首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 720 毫秒
1.
1IN T R O D U C T IO N As a risingindustry,modern logisticpslaya vitalrolein thedevelopment ofurban economy . Meantime , many expertsin theworld are interestedin modern logistic.s Study on modern logisticsismostly focused on man - agement and program (HES…  相似文献   

2.
1IN T R O D U C T IO N Urban tourismisa broad concept includingallkindsof recreationaalctivitietshattakeplaceincitie.s With the development of post-industrializat,i oncomprehen sive strengthofcitieshas been enhanced, and theimprove- ment of urban environm…  相似文献   

3.
1IN T R O D U C T IO N The western China isfacinggrowing problems of eco- logicaland economic development. The disparitiebse- tween the socio-economy of the western and eastern China were enlarging, and the major ecologicalprob- lems stilelvolve as past(H…  相似文献   

4.
1IN T R O D U C T IO N Many kindsofareaswith specialeconomic privilege—s liketherighttoraiselower taxes—have been established sincethe16th century. Sincethe1960s,a varietyofnew models have developed, and theirimportancehas risen on a globalscale. The wo…  相似文献   

5.
Land desertification isone ofthe m ajorissuesofw orld-w ide concern and considerable am ount of research onthis subject has been carried out at hom e and abroad(D O N G and LIU , 1993a; 1993b; H O U ER O U ,1996;ZH A and G A O ,1996),especially the com m …  相似文献   

6.
1IN T R O D U T IO N The dry-hotvalleyisone of the unique physiographic typesinSouthwest China, which ischaracterizedby its dry and hot climate, Savanna-likevegetationand its sharp contrastwith the surrounding landscape units (ZHANG ,1992 ).The dry-hotval…  相似文献   

7.
1IN T R O D U C T IO NDue to acceleratingurban sprawl and suburbanizatio,nlargeareaoffarmlandwere changed intonon-agricultur-allanduse sincethelate1990s,especiallyinSouth Chi-na.Meanwhile some villageswere surrounded by urbanbuilt-upareasand became"thevillagesin urban area",which arenamed hereas"urban villages."Specificallyindefinitio,nurban villageisa ruralcom munity inurbanbuilt-upareasbecause of drasticurban sprawl,subur-banizationand industriadlispersion.A nd inrealityur-ban villagee…  相似文献   

8.
1IN T R O D U C T IO NUrban green spaces can be consideredas the outdoorplacesintheurban covered with significanatmounts ofvegetation,naturalor manmade,as opposed to areasthatare paved or having buildingon them(JIM andC HEN,2003;SHIVANAND and SUZANA,2005)…  相似文献   

9.
A medium-sized delesseriaceous red alga has been collected from the subtidal area of the northern Huanghai Sea coast. The characteristics of the specimens precludes their being placed in any genus defined by the currently accepted criteria. Tsengiella gen. nov., with T. spinosa sp. nov., as the type and only known species, is created and allied with the Hypoglossum group of-the Delesserioideae (Delesseriaceae, Ceramiales, Rhodophyta).  相似文献   

10.
This sixty-day study was performed to determine the effects of short-term starvation and refeeding cycles on growth, feeding performances and body composition of rainbow trout(O ncorhynchus mykiss). Three hundred trout fingerlings with an average initial weight of 17.5±0.06 g were randomly distributed in 15 circular fiberglass tanks. The fish were exposed to 5 different feeding regimes; control: continuously fed twice daily to apparent satiation; T1 : starved for 1 day and re-fed for 2 days; T2 : starved for 1 day and re-fed for 4 days; T3 : starved for 3 days and re-fed for 12 days; T 4 : starved for 4 days and re-fed for 16 days. At the end of the experiment, growth performance, feed utilization, whole body ash and moisture contents were not significantly(P 0.05) different among the treatments. However, whole body protein content in T3 was significantly higher than other treatments(P 0.05). A significant difference in whole body fat content was observed between T3 and the control group at the end of the experiment(P 0.05). In conclusion this experiment suggests that feeding schedules involving starvation(1–4 days) and re-feeding cycles are a promising feed management tool for rainbow trout culture.  相似文献   

11.
1IN T R O D U C T IO NU rbanizationand eco-environment coupling is uniqueand complex,and itsmechanisms and ruleshave pro-voked much scholarship(B RENNA,1999).More than100yearsago,HOWARD(1898)publishedG ardenC ities of Tom orrow to revealthe interrelationshibpes-tween citygrowth and itseco-environment,and he triedtodealwiththeissuewithrationalplanningway,buthefailed(BOURNE and SIMMONS,1978).However,onlysincethe1920s had thetopicspeciallybeen intensfiied.AftertheChicago schoolhad…  相似文献   

12.
1IN T R O D U C T IO NAs we allknow,China isa countrywith vastpopulationand scarcelandpercapita(Y ANG and LI,2000)."T rea-suringlandverymuch,utilizinlgandrationallaynd pro-tectingthe cultivatedland conscientiously"is funda-mental statepolicyofChina.At the…  相似文献   

13.
Causes and control countermeasures of eutrophication in Chaohu lake,China   总被引：3，自引：0，他引：3  
1 IN T R O D U C T IO NC haohu Lake,located in the centralA nhuiProvince ofC hina, has m ultiple functions of flood control, w atersupply,irrigation,transportation,fishery and tourism .Itis fam ous for its beautifullandscape and historic sites.For thousan…  相似文献   

14.
1IN T R O D U C T IO N Timely up-gradatnig ofurban landuse and landcoverin- formationisessentialforurban environmentalmonitor- ing,planningand management purposes.Traditionall,y fieldsurveyand visualinterpretatiofnrom aerialphotog- raphy areprimary ways t…  相似文献   

15.
1IN T R O D U C T IO NThe concept ofthecorridorhas a long historyintheur-ban and regionalresearch.Because of itsgreatimpor-tanceand impacts,researchon corridors has receivedgrowing attentionof geographers.Studieshave rangedfrom the theoreticaulnderpinning…  相似文献   

16.
1IN T R O D U C T IO N With therapiddevelopment of urbanizatio,nurban land was exploitedand utilizetdoform differendtomains be- ing subjectto many potentialpollutionsourcessuch as vehicleemission, industrialactivitieasnd household garbage.Particularl, yur…  相似文献   

17.
Soil organic carbon (SOC) was considered to be a key index in evaluation of soil degradation and soil C sequestration. To discuss the spatial-temporal dynamics of SOC in arable layer in reversed desertification area, a case study was conducted in Yulin City, Shaanxi Province, China. Data of SOC were based on general soil survey in 1982 and repeated soil sampling in 2003. Soil organic carbon content (SOCC) was determined by K2Cr3O2-FeSO4 titration method, and soil organic carbon density (SOCD) was calculated by arithmetic average and area weighted average method, respectively. On average, SOCC and SOCD of the arable layer in the study area from 1982 to 2003 had increased 0.5 Ig/kg and 0.16kg/m2, respectively. Considering main soil types, the widest distributed Arid-Sandic Entisols had lowest values and increments of SOCC and SOCD during the study period; while the second widest Los-Orthic Entisols had higher values and increments of SOCC and SOCD, compared to the mean values of the whole region. The results indicated that reversed desertification process was due to the modification of land use and management practices, such as natural vegetation recovery, planting grass, turning arable land to grassland, and soil and water conservation etc., which can improve SOCC and SOCD and thus enhance soil C sequestration.  相似文献   

18.
1 IN T R O D U C T IO NZhaoyuan C ity, located in northeast of ShandongProvince,iscalled "G old C ity"and itisone ofim portantgold production bases in C hina.The exploitation ofthegold broughtoutthe extensive vacantareas,leading tolarge-scale ground subsi…  相似文献   

19.
Two new species of the genus Tinocladia Kylin, T. gracilis sp. nov. and T. microsporangii sp. nov,, are described. T. gracilis is characterized by its slender frond, variable size, infrequently branched medullary filaments, and short assimilating filaments with 2 - 7 cells. T. microsporangii is characterized by its medullary cells which are slightly larger than sub-cortical ones; narrow sub-cortical layer, usually consisting of 4- 6 cells and very small unilocular sporangia. The holotypes are deposited at the Herbarium of the Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.  相似文献   

20.
1IN T R O D U C T IO NCO2emissionfrom soiltoatmosphere,which isim por-tanttocontributetothecarbon balanceof ecosystem,isone of the largestfluxes in the global carbon cycle(SCHLESINGER and ANDREWS,2000).Further-more,thechange of CO2emission from soil,as a …  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号