风化壳离子吸附型稀土矿成矿作用及制约条件

风化壳离子吸附型稀土矿床是我国亚热带地区所特有的稀土资源,它的发现是对传统矿产形成条件认识的一次革命,是对稀土资源开发利用做出的重大贡献,其采、选、冶的优越性远超越了其他稀土矿床,它产品曾一度占据了世界稀土市场的绝对地位。该类矿床发现40多年来,不少地质工作者对矿床形成过程,稀土元素在矿床中的分布富集规律及控矿条件做了很多探讨,但至今积累的系统成果还是较少,作者拟在前人研究成果基础上,结合目前工作对离子吸附型稀土矿床中稀土的成矿作用及制约因素做一较系统探讨。     

赤潮水体红光波段反射光谱的模拟及形成机理

赤潮水体红光波段反射光谱中"荧光峰"的红移现象一直备受研究者的广泛关注。本文基于前向辐射传输模型,通过2011年7月9日在大连湾海域实测的赤潮水体吸收系数和后向散射系数模拟了弹性散射作用下的反射光谱,发现在未考虑叶绿素荧光的情况下,红光波段仍存在显著的反射峰,且随叶绿素浓度的增加,反射峰出现红移现象;加入叶绿素荧光后,模拟光谱红光波段反射峰的位置与高度出现不同程度的改变,与实测光谱的更接近;对比模拟光谱与实测光谱可确定,红光波段的反射峰由吸收、后向散射以及叶绿素荧光共同控制,而文献中通常提到的"荧光峰"红移实由浮游藻类红光波段的强吸收作用导致,与叶绿素荧光无关,因此反射峰红移的说法更为合理。     

Maximum theoretical power absorption of connected floating bodies under motion constraints

In this paper, a mathematical model is presented to evaluate the maximum mean power that can be absorbed by a three-dimensional system of connected floating bodies in waves under a weighted global constraint. The constraint imposed on the motion amplitudes of the system can be used to limit the motions of the bodies in order to make sure that the assumption of linear theory for wave–structure interaction remains valid. The absorbed power of a structure can be considered as the difference between excitation and radiated power without consideration of practical power take off. The solutions for the maximum relative capture widths of rigidly connected two rafts have a good agreement with the calculated ones for the same rafts being seen as a single whole structure. Meanwhile, the results of maximum power absorption of two hinged slender rafts in cuboid shape give a good agreement as well with those by using slender-body approximations. Then dynamics of a hinged two rafts are studied and results show how the maximum efficiency is affected by raft width and restricting the motions.     

裙带菜(Undaria pinnatifida)配子体对氨态氮和硝态氮的吸收利用比较

本文对裙带菜(Undaria pinnatifida)配子体丰富培养的氮源进行了研究,结果发现裙带菜配子体能够有效利用氨态氮和硝态氮进行扩增,在30μmol/L氮离子浓度条件下,裙带菜配子体的日生长率能达到25%,可以满足配子体快速扩增的需要。裙带菜配子体在同时含有硝态氮和氨态氮的培养液中培养时,同时吸收两种氮源,并没有出现相互抑制的现象;配子体对氨态氮的吸收速率略大于硝态氮的吸收;对裙带菜配子体的氮吸收速率进行了测定,吸收速率最高分别可达24.3μmol/(g·h)和20.73μmol/(g·h),吸收速率随着氮浓度的增加而升高。     

海水石油类物质吸收系数遥感化提取算法研究

Establishing the remote sensing algorithm of retrieving the absorption coefficient of seawater petroleum substances is an efficient way to improve the accuracy of retrieving a seawater petroleum concentration using a remote sensing technology. A remote sensing reflectance is a basic physical parameter in water color remote sensing. Apply it to directly retrieve the absorption coefficient of seawater petroleum substances is of potential advantage. The absorption coefficient of waters containing petroleum [ACWCP, a_o(λ)], consists of the absorption coefficient of pure water [ACPW, a_w(λ)], plankton [ACP, a_(ph)(λ)], colored scraps [ACCS, a_(d,g)(λ)], and petroleum substance [ACPS, a_(oil)(λ)]. Among those, ACCS consists of the absorption coefficient of nonalgal particle [ACNP, a_d(λ)] and colored dissolved organic matter [ACCDOM, a_g(λ)]. For waters containing petroleum, the retrieved ACCS using the existing method is a combination absorption coefficient of ACNP,ACCDOM and ACPA [CAC, a_(d,g,oil)(λ)]. Therefore, the principle question is how to extract ACPS from CAC.Through the analysis of the three proportion tests conducted between the year of 2013 and 2015 and the corresponding remote sensing data, an algorithm of retrieving the absorption coefficient of petroleum substances is proposed based on remote sensing reflectance. First of all, ACPS and CAC are retrieved from the reflectance using the quasi-analytical algorithm(QAA), with some parameter modified. Secondly, given the fact that the backscatter coefficient [BC, b_(bp)(555)] of total particles at 555 nm can be obtained completely from the reflectance, the relation between BC and ACNP in petroleum contaminated water can be established. As a result, ACNP can be calculated. Then, combining the remote sensing retrieving algorithm of a_g(440), the method of achieving the spectral slope of the absorption coefficient can be established, from which ACCDOM,can be calculated. Finally, ACPS can be computed as the residual. The accuracy of ACPS based on this algorithm is 86% compared with the in situ measurements.     

Numerical Wave Tank Based on A Conserved Wave-Absorbing Method

Recently the numerical wave tank has become a widely-used tool to study waves as well as wave-structure interactions, and the wave-absorbing method is very important as its effect on the quality of waves generated. The relaxation method and the derived momentum source method are often utilized, however, the damping weight is constant during calculation and repeated trials are required to obtain an acceptable wave-absorbing effect. To address the above- mentioned issues, a conserved wave-absorbing method is developed. The damping weight is determined by solving the mass conservation equation of the absorbing region at every time step. Based on this method, a two-dimensional numerical wave tank is established by using the VB language to simulate various waves by which the validation of this method is evaluated.     

花岗岩球状风化的形成机理新析

花岗岩球状风化现象在自然界比较常见,其成因国内一般认为受三维裂隙控制,出露地表接受风化时,由于棱角突出,角部受三个方向的风化,棱边受两个方向的风化,而面上只受一个方向的风化,故棱角逐渐缩减,最终趋向球形。国外也有其他成因认识,如liesegang现象、卸荷载、微裂隙、体积膨胀、后期风化作用等莫衷一是。本文通过认真观察,对比分析,总结出球状风化形成机理即亲水矿物吸水及失水造成的膨胀收缩的结果。     

太阳活动区上空两个微波超快速吸收现象的观测与分析

1987年5月19日世界05h50m17-05k50m25s和1986年6月29日世界时07h38m50s-07h38m58s两个罕见的微波超快速吸收现象分别出现在太阳活动区NOAA／USAF4808和5060上空的3.67GHz和4.00GHz大气层中.当云南天文台高时间分辨率射电望远镜观测到这种吸收现象时,在2.84GHz和1.42GHz大气层中出现的是尖峰辐射,两次超快速吸收现象的显著观测特征是：（1）吸收期的持续时间为20—25ms;（2）吸收的流量范围在17-215s．f.u．;（3）超快速吸收形态与快速吸收形态基本相似;（4）超快速吸收现象均叠加在秒级爆发上,秒级爆发分别为44NS和46C型;（5）相伴随的Ha耀斑分别为SF级和3B级．     

气溶胶和水汽e型吸收对低层大气长波辐射冷却率的影响

利用带模式方法计算了低层大气的长波冷却率。结果表明,在大气低层窗区ｅ型吸收的冷却率小于非窗区的水汽冷却率,约占总冷却率的１／３;气溶胶的长波冷却率小于水汽的冷却率,对总冷却率的贡献约为３０％;大气低层总冷却率的分布主要取决于水汽冷却率的分布。     

Absorption Spectra Measurements for the Ozone Molecule in the 350–830 nm Region

Absolute absorption cross-sections of ozone have been measured at ambient (295 K) and low temperature (218 K) in the visible region corresponding to the Chappuis bands. The temperature effect has been studied and found to be very small. The minimum of the absorption between the Hartley and the Chappuis bands is observed for the first time at 377,5 nm.