|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | Monitoring the impact of climate change and human activities on grassland vegetation dynamics in the northeastern Qinghai-Tibet Plateau of China during 2000–2015显示文摘Climate change and human activities can influence vegetation net primary productivity(NPP), a key component of natural ecosystems. The Qinghai-Tibet Plateau of China, in spite of its significant natural and cultural values, is one of the most susceptible regions to climate change and human disturbances in the world. To assess the impact of climate change and human activities on vegetation dynamics in the grassland ecosystems of the northeastern Qinghai-Tibet Plateau, we applied a time-series trend analysis to normalized difference vegetation index(NDVI) datasets from 2000 to 2015 and compared these spatiotemporal variations with trends in climatic variables over the same time period. The constrained ordination approach(redundancy analysis) was used to determine which climatic variables or human-related factors mostly influenced the variation of NDVI. Furthermore, in order to determine whether current conservation measures and programs are effective in ecological protection and reconstruction, we divided the northeastern Qinghai-Tibet Plateau into two parts: the Three-River Headwater conservation area(TRH zone) in the south and the non-conservation area(NTRH zone) in the north. The results indicated an overall(73.32%) increasing trend of vegetation NPP in grasslands throughout the study area. During the period 2000–2015, NDVI in the TRH and NTRH zones increased at the rates of 0.0015/a and 0.0020/a, respectively. Specifically, precipitation accounted for 9.2% of the total variation in NDVI, while temperature accounted for 13.4%. In addition, variation in vegetation NPP of grasslands responded not only to long-and short-term changes in climate, as conceptualized in non-equilibrium theory, but also to the impact of human activities and their associated perturbations. The redundancy analysis successfully separated the relative contributions of climate change and human activities, of which village population and agricultural gross domestic product were the two most important contributors to the NDVI changes, explaining 17.8% and 17.1% of the total variation of NDVI(with the total contribution >30.0%), respectively. The total contribution percentages of climate change and human activities to the NDVI variation were 27.5% and 34.9%, respectively, in the northeastern Qinghai-Tibet Plateau. Finally, our study shows that the grassland restoration in the study area was enhanced by protection measures and programs in the TRH zone, which explained 7.6% of the total variation in NDVI. | XIONG Qinli XIAO Yang Marwa Waseem A HALMY Mohammed A DAKHIL LIANG Pinghan LIU Chenggang ZHANG Lin Bikram PANDEY PAN Kaiwen Sameh B EL KAFRAWAY CHEN Jun | 2019 | Journal of Arid Land2019，11，5： | 10 |
| 2 | NaAlSi_3O_8-hollandite and other high-pressure minerals in the shock melt veins of the Suizhou meteorite显示文摘The Suizhou L6 chondrite contains a few very thin shock melt veins of 0.02-0.09 mm in width. In spite of small width of the veins, shock-induced high-pressure phases, such as coarse-grained NaAlSi3O8-hollandite, ringwoodite, majorite and fine-grained matrix majorite-pyropess have been discovered in these veins. NaAlSi3O8-hollandite, the high-pressure phase of plagioclase, in Suizhou shock veins occurs as a single phase mineral, no silicate glassy phase, such as albitic glass, was incorporated with it. The presence of above-mentioned high-pressure phases constrains the high pressure (up to 23-24 GPa) and high temperature (up to 1900-2000℃) regime in Suizhou shock veins, and indicates that the duration of high-pressure regime in the veins should be long enough (a few seconds) for phase transformation and crystallization of minerals under pressure. The discovery of the first natural single-phase crystalline NaAlSi3O8- holland-ite in Suizhou meteorite is of important significance in understanding the Earth’ | XIE Xiande, CHEN Ming, WANG Deqiang & El Goresy A.1.Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China 2. Max-Planck-Institute fur Chemie, 55128 Mainz, Germany | 2001 | Chinese Science Bulletin2001，46，13： | 8 |
| 3 | Experimental Study on Deoxidization of Bariumand Barium Alloy显示文摘Based on the review of latest papers related to the application of barium alloy, the deoxidizationeffects of barium and barium alloy, and the dynamic characteristics of molten bath have beensystematically studied by means of the convection free bath, natural convection bath, air andvacuum induction melting experiments. It was found that both the total oxygen content andsoluble oxygen content in molten bath decreased rapidly. The results obtained provided practicaland theoretical basis for further synthetic applications of barium alloy in metallurgical industry. | Shi, YF Chen, BP Fu, J El Gammal, T | 1999 | Journal of Materials Science & Technology1999，15，5： | 4 |
| 4 | Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) supports adhesion and migration of mesenchymal stem cells and tenocytes显示文摘AIM: To establish the potential of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) as a material for tendon repair. METHODS: The biocompatibility of PHBHHx with both rat tenocytes (rT) and human mesenchymal stem cells (hMSC) was explored by monitoring adhesive characteristics on films of varying weight/volume ratios coupled to a culture atmosphere of either 21% O2 (air) or 2% O2 (physiological normoxia). The diameter and stiffness of PHBHHx films was established using optical coherence tomography and mechanical testing, respectively. RESULTS: Film thickness correlated directly with weight/volume PHBHHx (r2 = 0.9473) ranging from 0.1 mm (0.8% weight/volume) to 0.19 mm (2.4% weight/volume). Film stiffness on the other hand displayed a biphasic response which increased rapidly at values > 1.6% weight/volume. Optimal cell attachment of rT required films of ≥ 1.6% and ≥ 2.0% weight/volume PHBHHx in 2% O2 and 21% O2 respectively. A qualitative adhesion increase was noted for hMSC in films ≥ 1.2% weight/volume, becoming significant at 2% weight/volume in 2% O2. An increase in cell adhesion was also noted with ≥ 2% weight/volume PHBHHx in 21% O2. Cell migration into films was not observed. CONCLUSION: This evaluation demonstrates that PHBHHx is a suitable polymer for future cell/polymer replacement strategies in tendon repair. | Alex J Lomas George GQ Chen Alicia J El Haj Nicholas R Forsyth | 2012 | World Journal of Stem Cells2012，4，9： | 2 |
| 5 | Degradation of dye pollutants by immobilized polyoxometalate with H2O2 under visible-light irradiation显示文摘 | Lei P X Chen C C Yang J el al | 2005 | Environmental Science and Technology2005，39，21： | 1 |
| 6 | Flepeated-bateh production of kojie acid in a cell- retention fermenter using Aspergillus oryzae M3B9 显示文摘 | H M Wan C C Chen R Giridhar el al | 2005 | Ind Mierobiol Biotechnol2005，32，： | 1 |
| 7 | lnterteukin-23 rather than interleukin-12 is the critical eytokine for autoimmune inflammation of the brain显示文摘 | Cua D J Sherlock J Chen Y el al | 2003 | Nature2003，421，6924： | 1 |
| 8 | Combined anterior and pos- terior surgeries in the treatment of spinal tuberculous Spondylitis 显示文摘 | Chen W J Wu CC Jtmg CH el al | 2002 | Clin Orthop Relat Res2002，39，8： | 1 |
| 9 | A Multilevel Study of Leadership, Empowerment, and Performance in Teams 显示文摘 | Chen G Kirkman B L Kanfer R et el | 2007 | Journal of Applied Psychology2007，92，2： | 1 |
| 10 | Fusion cross-sections for inertial fusion energy 显示文摘 | Li X Z Liu B Chen S el at | 2004 | Laser and Particle Beam2004，22，： | 1 |
| 11 | Serum thymidine kinase 1 correlates to clinical stagesand clinical reactions and monitors the outcome of therapy of 1247 can-cer patients in routine clinical settings显示文摘 | Chen Y Ying M’el al | 2010 | Int J Clin Oncol2010，15，4： | 1 |
| 12 | Clinical manifestations, disease course, and complications of adult-onset Still's disease in Taiwan显示文摘 | CHEN DY LAN JL HSIEH TY el al | 2004 | Journal of the Formosan Medical Association2004，103，11： | 1 |
| 13 | Thermal comfort in natu- rally ventilated buildings in hot - humid area of China 显示文摘 | Zhang Y F Wang J Y Chen H M el al | 2010 | Build- ing and Environment2010，45，11： | 1 |
| 14 | Stress proteins and tolerance to foemd cerebralisehemia显示文摘 | Chen J Graham S H Zhu R L el a1 | 1996 | J Cereb Blood Flow Metab1996，16，4： | 1 |
| 15 | Effects of transglutaminase treatment on the thermal properties of soy protein isolates显示文摘 | Chuan-He Tang Zhong Chen Lin l i el al | 2006 | Food Research International2006，，39： | 1 |
| 16 | Optimising the preparation of activated carbon from digested sewage sludge and coconut husk显示文摘 | J H Tay X G Chen S Jeyaseelan el al | 2001 | Chemosphere2001，44，： | 1 |
| 17 | Synthe sis of Self crosslinking Water Soluble Acrylic Resin and Development of Tetracolor Superimpose Printing Inks显示文摘 | TANG Jian-xin CHEN Hong NIE Li-bo el al | 2003 | Dongnan Daxue Xuebao (Ziran Kexue Ban)/Journal of Southeast University (Natural Science Edition)2003，33，1： | 1 |
| 18 | All the right moves:How entrepreneurial firms compete effectively显示文摘 | Katila R Chen EL H Piezunka | | 0，，： | 1 |
| 19 | Post-treatment human papillomavirus status and recurrence rates in patients treated with loop electrosurgical excision procedure conization for cervical intraepithelial neoplasia 显示文摘 | Du R Meng W Chen ZF el at | 2013 | European journal of gynaeeological oncology2013，34，6： | 1 |
| 20 | Effect of environmental factors on myeelial growth of Peronophythora litchi显示文摘 | Chen L C Lai S C Lee C C at el | 1998 | Plant Pathology Bulletin1998，，7： | 1 |
您所在的机构暂未开通此部分的功能，请联系管理员