Morphological and molecular evidence for natural hybridization between Sorbus pohuashanensis and S. discolor (Rosaceae)

In overlapping distribution areas of Sorbus pohuashanensis and S.discolor in North China(Mount Tuoliang,Mount Xiling and Mount Baihua),Sorbus indi-viduals were found with pink fruit,which have never been recorded for the flora of China.Fourteen morphological characters combined with four chloroplast DNA markers and internal transcribed spacer(ITS)were used to analyze the origin of the Sorbus individuals with pink fruits and their relationship to S.pohuashanensis and S.discolor.PCA,SDA and one-way(taxon)ANOVA of morphological characters provided convincing evidence of the hybrid ori-gin of Sorbus individuals with pink fruits based on a novel morphological character and many intermediate characters.Haplotype analysis based on four cpDNA markers showed that either S.pohuashanensis or S.discolor were maternal parents of Sorbus individuals with pink fruits.Incongru-ence of the position of Sorbus individuals with pink fruits between cpDNA and ITS in cluster trees supported by DNA sequence comparative analysis,implying former hybridiza-tion events between S.pohuashanensis and S.discolor.Mul-tiple hybridization events between S.pohuashanensis and S.discolor might have contributed to the generation of Sorbus individuals with pink fruits.This study has provided insights into hybridization between species of the same genus in sympatric areas,which is of great significance for the study of interspecific hybridization.

Study on Reproductive Performance of Improved Hybrid from Chinese Holstein Cattle

In order to overcome the problems such as decline in adaptability, low fertility and few utilization years due to continuously increasing coefficient of inbreeding of Chinese Holstein cattle, three dairy-beef dual-purpose cattle varieties （purebred Simmental, Montbeliard and Fleckvieh） were introduced as the male parents to be hybridized with Chinese Holstein cattle, so as to study the improvement effect in the reproduction performance and milk production performance of the hybrid cattle. The results showed that the first-filial generation of Montbeliard had a very significant difference in gestation period from Chinese Holstein cattle （ P 〈0.01）. The parity of Fleckvieh s first-filial generation had a very significant effect on 305 d milk yield （ P 〈0.01）; and for the first-filial generation of Montbeliard, mating times and open days significantly affected 305 d milk yield （ P 〈0.05）, and its total milk yield had a significant difference from Chinese Holstein cattle （ P 〈0.05）. Comprehensively, the reproduction traits of Montbeliard s first-filial generation are better than other two varieties.

《名古屋议定书》背景下我国传统知识的保护:以德昂族酸茶为例

中国于2016年9月6日成为《名古屋议定书》缔约方,意味着遗传资源及相关传统知识的保护以及获取与惠益分享制度,在国际和国内层面已经步入履行阶段。传统知识的防御性保护是防范生物剽窃,建设性保护是促进惠益分享。本研究通过多年的实地调研发现,德昂族酸茶作为一类与遗传资源相关的传统知识,在原持有方不知情同意的情况下,被某利用方申请了专利,构成了生物剽窃。本研究指出,传统知识防御性保护可考虑修订国内专利法,将传统知识强制性来源披露要求纳入其中,进而防范生物剽窃。为促进传统知识的持有方分享应得惠益和可持续利用,本研究建议依据《名古屋议定书》精神,通过立法制定特殊制度,创造性地发展出可行的惠益分享制度,区分不同的传统知识主体资格,以事先知情同意程序和共同商定条件为途径,以补偿责任或知识共享许可协议为手段,来实现《生物多样性公约》的保护与可持续利用两大目标,方能达成传统知识的建设性保护。

Patterned growth ofβ-Ga_(2)O_(3) thin films for solar-blind deep-ultraviolet photodetectors array and optical imaging application

Solar-blind deep-ultraviolet(DUV)photodetectors based on Ga_(2)O_(3)have attracted great attention due to their potential applications for many military and civil purposes.However,the development of device integration for optoelectronic system applications remains a huge challenge.Herein,we report a facile method for patterned-growth of high-qualityβ-Ga_(2)O_(3)thin films,which are assembled into a photodetectors array comprising 8×8 device units.A representative detector exhibits outstanding photoresponse performance,in terms of an ultra-low dark current of 0.62 pA,a large Ilight/Idark ratio exceeding 10^(4),a high responsivity of 0.72 A W^(-1) and a decent specific detectivity of 4.18×10^(11)Jones,upon 265 nm DUV illumination.What is more,the DUV/visible(250/400 nm)rejection ratio is as high as 10^(3) with a sharp response cut-off wave length at 280 nm.Further optoelectronic analysis reveals that the photodetectors array has good uniformity and repeatability,endowing it the capability to serve as a reliable DUV light image sensor with a decent spatial resolution.These results suggest that the proposed technique offers an effective avenue for patterned growth ofβ-Ga_(2)O_(3)thin films for multifunctional DUV optoelectronic applications.

Constitutive Relationship and Hot Processing Maps of Mg-Gd-Y-Nb-Zr Alloy

The hot working behavior of Mg-Gd-Y-Nb-Zr alloy was investigated using constitutive model and hot processing maps in this work. Isothermal compression tests were conducted with temperature and strain rate range of 703-773 K and 0.01-5 s^（-1）, respectively. Improved Arrhenius-type equation incorporated with strain compensations was used to predict flow behavior of the alloy, and the predictability was evaluated using correlation coefficient, root mean square error and absolute relative error. Processing maps were constructed at different strains for Mg-Gd-Y-Nb-Zr alloy based on dynamic materials model.The processing maps are divided into three domains and the corresponding microstructure evolutions are referred to the forming of straight grain boundaries, twinning, dynamic recrystallization and grain growth. Instability occurred mainly at the strain rate range of 0.3s^（-1）-0.5s^（-1）. The optimum processing domain is mainly at the temperature range of 703-765 K with the strain rate range of 0.01-0.1 s^（-1）.

Uncertainty quantification and reduction in metal additive manufacturing

Uncertainty quantification(UQ)in metal additive manufacturing(AM)has attracted tremendous interest in order to dramatically improve product reliability.Model-based UQ,which relies on the validity of a computational model,has been widely explored as a potential substitute for the time-consuming and expensive UQ solely based on experiments.However,its adoption in the practical AM process requires overcoming two main challenges:(1)the inaccurate knowledge of uncertainty sources and(2)the intrinsic uncertainty associated with the computational model.Here,we propose a data-driven framework to tackle these two challenges by combining high throughput physical/surrogate model simulations and the AM-Bench experimental data from the National Institute of Standards and Technology(NIST).We first construct a surrogate model,based on high throughput physical simulations,for predicting the three-dimensional(3D)melt pool geometry and its uncertainty with respect to AM parameters and uncertainty sources.We then employ a sequential Bayesian calibration method to perform experimental parameter calibration and model correction to significantly improve the validity of the 3D melt pool surrogate model.The application of the calibrated melt pool model to UQ of the porosity level,an important quality factor,of AM parts,demonstrates its potential use in AM quality control.The proposed UQ framework can be generally applicable to different AM processes,representing a significant advance toward physicsbased quality control of AM products.

Investigation on environment monitoring system for a combination of hydroponics and aquaculture in greenhouse

This work develops a distributed environmental monitoring system for the combination of hydroponics and aquaculture based on the internet of things technology,which mainly includes the information perception layer,the information transmission layer and the sys-tem architecture.The system has employed multiple sensors terminal to real-time acqui-sition,including air and water temperatures,dissolved oxygen etc.LoRa protocol is suitable for sending small data and the 4G was employed to collect data and send to the cloud plat-form.Java is used to develop background applications,to access cloud platforms and local data processing.Based on the collection and processing of environmental data and cloud service platform,the mobile application program client and remote login desktop have been developed.It has been implemented and tested in Tongzhou,Beijing for 3 months in 2020.The results showed the proposed monitoring system stability for overall operation and accuracy data transmission,which can support the actual hydroponics and aquacul-ture production management.After analysis of monitoring data collected from the devel-oped monitoring system,indoor air and water temperature have the obvious correlation with atmospheric pressure(0.7 and 0.9)and outdoor temperature(1.0 and 0.9),respectively.

Cloning,expression and improvement of catalytic activity of alginate lyase by site-directed mutation

Alginate lyase mainly produces active alginate oligosaccharides(AOS)by degrading alginate viaβ-elimination process.In this study,the Pseudoalteromonas sp.Alg6B alginate lyase-encoding gene alg6B-7 from polysaccharide lyase(PL)-7 family was successfully cloned,sequenced,expressed in Escherichia coli.Based on rational design and amino acid sequence alignment of the alginate lyase from various sources,four positive mutants were obtained.The specific enzyme activities of four mutants I62A,A99K,V132S,and L157T were 38.84%,42.85%,75.8%and 51.83%higher than that of the wild enzyme,respectively.The K_(cat)/K_(m) values of the four mutants were both increased,and the catalytic efficiency of V132S was 1.92-fold higher than that of the wild enzyme,especially.The rational design that was employed in this study achieved the dramatic improvement of catalytic activity,which may provide the application potential in industrial production.