积云模式在人工增雨中的应用研究   总被引：9，自引：4，他引：5  

郑淑贞  曾光平  张长安  隋平  何观芳 《气象》1999,25(2):22-27

采用胡志晋的一维时变双参数积云模式,利用福建省１９８５～１９９４年间的夏秋旱期可能出现的１２种天气类型（台风除外）对测站（福州）为主的十年旱期出现的积云降水日（Ｒ≥０．１ｍｍ）进行分类,并按１２种天气类型分别调试的结果（降水预报率达７５％以上）,经催化试验,确定福建省旱期积云降水的物理特征,人工增雨催化的方法、催化剂量和催化窗口,得到了一些有意义的结果,并根据催化试验的结果采用ＮＤＰ－ＦＯＲＴＲＡＮ和ＢＯＲＬＡＮＤＣ＋＋交互使用的方法,将云模式业务化成人工增雨指挥系统中的积云模式分系统,该系统可以进行旱期积云降水预报,人工增雨效果检验和作业方法的选择。  相似文献   

GENEBANKS: A GLOBAL PAYOFF*     

Nigel J. H. Smith 《The Professional geographer》1987,39(1):1-8

The number of crop genebanks, designed to conserve crop genetic resources and make them available to breeders, has risen dramatically in recent years. While few dispute the need to conserve crop germplasm to help boost and sustain agricultural productivity, the role of genebanks and their global distribution has become embroiled in controversy. Some suggest that genebanks are servicing mainly multinational seed companies and that industrial countries harbor the lion's share of crop germplasm collections. This article describes the importance of genebanks, analyzes their distribution and beneficiaries, and outlines how geographers can become more involved in the conservation and use of crop genetic resources.  相似文献   

马氏珠母贝早春育苗,缩短母贝养成期试验     

陈兆和  周庆堂  何水养  王忠 《广东海洋大学学报》1989,(Z1)

在室内人工飼养马氏珠母贝亲贝,进行早春育苗。比常规生产育苗提前二个月。生长快,贝体健壮,经养殖18个月长至壳高7.1厘米,体重52克。60％以上达施术贝标准,相当于常规生产贝苗26个月的生长水平。相对地缩短了养殖周期,提高了经济效益。且设备简单,操作方便,利于推广。  相似文献   

GIS支持下的复杂地形区冬小麦长势遥感监测方法   总被引：6，自引：2，他引：4  

陈怀亮  关文雅  邹春辉  尚红敏 《气象》1998,24(8):21-25

不同的地形,地貌和气候生态系统对小麦生长发育影响很大,也限制了小麦长势卫星遥感监测的精度。在分析豫西半山丘陵区不同地形（河川、丘陵）和气候生态条件（水热条件）对小麦生长影响的基础上,基于ＥＰＰＬ７地理信息系统（ＧＩＳ）,采用扫描、数据格式转化,建立数据库等方法,将ＮＯＡＡ／ＡＶＨＲＲ遥感资料和地形图,土壤图,年降水量图,年平均气温图,政区图等图件集成起来,并进行了监测区分层;根据系统监测和抽样调查  相似文献   

Effect of rhizobia inoculation on the seed (herbage) production of mungbean (Phaseolus aureusRoxb.) grown at Uzbekistan     

N.A. Provorov  U.B. Saimnazarov  I.U. Bahromov  D.Z. Pulatova  A.P. Kozhemyakov  G.A. Kurbanov 《Journal of Arid Environments》1998,39(4):569-575

In field trials conducted at Uzbekistan, inoculation of mungbean (Phaseolus aureusRoxb.) with commercial strain CIAM1901 ofBradyrhizobiumsp. (Phaseolus) increased (on average for two cultivars) the herbage mass by 46·6±6·0%, seed mass by 39·2 ± 3·6%, mass of 1000 seeds by 16·0 ± 0·8%, nitrogen content in seeds by 58·3 ± 8·9%, starch content in seeds by 30·0 ± 5·5% and number of nodules by 254%. Inoculation with this strain produced the same herbage (seed) mass as NH₄NO₃application (120 kg ha⁻¹of N), while the combined treatment of rhizobia and 60 kg ha⁻¹of N produced significantly higher yields than rhizobia inoculation alone or application of 120 kg ha⁻¹of N. The rhizobia strain M11 was isolated from Uzbekistan soils and significantly exceeded the commercial strain CIAM1901 in its influence on herbage mass by 3·9–10·6%. Two-factor analysis of variance demonstrated that the herbage mass and number of nodules are controlled mainly by the rhizobia strain genotypes, while seed yield, number of pods, mass of 1000 seeds and N and starch content in seeds are influenced by the plant cultivar genotypes.  相似文献   

Germination ofAcacia origena,A. pilispinaandPterolobium stellatumin response to different pre-sowing seed treatments, temperature and light     

Demel Teketay 《Journal of Arid Environments》1998,38(4):551-560

Seeds ofAcacia origena,A. pilispinaandPterolobium stellatumhave a hard seed coat that hampers imbibition of water and prevents maximum, uniform and rapid germination. Therefore, the seeds were subjected to different treatments involving mechanical scarification, concentrated sulphuric acid and boiling water to break the dormancy imposed by the hard seed coat. To determine the effects of different constant temperature regimes on germination, scarified seeds were incubated on a thermogradient at 10, 15, 20, 25 and 30°C. Germination of scarified seeds was also tested in light and dark. Mechanical scarification resulted in 100% germination for theAcaciaspecies and 94% forP. stellatum. ForA. origena, sulphuric acid treatments for 60, 90 and 120 min resulted in significantly higher per cent germination (>95%) than all the other treatments. ForA. pilispina, sulphuric acid treatments for 45 and 60 min, as well as immersing seeds for 1 min in hot water, gave significantly higher per cent germination (97%) than all the other treatments. ForP. stellatum, mechanical scarification and all the acid treatments applied resulted in significantly higher per cent germination (>85%) than the control and all hot water treatments. All seeds ofP. stellatumimmersed in hot water, even for 1 min, rotted soon after sowing, indicating that they are sensitive to high temperatures. Scarified seeds of the twoAcaciaspecies germinated to a higher degree (≥90%) between 10 and 30°C, while germination of scarified seeds ofP. stellatumranged from 48 to 82% between 10 and 30°C. Scarified seeds of the three species germinated to a large extent (>70%) both in light and dark, indicating that seeds do not require light for germination.  相似文献   

Water requirements for germination and early seedling establishment in four African savanna woody plant species   总被引：1，自引：0，他引：1  

T.B. Wilson  E.T.F. Witkowski 《Journal of Arid Environments》1998,38(4):541-550

The aim of this study was to determine the water requirements for germination and early seedling establishment of four African savanna tree species, namelyAcacia karroo, A. nilotica, A. tortilisandMundulea sericea. The acacias are characteristic of nutrient-rich, andM. sericeaof nutrient-poor savannas. Imbibition times of scarified seeds ofA. karroo(4 h),M. sericea(6 h) andA. tortilis(8 h) were rapid relative toA. nilotica(28 h) and were inversely correlated with seed size. Imbibed water is lost in about 2 h after drying at 25°C for all species exceptA. nilotica(only 70% moisture loss). Seeds ofA. karrooandM. sericeakept at 40°C dried to below their original moisture contents within 2 h. Seeds ofA. niloticaandA. tortilisdried at 40°C lost viability relative to (undried) control seeds, while there was no significant loss of viability forA. karrooandM. sericea. For fully imbibed seeds to germinate in sandy savanna soils, all four species required at least the equivalent of 3 mm rainfall every 2 days under mild greenhouse conditions. However, most ungerminated seeds were still viable despite drying-out from a fully imbibed state. Maintenance of soil at 50% field capacity (FC), or watering to FC every 9th day is the maintenance requirements for 2-week-old seedlings ofA. niloticaandM. sericeato continue growth for a further 5 weeks under greenhouse conditions, althoughA. niloticamostly survived 25% FC with one seedling surviving 12·5% FC. Root penetration was rapid in sandy soils, withA. niloticaandM. sericeaattaining a depth of 40 cm within 15 days. Frequent, but not necessarily high, rainfall appears to be essential for germination and seedling survival over the first 7 weeks.  相似文献   

A preliminary study on vegetation-erosion dynamics and its applications   总被引：5，自引：0，他引：5  

WANG Zhaoyin    WANG Guangqian  LI Changzhi & WANG Feixin . Department of Hydraulic Engineering  Tsinghua University  Beijing  China  . International Research  Training Center on Erosion  Sedimentation  Beijing  China 《中国科学D辑(英文版)》2005,48(5):689-700

The development of vegetation in mountainous and hilly areas depends on the local climate, precipitation, soil texture, parent material, topography, soil erosion, types of land use and human activities. Among them, soil erosion is an important natural factor and impacts the vegetation development directly and indirectly, changing the morphology and even changing the cli-mate. An erosion-induced efflux of carbon is about 1.14 billion tons per year totally from soil to the at-mosphere, which gen…  相似文献   

Study on the breeding technology of heterosis seedling of Laminaria and new combinations   总被引：1，自引：0，他引：1  

CHU Jiansong  LIU Tao  WANG Xiangyu  CUI Jingjin 《海洋学报(英文版)》2004,23(3):563-567

After continuous breeding gametophyte of Laminaria, then breaking protonema, heterosis seedling is got by bilineal hybridization. The result shows that the weight-increasing rate of female and male gametophyte clone cells are 14.03% and 13.87%, after 16 d crossbreeding, the rate of ovulation is up to100%; the length of juvenile sporophyte after 40 d breeding is 2-3 cm. By fanning on the sea, a hybrid combination is primarily screened.  相似文献   

花鲈人工育苗技术的研究     

张美昭  高天翔  阮树会  曲永琪  王强  苏纪宏 《中国海洋大学学报(自然科学版)》2001,31(3):339-344

利用人工培育的亲鱼所获得的受精卵 ,孵化出仔鱼 30 0万尾 ,在水温 18～ 2 0℃、微充气的培育条件下 ,使用海水小球藻、轮虫、卤虫无节幼体和不同规格的微颗粒配合饲料进行饲喂 ,经 58d培育出平均全长 2 .3cm的苗种 132万尾 ,育苗成活率高达 64.1% ,单位水体最高出苗量达 1.33万尾 / m3;另外 ,还有 1.3～ 1.9cm的苗种 68万尾  相似文献