六、放珠珠

请用九粒黑珠和九粒白珠巧放在图中小三角形的顶点上，要求小三角形的两个顶点上各有一黑一白两粒珠子。现三粒黑珠子和三粒白珠子已放，另外六粒黑珠子和白珠子该如何放？

Two newly recorded species of the genus Epidamaeus(Oribatida:Damaeidae) from China

Epidamaeus variabilis Fujikawa ＆ Fujita, 1985 and Epidamaeus mongolicus Bayartogtokh, 2000 are reported, with redescription, for the first time in China.

“珠英学士”诗歌活动考论

“珠英学士”因大型类书《三教珠英》的修撰而得名。在近四年中,“珠英学士”于修书之余,“日夕谈论,赋诗聚会”,客观上造成了一个唱和赋诗、研讨诗艺的大好机会,从而形成初唐后期规模最大的一个宫廷诗人群体。作为一部当代诗选,《珠英学士集》是研究初唐宫廷诗坛状况与诗风流变弥足珍贵的第一手资料。通过“珠英学士”诗歌活动和《珠英学士集》的考察,会使我们对诗歌声律化进程与初唐宫廷诗风流变获得一些新的认识。

五彩葡萄玛瑙石

葡萄玛瑙贵在“珠圆玉润”。珠珠圆又满，质地晶莹剔透，色彩艳丽又有形，才能称之为石中极品。

助贫困地区一臂之力

当改革信息化的鼓点越来越强劲地敲击着中国教育变革之时。我们不能不将眼光投向广大农村贫困地区。在这场深刻的教育现代化变革当中，贫困地区究竟该如何行动，它将如何载信息化之“舟”。加快当地教育发展水平，正成为人们日益关注的一个焦点。为此，记者走访了教育部电教办副主任王珠珠。

FORGING ASIA′S GLOBAL TRANSPARK IN THE PEARL RIVER DELTA AT ZHUHAI

The main purpose of the paper is to introduce the concept of the Global TransPark (GTP). It is a critical time to develop air logistics infrastructure in the New Economy. The paper also presents a brief review of the air cargo industry in the Asian-Pacific region and China,in particular China’s development in the industry as its economy has grown rapidly and globalized in the past two decades. The paper argues that China needs to develop a GTP to support its future growth,and explains why the Pearl River Delta-Hong Kong-Macao city-region or Extended Metropolitan Region (EMR) is the best location. Finally,it proposes that Zhuhai Airport,one of the five airports in the EMR,is the best site for the GTP. New policies from Chinese government as well as close cooperation between local governments of Guangdong and the two Special Administrative Regions of Hong Kong and Macao will be needed to make the establishment of the GTP possible.

Predicting Potential Distribution of Tibetan Spruce (Picea smithiana) in Qomolangma (Mount Everest) National Nature Preserve Using Maximum Entropy Niche-based Model

Tibetan spruce (Picea smithiana) is an endemic species of the Himalayas,and it distributes only in a re-stricted area with very low number.To address the lack of detailed distributional information,we used maximum en-tropy (Maxent) niche-based model to predict the species' potential distribution from limited occurrence-only records.The location data of P.smithiana,relative bioclimatic variables,vegetation data,digital elevation model (DEM),and the derived data were analyzed in Maxent.The receiver operating characteristic (ROC) curve was applied to assess the prediction accuracy.The Maxent jackknife test was performed to quantify the training gains from data layers and the response of P.smithiana distribution to four typical environmental variables was analyzed.Results show that the model performs well at the regional scale.There is a potential for continued expansion of P.smithiana population numbers and distribution in China.P.smithiana potentially distributes in the lower reaches of Gyirong Zangbo and Poiqu rivers in Gyirong and Nyalam counties in Qomolangma (Mount Everest) National Nature Preserve (QNNP),China.The species prefers warm temperate climate in mountain area and mainly distributes in needle-leaved evergreen closed to open forest and mixed forest along the river valley at relatively low altitudes of about 2000-3000 m.Model simulations suggest that distribution patterns of rare species with few species numbers can be well predicted by Max-ent.

FUTURE CHANGE OF PRECIPITATION EXTREMES OVER THE PEARL RIVER BASIN FROM REGIONAL CLIMATE MODELS

Based on RegCM4,a climate model system,we simulated the distribution of the present climate(1961-1990)and the future climate(2010-2099),under emission scenarios of RCPs over the whole Pearl River Basin.From the climate parameters,a set of mean precipitation,wet day frequency,and mean wet day intensity and several precipitation percentiles are used to assess the expected changes in daily precipitation characteristics for the 21 st century.Meanwhile the return values of precipitation intensity with an average return of 5,10,20,and 50 years are also used to assess the expected changes in precipitation extremes events in this study.The structure of the change across the precipitation distribution is very coherent between RCP4.5 and RCP8.5.The annual,spring and winter average precipitation decreases while the summer and autumn average precipitation increases.The basic diagnostics of precipitation show that the frequency of precipitation is projected to decrease but the intensity is projected to increase.The wet day percentiles(q90 and q95) also increase,indicating that precipitation extremes intensity will increase in the future.Meanwhile,the5-year return value tends to increase by 30%-45%in the basins of Liujiang River,Red Water River,Guihe River and Pearl River Delta region,where the 5-year return value of future climate corresponds to the 8-to 10-year return value of the present climate,and the 50-year return value corresponds to the 100-year return value of the present climate over the Pearl River Delta region in the 2080 s under RCP8.5,which indicates that the warming environment will give rise to changes in the intensity and frequency of extreme precipitation events.

Construction of cDNA subtractive library from pearl oyster (Pinctada fucata Gould) with red color shell by SSH

The molecular basis of color polymorphism in the shells of the pearl oyster Pinctada fucata is largely unknown. We developed a red-shelled family line and used suppression subtractive hybridization （SSH） to screen for differentially expressed genes in red- and non-red-shelled pearl oysters. We constructed forward and reverse cDNA subtractive libraries consisting of 2 506 and 797 clones, respectively. Among 343 randomly selected clones in the forward library, 304 sequences were identified in GenBank using BLASTx and BLASTn. Of the 304 sequences, 13 showed no similarity to known sequences and 291 were matched with known genes of the pearl oyster, including shematrin-1, shematrin-2, shematrin-6, shematrin-7, nacrein, nacrein-like protein, aspein for shell matrix protein, glycine-rich protein, mantle gene 5, 28S, EST00031, EST00036, 16S, and COl. In the reverse library, 7 clones were sequenced and analyzed by BLAST. Two sequences shared similarity with EST00036 from the P. fucata subtraction cDNA library, four with the P. fucata mitochondrial gene for 16S rRNA and 1 with P. fucata shematrin-2. We evaluated the expression of 12 genes from the forward library using RT PCR. Two sequences matched with 16S and CO1 so were considered to be false positives. The remaining 10 sequences were differentially expression in the red-shelled pearl oysters. Our results suggest that differential expression of these genes may be related to color variation in the red-shelled family line of the pearl oyster.

Urbanization effect on precipitation over the Pearl River Delta based on CMORPH data

Based on the satellite data from the Climate Prediction Center morphing(CMORPH) at very high spatial and temporal resolution, the effects of urbanization on precipitation were assessed over the Pearl River Delta(PRD) metropolitan regions of China. CMORPH data well estimates the precipitation features over the PRD. Compared to the surrounding rural areas, the PRD urban areas experience fewer and shorter precipitation events with a lower precipitation frequency(ratio of rainy hours, about 3 days per year less); however, short-duration heavy rain events play a more significant role over the PRD urban areas. Afternoon precipitation is much more pronounced over the PRD urban areas than the surrounding rural areas, which is probably because of the increase in short-duration heavy rain over urban areas.

Effect of Green and Carbonized Mesocarbon Microbeads on Development of Carbonaceous Mesophase

Two types of mesocarbon microbeads(MCMB), one of which was green sphere and the other carbonized at 1000 ℃, were used to modify coal tar pitches, and their influences on the development of carbonaceous mesophase in coal tar pitches were investigated. Optical microscopy was used to observe the changes caused by the additives. The green MCMB could promote the growth of mesophase spheres. When the holding time at the final temperature was prolonged to 100 min, the green MCMB-modified pitch would produce excellent bulk mesophase. Carbonized MCMB prohibited the coalescence of mesophase spheres and was beneficial to forming super large mesophase spheres. In the green MCMB-modified pitch, mesophase spheres grew up using the added MCMB spheres as nuclei, i.e. the green MCMB continued to grow during heat-treatment, which accelerated the formation, growth, and coalescence of mesophase spheres. For carbonized MCMB, their active sites were passivated and they could not continue to grow. These inert spheres could aggregate around the newly-formed mesophase spheres, prohibiting the growth and coalescence of the mesophase spheres.