有趣的海发光

海上看日出是一大奇观。如果你能在夜间观赏到海发光,那也是相当瑰丽的。它有时似星光万点,有时又似乳光一片,更似绚丽多彩的礼花。人们称这种现象为"海火",海洋学上则叫作"海发光"。这种迷人的景象是谁引起的呢?是谁的杰作呢?

让军魂在商海发光——记全国优秀退伍军人梁彦儒

“三年的军旅生涯,使我刚毅、坚强、成才;‘挂甲’还乡后,我要让军魂在商海发光,以实绩报效祖国,做一名永不褪色的退伍兵。”这是河南鹤壁市鑫大化工机械有限公司董事长兼总经理梁彦儒从一名普通退伍军人成长为一位成功企业家的人生奋斗格言。 1981年10月,梁彦儒以一个二等乙级伤残军人的身份退伍返乡,跨进了鑫大公司的前身——鹤壁市金属结构厂的门坎。从此,他涉足经济大潮。

《第一届全国灯用稀土荧光粉应用及学术研讨会》在上海召开

由中国稀土学会主办、中国发光学会和上海发光应用研究会协办的《第一届全国灯用稀土荧光粉应用及学术研讨会》于1993年11月1—4日在上海复旦大学召开.会议由上海跃龙有色金属有限公司和复旦大学材料科学研究所承办.参加这次会议的代表共70余人,来自9个高等院校和7个研究院所以及20多个工厂企业.会议邀请了蔡祖泉等许多著名的荧光材料和电光源专家就下列内容作专题报告:

海火奇观话冷光

1993年8月25日晚,星月朦胧,在山东长岛县大钦岛,渔民猛然发现渤海湾浪涌扑打处,有火光明灭,继而"大火"剧燃,此生彼灭,火苗四溅,如"火雨"跌落,蔚为壮观,直到40分钟后火苗才自行熄灭。这就是海洋上奇妙的海发光现象,渔民们称之为"海火"。其实,海发光现象并不罕见。

第一届全国灯用稀土荧光粉应用及学术研讨会在上海召开

由中国稀土学会主办、中国发光学会和上海发光应用研究会协办的第一届全国灯用稀土荧光粉应用及学术研讨会于1993年11月1～4日在上海复旦大学召开。会议由上海跃龙有色金属有限公司和复旦大学材料科学研究所承办。参加这次会议的代表共70余人。

Sporo-pollen Assemblage and Paleoclimate Events in Shelf Area of the Southern Yellow Sea Since 15 ka B.P.

Based on the authors’1986 to 1994 sporo-pollen assemblage analysis in the southern Yellow Sea area, data from 3 main cores were studied in combination with 14C, palaeomagnetic and thermoluminescence data. The evolution of the paleoclimate environments in the southern Yellow Sea since 15ka B.P. was revealed that, in deglaciation of the last glacial period, the climate of late glaciation transformed into that of postglaciation, accompanied by a series of violent climate fluctuations. These evolution events happened in a global climate background and related to the geographic changes in eastern China. We distinguished three short-term cooling events and two warming events. Among them, the sporo-pollen assemblage of subzone A 1 showed some cold climate features indicating that a cooling event occurred at about 15-14ka. B.P. in early deglaciation. This subzone corresponds to the Oldest Dryas. In subzone A 3, many drought-enduring herbal pollens and some few pollens of cold-resistant Picea, Abies, etc. were found, which indicated that a cooling event, with cold and arid climate, occurred at about 12-11ka. B.P. in late deglaciation. This subzone corresponds to the Younger Dryas. The sporo-pollen assemblage of zone B showed warm and arid climate features in postglaciation. Although the assemblage of subzone B 2 indicated a cold and arid climate environment, the development of flora in subzone B 2 climate was less cold than that in A 3. Subzone B 2 indicated a cooling event which occurred at about 9ka B.P. in early Holocene. Subzone A 2, with some distinct differences from subzone A 1 and A 3, indicated a warming event which occurred at 14-13ka. B.P. and should correspond to a warming fluctuation. The sporo-pollen assemblage of zone C showed features of warm-moist flora and climate, and indicated a warming event which universally occurred along the coast of eastern China at 8-3ka B.P. in middle Holocene, and its duration was longer than that of any climate events mentioned above. This period was climatic optimum and belonged to an altithermal period in postglaciation.

The Effects of Trehalose on the Bioluminescence and Pigmentation of the Phase I Variant of Photorhabdus luminescens

Photorhabdus luminescens is a Gram-negative, bioluminescent, pigment producing enteric bacterium, which is pathogenic to insects and has the capability to undergo phase variation. The phase I variant of P. luminescens exists as a mutualistic symbiont where it plays a critical role in the life-cycle of the soil-dwelling nematode, Heterorhabditis bacteriophora. Both the bacterium and the nematode receive their nutritional requirements from the bioconversion of the insect host which is rich in many macromolecules such as the disaccharide, trehalose. Trehalose is a non-reducing disaccharide of glucose that is formed by an a-1,1-glycosidic bond and is associated with the physiology of many bacteria, insects and nematodes. Trehalose has been shown to be the most abundant storage sugar found within insect hemolymph （1%-2%）. The physicochemical properties of trehalose allow this carbohydrate to act as a stress protectant where it has been implicated with thermal stress, dehydration, and osmotic protection of many microorganisms. Due to these properties, trehalose may allow culture stability of the phase I variant in vitro and in vivo. Traits of the phase I variant that were studied in this work include bioluminescence and the production of the red anthroquinone-derived pigment. The carbohydrates that were utilized in this study were glucose and trehalose; where shake flask cultures of the phase I variant were cultured at room temperature for up to six days in carbohydrate supplemented basal media with increasing carbohydrate concentrations of 0. 1%, 0.5% and 1.0% （v/v）. Relative luminosity, pigmentation and pH were graphed as a function of time, carbohydrate used, and carbohydrate concentration. Data obtained from this study suggests that the supplementation of 1.0% trehalose, when culturing the phase I variant ofP. luminescens, can maintain bioluminosity and pigmentation over extended periods of time （five days） as compared to basal media and basal media supplemented with 1.0% glucose.

New Approach for Rapid Assessment of Trophic Status of Yellow Sea and East China Sea Using Easy-to-Measure Parameters

To realize potential cost savings in coastal monitoring programs and provide timely advice for marine management, there is an urgent need for efficient evaluation tools based on easily measured variables for the rapid and timely assessment of estuarine and offshore eutrophication. In this study, using parallel factor analysis(PARAFAC), principal component analysis(PCA), and discriminant function analysis(DFA) with the trophic index(TRIX) for reference, we developed an approach for rapidly assessing the eutrophication status of coastal waters using easy-to-measure parameters, including chromophoric dissolved organic matter(CDOM), fluorescence excitation–emission matrices, CDOM UV-Vis absorbance, and other water-quality parameters(turbidity, chlorophyll a, and dissolved oxygen). First, we decomposed CDOM excitation-emission matrices(EEMs) by PARAFAC to identify three components. Then, we applied PCA to simplify the complexity of the relationships between the water-quality parameters. Finally, we used the PCA score values as independent variables in DFA to develop a eutrophication assessment model. The developed model yielded classification accuracy rates of 97.1%, 80.5%, 90.3%, and 89.1% for good, moderate, and poor water qualities, and for the overall data sets, respectively. Our results suggest that these easy-to-measure parameters could be used to develop a simple approach for rapid in-situ assessment and monitoring of the eutrophication of estuarine and offshore areas.

Sixty-four-slice computed tomography in surgical strategy of portal vein cavernous transformation

AIM:To investigate the role of 64-slice computed tomography(CT) in portal vein cavernous transformation to determine surgical strategy.METHODS:The site of lesions and extent of collateral circulation in 12 pediatric cases of cavernous transformation of the portal vein with surgical treatment were analyzed.RESULTS:Eleven of 12 children had esophageal varices and were treated with lower esophageal and gastric devascularization and splenectomy,and the other case was only treated with splenectomy.There were eight cases with spontaneous spleen/stomach-renal shunt,four with Retzius vein opening,which was reserved during surgery.Three cases of lesions involving the intrahepatic portal vein(PV) were treated with living donor liver transplantation.One patient died from PV thrombosis after liver transplantation,and the rest had no significant complications.CONCLUSION:The PV,its branches and collateral circulation were clearly seen by 64-slice spiral CT angiography,which helped with preoperative surgical planning.

Dissolved organic matter and its role in red tide succession in the East China Sea in spring

Dissolved fluorescent organic matter was measured using fluorescence excitation-emission matrix spectroscopy at three temporal points during a Synechococcus bloom after diatom bloom dispersion in spring, 2007. Carbohydrate and dissolved organic carbon were also analyzed. The relationship between organic matter and red tide succession was examined. The results show that after the diatom bloom, tyrosine-like fluorescence B intensity was very high within the water column and exhibited a negative correlation with chlorophyll a over the period of the Synechococcus bloom. Other organic matter did not exhibit this relationship with chlorophyll a. This implied that diatom bloom dispersion resulted in the release of large quantities of tyrosine-like compounds into the water. These may play a role as a nutrient source or growth-stimulating substance for the subsequent Synechococcus bloom.

Fuzzy Pattern Recognition System for Detection of Alga Distribution

To realize the on-line measurement and make analysis on the density of algae and their cluster distribution, the fluorescent detection and fuzzy pattern recognition techniques are used. The principle of fluorescent fiber-optic detection is given as well as the method of fuzzy feature extraction using a class of neural network.

Multiple Excitation Wavelength Fluorescence Emission Spectra Technique for Discrimination of Phytoplankton

In vivo fluorescence methods are efficient tools for studying the distribution of phytoplankton in nature.Different algae species usually have different pigments with different ratios,which results in different fluorescence emission spectra.Based on multiple excitation wavelength fluorescence emission spectra,a discrimination technique is established in this study.The discrimination method,established by multivariate linear regression and weighted least-squares,was used to differentiate the samples cultured in the laboratory and collected from Jiaozhou Bay near Qingdao at the division level.The correctly discriminated samples were ≥ 86% for single algae samples,≥ 88% for simulatively mixed ones,≥ 91% for physically mixed ones and 100% for samples collected from Jiaozhou Bay.The result in this research is more definite for the physically mixed samples in the laboratory.The method described here can be employed to monitor the phytoplankton population in the marine environment.

Construction of Inorganic Elemental Fingerprint and Multivariate Statistical Analysis of Marine Traditional Chinese Medicine Meretricis concha from Rushan Bay

Meretricis concha is a kind of marine traditional Chinese medicine(TCM), and has been commonly used for the treatment of asthma and scald burns. In order to investigate the relationship between the inorganic elemental fingerprint and the geographical origin identification of Meretricis concha, the elemental contents of M. concha from five sampling points in Rushan Bay have been determined by means of inductively coupled plasma optical emission spectrometry(ICP-OES). Based on the contents of 14 inorganic elements(Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Se, and Zn), the inorganic elemental fingerprint which well reflects the elemental characteristics was constructed. All the data from the five sampling points were discriminated with accuracy through hierarchical cluster analysis(HCA) and principle component analysis(PCA), indicating that a four-factor model which could explain approximately 80% of the detection data was established, and the elements Al, As, Cd, Cu, Ni and Pb could be viewed as the characteristic elements. This investigation suggests that the inorganic elemental fingerprint combined with multivariate statistical analysis is a promising method for verifying the geographical origin of M. concha, and this strategy should be valuable for the authenticity discrimination of some marine TCM.

Inorganic Elemental Determinations of Marine Traditional Chinese Medicine Meretricis concha from Jiaozhou Bay:The construction of Inorganic Elemental Fingerprint Based on Chemometric Analysis

The goal of this paper is to explore the relationship between the inorganic elemental fingerprint and the geographical origin identification ofMeretricis concha, which is a commonly used marine traditional Chinese medicine （TCM） for the treatment of asthma and scald bums. For that, the inorganic elemental contents ofMeretricis concha from five sampling points in Jiaozhou Bay have been determined by means of inductively coupled plasma optical emission spectrometry, and the comparative investigations based on the contents of 14 inorganic elements （A1, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Se and Zn） of the samples from Jiaozhou Bay and the previous reported Rushan Bay were performed. It has been found that the samples from the two bays are ap- proximately classified into two kinds using hierarchical cluster analysis, and a four-factor model based on principle component analysis could explain approximately 75% of the detection data, also linear discriminant analysis can be used to develop a prediction model to distinguish the samples from Jiaozhou Bay and Rushan Bay with accuracy of about 93%. The results of the present investi- gation suggested that the inorganic elemental fingerprint based on the combination of the measured elemental content and chemom- etric analysis is a promising approach for verifying the geographical origin ofMeretricis concha, and this strategy should be valuable for the authenticity discrimination of some marine TCM.

Influence of Interference Fit and Surface Roughness on Contact Resistance of Tubing Connections

Within offshore installations, making tubing connections conduct electricity is a developing interest. Being able to use tubing structures to carry the drive power needed downhole avoids installation of cables and lines. The challenge is making the connection good enough with minimum possible power loss. At the same time, the connection has to secure the transfer of the rated power without any danger of overheating. An overheating can eventually result in a welded connection. Previous studies on contact design have mainly focused on low level contact force, while this study aims to find out the influence of surface roughness and connection strength, at macro level, on contact resistance of tubing connections so as to know the power transfer capability of the connection. First, the connection is simplified by ＂rolling out＂ the tubes to flat sheet metals and the voltage drop at rated current was measured at various loads. Then experiment was conducted on contact pairs with two different surface finish qualities and three different contact fits. The results show that smoother surfaces ease the flow of current while high interference fit increases the contact stability. The influence of surface topography becomes insignificantly low at high connection interference.

海洋中的冷光源

许多光源都是由炽热的物体发出的,如火,电灯都是。可是,在我们所生存的地球上,也有不发热而只发光的光源,这就是生物发光。人们风趣地称这种光为“冷光”。 世界上许多生物都发光,包括我们人类在内,也能发光。