全文获取类型
收费全文 | 108篇 |
免费 | 0篇 |
国内免费 | 3篇 |
专业分类
安全科学 | 6篇 |
废物处理 | 16篇 |
环保管理 | 1篇 |
综合类 | 36篇 |
基础理论 | 13篇 |
污染及防治 | 31篇 |
评价与监测 | 2篇 |
社会与环境 | 6篇 |
出版年
2023年 | 1篇 |
2022年 | 3篇 |
2021年 | 3篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 2篇 |
2017年 | 3篇 |
2016年 | 6篇 |
2015年 | 1篇 |
2014年 | 6篇 |
2013年 | 6篇 |
2012年 | 14篇 |
2011年 | 5篇 |
2010年 | 3篇 |
2009年 | 4篇 |
2008年 | 6篇 |
2007年 | 4篇 |
2006年 | 2篇 |
2005年 | 8篇 |
2004年 | 3篇 |
2003年 | 3篇 |
2002年 | 3篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1963年 | 1篇 |
1959年 | 1篇 |
1954年 | 1篇 |
排序方式: 共有111条查询结果,搜索用时 15 毫秒
51.
52.
Antimony content in municipal waste was studied. Sampled municipal waste was dried, crushed and analyzed. Antimony determinations were performed by Kjeldahl decomposition--batch hydride generation spectrometry and neutron activation analysis. Overall content of antimony in waste was 40-50 g/t raw waste. It was estimated than 20% of the annual production of antimony was discarded as municipal waste in Japan. Leaching of antimony from antimony-added materials may occur, because "small tips" involved considerable amounts of antimony. 相似文献
53.
54.
Molting and breeding entail major energetic costs for female crustaceans. However, females of some hermit crabs perform a
molt immediately prior to copulation (prenuptial molt). The evolutionary significance of the prenuptial molt was examined
in Pagurus hermit crabs, and two hypotheses were tested: (1) prenuptial molt might enhance the success of the present clutch by cleaning
the pleopods of females and thereby preventing eggs from being dislodged from the pleopods, and (2) prenuptial molt might
function for growth and increase future fecundity at the cost of energetic expenditure on the present brood. Although these
hypotheses are not mutually exclusive, our results rejected the former hypothesis and supported the latter hypothesis. All
four Pagurus species examined showed significant negative relationships between prenuptial molting and continuity of breeding; i.e., they
showed high molting frequency after they had a long rest period from breeding. Females of P. minutus increased their size through the prenuptial molt, and showed a decreased clutch size due to the molt. The number of dislodged
eggs increased if females molted in P. minutus. These results suggest that hermit crabs undergoing a prenuptial molt might not gain any clear immediate advantage of enhanced
survival of eggs in the present clutch, and that the prenuptial molt would mainly contribute to growth. 相似文献
55.
Speciments of the red frog crab, Ranina ranina, examined in this study were collected off Hachijojima, Japan from 1987–1988 and 1990–1991. Ovigerous females occurred from May to September, and their carapace length ranged from 61.8 to 102.1 mm. Minimum size at the maturity was estimated to be 50 to 60 mm carapace length. The lobule-type ovary had a longitudinal ovarian cavity at the center. Germinal zones were located along the sides of the cavity. Oogenesis was divided into five main and ten detailed stages: proliferation (oogonium); previtellogenesis (bouquet, early chromatin nucleolus, late chromatin nucleolus); primary vitellogenesis (oil globule and yolk granule); secondary vitellogenesis (primary yolk platelet, secondary yolk platelet and prematuration); and maturation (maturation) stages. Vitellogenesis started at the oil globule stage when weakly positive periodic acid-Schiff granules appear in the cytoplasm. Based on the gonadosomatic index and histological changes in ovary, the reproductive cycle was divided into five stages: multiplication, from December to January; developing, from February to March; ripe in April and early May; spawning, from late May to August; and recovery, from August to November. Each crab spawned more than once during the spawning season. 相似文献
56.
57.
Sunamura E Hoshizaki S Sakamoto H Fujii T Nishisue K Suzuki S Terayama M Ishikawa Y Tatsuki S 《Die Naturwissenschaften》2011,98(5):361-368
Some invasive ants form large networks of mutually non-aggressive nests, i.e., supercolonies. The Argentine ant Linepithema humile forms much larger supercolonies in introduced ranges than in its native range. In both cases, it has been shown that little gene flow occurs between supercolonies of this species, though the mechanism of gene flow restriction is unknown. In this species, queens do not undertake nuptial flight, and males have to travel to foreign nests and cope with workers before gaining access to alien queens. In this study, we hypothesized that male Argentine ants receive interference from workers of alien supercolonies. To test this hypothesis, we conducted behavioral and chemical experiments using ants from two supercolonies in Japan. Workers attacked males from alien supercolonies but not those from their own supercolonies. The level of aggression against alien males was similar to that against alien workers. The frequency of severe aggression against alien males increased as the number of recipient workers increased. Cuticular hydrocarbon profiles, which serve as cues for nestmate recognition, of workers and males from the same supercolony were very similar. Workers are likely to distinguish alien males from males of their own supercolony using the profiles. It is predicted that males are subject to considerable aggression from workers when they intrude into the nests of alien supercolonies. This may be a mechanism underlying the restricted gene flow between supercolonies of Argentine ants. The Argentine ant may possess a distinctive reproductive system, where workers participate in selecting mates for their queens. We argue that the aggression of workers against alien males is a novel form of reproductive interference. 相似文献
58.
In the myrmicine ant Acanthomyrmex ferox, major workers have the same number of ovarioles as queens, thrice that of minor workers, making them well suited for egg-laying. In the queen's presence, infrequent aggression allows ranking of majors but they lay only unviable trophic eggs. Major workers engage each other, but not the minors, in antennal boxing and spectacular shaking contests, a novel interaction in ants. The absence of reversals allows a clear ranking of major workers. After queen removal, aggression becomes very frequent, but previous ranking is maintained. All majors start laying reproductive eggs although they show a skew in ovary development according to ranking. The dominant major, however, actively patrols the egg-pile and cannibalises eggs laid by subordinates. 相似文献
59.
60.
Kazuya Mimura Masayuki Endo Yoko Kawanishi Takeshi Kanagawa Kouji Nagata Keita Terui Makoto Fujii Masayuki Shiraishi Masaya Yamoto Miharu Ito Atsuo Itakura Hiroomi Okuyama Noriaki Usui the Japanese Congenital Diaphragmatic Hernia Study Group 《黑龙江环境通报》2023,43(8):993-1001
This systematic review and meta-analysis aimed to review the optimal timing of delivery at term for neonates with prenatally diagnosed congenital diaphragmatic hernia (CDH). We reviewed the literature up to December 19, 2022 using MEDLINE and the Cochrane Library databases. The inclusion criteria were original articles, comparative studies of CDH neonates delivered at an early term (37–38 weeks of gestation) and at full term (39 weeks of gestation or later), and comparative studies investigating outcomes of CDH neonates. Six studies met the inclusion criteria, including 985 neonates delivered at an early term and 629 delivered at full term. The cumulative rate of survival to discharge showed no significant difference between CDH neonates delivered at an early term (395/515; 76.7%) or at full term (345/467; 73.9%) (risk ratio [RR] 1.01; 95% confidence interval [CI], 0.89–1.16; p = 0.85). Furthermore, the number of neonates requiring oxygen therapy at discharge was not significantly different between CDH neonates delivered at an early term (32/370; 8.6%) and at full term (14/154; 9.1%) (RR, 0.99; 95% CI, 0.36–2.70; p = 0.99). Therefore, the optimal timing of delivery at term for neonates with CDH remains unclear. 相似文献