alloys were considerably increased both at room temperature and at 200 oC.

Current Status of and Opinions on Heart Transplantation in China

The purpose of this review is to provide a comprehensive update on recent advances in heart transplantation in China.Despite advances in pharmacologic and device treatment of chronic heart failure,long-term morbidity and mortality remain high,and many patients progress to end-stage heart failure.Heart transplantation has become standard treatment for selected patients with end-stage heart failure,though challenges still exist.However,multiple advances over the past few years will improve the survival and quality-of-life of heart transplant recipients.This article elaborates on the specific characteristics of heart transplantation in China,the current issues,development trends,and related experiences with heart transplantation in Wuhan Union Hospital.

Chromosome-scale assembly of the Dendrobium chrysotoxum genome enhances the understanding of orchid evolution

As one of the largest families of angiosperms,the Orchidaceae family is diverse.Dendrobium represents the second largest genus of the Orchidaceae.However,an assembled high-quality genome of species in this genus is lacking.Here,we report a chromosome-scale reference genome of Dendrobium chrysotoxum,an important ornamental and medicinal orchid species.The assembled genome size of D.chrysotoxum was 1.37 Gb,with a contig N50 value of 1.54 Mb.Of the sequences,95.75%were anchored to 19 pseudochromosomes.There were 30,044 genes predicted in the D.chrysotoxum genome.Two whole-genome polyploidization events occurred in D.chrysotoxum.In terms of the second event,whole-genome duplication(WGD)was also found to have occurred in other Orchidaceae members,which diverged mainly via gene loss immediately after the WGD event occurred;the first duplication was found to have occurred in most monocots(tau event).We identified sugar transporter(SWEET)gene family expansion,which might be related to the abundant medicinal compounds and fleshy stems of D.chrysotoxum.MADS-box genes were identified in D.chrysotoxum,as well as members of TPS and Hsp90 gene families,which are associated with resistance,which may contribute to the adaptive evolution of orchids.We also investigated the interplay among carotenoid,ABA,and ethylene biosynthesis in D.chrysotoxum to elucidate the regulatory mechanisms of the short flowering period of orchids with yellow flowers.The reference D.chrysotoxum genome will provide important insights for further research on medicinal active ingredients and breeding and enhances the understanding of orchid evolution.

The Phoebe genome sheds light on the evolution of magnoliids

Lauraceae includes the genus Phoebe,and the family is linked to the evolution of magnoliids.We sequenced the genome of Phoebe bournei Nanmu.The assembled genome size was 989.19 Mb,with a contig N50 value of 2.05 Mb.A total of 28,198 protein-coding genes were annotated in P.bournei.Whole-genome duplication(WGD)analysis showed that Lauraceae has experienced two WGD events;the older WGD event occurred just before the divergence of Lauraceae and Magnoliales,and the more recent WGD was shared by all lineages of Lauraceae.The phylogenetic tree showed that magnoliids form a sister clade to monocots and eudicots.We also identified 63 MADS-box genes,including AGL12-like genes that may be related to the regulation of P.bournei roots and FIN219-like genes encoding GH3 proteins,which are involved in photomorphogenesis.SAUR50-like genes involved in light signal-mediated pedicel or stem development were also identified.Four ATMYB46-and three PtrEPSP-homologous genes related to lignin biosynthesis were identified.These genes may be associated with the formation of straight trunks in P.bournei.Overall,the P.bournei reference genome provides insight into the origin,evolution,and diversification of Phoebe and other magnoliids.

Correction: The Cymbidium genome reveals the evolution of unique morphological traits

After online publication of the article 1 the author noticed minor typo in Fig.4c.CeSEP1/2/3/4 should be read as CeSEP1/3/4.Revised figure supplied during the proof correction was inadvertently not reproduced in the final version.In addition,the affiliation numbers of the authors revised in the original article during proof correction,but not reflected in the title page in Supplementary Information.

The Cymbidium genome reveals the evolution of unique morphological traits

The marvelously diverse Orchidaceae constitutes the largest family of angiosperms.The genus Cymbidium in Orchidaceae is well known for its unique vegetation,floral morphology,and flower scent traits.Here,a chromosomescale assembly of the genome of Cymbidium ensifolium(Jianlan)is presented.Comparative genomic analysis showed that C.ensifolium has experienced two whole-genome duplication(WGD)events,the most recent of which was shared by all orchids,while the older event was the t event shared by most monocots.The results of MADS-box genes analysis provided support for establishing a unique gene model of orchid flower development regulation,and flower shape mutations in C.ensifolium were shown to be associated with the abnormal expression of MADS-box genes.The most abundant floral scent components identi fied included methyl jasmonate,acacia alcohol and linalool,and the genes involved in the floral scent component network of C.ensifolium were determined.Furthermore,the decreased expression of photosynthesis-antennae and photosynthesis metabolic pathway genes in leaves was shown to result in colorful striped leaves,while the increased expression of MADS-box genes in leaves led to perianth-like leaves.Our results provide fundamental insights into orchid evolution and diversi fication.

The Cymbidium goeringii genome provides insight into organ development and adaptive evolution in orchids

Cymbidium goeringii is one of the important ornamental orchids,but its high-quality genome has not been previously published.Here,we report a chromosome-level genome of C.goeringii and report the gene family expansion,and contraction of the C.goeringii genome and the regulation mechanism of MADS-box genes in floral organ development.We constructed the pathways of carotenoids and anthocyanins that contribute to the different flower colors of C.goeringii and the metabolic pathways of the main components of flower fragrance.Moreover,we found the genes that regulate colourful leaves and analyzed the resistance genes involved in the adaptive evolution of C.goeringii.Our results provide valuable genomic resources for the improvement of orchids and other ornamental plants.

The level and influencing factors of quality of life in patients with brachial plexus injury

Purpose:To investigate the overall quality of life level and identify influencing factors in patients with traumatic brachial plexus injury.Methods:One hundred three patients with brachial plexus injury were assessed using the World Health Organization Quality of Life-BREF(WHOQOL-BREF)and Family Adaptability and Cohesion Evaluation Scale(FACESII-CV)questionnaires.Results:The overall quality of life score from patients with brachial plexus injury was 65.78
15.2.The scores for the physical,psychological and environmental factors were significantly lower than the norm(Ps<0.05).Regression analysis showed that age,injury located ipsilateral to the dominant hand,upper limb function score,score of family intimacy and family income were all factors influencing the of quality of life.Conclusions:A brachial plexus injury significantly compromises an individual’s quality of life.Multiple factors influence this quality,which should be targeted to augment the physical and psychological care provided.

Erratum to:Current Status of and Opinions on Heart Transplantation in China

The article"Current Status of and Opinions on Heart Transplantation in China",written by Yong-feng SUN,Zhi-wen WANG,Jing ZHANG Jie CAI,Feng SHI,Nian-guo DONG was originally published electronically on the publisher s internet portal on October 2021;without open access.

Vertex Distinguishing Equitable Total Chromatic Number of Join Graph

A vertex distinguishing equitable total coloring of graph G is a proper total coloring of graph G such that any two distinct vertices＇ coloring sets are not identical and the difference of the elements colored by any two colors is not more than 1. In this paper we shall give vertex distinguishing equitable total chromatic number of join graphs Pn VPn, Cn VCn and prove that they satisfy conjecture 3, namely, the chromatic numbers of vertex distinguishing total and vertex distinguishing equitable total are the same for join graphs Pn V Pn and Cn ∨ Cn.

A brief overview on secure control of networked systems

This paper focuses on the issues of the security of networked control systems by summarizing recent progress in secure control of this research and application area. We mainly discuss existing results, especially in modeling issues, of three aspects： （1） attack mechanisms and their impacts on control systems, （2） the identification and design of attacks, and （3） secure estimation and control strategies. A conclusion is drawn at the end of this paper. In addition, several promising research tendencies of the development for secure control in networked control system are presented.

On the Adjacent Vertex-distinguishing Equitable Edge Coloring of Graphs

Let G（V, E） be a graph. A k-adjacent vertex-distinguishing equatable edge coloring of G, k-AVEEC for short, is a proper edge coloring f if （1） C（u）≠C（v） for uv ∈ E（G）, where C（u） = {f（uv）｜uv ∈ E}, and （2） for any i, j = 1, 2,… k, we have ｜｜Ei｜ ｜Ej｜｜ ≤ 1, where Ei = {e｜e ∈ E（G） and f（e） = i}. χáve （G） = min{k｜ there exists a k-AVEEC of G} is called the adjacent vertex-distinguishing equitable edge chromatic number of G. In this paper, we obtain the χ áve （G） of some special graphs and present a conjecture.

On the Relations of Graph Parameters and Its Total Parameters

In this paper we get some relations between α（G）, α＇（G）, β（G）, β＇（G） and αT（G）, βT（G）. And all bounds in these relations are best possible, where α（G）, α＇（G）,/3（G）, β（G）, αT（G） and βT（G） are the covering number, edge-covering number, independent number, edge-independent number （or matching number）, total covering number and total independent number, respectively.