Gas chromatography–mass spectrometry (GC–MS), which can separate and quantify thousands of individual petroleum biomarker compounds, is generally acknowledged as the most powerful technique for oil fingerprinting nowadays. Traditional oil fingerprint studies employ the whole suite of biomarkers measured in chromatographic analysis, which is prone to introducing ambiguous variables in the whole set and being time and labour intensive. To extract the most representative and meaningful indicators for the oil fingerprinting and identification, this paper proposes a method based on principal component difference to select a simplified set of biomarkers, providing the possibility of faster elution and analysis procedures. For the purpose of further verifying the reliability and accuracy of our method, identification simulation experiments including principal component analysis (PCA) spatial clustering, hierarchical clustering, and generalized regression neural network are carried out with the whole set and the simplified set of biomarkers, respectively. All the results and analyses demonstrate that the simplified set of biomarkers selected by our proposed method can achieve almost the same or even better identification results than those of the whole set of biomarkers.

Sensitivity is crucially important for surface-enhanced Raman spectroscopy (SERS) application to detect trace-level polycyclic aromatic hydrocarbons (PAHs) in the seawater. In this study, a high sensitivity three-dimensional (3-D) SERS substrate composed with syringe filter, glycidyl methacrylate-ethylene dimethacrylate (GMA-EDMA) porous material and optimal parameters (57 nm, pH 13) gold nanoparticles (AuNPs) was developed for the detection of PAHs in water. The enhancement effect and repeatability of this 3-D substrate were also explored. The Raman intensity of pyrene using 3-D SERS substrate is about 8 times higher than that of substrate only using pH 13 gold colloid solution and about 12 times higher than that of substrate using natural AuNPs and GMA-EDMA porous material, which means both the pH 13 AuNPs and the GMA-EDMA porous material are important factors for the sensitivity of this 3-D SERS substrate. Good repeatability of this optimal 3-D substrate was obtained. The relative standard deviation (RSD) is less than 8.66% on the same substrate and less than 3.69% on other different substrates. Four kinds of PAHs, i.e., phenanthrene, pyrene, benzo(a)pyrene, benzo(k)fluoranthene and their mixture, were detected at the different concentrations. Their limits of detection (LODs) are 8.3×10−10 (phenanthrene), 2.1×10−10 (pyrene), 3.8×10−10 (benzo(a)pyrene) and 1.7×10−10mol L−1 (benzo (k)fluoranthene), respectively. In addition, these four PAHs were also detected by fluorescence spectroscopy to evaluate the sensitivity of SERS technology using this optimal 3-D SERS substrate. The results showed that the sensitivity of SERS based on the 3-D SERS substrate even using the portable Raman system was closed to that of fluorescence spectroscopy. Therefore, the SERS technology using this optimal 3-D substrate is expected to be an in-situ method for the detection of environmental PAHs.

To rapidly detect polycyclic aromatic hydrocarbons (PAHs) in coastal seawater, a portable surface-enhanced Raman scattering (SERS) sensor was designed and assembled. A large number of halide ions are present in seawater, and they easily combine with gold nanoparticles, which results in a significant SERS enhancement effect for PAHs. Therefore, a mixture of a gold colloid solution and NaCl solution that forms a large number of highly sensitive SERS-active clusters was used in this study. The extinction intensity of the gold colloid solution at 785 nm-that is, the SERS excitation wavelength-was greatly increased by the addition of Cl-. The SERS sensor was applied in five different coastal environments, and six or seven types of PAHs were detected without further sample processing. The seawater samples were also analyzed using a gas chromatography-flame ionization detector (GC-FID) for comparison and confirmation of the results. Ten to 13 types of PAHs were detected by GC-FID after dehydration, purification, and concentration under nitrogen, and naphthalene was not detected because of its volatility. The SERS sensor was proven to be a suitable alarm sensor for the in-situ detection of PAHs in coastal seawater and is proposed for use as a real-time qualitative and quantitative PAH monitoring sensor in the near future based on its promising improvement in sensitivity.

Developing an accurate, rapid and economic oil source recognition method is essential for water recourses protection. Concentration-synchronous-matrix-fluorescence (CSMF) spectroscopy combined with 2D wavelet packet and probabilistic neural network (PNN) was proposed for source recognition of crude oil and petroleum products samples in this study. 2D wavelet packet was used to extract wavelet packet coefficients as the feature vectors from CSMF contour image and four algorithms, Back-propagation (BP) neural network, Radial based function neural network (RBFNN), Support vector Machine (SVM) and probabilistic neural network (PNN) were carried out for pattern recognition. With the introduction of interference factors such as weathering and sea water adulteration to the three samples from Bohai bay territory of China, the comparison about accuracy and recognition time of the four methods was discussed and the results showed that PNN network maintain the highest recognition accuracy and speed. These findings may offer potential application for oil spill recognition for unconventional oil.

Transverse stimulated Raman scattering (TSRS) is strongly generated in the third-harmonic-generation crystal potassium dihydrogen phosphate (KDP) and can even damage the KDP crystal in inertial confinement fusion drivers. In this work, a method to suppress TSRS is proposed in which the polarization control plate (PCP) is moved to a new position in the existing optical path. The proposed method can suppress TSRS significantly and doubles the laser threshold intensity in KDP crystal when the order of the PCP is 16. This result is attributed to the reduction of the gain length for the Stokes radiation. The proposed method may also be used to suppress other nonlinear effects, including transverse stimulated Brillouin scattering in large-aperture optical components.

Suppression of stimulated rotational Raman scattering (SRRS) is essential for the effective long-distance transmission of high-intensity laser pulses in air. In this work, a method for SRRS suppression is proposed based on the reconstruction of the initial laser pulse via subpulse stacking. The proposed method can suppress SRRS significantly and doubles the threshold distance when the initial laser pulse is stacked using 30 subpulses; this capability is attributed to the mutually perpendicular polarization directions of the adjacent subpulses. Additionally, the SRRS gain decreases even further if different phases are added to adjacent subpulses. This pulse stacking scheme also has potential for use in the suppression of other nonlinear effects, including transverse stimulated Raman scattering and transverse stimulated Brillouin scattering in large aperture optical components. There may be some difficulties in the implementation of such a scheme, and the energy losses that occur during the stacking process may even be greater than the losses due to SRRS, but we believe that the proposed method can serve as an inspiration for SRRS suppression scheme design.

Oil spills occur every day worldwide. It is urgently required to develop a rapid, cost-effective, accurate, easy to use routinely fingerprinting technique which could offer decision-makers and model developers the preliminary information of spilled oils in a short period. In this paper, a species identification and concentration quantification technique using partial surface fitting method to concentration-synchronous-matrix-fluorescence (CSMF) spectra was introduced. In order to eliminate the errors due to concentration uncertainty, partial CSMF spectra in the small concentration range of the test oil spill samples were obtained, and for the oil spill candidate samples,the two-dimensional cubic convolution interpolation was used to make up the long interval of the concentration level. With the surface fitting of partial CSMF spectra of the test samples and the closely-related source crude oil samples were successfully discriminated, and the initial concentration of the test samples were also obtained. Cross validation results of the petroleum related sample set showed that the accuracy of the matching results was 92%. The parameters of this method were also discussed in detail. All results showed that this newly-developed method may become a more specifically applicable means in spilled oils identification.

The Lishui sag located at Southwest of the East China Sea Shelf Basin. It had undergone the four stages of syn-rift processes in Late Cretaceous to Paleocene: initial rift stage, main rift stage, stable rift stage and decline stage. The tectonic evolution has control effect on the development of sequence stratigraphy and the sediments distribution. Three second-order sequences, five third-order sequences and twelve system tracts are distinguished. Different sedimentary facies recognized in the Lishui sag.

A surface‐enhanced Raman scattering (SERS) active substrate for the detection of polycyclic aromatic hydrocarbons (PAHs) was developed, which used 25, 27‐dimercaptoacetic acid‐26, 28‐dihydroxy‐4‐terbutyl calix[4]arene (DMCX) to functionalize a gold colloid film. This SERS‐active substrate prepared by self‐assembly method exhibits a high sensitivity, especially for the detection of PAHs. With the use of this SERS‐active substrate and with the application of the shifted excitation Raman difference spectroscopy (SERDS) technique, Raman signals of pyrene and anthracene in aqueous solutions at low concentration level (500 pM) can be obtained. Moreover, because PAHs are blocked from being directly adsorbed on gold colloid by DMCX and the photochemical reactions of adsorbates are avoided, the Raman bands of PAHs adsorbed on DMCX‐fuctionalized gold colloid film can be one‐to‐one correspondence with those of solid PAHs, and additionally, this SERS‐active substrate can be easily cleaned and reused. The obtained results demonstrate that the DMCX‐functionalized gold colloid films prepared by self‐assembly method have great potential to be developed to an in situ PAHs detection substrate. Copyright © 2012 John Wiley & Sons, Ltd.

In this paper, a new method was developed to differentiate the spill oil samples. The synchronous fluorescence spectra in the lower nonlinear concentration range of 10(-2) - 10(-1) g x L(-1) were collected to get training data base. Radial basis function artificial neural network (RBF-ANN) was used to identify the samples sets, along with principal component analysis (PCA) as the feature extraction method. The recognition rate of the closely-related oil source samples is 92%. All the results demonstrated that the proposed method could identify the crude oil samples effectively by just one synchronous spectrum of the spill oil sample. The method was supposed to be very suitable to the real-time spill oil identification, and can also be easily applied to the oil logging and the analysis of other multi-PAHs or multi-fluorescent mixtures.

中国大量的文物因为种种原因而流失境外,因为流失的原因和方式众多,应通过多元化的追索途径,综合运用法律途径、外交途径和国际商业途径,最大限度实现流失文物的回归.

中国大量的文物因为种种原因而流失境外,应通过多元化的追索途径,综合运用法律途径、外交途径和国际商业途径,最大限度实现流失文物的回归。并应建立我国境外文物追索制度,发挥政府职能,建立专门的文物追索机构,制定国内立法,加强国际合作。

中国大量文物因种种原因而流失境外,学者对通过商业回购途径进行追索观点不统一。合理运用商业回购方式,运用国家重点珍贵文物征集专项经费征集、加强政府职能、促进国际合作并动员社会力量,最大限度实现流失文物的回归。

<正>我国是劳动力人口大国,对外劳务输出应该具有极大的发展空间。但由于种种原因,我国对外劳务输出存在诸多问题,严重阻碍了对外劳务输出的发展。

美国1930年关税法案中的337条款是美国贸易法的一条独特的条款,作为中国最重要贸易伙伴的美国,近年来频频对中国产品适用“关税法337条款”,使其成为影响中国企业出口的又一严重壁垒。对于国内企业来说,应对美国“337条款”已成为一项迫切的任务。

Mini-Trjal(微型审判程序),最早出现在美国,是ADR方式中的一种,主要用于解决公司之间的争议.与传统的诉讼程序相比,Mini-Trial可以更灵活地解决争议,体现当事人的意思自治,更为快捷地解决争议,并降低讼诉成本,减少费用支出,更有利于企业商业信誉的保护.

近两年,绿色壁垒出现了新的发展态势。特别是日本于2006年5月开始施行的“肯定列表制度”对山东半岛的农产品出口产生一系列不利影响。要规避这些不利影响,应正确认识和对待“肯定列表制度”,鼓励出口企业建立“公司+基地+标准化”的管理模式,同时应加强行业协会自律和政府管理调控职能,提高我国国内农药、兽药的检测技术与设备水平。

山东省是农业大省,也是农产品出口大省,2005年农产品出口69.1亿美元,占全国农产品出口的25.4%,连续多年居全国第一位.

乌拉圭回合后,贸易保护主义走向更为隐蔽的方式--绿色壁垒.特别是近两年,绿色壁垒出现了新的发展态势.如发达国家绿色壁垒标准提高、限制增加,出现了绿色壁垒的仿效效应,强制性技术标准增加等.

<正>海外投资保险制度(Overseas In-vestment Insurance scheme)又称为海外投资保证制度(Investment guaranty program),指资本输出国政府对本国海外投资者在国外可能遇到的政治风险提供保证或保险,投资者向本国投资保险机构申请保险后,若承保的政治风险发生,致