共查询到20条相似文献,搜索用时 167 毫秒
1.
The World Year of Physics (2005) is an international celebration to commemorate the 100th anniversary of Einstein’s “Annus
Mirabilis.” The United Nations has officially declared 2005 as the International Year of Physics. However, the impact of Einstein’s
ideas was not restricted to physics. Among numerous other disciplines, Einstein also made significant and specific contributions
to Earth Sciences. His geosciences-related letters, comments, and scientific articles are dispersed, not easily accessible,
and are poorly known. The present review attempts to integrate them as a tribute to Einstein in commemoration of this centenary.
These contributions can be classified into three basic areas: geodynamics, geological (planetary) catastrophism, and fluvial
geomorphology. Regarding geodynamics, Einstein essentially supported Hapgood’s very controversial theory called Earth Crust
Displacement. With respect to geological (planetary) catastrophism, it is shown how the ideas of Einstein about Velikovsky’s
proposals evolved from 1946 to 1955. Finally, in relation to fluvial geodynamics, the review incorporates the elegant work
in which Einstein explains the formation of meandering rivers. A general analysis of his contributions is also carried out
from today’s perspective. Given the interdisciplinarity and implications of Einstein’s achievements to multiple fields of
knowledge, we propose that the year 2005 serve, rather than to confine his universal figure within a specific scientific area,
to broaden it for a better appreciation of this brilliant scientist in all of his dimensions. 相似文献
2.
Wenfeng Sun Ruibao Jia Baoyu Gao 《Frontiers of Environmental Science & Engineering in China》2012,6(1):66-74
In this paper, a method using solid-phase extraction (SPE) and gas chromatography-mass spectrometry (GC-MS) was developed
to simultaneously analyze five taste and odor compounds in surface water, i.e., 2-methylisoborneol (2-MIB), 2,4,6-trichloroanisole
(TCA), 2-isopropyl-3-methoxy pyrazine (IPMP), 2-isobutyl-3-methoxy pyrazine (IBMP), and trans-1,10-dimethyl-trans-9-decalol (geosmin, GSM). The mass spectrometry was operated in selective ion monitoring (SIM) mode. Three kinds of SPE columns
and three eluting solvents were compared, the C18 column was chosen as optimum SPE column, and methanol was chosen as the
optimum eluting solvent. It was found that the method showed good linearity in the range of 1–200 ng·L−1 and gave detection limits of 0.5–1.5 ng·L−1 for individual compounds. Good recoveries (93.5%–108%) and relative standard deviations (1.58%–7.31%) were also obtained.
Additionally, concentrations of these taste and odor compounds in Jinan’s surface and drinking water were analyzed by applying
this method, and the results showed that GSM and 2-MIB were the dominant taste and odor compounds in Jinan’s raw water. 相似文献
3.
Male–male competition for females can significantly affect a male’s reproductive success and hence his fitness. Game theory
predicts that an individual should avoid fighting when its future reproductive potential is high, but should fight forcefully
when its future reproductive potential is insignificant. When mates are scarce, extreme competition and fatal fighting is
expected. We recently showed that Nephilengys malabarensis eunuchs, i.e. sterile spider males that lost their genitals during copulation, become more aggressive during male–male contests.
Here, we add crucial comparative data by exploring eunuch fighting behaviour in Nephilengys livida from Madagascar, specifically by testing the ‘better fighter hypotheses’ in a laboratory setting. Similar to N. malabarensis, N. livida copulations resulted in total male castration with the severed palp plugging the female genitals in 70.83% cases, which mostly
(63.63%) prevented subsequent copulations. Unexpectedly, however, N. livida eunuchs exhibited lower aggressiveness than virgin males. We interpret these results in the light of different mating biology
between the so far studied species known for the eunuch phenomenon, which might reflect differing plug effectiveness due to
variation in genital anatomy in N. livida, N. malabarensis and Herennia multipuncta. However, detected differences in aggressive behaviour of N. livida versus N. malabarensis eunuchs might also be explained by the species’ ecology, with lower population densities resulting in a relaxed male–male
competition making excessive aggression and mate guarding redundant. This study thus questions the generality of overt aggressiveness
in mated males with no reproductive value, and highlights the importance of understanding the natural history of species in
the question. 相似文献
4.
Adding iron salt or iron hydroxide to sludgemixed liquor in an aeration tank of a conventional activated sludge processes
(bioferric process) can simultaneously improve the sludge’s filterability and enhance the system’s treatment capacity. In
view of this, Fe(OH)3 was added to a submerged membrane bioreactor (SMBR) to enhance the removal efficiency and to mitigate membrane fouling. Bioferric
process and SMBR were combined to create a novel process called Bioferric-SMBR. A side-by-side comparison study of Bioferric-SMBR
and common SMBR dealing with dyeing wastewater was carried out. Bioferric-SMBR showed potential superiority, which could enhance
removal efficiency, reduce membrane fouling and improve sludge characteristic. When volumetric loading rate was 25% higher
than that of common SMBR, the removal efficiencies of Bioferric-SMBR on COD, dye, and NH4
+-N were 1.0%, 9.5%, and 5.2% higher than that of common SMBR, respectively. The trans-membrane pressure of Bioferric-SMBR
was only 36% of that in common SMBR while its membrane flux was 25% higher than that of common SMBR. The stable running period
in Bioferric-SMBR was 2.5 times of that in common SMBR when there was no surplus sludge discharged. The mixed liquor suspended
solids concentration of Bioferric-SMBR was higher than that of common SMBR with more diversified kinds of microorganisms such
as protozoans and metazoans. The mean particle diameter and specific oxygen uptake rate of Bioferric-SMBR were 3.10 and 1.23
times the common SMBR, respectively.
Translated from Environmental Science, 2005, 26(6): 65–70 [译自: 环境科学] 相似文献
5.
Geng Jinju Wang Qiang Niu Xiaojun Wang Xiaorong 《Frontiers of Environmental Science & Engineering in China》2007,1(1):120-124
Effects of pH, temperature, and oxygen on the production and release of phosphine in eutrophic lake sediments were investigated
under laboratory tests. Results indicated that the elimination of matrix-bound phosphine was accelerated under initial pH
1 or 12. Phosphine levels could reach maximum under initial pH 10. The contents of phosphine increased with the addition of
alkali under pH 4–12. The rates of phosphine production and release from lake sediments varied with temperature. 20°C was
the most favorable temperature for the production of matrix-bound phosphine. Oxygen showed little effect on matrix-bound phosphine.
Matrix-bound phosphine concentrations in lake sediments were concluded to be dependent on a balance of natural generation
and depletion processes.
Translated from Acta Scientise Circumstantiae, 2005, 25(5): 681–685 [译自: 环境科学学报] 相似文献
6.
7.
The intertidal midge Clunio, which reproduces on exposed rocky seashores, becomes enclosed in an irregularly shaped air bubble during short submersion
by incoming waves. This water-repellent property of Clunio’s cuticle is caused by a complete cover of hydrophobic microtrichia offering an effective surf tolerance. These microtrichia
not only trap a thin air layer above the cuticle but also maintain a larger air bubble between the insect’s ventral side and
legs. The effectiveness of the water repellence was quantitatively characterised on the basis of a known model (Crisp and
Thorpe, Discuss Faraday Soc 3:210–220, 1948). The parameters of the model are the contact angle θ (>90°) at the contact line of air/water/microtrichia and the distance between individual microtrichia and their radius. When
the microtrichia are 1.1 μm apart and have a radius of 0.1 μm and an estimated contact angle θ of 140°, the air layer is stable against hydrostatic pressures of up to 3 m water column. As shown by a modified version
of the model, considerably larger air bubbles can be trapped by the microtrichia cover of the legs up to distances of 0.5 mm
from the body. The widely spaced (about 8 μm apart) and longer setae of Clunio are not involved in the formation of air layers and air bubble. 相似文献
8.
9.
Veronika Dornburg Gregg Marland 《Mitigation and Adaptation Strategies for Global Change》2008,13(3):211-217
Kirschbaum (Mitig Adapt Strat Glob Change 11:1151–1164, 2006) explores the climatic impact over time of temporarily sequestering carbon from the atmosphere. He concludes that temporary
storage of carbon in the terrestrial biosphere “achieves effectively no climate-change mitigation”. His strongly worded statement
begs for a response. This paper argues that Kirschbaum’s conclusion is an artifact of the specific perspective of his analysis
and his choice of a definition for climate-change impact. Even temporary sinks put us on a lower path for climate change,
a path that will not otherwise be accessible. For carbon sinks in the terrestrial biosphere, we argue that sooner is better
and longer is better, but even known temporary sinks have value.
相似文献
Gregg Marland (Corresponding author)Email: |
10.
Guo Xiurui Mao Xianqiang Yang Jurong Yang Zhifeng 《Frontiers of Environmental Science & Engineering in China》2007,1(3):299-304
Ecosystem health has been a focal point and research frontier of applied ecology in recent years, increasingly used in urban
ecological studies. To quantify the effect of ecological improvement from eco-planning, an ecosystem health assessment method
is used in eco-planning evaluation and decision support in the urban eco-planning research of Guangzhou City of China. Based
on features of an urban ecosystem, five factors such as vigor, organizational structure, resilience, ability to maintain ecosystem
service, and influence on people’s health were selected to develop the assessment indicator system. Then, to evaluate the
validity of planning measures, a cost-effect analysis of the different scenarios on eco-planning was made, taking investment
of the planned projects as the cost and ecosystem health state after implementing the scenarios as the effect. To establish
priority of all the proposed planning schemes or countermeasures, variation of the ecosystem health state was evaluated when
the investment of eco-environmental construction projects changes by ±10%, ±20% and ±50%, respectively. Thus, the order of
importance of eco-environment construction projects to the urban ecosystem health state can be worked out, providing a reference
for prioritizing the implementation of such urban eco-environmental projects. The study proved the trial value of an ecosystem
health evaluation method in urban eco-planning research.
Translated from China Population, Resources and Environment, 2005, 15(5): 126–130 [译自: 中国人口资源与环境] 相似文献
11.
Nakano R Ishikawa Y Tatsuki S Surlykke A Skals N Takanashi T 《Die Naturwissenschaften》2006,93(6):292-296
Although sex pheromone communication in the genus Ostrinia (Lepidoptera: Crambidae) has been studied intensively, acoustic communication in this genus has not been explored. In this
study, we report that male-produced ultrasound serves as a courtship song in the Asian corn borer moth, O. furnacalis. Upon landing close to a pheromone-releasing female, a male showed a series of courtship behaviors involving emission of
ultrasound. The sounds were produced when the wings were vibrated quickly in an upright position. The male song was composed
of chirps, i.e., groups of pulses (duration of a chirp = 58.9 ms, 8.8 pulses/chirp), with a broadband frequency of 25–100 kHz.
In flight tunnel experiments, deaf and hearing females showed a significant difference in the incidence of three behavioral
responses to courting males, i.e., immediate acceptance, acceptance after walking, and rejection. Deaf females showed more
‘rejection’ and less ‘acceptance after walking’ than hearing females, indicating that the detection of male-produced ultrasound
plays an important role in the acceptance of a male. The findings are discussed in the context of exploitation of receiver
bias and mate choice. 相似文献
12.
13.
The train is an important vehicle in China, but its air quality has important impacts on passengers’ health. In this work,
pollution from carbonyl compounds was measured in the air of six trains. The objectives of this work were to investigate carbonyl
compound levels in selected air from trains, identify their emission sources, and assess the intake of carbonyl compounds
for passengers. The methods for sampling and analyzing 10 carbonyl compounds such as formaldehyde, acetaldehyde, acrolein,
acetone, propionaldehyde, crotonaldehyde, butyraldehyde, benzaldehyde, cyclohexanone, and valeraldehyde in indoor air were
proposed with the sampling efficiency, recovery, and detection limit being 92%–100%, 91%–104%, and 0.26–0.82 ng/m3, respectively. It was indicated that the total concentrations of carbonyl compounds were 0.159–0.2828 mg/m3 with the average concentration of 0.2330 mg/m3. The average concentrations of form aldehyde, acetaldehyde and acetone were 0.0922, 0.0499, and 0.0580 mg/m3, accounting for 42.6%, 21.4%, and 24.9% of the total concentrations of carbonyl compounds, respectively. The carbonyl compounds
probably came from woodwork and cigarette smoking. The intake of carbonyl compounds for the passengers was approximately 0.043–0.076
mg/h. The carbonyl compounds in train air could be harmful to human health.
Translated from Environmental Science, 2006, 27(1) 91–94 [译自: 环境科学] 相似文献
14.
Xi Haiyan Cai Qiang He Miao Shi Hanchang 《Frontiers of Environmental Science & Engineering in China》2007,1(3):381-384
This research describes a fast detection method on the basis of enzyme-linked immunosorbent assay (ELISA) for Escherichia coli in drainage of wastewater treatment plants. Optimized conditions such as the reaction format (sandwich or direct), the concentrations
of diluted horseradish peroxidase (HRP)-E. coli conjugate, and anti-HPR antibody and pretreatment of E. coli were studied. Those results showed that the linear range of detection for E. coli was 10 cfu/mL-6 × 104 cfu/mL. Compared with conventional methods, it is a convenient and sensitive detection method with low cost.
Translated from Environmental Science, 2005, 26(5): 128–131 [译自: 环境科学] 相似文献
15.
Yunrui ZHOU Wanpeng ZHU Xun CHEN 《Frontiers of Environmental Science & Engineering in China》2008,2(3):354-357
In this paper, factors influencing the mineralization of dimethyl phthalate (DMP) during catalytic ozonation with a cerium-doped
Ru/Al2O3 catalyst were studied. The catalytic contribution was calculated through the results of a comparison experiment. It showed
that doping cerium significantly enhanced catalytic activity. The total organic carbon (TOC) removal over the doped catalyst
at 100 min reached 75.1%, 61.3% using Ru/Al2O3 catalyst and only 14.0% using ozone alone. Catalytic activity reached the maximum when 0.2% of ruthenium and 1.0% of cerium
were simultaneously loaded onto Al2O3 support. Results of experiments on oxidation by ozone alone, adsorption of the catalyst, Ce ion’s and heterogeneous catalytic
ozonation confirmed that the contribution of heterogeneous catalytic ozonation was about 50%, which showed the obvious effect
of Ru-Ce/Al2O3 on catalytic activity.
__________
Translated from China Environmental Science, 2006, 26(4): 445–448 [译自: 中国环境科学] 相似文献
16.
Marcelo H. Cassini Laura Fasola Claudio Chehébar David W. Macdonald 《Die Naturwissenschaften》2009,96(5):593-599
The Southern river otter or ‘huillin’, Lontra provocax, is an endangered species endemic of the Andean Patagonian region of Argentina and Chile. It feeds almost exclusively on
the genera of macro-crustacea: Aegla and Sammastacus. The aim of this study was to analyse the role of food availability on the huillin’s distribution using a scale-dependent
analysis of crustacean and otter distributions. We compared the distributions of otters and macro-crustaceans along a north–south
regional gradient, between river basins of northern Patagonia, in an altitudinal gradient within a river basin, and between
habitat types within a lake. We investigated the distribution of otters by sign surveys along lake shores, river banks and
marine coasts, and of crustaceans using surveys in the water, undigested remains in mink (Mustela vison) scats, presence of external skeletons at the waterside and through interviews with local people. Our results show that there
were heterogeneities in the distributions of macro-crustaceans at four scales and these were generally reflected in the distributions
of freshwater otters. We conclude that the main factor limiting the distributions of L. provocax in freshwater environments is the availability of macro-crustaceans. This paper shows how scale-dependent type analyses of
population distribution serves as a method for identifying key environmental factors for species for which the use of long-term
demographies is unfeasible. 相似文献
17.
Where clocks are redundant: weak circadian mechanisms in reindeer living under polar photic conditions 总被引:1,自引:0,他引:1
Biological rhythms are a result of interplay between endogenous clocks and the ambient light–dark (LD) cycle. Biological timing
in resident polar organisms presents a conundrum because these experience distinct daily LD cycles for only a few weeks each
year. We measured locomotor activity in reindeer, Rangifer tarandus platyrhynchus (SR, n = 5 and 6) and R. tarandus tarandus (NR, n = 6), ranging freely at 78 and 70°N, respectively, continuously throughout 1 year using data loggers. NR, but not SR, are
gregarious which enabled us to examine the integrated effects of differences in social organisation and the photic environment
at two different latitudes on the organisation of activity. In both sub-species, ultradian bouts of activity and inactivity
alternated across the 24-h day throughout the year. This pattern was modified by the LD cycle in NR but barely at all in SR.
Periodogram analysis revealed significant ultradian rhythmicity in both sub-species; the frequency of daily cycles of activity
increased from three per day in winter to nearly five in summer. We conclude that this increase, and a concomitant increase
in the level of daily activity, reflected the seasonal increase in the animals’ appetite and the quality of their forage.
Secondly, the combination, most evident in SR, of a weak photic response, weak circadian mechanisms and a weak social synchronization
reduces the constraints of biological timing in an environment which is effectively non-rhythmic most of the year and permits
expression of the basic ultradian pattern of ruminant activity. Third, the weaker 24-h rhythmicity in SR compared to NR indicates
a latitudinal decrease in circadian organization and photic responsiveness in Rangifer. 相似文献
18.
Males of the gypsy moth, Lymantria dispar, are attracted by a pheromone released by females. Pheromones are detected by olfactory neurons housed in specialized sensory
hairs located on the antennae of the male moth. Once pheromone molecules enter the sensilla lymph, a highly abundant pheromone-binding
protein (PBP) transports the molecule to the sensory neuron. The PBPs are members of the insect odorant-binding protein family,
with six conserved cysteine residues. In this study, the disulfide bond connectivities of the pheromone-binding proteins PBP1
and PBP2 from the gypsy moth were found to be cysteines 19–54, 50–109, and 97–118 for PBP1, and cysteines 19–54, 50–110, and
97–119 for PBP2, as determined by cyanylation reactions and cyanogen bromide chemical cleavage. We have discovered that the
second disulfide linkage is the most easily reduced of the three, and this same linkage is missing among four cysteine-containing
insect odorant-binding proteins (OBPs). We are the first to identify the unique steric and electronic properties of this second
disulfide linkage.
Electronic Supplementary Material Supplementary material is available for this article at
相似文献
Erika PlettnerEmail: |
19.
Xu Wenying Gao Tingyao Zhou Rongfeng Ma Lumin 《Frontiers of Environmental Science & Engineering in China》2007,1(2):207-212
The electrochemical reduction characteristics of chlorinated hydrocarbons were investigated by cyclic voltammetry technique.
The reduction mechanism and activity of the chlorinated hydrocarbons at the copper electrode were explored. The relationship
between the structure of chlorinated hydrocarbons and their reductive activity were discussed. The experimental results showed
that chlorinated alkanes and a portion of chlorinated aromatic hydrocarbons could be reduced directly at the copper electrode.
However, chlorinated aromatic hydrocarbons were not easy to reduce at the copper electrode. The results provided a theoretical
basis for the catalyzed iron inner electrolysis method.
Translated from Environmental Science, 2005, 26(4): 51–54 [译自: 环境科学] 相似文献
20.
Laura Domingo Stephen T. Grimes M. Soledad Domingo M. Teresa Alberdi 《Die Naturwissenschaften》2009,96(4):503-511
Expansion of C4 grasses during Late Miocene and Early Pliocene constitutes one of the most remarkable biotic events of the Cenozoic era.
The Teruel–Alfambra region (northeastern Spain) contains one of the most complete Miocene–Pliocene sequences of mammalian
fossil sites in the world. In this study, stable isotope (δ
13C and δ
18O) analyses have been performed on the tooth enamel from the equid Hipparion from 19 localities spanning a time interval from approximately 10.9 to 2.7 Ma. This time range starts with the first appearance
of this genus in Spain and ends at its extinction. An increase in δ
13C at about 4.2 Ma has been observed, indicative of a shift toward a more open habitat. This shift may be related to a large
scale vegetation change which occurred across the Miocene–Pliocene boundary when C4 grasses expanded. This expansion might in turn be linked to global tectonic events such as the uplift of the Himalaya and/or
the closure of the Panama Isthmus. However, other more regional factors may have ultimately enhanced the trend toward more
open habitats in the Western Mediterranean Basin. The Messinian Salinity Crisis was a major environmental event that may have
been responsible for the isotopic changes seen in the equid Hipparion from the Iberian Peninsula along with an increase in the aridity detected ~4.6 Ma ago in the Sahara. Even though the exact
factor triggering the isotopic change observed in the Hipparion enamel remains mostly unknown, this study demonstrates that the global environmental changes detected across the Miocene–Pliocene
boundary are also recorded in the realm of the Iberian Peninsula.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献