The genomic and bulked segregant analysis of \u3ci\u3eCurcuma alismatifolia\u3c/i\u3e revealed its diverse bract pigmentation

Compared with most flowers where the showy part comprises specialized leaves (petals) directly subtending the reproductive structures, most Zingiberaceae species produce showy ‘‘flowers’’ through modifications of leaves (bracts) subtending the true flowers throughout an inflorescence. Curcuma alismatifolia, belonging to the Zingiberaceae family, a plant species originating from Southeast Asia, has become increasingly popular in the flower market worldwide because of its varied and esthetically pleasing bracts produced in different cultivars. Here, we present the chromosome-scale genome assembly of C. alismatifolia ‘‘Chiang Mai Pink’’ and explore the underlying mechanisms of bract pigmentation. Comparative genomic analysis revealed C. alismatifolia contains a residual signal of wholegenome duplication. Duplicated genes, including pigment-related genes, exhibit functional and structural differentiation resulting in diverse bract colors among C. alismatifolia cultivars. In addition, we identified the key genes that produce different colored bracts in C. alismatifolia, such as F3\u275’H, DFR, ANS and several transcription factors for anthocyanin synthesis, as well as chlH and CAO in the chlorophyll synthesis pathway by conducting transcriptomic analysis, bulked segregant analysis using both DNA and RNA data, and population genomic analysis. This work provides data for understanding the mechanism of bract pigmentation and will accelerate breeding in developing novel cultivars with richly colored bracts in C. alismatifolia and related species. It is also important to understand the variation in the evolution of the Zingiberaceae family

Do 2H and 18O in leaf water reflect environmental drivers differently?

We compiled hydrogen and oxygen stable isotope compositions (δ H and δ O) of leaf water from multiple biomes to examine variations with environmental drivers. Leaf water δ H was more closely correlated with δ H of xylem water or atmospheric vapour, whereas leaf water δ O was more closely correlated with air relative humidity. This resulted from the larger proportional range for δ H of meteoric waters relative to the extent of leaf water evaporative enrichment compared with δ O. We next expressed leaf water as isotopic enrichment above xylem water (Δ H and Δ O) to remove the impact of xylem water isotopic variation. For Δ H, leaf water still correlated with atmospheric vapour, whereas Δ O showed no such correlation. This was explained by covariance between air relative humidity and the Δ O of atmospheric vapour. This is consistent with a previously observed diurnal correlation between air relative humidity and the deuterium excess of atmospheric vapour across a range of ecosystems. We conclude that H and O in leaf water do indeed reflect the balance of environmental drivers differently; our results have implications for understanding isotopic effects associated with water cycling in terrestrial ecosystems and for inferring environmental change from isotopic biomarkers that act as proxies for leaf water

A Fiber Bragg Grating Borehole Deformation Sensor for Stress Measurement in Coal Mine Rock

A borehole deformation sensor for long-term stress monitoring in coal mine rock based on optical fiber Bragg gratings (FBGs) is presented. The sensor converts borehole deformation into optical fiber strain by using four rings. For each ring, two FBGs are bonded with the ring to measure the borehole deformation, and a reference FBG free from mechanical load is introduced to remove the temperature effect. Two simple checks on the test data can be performed to improve the test accuracy. Laboratory and field tests were conducted to validate the accuracy and long-term performance of the sensor. The results show that the sensor is capable of measuring stress in rock with good accuracy, and it performs well over a long period of time in coal mines. The developed sensor provides an approach for the long-term monitoring of stress changes in coal mine rock

An Experimental Study on Dynamic Mechanical Properties of Fiber-Reinforced Concrete under Different Strain Rates

Fiber-reinforced concrete (FRC) has a great advantage in earthquake-resistant structures, as compared with regular concrete. However, there are many difficulties in the construction and maintenance of concrete structures due to the high density and easy corrosion of the steel fiber in commonly used steel FRC. With the development of polymer material science, polyvinyl alcohol (PVA) fiber has been rapidly promoted for use in FRC because of its low density, high strength, and large elongation at break value. Dynamic uniaxial compression and splitting tensile experiments of FRC with PVA fiber were carried out with two matrix strengths (i.e., C30 and C40), which were blended with PVA fibers with a length of 12 mm in different volume contents (0, 0.2, 0.4, and 0.6%), at the age of 28 days, under different strain rates (i.e., 10−5, 10−4, 10−3, and 10−2 s−1). The results show that PVA has an obvious enhancing and toughening effect on concrete, which can improve its brittle properties and residual strength. With increasing strain rate, the compressive strength, split tensile strength, and elastic modulus increase to a certain extent, while the toughness index and the peak strain decrease to a certain degree. The post-peak deformation characteristic changes from a brittle failure of sudden caving to a ductile failure with dense cracking. The effect of PVA is different when enhancing the concrete with two different matrix strengths. The lower the matrix strength, the more obvious the enhancement effect of the fiber, showing characteristics of a higher compressive strength and low split tensile strength in FRC with low strength and a smoother post-peak stress–strain curve

Numerical test on polystyrene tunnel seismic-isolation material

Stress-strain mechanical properties of polystyrene foam plastic material were tested under different loading conditions. An empirical constitutive model for describing metal materials was proposed for the polystyrene plastic foam. The static and dynamic tests results show that the ductility and watertightness of the polystyrene plastic foam are significantly improved. At the same time, in order to check its seismic-isolation property, the high-performance foam concrete as filling materials of Galongla tunnel in Tibet was simulated by FEM. The simulated results show that the polystyrene plastic foam can remarkably decrease the stress and the plastic zone in final lining, so it can effectively reduce the seismic damage of the tunnel. Considering the seismic-isolation property and low price of polystyrene plastic foam, it is a good reference for the anti-seismic design of tunnels in high intensity zones

A Study on Seismic Isolation of Shield Tunnel Using Quasi-Static Finite Element Method

Using a quasi-static method based on an axisymmetric finite element model for seismic response analysis of seismically isolated tunnels, the seismic isolation effect of the isolation layer is studied, and the seismic isolation mechanism of the isolation layer is clarified. The results show that, along the longitudinal direction of the tunnel, the seismic isolation effect is mainly affected by the shear modulus of the isolation material. The smaller the shear modulus is, the more evident the seismic isolation effect is. This is due to the tunnel being isolated from deformation of its peripheral ground through shear deformation of the isolation layer. However, along the transverse direction of the tunnel, the seismic isolation effect is mainly affected by the shear modulus and Poisson’s ratio of the isolation material. When Poisson’s ratio is close to 0.5, a seismic isolation effect is not evident because the tunnel cannot be isolated from deformation of its peripheral ground through compression deformation of the isolation layer. Finally, a seismic isolation system comprising a shield tunnel in which flexible segments are arranged at both ends of an isolation layer is proposed, and it is proved that the seismic isolation system has significant seismic isolation effects both on the longitudinal direction and on the transverse direction

Vibration Test and Control of Factory a Building under Excitation of Multiple Vibrating Screens

In order to reduce the excessive vibration responses of a reinforced concrete frame structure induced by several vibrating screens working simultaneously, field vibration monitoring and some vibration reduction measures are carried out. The results of field vibration monitoring show that the maximum vertical vibration of the structure exceeds 106% of the limitation of building vibration. The results of the structural response analysis show that the excessive structural vibration is attributed to the resonance, as the frequency of the vibrating screens coincides with vertical natural frequency of the floors of the factory structure. Based on this fact, three vibration control measures, including damping, active vibration isolation of vibrating screens and structural vibration absorption, are proposed to mitigate the excessive vibration. In order to analyze the vibration control performance of the proposed schemes, the finite element dynamic model of the factory building structure is established, and the model is verified by the results of vibration and mode tests. Then, the damping system, vibration isolation system and vibration absorption system are set up in the models, and the vibration control performance of the three schemes are investigated. The results show that the measures, including vibration isolation and absorption, can reduce the vibration by more than 80%. Combined with the demand for a short construction period, the active vibration isolation of vibrating screens is finally selected. After the implementation of the scheme, the field monitoring data show that the structural vibration response is consistent with the finite element result and obviously weakened to meet the limitation. This study can provide a reference for the vibration control design for similar screening factory buildings

The Constraints of Carbonaceous Mudstone Re-Os and Detrital Zircons U-Pb Isotopic Dating on the Diagenetic and Metallogenic Ages from the Dabaoshan Copper Deposit in Guangdong Province

BACKGROUND: With the development of high-precision negative thermal ionization mass spectrometry (N-TIMS) technology, Re-Os isotopic dating of carbonaceous mudstone is more and more widely used in the determination of sedimentary age. The controversy over the diagenetic and metallogenic ages of the Dabaoshan copper deposit in Guangdong Province has always been a key restricting the study of the genetic mechanism.OBJECTIVES: To constrain the diagenetic and metallogenic ages of the Dabaoshan copper deposit.METHODS: Re-Os isotope ratios were determined by high precision N-TIMS after dissolving carbonaceous mudstone powder by reverse aqua regia in the Carius tube. Zircon U-Pb age was determined by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS).RESULTS: (1) The contents of Re and Os ranged from 0.976×10-9 to 2.997×10-9 and 0.067×10-9 to 0.115×10-9, respectively. The 187Re/188Os ratio varied from 78.236 to 154.799, and the 187Os/188Os ratio varied from 1.642 to 1.885. The Re-Os isotopic isochron age of black carbonaceous mudstone was 195±28Ma (n=6, MSWD=17). (2) The 206Pb/238U age ranged from 2631 to 236Ma, including two Mesozoic zircons, accounting for 2.50% of the total zircons, 19 Paleozoic zircons, accounting for 23.8% of the total zircons, 58 proterozoic zircons, accounting for 73% of the total zircons, 1 Archean zircon, accounting for 1% of the total zircons. The results of detrital zircon U-Pb age were broad and developed multiple peak periods, among which the youngest source magmatic zircon was formed in the Indosinian period.CONCLUSIONS: The diagenetic and metallogenic age of the Dabaoshan copper deposit in Guangdong Province was constrained to the early Yanshanian. The distribution characteristics of detrital zircon U-Pb age further indicate that the Lower Jurassic Jinji Formation was formed at the stable continental margin, and its detrital material comes mainly from the ancient continental basement

Vibration Test and Control of Factory a Building under Excitation of Multiple Vibrating Screens

In order to reduce the excessive vibration responses of a reinforced concrete frame structure induced by several vibrating screens working simultaneously, field vibration monitoring and some vibration reduction measures are carried out. The results of field vibration monitoring show that the maximum vertical vibration of the structure exceeds 106% of the limitation of building vibration. The results of the structural response analysis show that the excessive structural vibration is attributed to the resonance, as the frequency of the vibrating screens coincides with vertical natural frequency of the floors of the factory structure. Based on this fact, three vibration control measures, including damping, active vibration isolation of vibrating screens and structural vibration absorption, are proposed to mitigate the excessive vibration. In order to analyze the vibration control performance of the proposed schemes, the finite element dynamic model of the factory building structure is established, and the model is verified by the results of vibration and mode tests. Then, the damping system, vibration isolation system and vibration absorption system are set up in the models, and the vibration control performance of the three schemes are investigated. The results show that the measures, including vibration isolation and absorption, can reduce the vibration by more than 80%. Combined with the demand for a short construction period, the active vibration isolation of vibrating screens is finally selected. After the implementation of the scheme, the field monitoring data show that the structural vibration response is consistent with the finite element result and obviously weakened to meet the limitation. This study can provide a reference for the vibration control design for similar screening factory buildings

Genome-wide Investigation of microRNAs and Their Targets in Brassica rapa ssp. pekinensis Root with Plasmodiophora brassicae Infection

Increasing evidence has revealed that microRNAs play a pivotal role in the post transcriptional regulation of gene expression in response to pathogens in plants. However, there is little information available about the expression patterns of miRNAs and their targets in Chinese cabbage (Brassica rapa ssp. pekinensis) under Plasmodiophora brassicae stress. In the present study, using deep sequencing and degradome analysis, a genome-wide identification of miRNAs and their targets during P. brassicae stress was performed. A total of 221 known and 93 potentially novel miRNAs were successfully identified from two root libraries of one control (635-10CK) and P. brassicae-treated Chinese cabbage samples (635-10T). Of these, 14 known and 10 potentially novel miRNAs were found to be differentially expressed after P. brassicae treatment. Degradome analysis revealed that the 223 target genes of the 75 miRNAs could be potentially cleaved. KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway analysis suggested that the putative target genes of the miRNAs were predominately involved in selenocompound metabolism and plant hormone signal transduction. Then the expression of 12 miRNAs was validated by quantitative real-time PCR (qRT-PCR). These results provide insights into the miRNA-mediated regulatory networks underlying the stress response to the plant pathogen P. brassicae