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The radiator of special vehicle often exposed to sand condition, and the sand have great influence on the performance of radiator, in order to figure out the impact, the physical model of a radiator is built, the three-dimensional numerical simulation of the gas and water flow field of the radiator is carried out by adopting discrete phase model (DPM) as well as the SIMPLE scheme. Then, the relationship between different factors (such as air velocity, sand particle size, sand concentration) and heat transfer coefficient are obtained by means of simulation, which provides a basis for the optimization design of the special vehicle radiator. A test bench is built, and the simulation is verified to be correct by comparing the simulation result with the test result.

The W-4.9Ni-2.1Fe alloy with different addition of Y2O3 was prepared by high energy ball milling and spark plasma sintering techniques, the microstructure, mechanical property, friction and wear behavior of the high density alloy were investigated by the Rockwell hardness tester, X-ray diffractometer, reciprocating friction and wear tester, 3D profiler, etc. The results show that adequate doping of the trace Y2O3 can effectively inhibit the grain size, promote the γ-(Ni,Fe) bonding phase and tungsten particles uniformly distribute, increase the relative density, hardness, friction and wear properties. But the excessive Y2O3 addition can easily aggregate at grain boundary, weaken the inhibition effect, and decrease the mechanical and wear properties of the alloy. So the addition of Y2O3 should be appropriate. When the adding mass fraction of Y2O3 particles is 0.4%, the comprehensive performance of the alloy is the best.

Laser Ablation (LA) combined with Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) avoids cumbersome analysis of solution and time-consuming pre process, thus reducing possible pollution during sample preparation. Moreover, LA-ICP-MS has the advantages of low cost, rapid determination, and high precision of analysis data. The lower fractionation effect of elements is discussed by combing laser energy density and denudation frequency. Meanwhile, the main working parameters such as RF power, sampling depth, carrier gas and He gas flow rate are matched to obtain high sensitivity and stability of the signal. Based on these, the optimal parameters of the instrument are obtained and reliable zircon U-Pb dating method is established. By mutual determination of zircon age standard substance 91500, GJ-1, and Plešovic, the respective weighted average ages of 206Pb/238U were 1063.9±6.0 Ma (2σ, n=20), 600.3±2.6 Ma (2σ, n=27), and 337.6±1.7 Ma (2σ, n=20). The accuracy and precision are within 1%, consistent with previous studies. Using the optimized parameters of the instrument, the quartz-orthoclase diorite porphyrite from the Tonglushan Orefield in Southeast Hubei has the 206Pb/238U age of zircon, basically consistent with the previous results, indicating that this method can be used for zircon U-Pb dating.

Background: Endometriosis is one of the most challenging diseases for doctors helping infertile women conceive, which has become a common method to help maternal endometriosis-associated infertility. Women with advanced endometriosis possess a higher risk of several adverse outcomes both during pregnancy and at the time of delivery. Whether endometriosis gives rise to a higher occurrence of congenital abnormalities in infants via in vitro fertilization and frozen–thawed embryo transfer (IVF-ET) remains unknown.Methods: Data collected on 22,865 women undergoing IVF using a freeze-all strategy from 2007 to 2017 were analyzed to estimate the rate of congenital malformations. We used an adjusted OR to compare the fertility outcomes of women with advanced endometriosis to the control group.Results: We studied 1,495 infants born from women with advanced endometriosis and 27,105 infants born from endometriosis-free women. There was a 1.557-fold risk that the infants with advanced maternal endometriosis would develop a congenital malformation (adjusted OR: 1.557, 95% CI: 1.03–2.35). Compared with singletons, twins were 1.957 times more likely to experience an adverse outcome (OR: 1.957, 95% CI: 1.561–2.455). When analyzing specific categories of birth defects, the proportion of circulatory system defects was higher than the other categories of birth defects in total (0.56%), followed by musculoskeletal system defects (0.15%).Conclusions: Maternal advanced endometriosis might increase the risk of congenital malformations for infants born after IVF-ET. The organ system most frequently affected by congenital malformations was the cardiovascular system, followed by the musculoskeletal system.

With the rapid development of economy and society, in the face of an increasingly large expressway consumer group, the expansion and upgrading of the expressway service area to marketization and industrialization is the only way for the sustainable development of the service area. The service area should be adapted to local conditions when expanding functions, and be expanded in a targeted manner according to the characteristics of each service area.

The ablation of liver tumors located close to the gallbladder is likely to lead to complications. The aim of this article is to compare the safety and efficacy of irreversible electroporation (IRE) and cryoablation in rabbit livers at a location close to the gallbladder.

The aim of this paper is to study the hydrated lime to the high temperature characters, resist ability of aging, together with workability. Different contents of hydrated lime in asphalt mastic were tested with Dynamic Shear Rheological and Viscosity Tests. The results illustrated that hydrated lime was an appropriate addition agent which can improve asphalt mastic properties greatly, however, too much hydrated lime may result in the decrease of asphalt mixture performances.

The China spallation neutron source (CSNS) was built and started running since 2018. It produces neutrons by impinging 1.6 GeV protons onto a tungsten target with 25 Hz repetition frequency. A beam line exploiting the back-streaming neutrons (Back-n) was built mainly for nuclear data measurement and started commissioning simultaneously with CSNS in 2018. There are two experimental endstations along the Back-n beam line: endstation 1 (#ES1) with a neutron flight path of about 55 m and endstation 2 (#ES2) with about 76 m. The neutron energy spectra of both #ES1 and #ES2 were measured since it is important for feasibility study and analysis. In this paper, the measurement of the neutron energy spectrum of Back-n #ES1 is reported. It is measured by a multi-layer fission chamber using the 235U samples as the neutron converters. The neutron energy spectrum from 0.1 eV to 30 MeV is obtained. The integral neutron flux (from 0.1 eV to 30 MeV) normalized to the proton beam power of 100 kW is 1.55×107 neutrons/cm2/s.

Multiband SAR is an important trend in SAR technology. Accurate registration among different band SAR images is a prerequisite for the comprehensive utilization of the information of multiband SAR images. Errors in the motion measurement system (i.e., residual motion) are major error sources affecting image registration. To solve this problem, the effect of residual motion error on SAR imaging geometry positioning is investigated. The relation between residual motion and image registration accuracy of airborne multiband SAR is analyzed quantitatively. The results of the theoretical analysis are verified by simulation experiments.