Z箍缩内爆的MARED程序1维模拟分析

研制可靠的数值模拟工具对Z箍缩内爆产生X光辐射过程进行理论研究、实验分析以及负载设计至关重要。介绍了2维三温辐射磁流体力学程序(MARED)的物理方案,给出了MARED程序的1维检验结果,验证表明MARED程序适用不同装置条件、不同负载参数。结合丝阵Z箍缩实验的数值模拟和分析表明:相同负载质量条件下,钨丝阵内爆产生的X光辐射功率远大于铝丝阵产生的X光功率;相同负载电流条件下,负载质量越大,计算得到X光功率越低;X光功率随着负载电流增加而增加。

巷道CSAMT法的目标体分辨能力研究

目前地表矿、浅部矿越来越少,寻找深部盲矿体变得尤为重要.可控源音频大地电磁法(CSAMT)具有抗干扰能力强、分辨率高等特点,在探测矿产资源中已经取得了较好效果,但是通常CSAMT在矿区找深部矿时,由于在巷道上方的地表接收电磁信号会受到地面不同类型的强电磁干扰,同时由于该方法对深部矿体分辨率较低的缘故,大大影响了CSAMT的应用效果.本文尝试将CSAMT的接收系统置于巷道中,使得接收系统更加接近地下目标体,期望提高对于目标体识别的准确性,保证资源勘查的工作效率和成功率.基于积分方程法对不同类型地质模型进行了CSAMT正演模拟,并对不同模型不同深度接收的CSAMT响应特征进行了分析,同时以MARE2DEM软件模拟的二维模型响应加以验证积分方程结果的正确性.结果表明在无电磁干扰条件下,在巷道接收到的电磁场信号虽弱于地面,但其对于深部盲矿或目标体具有较强的识别度.

形状记忆聚合物热致形状记忆行为的有限元数值模拟

由于TOBUSHI本构模型难以分析形状和加载条件复杂的形状记忆聚合物(Shape Memory Polymer,SMP)构件及增强SMP材料的形状记忆行为,针对其形状记忆行为,利用有限元软件MSC Marc,基于黏弹性理论对SMP材料的热致形状记忆行为进行有限元数值模拟,得到的应力、应变和温度之间的关系与TOBUSHI的实验结果基本吻合,从而发展适用于复杂SMP构件及增强SMP材料形状记忆行为的有限元分析方法.

A comparative evaluation of methicillin-resistant staphylococci isolated from harness racing-horses,breeding mares and riding-horses in Italy

Objective:To investigate the prevalence of methicillin-resistant staphylococci(MRS)which is a potencial risk factor of transmission between animals and humans in different types of horses(harness racing-horses,breeding mares and riding-horses)and to compare the antimicrobial resistance of the isolates.Methods:A total of 191 healthy horses,housed at different locations of the Campania Region(Italy),were included in the study.Nasal swab samples were collected from each nostril of the horses.The mecA gene was detected by a nested PCR technique.Antibiotic susceptibility was tested for each isolate.Results:MRS was isolated from nasal samples of 68/191(35.6%;95%CI:28.9%-42.9%)healthy horses.All isolates were coagulase-negative with the exception of two coagulase-positive MRS strains,identified as Staphylococcus aureus and Staphylococcus pseudintermedius.2/83(2.4%;95%,CI:0.4%-9.2%).Interestingly,both coagulase-positive MRS isolates were from harness racing-horses.These horses also presented a significantly higher positivity for MRS(53.3%;95%CI:40.1%-66.1%)than the breeding mares and riding-horses groups.Antibiotic susceptibility testing showed difference between isolates due to different origins except for an almost common high resistance to aminopenicillins,such as ampicillin and amoxicillin.Conclusions:It can be concluded that harness racing-horses may act as a significant reservoir of MRS as compared to breeding mares and riding-horses.

教育扩张、教育机会分配机制与教育不平等

受到现代化理论和功能主义的启发,各国试图用扩大教育规模和改革教育机会分配机制这两种手段促进教育公平。然而多国的教育发展经验和教育分层研究结果却表明,新增的教育机会通常被优势阶层占有,他们也能够巧妙地避开各种制度对其的约束,从而导致政府的教育公平改革收效甚微。同时各种教育制度之间也存在相互作用、相互制约的关系,共同决定着教育公平的发展方向。Mare模型在一定程度上揭示了教育扩张和教育分配改革之间复杂的关系,以及二者分别对教育不平等的作用。该模型试图控制教育机会数量变化的边际效应,从而考察教育机会在各阶层之间的分配。

Estimation of the elastic thickness over ancient Mare Moscoviense

The Moscoviense basin is an atypical lunar impact basin with concentric rings of positive and negative gravity anomalies. This basin can provide insights into the inhomogeneous thermal activities across the farside of the Moon. Based on an updated spherical harmonic thin elastic-shell loading model, we used localized admittance analyses to estimate the elastic thickness as well as other associated selenophysical parameters for the Moscoviense basin. The high precision gravity and topography data employed in our estimation were collected by the Gravity Recovery and Interior Laboratory and the Lunar Orbiter Laser Altimeter missions. Our results indicate that the crust-mantle interface is mainly compensated by the prefilling depth rather than the observed surface topography. The results constrained within two standard deviations yielded a small load ratio(~0.168), a best-fit crustal thickness of 36.2 km, and an optimized crustal density of 3159.5 kg m-3. Such large density approaches the density of olivine-rich mantle materials, implying that the excavation of the Mare Moscoviense occurred during a basin-forming impact. The inversed elastic thickness at Mare Moscoviense was around 18 km, lower than the previous results(~60 km) found over Mare basins on the lunar nearside. These results indicate that extreme thermal activity existed during the Moscoviense basin-forming period such as reheating mechanisms from a double-impact process and mare volcanism.

Two Lunar Mare Soil Simulants

Two new lunar mare soil simulants,NAO-2 and NAO-3,have been created in National Astronomical Observatories(NAO),Chinese Academy of Sciences.These two simulants were produced from low-titanium basalt and high-titanium basalt respectively.The chemical composition,mineralogy, particle size distribution,density,angle of internal friction,and cohesion of both simulants have been analyzed,indicating that some characteristics of NAO-2 and NAO-3 are similar to those of Apollo 14 and Apollo 11 landing site soils.NAO-2 and NAO-3 will be of great benefit to the scientific and engineering research on lunar soil.

Time of foaling in Arabian mares raised in Tiaret, Algeria

Objective:To enhance effectiveness of reproduction management in Arabian mares,factorsinfluencing the time of foaling were investigated in this study.Methods:Data were collectedat the National Haras of Tiaret in Algeria from 2003 to 2010.The foaling time of 255 Arabian purebred mares,aged from 3 to 20 years were used for this study.Results:A total of 78.07%of foalinghappens between 7 pm and 6 am.Conclusions:The influence of the month of foaling and the sexof the foal,on the time of foaling was statically significant.

Endoscopic monitoring the estrous phase of Arabian mares with assaying its biopsy

Objective:To evaluate the changes occur in the vagina, cervix and endometrium during the pre- ovulatory period in Arabian mares by using endoscope as a diagnostic tool as well as the availability of taking an endoscopic biopsy during this stage.Methods:Ten cyclic and healthy arabian mares were subjected to ultrasound scanning of their ovaries to estimate the diameter of the preovulatory follicles, collection of blood samples for estimating the hormonal levels (Estradiol-17β and progestrone) for confirming the estrous phase, endoscopic monitoring their vagina, cervix and endometrium, the availability of taking biopsical samples and histological examination of the obtained samples.Results:The obtained data revealed that, the mean diameter of the preovulatory follicles was (3.95±0.34) cm, the plasma estradiol and progestrone levels were (85.98±5.26) pg/mL and (0.73±0.23) ng/mL, respectively, endoscopic monitoring the vagina, cervix and endometrium revealed hyperemic vaginal mucous membrane, soft and opened cervical ostium with abundant estrous mucous and folding, hyperemic and edematous appearance of the endometrium, respectively and the histological features of the biopsical endometrial samples revealed that, The lamina propria-sub mucosa was packed with simple or branched tubular glands lined with simple columnar epithelium showing oval or rounded dark nuclei with different degrees of secretory activities of the glands.Conclusions: The endoscope proved to be a reliable tool for confirming the estrous phase in mares and monitoring the gross features of the vagina, the cervix and the endometrium, in addition to the availability of taking biopsical smears.

Determination of Fatty-Acid Composition in Oils of Animal Origin by Near-Infrared Spectroscopy

The authentication of milk requires the use of sophisticated and expensive analytical techniques. There is a huge need for reliable and cheap analytical technologies for use as fast and effective screening methods. This paper proposes the use of myristic acid in the authentication of cow, mare, camel and goat milk, using near infrared spectrometry. Comparison has been made with traditional gas chromatography methods, so that both methods can be used in the authentication of different types of dairy products.

Collagen types in relation to expression of estradiol and progesterone receptors in equine endometrial fibrosis

The aim of this study was to determine the influence of collagen I and III on the expression of estrogen and progesterone receptors in equine endometrial fibrosis. A total of 25 crossbred mares were studies. Two endometrial samples were collected from each mare,1 inthe estrus and1 inthe diestrus phase. The samples were classified according to histological changes. Collagen was typed and quantified using the picrosirius red histochemical technique, and steroid receptors were identified by immunohistochemistry. The results showed a predominance of collagen type III in all the endometrial samples. The expression of estrogen (RE2) and progesterone (RP4) receptors varied according to the estrous cycle. RE2 and RP4 expression varied in the estrus and diestrus phases;there was no influence of collagen I or II on receptor expression.

Case Study: A Human Pre-Natal Experiment in 1944—“Do No Harm”

Iris du Pré, a professional pianist, wanted a second child, did not conceive quickly and was injected in 1944 by a doctor in Oxford with pregnant mare serum gonadotropin (PMSG). The doctor joked “This child will be a racehorse winner!” In January 1945, Jacqueline du Pré, the remarkable, world-famous cellist was born. In the 1920's and 1930's, animal experimentation and clinical studies had shown that pituitary glycoproteins stimulated the ovary (follicle-stimulating hormone, FSH) and the corpus luteum (luteal-stimulating hormone, LH) which prepared the human womb for embedding a fertilized ovum and that pregnant mare’s blood and urine contained the glycoprotein, PMSG whose origin was placental cells, but surprisingly in humans had the actions of both FSH and LH. However, the PMSG serum alone did not bring about pregnancy. The doctor did not know that without subsequent injection of another factor in correct sequence and timing, PMSG was pointless. In 1947, a placental glycoprotein, found in the 1920's in urine of pregnant women (human chorionic gonadotropin, hCG), when injected in mice subsequent to PMSG, achieved ovulation but not pregnancy. Human application of those findings was extremely risky due to impurities (up to 95%). The Federal Drug Administration (FDA), established in 1938, requested easily bye-passed marketing safety. Companies offered material “sufficiently” purified;professional bodies negated clinical use, tempting to a few. Evidence also suggests that, to sustain pregnancy the doctor also prescribed the new “eostrogen”, diethyl stilbestrol (DES) of negative fame. In 1947, the Nuremberg Code of ethics demanded human experiments by qualified personnel and trials preceded by adequate animal studies. It is not the case here. From five, du Pré had a most exceptional musical memory, almost obsessive musicality and a very difficult school-time socially. Later history: adult masculine build, awkward gait, tendency to recurrent depressions from mid-adolescence, unbalanced thyroidal metabolism, symptoms of numbness in late teens, long breaks for rest from age 25, MS diagnosis at 28 when unable to play, death aged 42. Yet at sixteen and after, she astounded all with technique, passion and unique musical interpretation. Her husband, an outstanding musician: “She had a capacity to imagine sound such as I never met in any other musician”. A close musician colleague: “... it was done before she was born”;perhaps much closer to the truth than realization, for her history it may suggest a fetal neurodevelopment abused in the womb.

A novel strategy to extract lunar mare KREEP-rich metal resources using a silicon collector

The lunar mare potassium(K)-,rare-earth elements(REEs)-and phosphorous(P)-rich(KREEP-rich) region is a unique late-stage product of magma crystallization,in which ilmenite and incompatible elements have high grades,thus forming a giant natural reservoir.The extraction and purification of the high-value metal resources in the KREEP-rich region not only meet the construction needs of the lunar base but also solve the problem of resource scarcity on Earth.In this study,photovoltaic elemental silicon(Si) was used as a collector to extract ilmenite resources,REEs,and nuclear energy elements from basalt in the lunar mare KREEP-rich region at 1873 K.Based on experimentation,the metals titanium(Ti)and iron(Fe) in the lunar mare ilmenite are found to be enriched and solidified in the form of Si-based alloys.The contents of valuable incompatible elements in the KREEP-rich area are also found to be enriched and contained in the incompatible trace elements(ITEs) phase of the alloy.Among them,REEs(e.g.,cerium(Ce) and thulium(Tm)) and nuclear elements(e.g.,thorium(Th) and uranium(U)) are found to account for 82.61 wt% of the ITEs phase.This process provides a simple and feasible scheme for the insitu resource utilization(ISRU) of the lunar surface and is suitable for the extraction and enrichment of lunar metal resources.

KREEP-rich breccia in Chang'E-5 regolith and its implications

Lunar breccias provide crucial insights into the lithological diversity,shock processing and evolution of the lunar crust.Here,we report a unique regolith breccia(CE5C0000YJYX070GP,hereafter CE5C)returned from the Chang'E-5(CE-5)mission.CE5C is one of the largest CE-5 breccias with a wide variety of lithologies,dominated by basaltic and mineral fragments as well as impact-melted clasts(including mid-Ti glasses,high-Al glasses,and crystal-bearing impact melt clasts).A comprehensive study of petrology and mineralogy on several representative clasts was conducted by integrating Scanning Electron Microscopy(SEM),Tescan Integrated Mineral Analysis(TIMA),Electron Probe Microanalysis(EPMA)and Laser Ablation Inductively Coupled Plasma Mass Spectrometry(LA-ICP-MS)techniques.Evidence is sufficient that CE5C is a mixed mare-highland regolith breccia,with a high percentage of KREEPy material(>20 vol.%),which has not been previously reported in other CE-5 samples.The mid-Ti impact glasses are characterized by high FeO(24.0 wt.%)and intermediate TiO_(2)(5.5 wt.%)contents,while the high-Al impact glasses have a chemical composition compatible with KREEP.Integrated with the regional geological context of the CE-5 landing site,we propose that CE5C is likely derived from a mixed region between the P58/Em4 mare unit and its contiguous eastern highlands.Despite the difficulty in assessing the representativeness of CE5C,the substantial presence of KREEPy material may provide valuable clues to the provenance of exotic ejecta,including the identification of unrecognized source craters situated in the eastern periphery of the sampling unit.

Z箍缩内爆的MARED程序数值模拟分析

MARED程序是模拟Z箍缩内爆过程的二维三温辐射磁流体力学程序,它适用于不同装置条件和不同负载参数.利用MARED程序对Z箍缩内爆进行模拟,结合丝阵Z箍缩实验分析表明:相同负载质量条件下,钨丝阵内爆产生的X射线辐射功率远大于铝丝阵产生的X射线功率;相同负载电流条件下,负载质量越大,计算得到的X射线功率越低;X射线功率随着负载电流增加而增加.MARED程序能够较好地反映Z箍缩内爆动力学过程,特别是不稳定性发展的二维图像,能够给出与不稳定性简化模型的理论分析及实验结果定性一致的演化规律.MARED程序模拟丝阵填充泡沫形成辐射场的初步计算得到了与Sandia实验室模拟Z装置上丝阵填充泡沫定性一致的结果.

SIMS Pb/Pb dating of Zr-rich minerals in lunar meteorites Miller Range 05035 and LaPaz Icefield 02224:Implications for the petrogenesis of mare basalt

Miller Range (MIL) 05035 and LaPaz Icefield (LAP) 02224 are unbrecciated lunar basalt meteorites. In this report, we studied their petrography and mineralogy and made in situ uranogenic Pb/Pb dating of Zr-rich minerals. Petrography and mineralogy of these two lunar meteorites are consistent with previous investigations. The zirconolite Pb/Pb age of MIL 05035 is 3851±8 Ma (2σ), in excellent agreement with previous reports. This age suggests that MIL 05035 could be paired with Asuka 881757, a low-Ti mare basalt meteorite. The magmatic event related to MIL 05035 was probably due to the late heavy impact bom- bardment on the moon around 3.9 Ga. One baddeleyite grain in LAP 02224 shows a large variation of Pb/Pb age, from 3109±29 to 3547±21 Ma (2σ), much older than the whole-rock age of the same meteorite (~3.02±0.03 Ga). The other baddeleyite grain in LAP 02224 has an age of 3005±17 Ma (2σ). The result indicates that the minimum crystallization age of LAP 02224 is ~3.55 Ga and the younger ages could reflect late thermal disturbance on U-Pb system.