暗物质和暗能量是忽悠？

玄而又玄的暗物质和暗能量曾经让许多人痴迷，如今有人说这些概念可能也是忽悠。 一些英国科学家声称，用于计算宇宙构成的方法也许是错误的。已有数十年历史的标准模型认为，我们所知的宇宙——由行星、恒星、小行星和气体等可认识的部分构成——只占宇宙的4％。     

江苏辐射沙洲海区潮流对涌浪能量传播的影响

为研究了江苏辐射沙洲地区潮流场对涌浪能量传播的影响,本文利用双向耦合的Delft3D-FLOW和SWAN模型进行了对江苏辐射沙洲地区风-浪-潮流的整体模拟。时间尺度,是表达波能传播速率的有量纲参数。本文利用时间尺度这一物理概念来描述涌浪的波能在地理空间和谱空间中的传播规律。时间尺度越小,波能的传播速率越快。研究发现,通过计算和对比波能的时间尺度在地理空间、谱空间内的变化规律,发现在辐射沙洲地区,波能时间尺度在谱空间内变化偏大。而在潮流影响下,涌浪的频率运移表现更明显。通过理想实验的对比,发现涌浪能量的时间尺度在有潮流明显较无潮流作用时变小,这反映了潮流对于涌浪能量的传递速率有正向作用。在地理空间上,波能的时间尺度在涨潮时刻减小,落潮时刻增大。     

黄海辐射沙洲沉积物地球化学特征及其环境意义

对黄海辐射沙洲烂沙洋水道区域的3个钻孔共81个沉积物样品进行了微量、常量元素分析和^14C测年分析．化学元素质量分数的变化与当时沉积环境的变化相对应。突发事件(如风暴潮)的发生不但在沉积物的岩性上有所体现,而且在微量元素质量分数的变化上也有很明显的体现。微量元素Zr可作为沉积能量变化的地化指示剂,潮汐通道北部的西太阳沙区域的沉积动力环境在4000a以前是较弱的。潮流通道的上段沉积物是来自水深较浅的区域,由于潮流和波浪的作用使其能够保持稳定的水深。     

珠江河口的能量传播和能量耗散

建立了包括河网区、河口湾区和近海水域的ECOMSED-3D数学模型,计算了珠江河口的能量传播和能量耗散特征。研究表明:1)珠江河口能量来源受潮汐和径流共同作用,季节性变化明显;2)珠江河口存在若干高能耗区,其单位面积能耗率比上下游河段平均能耗率高1—2个量级,它们和一定的动力结构与地貌单元相联系。根据地貌特征和消能特点,可以划分为以下3种类型:门的高能耗区、曲折河段高能耗区和分汊汇流高能耗区。     

Barriola-Vilenkin黑洞Dirac场的广义Stefan-Boltzmann定律

利用薄膜模型研究Barriola-Vilenkin黑洞的热辐射,得到了黑洞的热辐射满足广义Stefan-Boltzmann定律的结论,导出的广义Stefan-Boltzmann系数不再是一个恒量,当截断距离以及薄膜厚度取定后,它是一个与黑洞视界附近的时空度规以及辐射粒子的径向平均泻流速率有关的比例系数.得到的Barriola-Vilenkin黑洞视界附近Dirac场的辐射能通量与薄层膜内辐射粒子的径向平均泻流速率成正比,与黑洞的质量平方成反比.     

浅水有界水域水下目标辐射噪声测量修正方法

由于适合水下目标辐射噪声测量的理想水域较少,因此测量试验大多在浅水有界水域开展,测量结果难免会受到试验现场界面反射波影响,导致测量的宽带声压级及各频率声压谱级产生偏差。利用虚源法对浅水有界水域下的声场模型进行了数值仿真,重点分析了导致传播损失异常的各项因素,然后基于脉冲声技术提出了一种水下目标浅水有界水域辐射噪声测量结果的修正方法,并进行了外场辐射噪声测量和传播损失异常值标定验证试验,最后对试验数据的测量结果进行了修正。     

草鱼混养生态系统能量收支的研究

采用陆基围隔实验法,对草鱼(Ctenopharyngodon idellus)、鲢鱼(Hypophythalmichthys molitrix)和鲤鱼(Cyprinus carpio)不同混养系统的能量收支和转化效率进行了研究。实验共设置7个处理组,分别为草鱼单养(G)、草鱼和鲢鱼二元混养(GS)、草鱼和鲤鱼二元混养(GC)以及草鱼、鲢鱼和鲤鱼按照不同比例放养的三元混养(GSC1、GSC2、GSC3和GSC4)。研究结果表明,实验期间各系统接收的总太阳辐射能为4 970MJ.m-2;光能利用率在0.25%～0.33%之间,各处理组之间差异显著(P<0.05);光合能转化效率以草鱼单养组最低,且与GS、GSC2、GSC3和GSC4处理组之间差异显著(P<0.05);各混养组与草鱼单养组相比,总能量转化效率分别提高了43.51%、11.62%、30.16%、64.30%、38.49%和61.90%,其中,以GSC2为最高,GSC4次之;单位净产量耗饲料能以单养草鱼组最高,显著高于GS、GSC2和GSC4处理组(P<0.05);各处理组沉积能量在3.42～17.73MJ.m-2之间,各处理组间差异显著(P<0.05),各组沉积能量占总投入能量的比例分别为30.92%、12.18%、39.08%、29.43%、28.90%、28.87%和29.80%。本研究结果表明,不同食性鱼类混养系统能够提高光合能转化效率和总能量利用率,降低沉积能量,从而有效提高系统对输入能量的利用效率。     

基于超像素和暗通道先验的图像去雾复原方法

基于暗通道先验的图像去雾算法因其简单有效而得到广泛应用。经典算法中由于透射率图估计存在块效应而需要对透射率图进行滤波细化。本文提出了一种基于超像素分割和暗通道先验的透射率估计方法,用超像素分割获得的不规则区域替代经典算法中的固定窗口,从而避免了透射率图估计的块效应问题,并采用松弛策略以获得鲁棒性和准确性更好的透射率结果,无需进行另外的滤波细化步骤即可完成图像去雾复原。实验结果证实了本文所提方法的有效性。     

基于暗原色先验的单幅雾天降质图像复原方法

恶劣的气象条件是制约遥感数据获取的重要因素之一。 首先引入“暗原色先验”作为约束条件用以获取场景深度和大气条件等参数,并基于雾天成像模型,设计单幅影像的去雾处理流程;然后针对其中大气透射率内插优化过程计算量巨大的实际问题,采用小波变换技术对原始影像进行预处理,将原来弥漫在整幅影像空间的低频薄雾信息集中到一个非常小的图像块内进行复原处理,大大降低了计算量,提高了处理效率;最后,利用多幅黄山地区的航空遥感影像进行试验,结果表明该方法能够快速、有效的去除薄雾影响。     

用于太阳紫外辐射测量传感器的设计

介绍了太阳紫外辐射的测量原理,为了提高入射光学系统的余弦响应特性而设计的余弦漫射器,以及等效辐射平面位置的计算方法。设计了适用于海滨浴场等场所的太阳紫外线辐射传感器的光学系统结构,研制了试验样机,开展了相应的试验,并对试验结果进行了分析。     

Massive particle radiation from Gibbons-Maeda black hole

This paper investigated the massive particle radiation from Gibbons--Maeda black hole by using a semi-classical method. The calculations showed that, if the self-gravitation of the radiated particle is taken into account, the radiation spectrum deviates from exact black body spectrum and the rate of tunneling equals precisely the exponent of the difference of the black hole entropies before and after emission. The conclusion supports the viewpoint of information conservation.     

Radiation energy flux of Dirac field of static spherically symmetric black holes

By the statistical entropy of the Dirac field of the static spherically symmetric black hole, the result is obtained that the radiation energy flux of the black hole is proportional to the quartic of the temperature of its event horizon. That is, the thermal radiation of the black hole always satisfies the generalised Stenfan--Boltzmann law. The derived generalised Stenfan--Boltzmann coefficient is no longer a constant. When the cut-off distance and the thin film thickness are both fixed, it is a proportional coefficient related to the space--time metric near the event horizon and the average radial effusion velocity of the radiation particles from the thin film. Finally, the radiation energy fluxes and the radiation powers of the Schwarzschild black hole and the Reissner--Nordstrõm black hole are derived, separately.     

A study of the microbial mineralization in submarine black smoker chimneys from the Okinawa Trough

Large amounts of microfossil records discovered in the seafloor black smoker chimney are reported from the Okinawa Trough. They are well preserved and can be divided into four types of filamentous microfossils. It suggests that the fossils may be derived from sulfur or iron oxidation chemolithotrophic prokaryotes and fungi. Based on the comparison studies of the microbial mineralization processes, two steps of biomineralization were hypothesized:(1) biology controlled mineralization; and (2) biology induced mineralization. At the early stage of the mineralization, the biology controlling mineralization is dominating; at the later stage, the biology inducing mineralization is the main mechanism. The composition of the fluids and the species of the microbes will determine the types of the minerals formed.     

冲绳海槽海底硫化物中微生物矿化研究

报道了冲绳海槽伊平屋海洼海底黑烟囱样品中保留完好的矿化微生物群,它们的形态完好。主要有四种不同类型的丝状体,这些丝状体可能是硫或者铁氧化化能自养细菌和真菌矿化而成。对这些微生物矿化过程的研究表明,它们主要经过了两个阶段的矿化:(1)生物控制矿化阶段;(2)生物诱导矿化阶段。早期以生物控制矿化为主,晚期以生物诱导矿化为主。形成的矿物与热液成分以及微生物种类有关。     

Response of the soft coral Heteroxenia fuscescens to ultraviolet radiation regimes as reflected by mycosporine-like amino acid biosynthesis

The variation in mycosporine‐like amino acid (MAA) concentration in the soft coral Heteroxenia fuscescens in relation to changes in ultraviolet radiation (UVR) regimes was investigated at the Gulf of Eilat, northern Red Sea. Solar radiation (300–700 nm) was measured for different depths and seasons. The UVR irradiance was measured to a depth of 25 m on the reef. The mean attenuation coefficient for UV‐B measured in winter was twofold that of the summer value. Separation of H. fuscescens extracts by reverse‐phase isocratic high‐performance liquid chromatography revealed a single MAA compound, palythine (λ_max = 320 nm). Possible seasonal changes in MAAs in colonies of H. fuscescens along a depth gradient were examined on different dates. Palythine concentrations in the colonies were significantly higher in summer than in the other seasons particularly in shallow water. Possible changes in MAA content in colonies of H. fuscescens as a result of UVR protection, were determined by experiments conducted for periods of 1 week, 1 month and 3 months, at a depth of 5 m. In these experiments colonies were removed from the natural substrate and placed underwater, protected from UVR by a PVC filter. Significant differences between UV‐exposed and protected colonies of H. fuscescens were found only in the 3‐month experiment conducted during the summer. These findings demonstrate that UVR is an important environmental factor regulating MAA biosynthesis in the soft coral H. fuscescens.     

夏季南海浮游植物光合固碳对不同波长阳光紫外辐射的响应

阳光紫外(UV)辐射影响浮游植物光合固碳,且不同波长UV辐射的生理效应不一.本文以夏季南海近岸海域浮游植物为研究对象,采用生物加权函数(Biological weighting function,BWF,亦被称为UV辐射作用光谱)的研究方法,探讨了不同波长UV辐射对浮游植物群落光合固碳的作用.结果表明,在只有可见光情况...     

Short-term and diurnal temperature changes alter the response of harmful algal blooms of Pseudo-nitzschia pungens to solar ultraviolet radiation

In this study, we explored the interactive effects of temperature and solar ultraviolet radiation (UVR) on the growth, pigment contents, photochemical efficiency and non-photochemical quenching (NPQ) of Pseudo-nitzschia pungens, which forms harmful algal blooms globally. Cells were first pre-acclimated to temperatures of 20°C, 25°C or 28°C for 10 days. They were then exposed to three different types of solar radiation for 60?min. We then measured the photochemical efficiency of the cells during the 60-min exposure and a 360-min recovery period under dim light (20?μmol?photons?m^?2?s^?1). In addition, we analysed the diural change in photochemical efficiency and NPQ over a 10-h period. We found that P. pungens that were exposed to higher temperatures in the short term (i.e. 20–25°C, 20–28°C and 25–28°C) or long term (i.e. 25–25°C and 28–28°C) exhibited lower levels of photoinhibition and faster recovery rates than samples exposed to a lower temperature (i.e. 20–20°C). This indicated that the deleterious effects of UVR can be minimised by both chronic and acute exposure to higher temperatures within the tolerated temperature range for P. pungens.     

On the radiation and diffraction of linear water waves by an infinitely long rectangular structure submerged in oblique seas

The radiation and diffraction of linear water waves by an infinitely long rectangular structure submerged in oblique seas of finite depth is investigated. The analytical expressions for the radiated and diffracted potentials are derived as infinite series by use of the method of separation of variables. The unknown coefficients in the series are determined by the eigenfunction expansion matching method. The expressions for wave forces, hydrodynamic coefficients and reflection and transmission coefficients are given and verified by the boundary element method. Using the present analytical solution, the hydrodynamic influences of the angle of incidence, the submergence, the width and the thickness of the structure on the wave forces, hydrodynamic coefficients, and reflection and transmission coefficients are discussed in detail.     

The chemical changes of DOM from black waters to coastal marine waters by HPLC combined with ultrahigh resolution mass spectrometry

How dissolved organic matter (DOM) undergoes chemical changes during its transit from river to ocean remains a challenge due to its complex structure. In this study, DOM along a river transect from black waters to marine waters is characterized using an offline combination of reversed-phase high performance liquid chromatography (RP-HPLC) coupled to electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR-MS), as well as tandem ESI-FTICR-MS. In addition, a water extract from degraded wood that mainly consists of lignins is used for comparison to the DOM from this transect. The HPLC chromatograms of all DOM samples and the wood extract show two major well-separated components; one is hydrophilic and the other is hydrophobic, based on their elution order from the C₁₈ column. From the FTICR-MS analysis of the HPLC fractions, the hydrophilic components mainly contain low molecular weight compounds (less than 400 Da), while the hydrophobic fractions contain the vast majority of compounds of the bulk C₁₈ extracted DOM. The wood extract and the DOM samples from the transect of black waters to coastal marine waters show strikingly similar HPLC chromatograms, and the FTICR-MS analysis further indicates that a large fraction of molecular formulas from these samples are the same, existing as lignin-like compounds. Tandem mass spectrometry experiments show that several representative molecules from the lignin-like compounds have similar functional group losses and fragmentation patterns, consistent with modified lignin structural entities in the wood extract and these DOM samples. Taken together, these data suggest that lignin-derived compounds may survive the transit from the river to the coastal ocean and can accumulate there because of their refractory nature.