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101.
Using the data, especially the GPS rawinsode data, observed in Anduo area of the Tibetan Plateau during the intensive observation period of GAME/Tibet in 1998, the transition from the dry to the rainy season along with their boundary layer characteristics is analyzed comprehensively. The result shows that the formation of the rainy season in Anduo area is related closely to the general atmospheric circulation. The westerly belt moving north and the southeast damp current are basic conditions for development of the rainy season in Anduo area. In the dry season, the air is drier, air temperature higher, and the atmospheric boundary layer is strongly developed to cause its maximum height to reach about 3550 m. Moreover the sensible heat flux is dominant, and the latent heat flux is small in the interaction of land-atmosphere energy exchange, and a reverse humidity phenomenon occurs frequently. In the rainy season, the air is damper, air temperature lower, and the ABL height, with maximum of only about 2300 m, is lower. And the sensible heat flux becomes much smaller, the latent heat flux much larger in the interaction of land-atmosphere energy exchange. The reverse humidity phenomenon disappears.  相似文献   
102.
从发挥图书馆职能入手,阐述了学科馆员产生的必要性,通过对学科馆员的概念内涵、岗位职责、与传统参考馆员比较及我国高校图书馆学科馆员现状的分析,探讨了如何才能做好学科馆员,为读者提供优质服务。  相似文献   
103.
We develop a small model for forecasting inflation for the euro area using quarterly data over the period June 1973 to March 1999. The model is used to provide inflation forecasts from June 1999 to March 2002. We compare the forecasts from our model with those derived from six competing forecasting models, including autoregressions, vector autoregressions and Phillips‐curve based models. A considerable gain in forecasting performance is demonstrated using a relative root mean squared error criterion and the Diebold–Mariano test to make forecast comparisons. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   
104.
水色遥感理论模型探讨   总被引:4,自引:0,他引:4  
由于目前技术条件的限制 ,黑箱模型在水体组份反演的研究中占据了主导地位 ,但其理论基础不足 ,针对具体成像条件推得的黑箱模型难以推广 ,故需从水色遥感成像机理出发来研究理论模型的识别和求解。意识到辐射传输方程难以实用 ,提出基于辐射传输方程求解结论的水色遥感理论模型架构。并讨论了模型的若干影响因素。特别指出 ,应该使用传感器灵敏度积分的方法来关联传感器接收到的辐射率和灰度值数据 ,而不是简单地使用传感器在波段中心波长处接收的辐射率。  相似文献   
105.
随机多址访问协议中最优帧模式的混合遗传算法   总被引:1,自引:0,他引:1  
在随机接入协议中 ,竞争时隙与预约时隙在一帧中的相对位置 (帧模式 )对系统的吞吐量有很大的影响 .利用混合遗传算法搜索出不同业务量下的最优帧模式 ,提高了系统的吞吐量 .  相似文献   
106.
Retinitis pigmentosa (RP) comprises a clinically and genetically heterogeneous group of diseases that afflicts approximately 1.5 million people worldwide. Affected individuals suffer from a progressive degeneration of the photoreceptors, eventually resulting in severe visual impairment. To isolate candidate genes for chorioretinal diseases, we cloned cDNAs specifically or preferentially expressed in the human retina and the retinal pigment epithelium (RPE) through a novel suppression subtractive hybridization (SSH) method. One of these cDNAs (RET3C11) mapped to chromosome 1q31-q32.1, a region harbouring a gene involved in a severe form of autosomal recessive RP characterized by a typical preservation of the para-arteriolar RPE (RP12; ref. 3). The full-length cDNA encodes an extracellular protein with 19 EGF-like domains, 3 laminin A G-like domains and a C-type lectin domain. This protein is homologous to the Drosophila melanogaster protein crumbs (CRB), and denoted CRB1 (crumbs homologue 1). In ten unrelated RP patients with preserved para-arteriolar RPE, we identified a homozygous AluY insertion disrupting the ORF, five homozygous missense mutations and four compound heterozygous mutations in CRB1. The similarity to CRB suggests a role for CRB1 in cell-cell interaction and possibly in the maintenance of cell polarity in the retina. The distinct RPE abnormalities observed in RP12 patients suggest that CRB1 mutations trigger a novel mechanism of photoreceptor degeneration.  相似文献   
107.
The“cut-and-sewn” pressure garments are normally tailored made in various sizes according to the size of human body as well as the area of burn wounds.When a tubular pressure garment is cut in different length and width measurements,different aspect ratio will be occurred on the elastic fabric for making up the pressuregarment. Many therapists in Hong Kong concerned the change of aspect ratio may affect the tensile properties of the elastic fabric and ultimately will affect the skin-and-garment interface pressure for the patient.The aim of  相似文献   
108.
Behavioral tests carried out with the four stereoisomers of 4-methyl-3-heptanol revealed thatLeptogenys diminuta ants respond specifically only to the (3R, 4S)-isomer.  相似文献   
109.
Prader-Willi syndrome (PWS) is associated with paternally derived chromosomal deletions in region 15q11-13 or with maternal disomy for chromosome 15. Therefore, loss of the expressed paternal alleles of maternally imprinted genes must be responsible for the PWS phenotype. We have mapped the gene encoding the small nuclear RNA associated polypeptide SmN (SNRPN) to human chromosome 15q12 and a processed pseudogene SNRPNP1 to chromosome region 6pter-p21. Furthermore, SNRPN was mapped to the minimal deletion interval that is critical for PWS. The fact that the mouse Snrpn gene is maternally imprinted in brain suggests that loss of the paternally derived SNRPN allele may be involved in the PWS phenotype.  相似文献   
110.
T Langer  C Lu  H Echols  J Flanagan  M K Hayer  F U Hartl 《Nature》1992,356(6371):683-689
The main stress proteins of Escherichia coli function in an ordered protein-folding reaction. DnaK (heat-shock protein 70) recognizes the folding polypeptide as an extended chain and cooperates with DnaJ in stabilizing an intermediate conformational state lacking ordered tertiary structure. Dependent on GrpE and ATP hydrolysis, the protein is then transferred to GroEL (heat-shock protein 60) which acts catalytically in the production of the native state. This sequential mechanism of chaperone action may represent an important pathway for the folding of newly synthesized polypeptides.  相似文献   
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