全文获取类型
收费全文 | 64篇 |
免费 | 0篇 |
国内免费 | 3篇 |
专业分类
安全科学 | 2篇 |
废物处理 | 18篇 |
环保管理 | 2篇 |
综合类 | 8篇 |
基础理论 | 15篇 |
污染及防治 | 16篇 |
评价与监测 | 3篇 |
社会与环境 | 3篇 |
出版年
2021年 | 1篇 |
2019年 | 1篇 |
2017年 | 2篇 |
2016年 | 1篇 |
2015年 | 3篇 |
2014年 | 3篇 |
2013年 | 3篇 |
2012年 | 6篇 |
2011年 | 6篇 |
2010年 | 4篇 |
2009年 | 5篇 |
2008年 | 4篇 |
2007年 | 2篇 |
2006年 | 4篇 |
2005年 | 1篇 |
2004年 | 5篇 |
2003年 | 2篇 |
2002年 | 1篇 |
2001年 | 2篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1986年 | 2篇 |
1976年 | 1篇 |
1954年 | 1篇 |
排序方式: 共有67条查询结果,搜索用时 31 毫秒
41.
The social spider mites (Acari: Tetranychidae) of Stigmaeopsis weave dense nests on the underside of host leaves. Four species occur on the leaves of bamboo in Japan: Stigmaeopsis longus, S. celarius, S. takahashii and S. saharai. We initially reconfirmed the occurrence of distinct variation in nest size among the species. Based on the hypothesis that this variation plays a role in protecting the spider mites from predators, we looked at the behavior of the natural enemies that occur on the host plants along with members of Stigmaeopsis. We found considerable variation in the ability of nests to protect the spider-mite eggs. The smallest nests protected the eggs against three predators, whereas the largest nests protected the eggs against only one predator species. So, decreases in nest size increased egg defense. Thus we concluded that nest-size variation reflects a strategy for reducing predation.Communicated by D. Gwynne 相似文献
42.
43.
As one of a series of studies concerning the relationship between the higher-order structure and the biodegradability of a biodegradable plastic, the effects of the crystal structure of the plastic on microbial degradation were investigated. Bacterial poly(d-(–)-3-hydroxybutyrate) (PHB) films which had a wide range of crystallinity were prepared by the melt-quenching method. Results of the microbial degradation indicated that the development of crystallinity evidently depressed the microbial degradability. From scanning electron microscopy (SEM) observations, it is suggested that the microbial degradation proceeded in at least two manners. One was preferential degradation of the amorphous region leaving the crystalline lamellae intact, which was considered to be a homogeneous enzymatic degradation over the surface. The other was nonpreferential spherical degradation on the surface. The SEMs indicate that the spherical holes were the result of colonization by degrading bacteria. The holes varied in size and number with the change of crystal structure. Therefore, it is considered that the crystal structure of PHB also influenced the physiological behavior of the degrading bacteria on the PHB surface. 相似文献
44.
膜采样离线分析与在线测定大气细粒子中元素碳和有机碳的比较 总被引:3,自引:1,他引:2
针对普遍采用的膜采样离线分析与在线测定大气细粒子中元素碳和有机碳的方法进行了比较分析. 2006年1月~2007年4月期间在北京大学校园内应用膜采样离线分析和在线分析分季节同时测定了PM2.5中元素碳(EC)和有机碳(OC),并将结果进行对比.结果显示,膜采样法测得的OC约为在线仪器测得的OC的2倍, 2种方法差别主要体现在对OC的测量上.不加平行板有机物扩散吸收管引入OC比较大的正误差,而加平行板有机物扩散吸收管又将引入OC的负误差,约10%.同时采用平行板有机物扩散吸收管和后置膜的离线分析方法同在线观测的结果具有比较好的一致性. 相似文献
45.
Yutaka Saito Anthony R. Chittenden Kotaro Mori Katsura Ito Atsushi Yamauchi 《Behavioral ecology and sociobiology》2008,63(1):33-42
The number of nests containing egg masses a female makes over her lifetime and the pattern of scattering nests vary among
species in a genus of nest-weaving spider mites (Stigmaeopsis). We hypothesized that the scattered nests of small nest builders have a previously overlooked indirect effect in that the
void nests created after predation take on a new role as hindering devices that effectively decrease predator searching efficiency.
First, we demonstrated that the experimental design used in this study is a good reflection of the nest distribution pattern
of Stigmaeopsis takahashii (an intermediate-sized nest builder) in the field. Using this species as a model, we tested how different nest-scattering
patterns affect the predator to examine how scattering may indirectly provide an anti-predation strategy by increasing a predators
searching time. Next, we observed how artificially arranged void nests disturb predatory behavior in both starved and fully
fed predator females and showed that void nests have a strong hindering effect on predators. Thus, we concluded that the nesting
behavior of this mite species not only has anti-predator effects but must also have a stabilizing effect on predator–prey
interaction systems at the population level. 相似文献
46.
2-Methylene-1,3,6-trioxocane (MTC) was polymerized via ring-opening in the presence of a radical initiator and the obtained
polyester was biodegradable. MTC could also copolymerize with various vinyl monomers such as styrene, vinyl acetate, methyl
vinyl ketone, N-vinyl-2-pyrrolidone, N-isopropyl acrylamide, and maleic anhydride. By copolymerizing MTC with these vinyl monomers in the presence of a radical
initiator, we could obtain various biodegradable polymers with ester group introduced into the backbone. In addition the obtained
copolymers exhibit certain functionalities such as photolysis, water-solubility, thermosensitivity, detergent builder, and
water-absorbability. 相似文献
47.
Nasri S. Kawar Yutaka Iwata Margarete E. Düsch Francis A. Gunther 《Journal of environmental science and health. Part. B》2013,48(5):505-513
Abstract Dialifor and methidathion were added to diluted “Zinfandel”; grape concentrate at 25 ppm and dimethoate at 1.0 and 25 ppm prior to fermentation with Saccharomyces cerevisiae. The finished wine 56 days later contained 10% (2.5 ppm) of the dialifor, 46% (12 ppm) of the methidathion and 85% (21 and 0.98 ppm) of the dimethoate added to the grape must. Residues in wine stored at 24°C dissipated by hydrolysis; half‐lives in wine were 7 days for dialifor and methidathion and 30 days for dimethoate. Residues were unchanged in wine in frozen storage for one year. Analysis of seven commercial wines for dimethoate indicated less than 0.03 ppm dimethoate was present; identity could not be confirmed by thin‐layer chromatography at this level. 相似文献
48.
Middle-thermophilic sulfur-oxidizing bacteria Thiomonas sp. RAN5 strain for hydrogen sulfide removal
Asano R Hirooka K Nakai Y 《Journal of the Air & Waste Management Association (1995)》2012,62(1):38-43
Hydrogen sulfide (H2S) is one of the most toxic and offensively odorous gases and is generated in anaerobic bioreactors. A middle-thermophilic sulfur-oxidizing bacterium (SOB), Thiomonas sp. strain RAN5, was isolated and applied for H2S removal from both artificial and anaerobically digested gas. When a bioreactor containing medium inoculated with RAN5 was aerated continuously with artificial gas (containing 100 ppm H2S) at 45 degrees C for 156 hr, the H2S concentration in the vented gas was reduced by 99%. This was not affected by the presence of other microbes in the bioreactor The H2S removal efficiency of the RAN5 bioreactor for anaerobically digested gas was greater than 99% at influent H2S concentrations ranging from 2 to 1800 ppm; the efficiency decreased to 90% at influent H2S concentrations greater than 2000 ppm. Thiomonas sp. strain RAN5 cannot survive at room temperature, and thus its leakage from a wastewater treatment plant would not damage sewage systems. These data suggest that Thiomonas sp. strain RAN5 may be a useful microorganism for H2S removal. 相似文献
49.
Nobuyuki Tsuji Anthony R. Chittenden Takuya Ogawa Takenori Takada Yan-Xuan Zhang Yutaka Saito 《Sustainability Science》2011,6(1):97-107
Since the late 1980s, spider mite pests have caused serious damage to many moso bamboo (Phyllostachys pubescens) forests in China’s Fujian province. The culms of this plant are an essential component of the building and handicraft industries,
and the shoots are a prized food item in many Asian countries. Furthermore, bamboo forests play an important soil conservation
role in mountainous areas. We examined pest mite outbreaks in several moso bamboo plantations in Fujian, and could show that
a change in cultivation style from polyculture (a kind of mixed forest) to monoculture (all plants other than bamboo were
removed) was primarily responsible for the local extinction of an important predaceous mite species. This phenomenon is due
to the periodic shedding of leaves by the bamboo, which forces the predator mites occurring on bamboo to switch to prey mite
species that occur on other plants. We then tried to elucidate the factors that resulted from such a cultivation change. Adopting
a computer simulation approach, we could successfully show that at least two plants, moso bamboo and Chinese silvergrass,
are necessary to maintain stable predator–prey interactions in moso forests. That is, systems consisting of one common predator
and two host-specific pest mites on different host plant species frequently became stable when the pest mites were at low
density. This finding indicates clearly that bio-diversity, even when it consists of only two plants and three mite species
as in this study, is necessary for the sustainable regulation of large-scale forests, such as moso bamboo plantations. 相似文献
50.
Yutaka Kuwayama Mayumi Ito Maiko Akatsuka Naoki Hiroyoshi Masami Tsunekawa 《Journal of Material Cycles and Waste Management》2011,13(2):156-163
Automobile shredded residue is a potential solid fuel when its metal and chlorine-containing parts have been removed. The
authors have investigated physical separation of automobile shredded residue to obtain the components that may be used in
solid fuel and found that agglomerates of entangling fiber-like components are formed during crushing, making removal of metals
and chlorine-containing parts difficult. In this paper, a reattachment ratio, entrapment ratio, and disentanglement ratio
are proposed to evaluate the entanglement properties of crushed automobile shredded residue. It is found that products smaller
than 16 mm were not reattached easily in the sieving process, and an index based on entanglement properties proposed here
is useful to predict suitable crushing conditions. Wet detachment of entrapped particles from agglomerates of entangling materials
was also applied to separate particulate matter from crushed ASR. 相似文献