Resonance transition periodic orbits in the circular restricted three-body problem

This work studies a special type of cislunar periodic orbits in the circular restricted three-body problem called resonance transition periodic orbits, which switch between different resonances and revolve about the secondary with multiple loops during one period. In the practical computation, families of multiple periodic orbits are identified first, and then the invariant manifolds emanating from the unstable multiple periodic orbits are taken to generate resonant homoclinic connections, which are used to determine the initial guesses for computing the desired periodic orbits by means of multiple-shooting scheme. The obtained periodic orbits have potential applications for the missions requiring long-term continuous observation of the secondary and tour missions in a multi-body environment.     

Global Statistical Assessment and Cross-Calibration with Jason-2 for Reprocessed HY-2 A Altimeter Data

HY-2 A (Haiyang-2 A) satellite was launched on August 16, 2011 and radar altimeter is one of its main payloads. We reprocessed two years of HY-2 A altimeter sensor geophysical dataset records (SGDR) data. This paper presents the main results in terms of reprocessed HY-2 A altimeter data quality: verification of data availability and validity, monitoring several relevant altimeter parameters, and assessment of the HY-2 A altimeter system performances. A cross-calibration analysis of reprocessed HY-2 A altimeter data with Jason-2 was conducted. The reprocessed HY-2 A altimeter data show good quality and have a low level of noise with respect to Jason-2. The same geophysical correction methods were used to calculate the sea surface height (SSH) for the two missions. The mean standard deviations of the crossover differences for HY-2 A and Jason-2 are 5.24 cm and 5.34 cm, respectively. The mean standard deviation of the crossover differences between HY-2 A and Jason-2 is 5.37 cm. These show that HY-2 A can provide SSH measurements at almost the same level of accuracy as Jason-2. The relative SSH bias between HY-2 A and Jason-2 due to the Ultra Stable Oscillator (USO) drift is obviously observed, and it can affect the calculation of mean sea level and should be further studied and corrected.     

Evolutionary dynamics of the Wnt gene family: implications for lophotrochozoans

Journal of Oceanology and Limnology - Genes encoding Wnt ligands, which have important roles in cell communication and organ development, are restricted to multicellular animals. We systematically...     

银纳米杆高温熔化断裂弛豫性能的原子级模拟研究

采用分子动力学模拟方法,研究了不同长度银纳米杆在不同温度弛豫过程中的结构演变过程.结果表明:银纳米杆存在一与杆长相关的临界熔断温度,该临界熔断温度随杆长增加而显著降低.当温度大于熔点而小于临界熔断温度时,体系形成一个高度无序的球形团簇,而温度大于临界熔断温度时,体系则熔断成两个球形团簇.并给出了银纳米杆的产生该熔断现象的机理.     

基于闪锌矿晶体中受激电磁耦子散射产生可调谐太赫兹波的理论研究

基于受激电磁耦子散射原理,采用已报道的利用非线性光学参量振荡方法产生可调谐太赫兹波的实验条件作为理论分析的实验模型,以GaAs,GaP, InP,ZnTe晶体为代表,计算分析了在闪锌矿晶体中参量振荡产生太赫兹波的吸收、增益特性,对输出THz波的调谐特性给出了详尽分析.分析太赫兹波高效耦合输出的腔型结构,并与掺氧化镁铌酸锂晶体组成的太赫兹波参量振荡器做对比.     

局域椭圆偏振光束强聚焦性质的研究

数值计算了局域椭圆偏振光束强聚焦时在焦平面上的横向场强分布、纵向场强分布、横向能流以及纵向角动量分布.结果显示在焦平面上光束总的纵向角动量为零,但在不同象限光束具有不同方向的纵向角动量.当相位延迟角度在0到π之间变化时横向场强分布基本不变,但纵向场强分布有很明显的变化.液晶相位延迟器由外部电压控制,使其相位延迟角度能在0到π之间可以连续取值.因而液晶相位延迟器的外接电压可以实现对焦平面上的纵向场强以及纵向角动量的实时调控.     

四川盆地东部再生稻高温伏旱区腋芽萌发期气象适宜度

以四川盆地东部再生稻高温伏旱区为研究区,基于气象条件对腋芽萌发期再生稻生长发育的影响机理,采用结构方程模型探明了腋芽萌发的影响因素、影响路径及影响强度。进一步结合隶属函数和层次分析法,构建了再生稻腋芽萌发气象适宜度模型,并分析了1981—2021年研究区腋芽萌发期气象影响因素及气象适宜度的变化特征。结果表明：气温、空气湿度、降水是四川盆地东部再生稻高温伏旱区腋芽萌发的关键影响因素,基于以上因素的气象适宜度模型能较好地评价再生稻腋芽萌发期的气象影响。1981—2021年研究区气温适宜度、空气湿度适宜度及综合气象适宜度均呈下降趋势,降水适宜度没有表现出明显的变化趋势。气温适宜度、空气湿度适宜度及综合气象适宜度总体呈“西高东低”的空间分布特征,降水适宜度则表现为“东西高、中部低”。1981—2021年研究区气温上升趋势与空气湿度下降趋势显著,导致致害高温（日平均气温≥32℃）积温和致害低湿（日平均相对湿度≤65％）日数明显增加,这是再生稻腋芽萌发期气象适宜度总体呈下降趋势的诱因。     

我国南方燕山期不同矿化花岗岩的判别

在我国南方,广泛发育各种酸性岩浆侵入体,蕴藏着丰富的稀土、稀有和放射性元素等矿产资源。找矿勘探及地质研究证明,其中大部分与燕山期花岗岩体有密切关系。实际情况是只有部分燕山期花岗岩体中,上述有用元素能富集成矿,而在更多的燕山期花岗岩体中,并未发现有工业价值的矿床。铌钽矿化与钨矿化可在一地存在,也可在不同岩体中出现,但铌钽矿化、钨矿化与铀矿化经常不在一地。上述现象纯属偶然的巧合,还是某种内在联系的反映呢?含矿花岗岩与不含矿的花岗岩在化学元素组合上有没有差异?研究这个问题对今后的找矿和勘探显然是有重要意义的。     

激光探针质谱及单颗粒矿物^40Ar／^39Ar法年龄的测定

将掺钕的钇铝榴石（Ｎｄ：ＹＡＧ）激光器与高精密ＭＭ１２００质谱计、电子倍增器联网，应用连续激光质谱对单颗粒矿物、光片样品进行微区４０Ａｒ／３９Ａｒ测年、坪年龄和等时线年龄研究。在光片上测定南极乔治王岛北海岸玄武岩等时线年龄（５２．３８±１．０５）Ｍａ和贵州绿豆岩年龄（２３９．１６±１４．１３）Ｍａ，两者与实际地质背景吻合。对两个中生代和太古代单颗粒黑云母进行连续激光质谱阶段升温４０Ａｒ／３９Ａｒ坪年龄谱测定，获得与常规法相一致的坪年龄谱     

Duobaoshan Porphyry Copper Deposit and Its Associated Components

Duobaoshan porphyry copper deposit,situated in Nen-jiang County of Heilongjiang Province,Northeast China,liestectonically in the Mongolian-Okhotsk geosyncline.Duobaoshan porphyry copper ore field consisting ofDuobaoshan copper deposit and Tongshan copper deposit con-tains rich copper associated with molybdenum,gold,silverand osmium (Os1 87) . In this sense,this porphyry copper orefield will turn into a large industrial base of copper,gold,sil-ver and osmium.At present,in Duobaoshan porphy…