Effects of injection rate profile on combustion process and emissions in a diesel engine

When multi-injection is implemented in diesel engine via high pressure common-rail injection system, changed interval between injection pulses can induce variation of injection rate profile for sequential injection pulse, though other control parameters are same. Variations of injection rate shape which influence the air-fuel mixing and combustion process will be important for designing injection strategy. In this research, CFD numerical simulations using KIVA-3V were conducted for examining the effects of injection rate shape on diesel combustion and emissions. After the model was validated by experimental results, five different shapes (including rectangle, slope, triangle, trapezoid and wedge) of injection rate profiles were investigated. Modelling results demonstrate that injection rate shape can have obvious influence on heat release process and heat release traces which cause different combustion process and emissions. It is observed that the baseline - rectangle (flat) shape of injection rate can have better balance between NOx and soot emissions than other investigated shapes. As wedge shape brings about the lowest NOx emissions due to retarded heat release, it produces highest soot emissions among five shapes. Trapezoid shape has the lowest soot emissions, while its NOx is not the highest one. The highest NOx emissions was produced by triangle shape due to higher peak injection rate

Interconversion of intrinsic defects in SrTiO3(001)SrTiO_3(001)

Photoemission features associated with states deep in the band gap of n−SrTiO₃ (001) are found to be ubiquitous in bulk crystals and epitaxial films. These features are present even when there is little signal near the Fermi level. Analysis reveals that these states are deep-level traps associated with defects. The commonly investigated defects—O vacancies, Sr vacancies, and aliovalent impurity cations on the Ti sites—cannot account for these features. Rather, ab initio modeling points to these states resulting from interstitial oxygen and its interaction with donor electrons

The Ph-3 gene from Solanum pimpinellifolium encodes CC-NBS-LRR protein conferring resistance to Phytophthora infestans

Late blight, caused by Phytophthora infestans, is one of the most destructive diseases in tomato. The resistance (R) gene Ph-3, derived from Solanum pimpinellifolium L3708, provides resistance to multiple P. infestans isolates and has been widely used in tomato breeding programmes. In our previous study, Ph-3 was mapped into a region harbouring R gene analogues (RGA) at the distal part of long arm of chromosome 9. To further narrow down the Ph-3 interval, more recombinants were identified using the flanking markers G2-4 and M8-2, which defined the Ph-3 gene to a 26 kb region according to the Heinz1706 reference genome. To clone the Ph-3 gene, a bacterial artificial chromosome (BAC) library was constructed using L3708 and one BAC clone B25E21 containing the Ph-3 region was identified. The sequence of the BAC clone B25E21 showed that only one RGA was present in the target region. A subsequent complementation analysis demonstrated that this RGA, encoding a CC-NBS-LRR protein, was able to complement the susceptible phenotype in cultivar Moneymaker. Thus this RGA was considered the Ph-3 gene. The predicted Ph-3 protein shares high amino acid identity with the chromosome-9-derived potato resistance proteins against P. infestans (Rpi proteins)

Efficacy and safety of triazavirin therapy for coronavirus disease 2019 : A pilot randomized controlled trial

Acknowledgements: We are deeply grateful to the front-line clinicians who participated in the study while directly fighting the epidemic. This study was supported by the Chinese Academy of Engineering Projects for COVID-19 (2020-KYGG-01-04) and Heilongjiang Province Urgent Project-6 for COVID-19. Data and safety monitoring board members of this trial included Kang Li, Yong Zhang, Songjiang Liu, and Yaohui Shi.Peer reviewedPublisher PD

同源转基因将成为利用野生资源进行作物育种的种有效手段

A major bottleneck of crop breeding is the narrow genetic base of cultivated species. It is a must to introgress new beneficial alleles from wild germp lasm. Due to crossing barrier and linkage drag, conventional breeding isnpt effective in use of these beneficial alleles. The rap id development of genomics enablesthe isolation of a number of plant genes in an easyway. Cisgenesis is a genetic modification app roach to quickly transfer beneficial alleles from crossable species into elite cultivars. This app roach will not only speed up breeding process but also avoid linkage drag. As the origins of target genes by cisgenesis and conventional breeding are the same, cultivars released by these two app roaches are same in safety. If regulators could treat cisgenic plants the same as conventionally bred p lants, cisgenesis will become an effective tool of crop improvement in use of wild germplasm

Identification and Characterization of microRNA during Bemisia tabaci Infestations in Solanum lycopersicum and Solanum habrochaites

MicroRNAs (miRNAs) are a class of small non-coding RNAs that can regulate target gene expression during many plant growth and development processes. In recent years, several studies identified the miRNAs involved in fruit development, leaf development, and abiotic responses in tomato. However, little is known about the miRNAs that respond to insect attack. Here, miRNAs were identified by high-throughput sequencing at different stages after infections by the whitefly Bemisia tabaci in Solanum lycopersicum and Solanum habrochaites, which are susceptible and resistant to whitefly, respectively. A total of 44 known miRNA families were identified, and 33 were shared between the two species. Among these, 13 miRNA families were newly reported in tomato. After strict filtering, some novel miRNAs were also discovered. The global expression patterns of the miRNAs exhibited were different between the two species, reflecting their different responses and resistance levels to whitefly attack. Some of the predicted target genes of differentially expressed miRNAs may be involved in responding to, and defending against, diseases and insects. Thus, plant miRNAs are important in the responses to, and resistance against, insects and provide a useful resource for further investigations into the mechanism of miRNA-mediated plant–insect interactions. Keywords: Solanum lycopersicum, Solanum habrochaites, Bemisia tabaci, miRNAs, whitefly infection, high-throughput sequencin