全文获取类型
收费全文 | 119篇 |
免费 | 6篇 |
国内免费 | 29篇 |
专业分类
测绘学 | 2篇 |
大气科学 | 4篇 |
地球物理 | 26篇 |
地质学 | 10篇 |
海洋学 | 61篇 |
综合类 | 25篇 |
自然地理 | 26篇 |
出版年
2024年 | 2篇 |
2023年 | 1篇 |
2022年 | 5篇 |
2021年 | 5篇 |
2020年 | 5篇 |
2019年 | 2篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2016年 | 3篇 |
2015年 | 3篇 |
2014年 | 3篇 |
2013年 | 7篇 |
2012年 | 10篇 |
2011年 | 8篇 |
2010年 | 13篇 |
2009年 | 8篇 |
2008年 | 11篇 |
2007年 | 9篇 |
2006年 | 7篇 |
2005年 | 4篇 |
2004年 | 9篇 |
2003年 | 5篇 |
2002年 | 3篇 |
2001年 | 3篇 |
2000年 | 10篇 |
1999年 | 2篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1954年 | 1篇 |
排序方式: 共有154条查询结果,搜索用时 46 毫秒
91.
Hillary Jenks 《GeoJournal》2008,73(3):231-244
The “Little Tokyo” neighborhood of Los Angeles was the center of pre-internment community life for Japanese immigrants and
their children and is still considered the symbolic home of later generations of Japanese Americans in Southern California.
Drawing on three years of ethnographic research in Little Tokyo, I explore in this article how contemporary Japanese Americans
have used and transformed this ancestral landscape in order to express, contest, and formalize collective memories of the
Japanese American experience, particularly with regard to their place in the national body politic. Historical narratives
inscribed at many places in Little Tokyo, both informal and institutional, project a narrative of sacrifice, suffering, and
redemption in the context of internment and military service, articulating neatly with mainstream American tropes of overcoming
hardship as a process of ‘earning’ citizenship and its benefits. However, such narratives are also contested by alternative
interpretations and representations of these spaces that describe a special role for Japanese Americans in making demands
of their government, rather than just sacrifices to it. The resulting debates, disagreements, and even occasional consensus
around constructions of nation, identity, community, and belonging are rooted in the ‘sacred ground’ of Little Tokyo, gathering
meaning and persuasive power through their connection to a symbolically dense site of shared memory. The multiple memory projects
of this landscape reveal how Japanese Americans have envisioned their relationship to the concept of America, to each other,
and to other communities with shared experiences in a diverse metropolis.
相似文献
Hillary JenksEmail: |
92.
The Japanese medaka (Oryzias latipes) was used in the medaka embryo-larval assay (MELA) to determine possible adverse developmental effects of ethanol and the spice component, cinnamaldehyde (CAD). Fish may be exposed to waterborne ethanol and a variety of natural products from non-point sources or leaks during ethanol use as a fuel and from point source processing plant effluents. Consumption of ethanol during human pregnancy is known to cause fetal alcohol syndrome (FAS), a collection of birth defects including craniofacial abnormalities thought to be caused by the generation of free radicals during ethanol metabolism by both alcohol and aldehyde dehydrogenase(s). Fish are also susceptible to FAS (Dasmahapatra et al., meeting abstract). The activity of aldehyde dehydrogenase is inhibited by CAD [Biochem. J. 282 (1992) 353-360; Biochem. Pharmacol. 45 (1993) 1621-1630], and CAD is known to cause developmental abnormalities in the rat [Food Chem. Toxicol. 27 (1989) 781-786]. Therefore, the combined effects of treatment with both ethanol and CAD would be expected to produce additive or greater than additive effects in the MELA assay. Medaka were exposed to ethanol at 100 mM, CAD at 10, 1.0, 0.67 or 0.50 mM, to ethanol and CAD combined, or were non-treated controls. Ethanol at 100 mM was without effect. CAD alone at 10 mM and 1.0 mM was lethal by 1 dpf. Embryos exposed to 100 mM ethanol and 0.67 mM CAD exhibited cardiovascular and pigmentation defects and delayed hatching. Embryos exposed to 0.50 mM CAD alone had less severe cardiovascular problems as compared to the combined ethanol and CAD treatment. Taken together the results indicate that the combined effects of ethanol and CAD are greater than the individual effects and indicate the need to monitor effluents in fish nursery areas to protect natural fish populations. Supported by PHS/NIH ES07929. 相似文献
93.
卵胎生硬骨鱼褐菖精子发生的超微结构研究 总被引:4,自引:0,他引:4
研究了卵胎生硬骨鱼褐菖 Sebastiscus marmoratus精子发生的过程.褐菖的精子发生经历了初级精原细胞、次级精原细胞、初级精母细胞、次级精母细胞、精子细胞等阶段,最终形成精子.在初级精原细胞和次级精原细胞阶段,细胞核中释放出拟染色体.拟染色体分布于精原细胞和前期Ⅰ的初级精母细胞的细胞质中.在前期Ⅰ以后的初级精母细胞、次级精母细胞和精子细胞中,拟染色体已消失.在初级精母细胞阶段,前期Ⅰ至末期Ⅰ的细胞形态变化明显.在前期Ⅰ的偶线期,同源染色体开始配对并形成联会复合体;在粗线期,联会复合体完全形成;在双线期,联会复合体开始解体. 相似文献
94.
Reaction of juvenile flounder to grid separators 总被引:1,自引:0,他引:1
Matsushita Yoshiki; Fujita Kaoru; Ikegami Naoya; Ohata Satoshi 《ICES Journal of Marine Science》2004,61(7):1174-1178
95.
In teleost sPeCies, it is well accepted that estradiol--l75 (E2 )is generated from ovarian fOl-licles stimulated by pituitary gonadOtropins (GTH) (Nagahama, l987). FUrthermore, E2 canstimulate hepatic vitellngenesis and elevate plasrna yOlk protein precursor vite1lOgenin, totalCa and W levels in several teleosts (KorSgaard and Petersen, l976, l978; Whiteheadet al., l978; Elliott et al., l979; Pertersen et al., l983; Wallace, 1985; tapigliati etal., 1999). On the other hand, many stud… 相似文献
96.
Geographic scholarship in critical toponymy has highlighted the importance of place naming as a form of discursive power within processes of urbanization. This paper builds on such literature and advances a novel theory of toponymic assemblage to interpret findings from a participatory research project in the Downtown Eastside of Vancouver, Canada. We foreground neighborhood history in the form of a Japanese Canadian enclave and its wartime uprooting and dispossession, and trace the historical antecedents of a resurrected toponymy of “Japantown” that has appropriated and renarrated Japanese Canadian history to facilitate further rounds of dispossession. Using a genealogical method, we highlight three “moments” of Japanese Canadian uprooting, return, presence, and activism, demonstrating how toponymies are assembled in place in heterogeneous and historically contiguous ways. This approach expands on current research in critical toponymy, offering a novel methodology for exploring the enrolment of toponymy, discourse, and materiality in the formation of place. 相似文献
97.
Takanori Sato Nobuaki Tanaka Anand Nainar Koichiro Kuraji Mie Gomyo Haruhiko Suzuki 《水文科学杂志》2020,65(13):2322-2335
ABSTRACT Many studies have focused on soil erosion in unmanaged Japanese cypress plantations because the sparse understory vegetation and litter covering the forest ground enhance soil erosion. In this study, soil erosion, litter, and overland flow measurements were conducted over 14 months to identify the spatio-temporal variation and examine the optimal sample size. Fifteen traps (each 0.25 m wide) were installed in line along the bottom of a 15-m-wide slope. Soil erosion and overland flow had large spatial variations as compared to litter. The temporal coefficient of variation of soil erosion and overland flow was highest during dry seasons, while smaller during wet seasons. The random sampling analysis showed that the rate of decrease in spatio-temporal variation became moderate as the sample size increased beyond six. This result indicated that the optimal sample size was five, the total width of which was equivalent to about 8% of the monitored slope width. 相似文献
98.
INTERDECADAL SEA LEVEL VARIATION AT THE JAPANESE COAST AND LARGE SCALE CLIMATE STATE 总被引:2,自引:1,他引:2
崔茂常 《中国海洋湖沼学报》1995,13(4):303-309
Thirty years of monthly mean anomalies of sea level(SL) at 15 Japanese coastal stations, sea sur-face temperature (SST) and sea level pressure (SLP) in or over the northern Pacific were analyzed bycanonical correlation analysis (CCA) to study the relationship between the interdecadal SL variationand large scale climate state. Given two time-varying fields this technique identifies the pair ofspacial patterns with optimally correlated time series.The results show that there are two important air-sea interactive processes in the extratropicalPacific region for the variation of the SL at the Japanese coast on interdecadal scale. One is theocean heating or cooling of the atmosphere over the Kuroshio extension region, which results in ahuge SLP anomalous vortex with planetary spacial scale big enough to change the global climate. An-other is the large Kuroshio meander phenomenon controlled by the large-scale wind-stress curls oneyear earlier in the adjacent region of the Hawaiian Islands. The first process im 相似文献
99.
100.
A method for the calculation of seismic waves velocities at focal depth is here proposed. A stratified earth model with spherical symmetry and the analytical relationship between the epicentral distance and the travel times of seismic waves are used.This method, applied to the southern Tyrrhenian region and to the Japanese islands, allows to reduce the observed travel times to the focal depth independently of a particular velocity model. 相似文献