The Earliest Perfect Flower

Despite of angiosperms in the Yixian Formation (>125 Ma, early Cretaceous), there is no perfect flower typical of angiosperms to date. Here we report _Euanthus dilaensis_ gen. et sp. nov as the earliest perfect flower known to date. The flower includes tepals, androecium and gynoecium. The anthers are globose in form, with bristles atop and in situ round-triangular pollen grains. The gynoecium is composed of probably two carpels with plumose stigmas and a carpel-enclosing receptacle. The discovery of _Euanthus_ increases the diversity of early angiosperms, and indicates that perfect flowers occurred as early as 125 Ma ago.
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The Matthew Effect of a Fault Classification Mechanism and Its Application

When using the classification algorithm to classify a single sample, the classification accuracy often cannot achieve an ideal effect. To solve this problem, the following two aspects of research work are carried out and presented in this paper. On the one hand, according to the memory characteristics of mechanical faults, a voting classification mechanism for the sample sequence to be classified is proposed. It is found that the classification mechanism of the sample sequence to be classified with memory has the Matthew effect of accumulated advantage. Using this effect, one can improve the accuracy of fault classification. On the other hand, because the length of the sample sequence to be classified increases, the delay of the classification results increases. To solve this problem, the classification algorithm is optimized to minimize the delay on the assumption that the classification accuracy meets the expected requirements

Petrogenesis of the Northwest Africa 4898 high-Al mare basalt

Northwest Africa (NWA) 4898 is the only low-Ti, high-Al basaltic lunar meteorite yet recognized. It predominantly consists of pyroxene (53.8 vol%) and plagioclase (38.6 vol%). Pyroxene has a wide range of compositions (En_(12–62)Fs_(25–62)Wo_(11–36)), which display a continuous trend from Mg-rich cores toward Ca-rich mantles and then to Fe-rich rims. Plagioclase has relatively restricted compositions (An_(87–96)Or_(0–1)Ab_(4–13)), and was transformed to maskelynite. The REE zoning of all silicate minerals was not significantly modified by shock metamorphism and weathering. Relatively large (up to 1 mm) olivine phenocrysts have homogenous inner parts with Fo ~74 and sharply decrease to 64 within the thin out rims (~30 μm in width). Four types of inclusions with a variety of textures and modal mineralogy were identified in olivine phenocrysts. The contrasting morphologies of these inclusions and the chemical zoning of olivine phenocrysts suggest NWA 4898 underwent at least two stages of crystallization. The aluminous chromite in NWA 4898 reveals that its high alumina character was inherited from the parental magma, rather than by fractional crystallization. The mineral chemistry and major element compositions of NWA 4898 are different from those of 12038 and Luna 16 basalts, but resemble those of Apollo 14 high-Al basalts. However, the trace element compositions demonstrate that NWA 4898 and Apollo 14 high-Al basalts could not have been derived from the same mantle source. REE compositions of its parental magma indicate that NWA 4898 probably originated from a unique depleted mantle source that has not been sampled yet. Unlike Apollo 14 high-Al basalts, which assimilated KREEPy materials during their formation, NWA 4898 could have formed by closed-system fractional crystallization

Design and Operation of Biomass Circulating Fluidized Bed Boiler with High Steam Parameter

Two circulating fluidized bed(CFB) boilers with capacity of 12 MWe and 25 MWe, respectively, with biomass as fuel, adopting the basic technology independently developed by Institute of Engineering Thermophysics (IET), Chinese Academy of Sciences, have been in commercial operation since March 2010 in China. This paper focuses on the design principles, the design specifications and operating results of the two CFB boilers

Process Simulation and Optimization of Fluid Catalytic Cracking Unit’s Rich Gas Compression System and Absorption Stabilization System

In a fuel-based refinery, rich gas in the fluid catalytic cracking (FCC) unit is further processed to separate dry gas and refinery products (i.e., stabilized gasoline and liquified petroleum gas). The process is utility-intensive and costly and includes a two-stage compressor, pumps, an absorber, a stripper, a stabilizer, and a re-absorber. The optimization was conducted with respect to the compressor outlet pressure from the gas compression system (GCS) and the flow rate of absorbent and supplementary absorbent from the Absorption-stabilization System (ASS) using the process simulation software Aspen Plus. Compared to the base case of a 725 kt/a rich gas FCC unit, a refinery can save 2.42% of utility costs under optimal operation. Through optimized operation, medium-pressure steam consumption has been reduced by 2.4% compared to the base case, resulting in a significant improvement in total operational cost. The optimization strategy can provide insightful guidance for the practical operation of GCS and ASS.</p