北雁荡山风景区的旅游气候优势

本文首先根据生理气候的研究成果，结合北雁荡山风景区环境温废的时空分布规律，论L北雁荡山风景区是较理想的避寒和避暑胜地.然后，着重研讨气候主要因子的造景功能，深入讨论了自然降水是形成北雁荡山风景区瀑布奇观的主角.从温度与降水两方面揭示北雁荡山风景区的气候优势     

The molecular structure and conformation of gaseous bis(chloromethyl)dimethyl silane as determined by electron diffraction

The molecular structure of bis(chloromethyl) dimethyl silane has been investigated in the gas phase at a nozzle temperature of 60° C. The molecules exist mainly in the GG form with the presence of 30% (+10%, ?20%) AG form. The values of the principal distances (r_a) and angles with estimated error limits of 2σ are r(C-H) = 1.093 (0.009) Å, r(C-Cl) = 1.801 (0.019) Å, r(Si-C) (the average Si-C bond) = 1.875 (0.009) Å, ∠(CSiC) = 109.5°, ∠(SiCCl) = 110.5° (0.4), ∠(CCH) = 112.5° (1.8) and φ (the gauche torsion angle relative to 0° for the anti form) = 117.4° (3.8).     

Long-term trend in aerosol optical depth from 1980 to 2001 in north China

Using the Total Ozone Mapping Spectrometer （TOMS） monthly aerosol optical depth （AOD） at 500 nm data from 1980 to 2001 in north China, the spatial and temporal variations of AOD were examined. Seasonal AODs in Taklimakan Desert were 0.69 and 0.44 in spring and summer, respectively, which were mainly due to frequent occurrences of dust events in this region. Dust activities in spring also led to high aerosol loading in Gobi Desert and in northeast China where spring AODs were 0.33 and 0.29, respectively. Heavily impacted by events such as volcano eruption, forest fires and extraordinary dust storms, AODs showed large inter-annual variations. A decreasing tendency in AOD was observed in north China during 1980-1991, though a reverse tendency was revealed during 1997-2001, especially for spring AOD in northeast China. Further study is required to figure out how much human activities have contributed to the AOD tendency in north China.     

2D unstructured mesh generation for oceanic and coastal tidal models from a localized truncation error analysis with complex derivatives

A method for computing target element size for tidal, shallow water flow is developed and demonstrated. The method, Localized truncation error analysis with complex derivatives (LTEA-CD) utilizes localized truncation error estimates of the linearized shallow water momentum equations consisting of complex derivative terms. This application of complex derivatives is the chief way in which the method differs from a similar existing method, LTEA. It is shown that LTEA-CD produces results that are essentially equivalent to those of LTEA (which in turn has been demonstrated to be capable of producing practicable target element sizes) with reduced computational cost. Moreover, LTEA-CD is capable of computing truncation error and corresponding target element sizes at locations up to and including the boundary, whereas LTEA can be applied only on the interior of the model domain. We demonstrate the convergence of solutions over meshes generated with LTEA-CD using an idealized representation of the western North Atlantic Ocean, Caribbean Sea and Gulf of Mexico.     

Plant protein-based feeds and commercial feed enable isotopic tracking of aquaculture emissions into marine macrozoobenthic bioindicator species

Brittle stars (Ophiura spp.) and other benthic macrofauna were collected in a prospective mariculture area in the North Sea to determine if these taxa could be used as indicator species to track nutrients released from future offshore aquaculture sites. We analysed natural carbon and nitrogen stable isotopic signatures in tissues from macrofauna and compared these to six feed ingredients and four experimental diets made thereof, as well as to a commercial feed with and without lipid and carbonate removal. Our data suggest practicability of using isotopic signatures of Ophiura spp. to track aquaculture-derived organic material if plant-based fish diet ingredients and commercial feed were used for fish farming in the German Exclusive Economic Zone. Diets with high fish meal content would not be detected in Ophiura spp. using isotopic measures due to the similarity with the marine background. Our data provide valuable baseline information for studies on the impact of offshore aquaculture on the marine environment.     

中国-东盟自由贸易区效应对广西和云南企业迁移作用的比较研究

对中国-东盟自由贸易区效应对广西和云南企业迁移作用进行比较研究具有重要的理论和实践意义。通过界定中国-东盟自由贸易区效应对企业迁移作用机理的研究假设,构建相应的理论模型,并以中国-东盟自由贸易区效应为潜在自变量,区域产业环境、区域产业技术、区域产业绩效为潜在的中介变量,以企业迁移为潜在的因变量,对广西和云南相关的企业作为调查对象进行问卷调查,运用结构方程模型来分析中国-东盟自由贸易区效应对广西和云南企业迁移的作用路径的差异。研究结果表明,中国-东盟自由贸易区效应对广西和云南企业迁移的作用路径相似,但对广西企业迁移的影响是通过直接和间接两方面同时进行的,而对云南企业迁移的影响则只存在间接方面,且对广西企业迁移的总体效果要高于对云南企业迁移的总体效果。     

高效液相色谱法测定北柴胡地下部分黄酮类化合物的含量

建立了高效液相色谱法测定北柴胡地下部分黄酮类化合物含量的方法。采用SepaxGP-C18色谱柱(250×4.6 mm,5μm),流动相为乙腈-0.4%磷酸(体积比35∶65),检测波长360 nm,柱温30℃,流速1.0 mL/min。结果表明,北柴胡地下部分含有槲皮素。芦丁、木犀草素、槲皮素、山奈酚、芹菜素分别在0.0050～0.0248、0.0050～0.0248、0.0051～0.0256、0.0046～0.0232、0.0054～0.0272 mg/mL范围内线性关系良好,相关系数分别为0.9957、0.9995、0.9998、0.9998、0.9998,槲皮素的平均回收率为98.34%,相对标准偏差(RSD)为0.76%。该法简便,快速,准确,重复性好,可作为北柴胡药材质量控制的方法。     

A simple oxidation procedure for biological material prior to analysis for mercury

The stability constants of aluminium(III), gallium(III), indium(III) and scandium(III) with 8-hydroxyquinoline and its 2-methyl derivative have been determined by potentiometric titration, with computation by the SCOGS program. In contrast to previous work, the results show that protonated species occur in several of the equilibria. The constants are discussed in terms of the nature of metal-to-ligand bonding in the complexes. X-ray photoelectron spectroscopy of the ligand coordinating atoms in the solid complexes confirms the significantly increased covalency of the gallium—oxygen bond compared to the same bond in the aluminium complex.     

Deposition of Sulfate,Chloride and Sodium at Japanese Meteorological Observatories and on the Western North Pacific

Abstract

A simple plastic sampler was tested to get the information on the deposition amount of chemical components throughout Japan and the neighbouring regions. Polypropylene cylinders of diameter 117 mm which contained 300ml pure water were set in the observation fields and kept open for one month. At the end of the month the samplers were covered with caps and sent to Meteorological College, Kashiwa, Chiba. The sample solutions were filtered through Millipore filter (0.45μm pore size) and used for the determination by ion chromatography, atomic absorption and flame emission analyses. Monthly deposition amounts of sulfate, chloride and sodium ions were determined simultaneously at 21 Japanese meteorological observatories in June and October 1987. Similar samples were also set on the upper deck of RV Ryofu-maru for 4–7 days during cruises across the western North Pacific in 1987 and 1988. The deposition amount of SO₄(excess) (SO₄–Na × SO₄(seasalt)/Na(seasalt)) was calculated. The strongest source regions of SO₄(excess) were found to be on the Pacific side of Honshu, where big cities such as Tokyo and Osaka are situated. The deposition amount generally decreased depending upon the distance from these sources. Another strong source region of SO₄ (excess) was Kagoshima. It is suggested that the deposition at this station was influenced by the volcanic activity of Mt. Sakurajima, because the deposition amount of Cl(excess) was also found to be high, reflecting the composition of the volcanic gases of this region.     

我国北方不同类型下垫面地表反照率特征

地表反照率反映了地面对太阳辐射的反射能力,在地表能量平衡中起着非常重要的作用,本文利用"中国北方协同观测"的资料,分析了不同下垫面10个站点7-9月的反照率变化特征和对降水的响应,并讨论了榆中、通榆草地、通榆农田、密云、玛曲和锦州站地表反照率与太阳高度角和土壤湿度的关系,结果表明:反照率的相对关系是东北干旱草甸西北高寒草甸西北绿洲农田黄土高原自然植被东北半干旱草甸东北农田东北果林,并且反照率基本上和降水对应,降水量大的站点反照率小,降水量小的站点反照率大,反照率的日变化曲线分为早晚对称型,早上比较大、中午下午比较小和晚上最大、早上最小的不对称型三种,选取的6个观测站反照率的谷值一般出现在降水日,峰值一般出现在没有降水、太阳辐射比较强的日子,地表反照率随着太阳高度角的增大而减小,当太阳高度角大于40°时,地表反照率基本不变,榆中和通榆农田地表反照率随着土壤湿度增大减小较明显,其次是通榆草地,玛曲、密云和锦州地表反照率随着土壤湿度变化不明显。