三江平原中东部沼泽湿地形成及其演化趋势的探讨

三江平原中东部是沼泽湿地集中连片分布地区。研究区有阶地沼泽和河漫滩沼泽两大类型沼泽分布,进一步可划分为4个沼泽体,即小叶章（Calamagrostis angustifolia）—毛苔草（Carex lasiocarpa）沼泽;毛苔草沼泽;睡菜（Menyanthes trifoliata）—水木贼（Equisetum limosum）沼泽;漂筏苔草（Carex pseudocuraica）—毛苔草沼泽。研究区沼泽湿地形成的主要自然因素为：①新构造运动的大面积沉降;②地势低平,坡降平缓、河道变迁,复杂的微地貌,易于积水,促使沼泽湿地的大面积形成;③厚3～17m的第四纪粘土层沉积地表,使地表渗透性差;④气候因素,研究区处于温带大陆性湿润季风气候区,雨量集中于夏季,且多秋雨,冬季积雪深度大,封冻期长,季节性冻土层厚;⑤水文因素,河流比降小,糙率大,流速缓,多为沼泽性河流,春汛与夏汛之间只出现平水不出现枯水,洪水期间,洼地和河流受松花江、黑龙江等大河、大江的洪水顶托,研究区的承泄条件差,内水不能外排,长期积蓄地表。目前研究区沼泽有变干的趋向。     

Design and Application of the Annual Report of Globally Important Agricultural Heritage Systems (GIAHS) Monitoring

Scientific and effective heritage monitoring can not only realize the conservation of the heritage itself and the maintenance of its values, but it can also realize the sustainable development of the heritage site. In order to promote the conservation and management of Globally Important Agricultural Heritage Systems (GIAHS), this study proposed a design for the annual report of GIAHS monitoring under the overall framework of the GIAHS monitoring system, and explored the application of the annual report in the first GIAHS site in China: the Qingtian Rice-Fish Culture System. In the design scheme of this study, the GIAHS annual monitoring report is composed of 24 monitoring items, with each of them logically related. It is to be filled in by the bureaus of the heritage site and reported through the GIAHS dynamic monitoring system. The results of an analysis of the annual reports of Qingtian Rice-Fish Culture System for four years showed that Qingtian County has taken a series of conservation and development measures which have reduced the area of abandoned paddy, enhanced the unit benefit of agri-products, and increased the farmers’ income. At the same time, the heritage site is faced with various challenges and threats, such as the weakening of the tourism attraction, the aging of the heritage practitioners, and the limitation of the heritage-themed agri-products and tourism income, which need to be addressed with proper measures. The results can also provide guidance for other GIAHS based on indications that heritage sites should improve the development of cultural products, the construction of social organization and the cultivation of spontaneous publicity, and an exchange and learning mechanism should be established among them in the future. The design and application of the GIAHS annual monitoring reports can not only provide specific guidance for conducting the GIAHS monitoring, but also lay the foundation for evaluating the effectiveness of GIAHS conservation and management. This study is expected to help enrich the theory of GIAHS monitoring, further promote China’s GIAHS monitoring work, and also provide China’s experience for the benefit of international GIAHS monitoring efforts.     

三河-平谷8.0级地震区浅层三维密度结构反演研究

为研究三河-平谷地震区浅层构造背景、地震孕育机理及地震与构造的关系,利用高精度重力异常数据,采用基于块体生长模式的重力三维反演算法对地震区浅层三维密度结构进行反演,并通过模拟试算验证基于块体生长模式反演方法的有效性和稳定性。高精度布格重力异常显示,三河-平谷8.0级地震位于大兴重力局部高、三河-马坊重力局部高与大厂重力低之间的交汇过渡低值区域。研究区浅层三维密度结构反演结果表明,1679年三河-平谷M8.0地震明显受NE向夏垫断裂控制,断裂两侧密度差异明显且向下延伸约10 km,推测发震部位深约10 km。     

甘肃敦煌西湖荒漠湿地植物群落物种多样性特征研究

 基于375个样方和150条样线的调查,对甘肃敦煌西湖荒漠-湿地生态系统植物群落物种多样性进行了研究。结果表明:①区内共记录植物26种,分属16科24属,芦苇（Phragmites australis）、多枝柽柳（Tamarix ramosissima）和胡杨（Populus euphratica）为绝对优势种,苏枸杞（Lycium ruthenicum）、疏叶骆驼刺（Alhagi sparsifolia）和胀果甘草（Glycyrrhiza inflata）为主要伴生种,其平均重要值依次为0.4728、0.4563、0.4342、0.2908、0.2594和0.2455。植物群落分多枝柽柳群落、胡杨群落、胀果甘草群落、疏叶骆驼刺群落、多枝柽柳沙包群落、苏枸杞群落、芦苇沼泽群落和芦苇群落8个类型。②植物群落物种多样性指数偏低（0.784～1.379）,多枝柽柳群落、胡杨群落和芦苇群落物种多样性指数最大（1.379、1.266和1.194）,群落之间差异显著（P＜0.05）;疏叶骆驼刺群落和苏枸杞群落次之（1.154、1.077）,胀果甘草群落、芦苇沼泽和多枝柽柳沙包群落最低（0.919、0.881、0.784）,各群落之间不存在显著差异。③灌（乔）木层是敦煌西湖植被主要层次,灌（乔）木层物种多样性指数（0.549～1.077）大于草本层（0.052～1.038）。④物种多样性指标H′、D、J和Ma随海拔梯度增加基本均显下降趋势,而指数C变化趋势则相反,表现为上升,均匀度指数变化幅度不显著。⑤物种多样性指标H′、D、J和Ma随经纬度升高变化趋势基本一致,均表现为先下降,后上升,再下降,而优势度指数C变化趋势则相反。     

阻燃级氢氧化镁制备过程中表面有机化改性

文章通过论述阻燃剂型氢氧化镁制备过程中的表面有机化改性,对改性剂、作用机理和改性工艺等进行了探讨,说明了对阻燃剂型氢氧化镁表面有机化改性的重要性,及在氢氧化镁制备过程中综合分析、系统研究的必要性。     

事件旅游对新疆旅游业的影响分析

事件旅游给区域旅游业发展带来了一系列积极或者消极的影响,正确分析和评价事件旅游的影响,有利于发现事件旅游的影响规律并提出相应的管理办法。使用1986-2007年的新疆旅游统计数据,利用旅游本底趋势线模型分析旅游危机事件和旅游节庆事件对新疆旅游业的影响,并建立了入境旅游、国内旅游、旅游外汇收入、国内旅游收入4条本底趋势线。研究结果显示:入境旅游对事件影响比较敏感,容易形成明显的凸形峰和凹形谷,且持续时间长;新疆国内旅游受各类事件影响的程度较小,影响持续时间短;相对而言,事件对于新疆入境旅游的影响比国内旅游影响时间更长,影响程度更深。旅游本底趋势线虽属描述性模型,但在事件效应定量评估方面是个有益的尝试。     

Researches on the Internal Molecular Weight Uniformity of Chitosan Biomaterials

Uniform molecular weight(Mw)chitosan(CS)is highly demanded in medical biomaterial industry.This present article described heterogeneous degradation of CS in aqueous HCl/ethanol solution,in which progress uniform Mw CS was successfully prepared.The Mw distribution of CS was measured by gel permeation chromatography(GPC)analysis.Moreover,the structure and properties of degraded CS were characterized by Fourier transform infrared spectroscopy(FT-IR),nuclear magnetic resonance spectroscopy(^1H NMR),X-ray diffraction(XRD)and thermogravimetric(TG)analysis.In addition,the biocompatibility of degraded CS was also assessed by hemolysis rate(HR)measurement.The Mw of CS dramatically decreased from 246 KDa to 76 k Da at the initial 30 min,and stabilized at 18 kDa after 24 h.GPC analysis results showed that the degraded CS molecular become homogenization.FT-IR and 1 H NMR analysis confirmed the basic structure of CS molecular backbone was not destroyed during this progress.Besides,the water solubility of CS was not significantly influenced by this reaction.Moreover,the XRD analysis revealed that crystallinity of degraded CS increased from 70.32% to 99.25%with time.The TG analysis showed improved thermal stability of degraded CS.HR measurement demonstrated the degraded CS possessed excellent biocompatibility.This simple and efficient heterogeneous degradation would open up a new route to produce uniform Mw CS.     

Fatty Acid Composition Analyses of the DCMU Resistant Mutants of Nannochloropsis oculata (Eustigmatophyceae)

1　Introduction　Nannochloropsissp .areoneofpotentialsourcesofpolyunsaturatedfattyacids ,especiallytheeicosapen taentaenoicacid (EPA ,C2 0∶5 ) ,whichisimportantforbothanimalsandhumans .　Thefattyacidcompositionofthisalgaisaffectedbyvariousenvironmentalfactors ,suchaslightintensity(Sukeniketal.,1989;Sukeniketal.,1990 ) ,imply ingthatafactorinfluencingthephotosyntheticprocessmayaffectcellularfattyacidsynthesisandtheirmetabolism .AselectionprogramofincreasingcellularEPAcontenthasbeencarriedo…     

辽东、辽西下石炭统孢粉组合特征

辽东、辽西石炭系（地台型）发育，化石丰富，是研究我国北方石炭系及矿产的理想地区。华北缺失下石炭统早已成“定论”，但笔者通过植物化石研究证实东北南部存在早石炭世地层无疑，并建立了Ｓｕｂ－ｌｅｐｉｄｏｄｅｎｄｒｏｎ－Ａｃｈａｅｏｃａｌａｍｉｔｅｓ－Ｃａｒｄｉｏｐｔｅｒｉｄｉｕｍｓｐｅｔｓｂｅｒｇｅｎｓｅ组合带。与此同时，作者又在辽东、辽西石炭系下部采到了丰富的孢粉化石共３６属７５种，并归结为Ｌｙｃｏｓｐｏｒａｐｕｓｉｌｌａ－Ｃｒａｓｓｉｓｐｏｒａｋｏｓａｎｋｅｉ组合，时代为早石炭世晚期，即维宪－纳缪尔Ａ期。从而孢粉、植物大化石互为佐证，进一步肯定辽东、辽西存在早石炭世地层，进而改写了华北地质史的内容，并对古构造、古地理的研究具有重要意义。另外，孢粉层位还发现了丰富的叶肢介化石，这是我国石炭纪的第３处叶肢介产地，对叶肢介的起源、演化及利用多门类生物化石解决石炭系的内部界线划分积累了资料。     

变暖背景下陕西极端气候事件变化分析

利用1961-2010年陕西省78个气象观测站的逐日最高温度、最低温度、平均温度以及日降水量资料,采用趋势分析方法对该地区极端气候事件的变化进行了分析。结果表明:①近50 a来陕西降水极端事件没有显著的增减变化趋势,但存在明显的阶段性。②近50 a来区域严重干燥事件在显著增加而严重湿润事件趋于减少,2000年以后严重干湿事件均偏多,区域降水有向不均衡、极端化发展的趋势。③区域年极端高（低）温事件在近50 a来呈现显著的增加（减少）趋势,其空间分布具有较好的一致性。极端温度事件的变化在各季节存在差异,冬、春季变暖的趋势比较显著。在显著变暖的20世纪90年代以后,相对于降水极端事件,温度极端事件显现地更为突出。