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1.
Personal radio frequency electromagnetic field (RF-EMF) exposure, or exposimetry, is gaining importance in the bioelectromagnetics community but only limited data on personal exposure is available in indoor areas, namely schools, crèches, homes, and offices. Most studies are focused on adult exposure, whereas indoor microenvironments, where children are exposed, are usually not considered. A method to assess spatial and temporal indoor exposure of children and adults is proposed without involving the subjects themselves. Moreover, maximal possible daily exposure is estimated by combining instantaneous spatial and temporal exposure. In Belgium and Greece, the exposure is measured at 153 positions spread over 55 indoor microenvironments with spectral equipment. In addition, personal exposimeters (measuring EMFs of people during their daily activities) captured the temporal exposure variations during several days up to one week at 98 positions. The data were analyzed using the robust regression on order statistics (ROS) method to account for data below the detection limit. All instantaneous and maximal exposures satisfied international exposure limits and were of the same order of magnitude in Greece and Belgium. Mobile telecommunications and radio broadcasting (FM) were most present. In Belgium, digital cordless phone (DECT) exposure was present for at least 75% in the indoor microenvironments except for schools. Temporal variations of the exposure were mainly due to variations of mobile telecommunication signals. The exposure was higher during daytime than at night due to the increased voice and data traffic on the networks. Total exposure varied the most in Belgian crèches (39.3%) and Greek homes (58.2%).  相似文献   

2.
A framework for the combination of near‐field (NF) and far‐field (FF) radio frequency electromagnetic exposure sources to the average organ and whole‐body specific absorption rates (SARs) is presented. As a reference case, values based on numerically derived SARs for whole‐body and individual organs and tissues are combined with realistic exposure data, which have been collected using personal exposure meters during the Swiss Qualifex study. The framework presented can be applied to any study region where exposure data is collected by appropriate measurement equipment. Based on results derived from the data for the region of Basel, Switzerland, the relative importance of NF and FF sources to the personal exposure is examined for three different study groups. The results show that a 24‐h whole‐body averaged exposure of a typical mobile phone user is dominated by the use of his or her own mobile phone when a Global System for Mobile Communications (GSM) 900 or GSM 1800 phone is used. If only Universal Mobile Telecommunications System (UMTS) phones are used, the user would experience a lower exposure level on average caused by the lower average output power of UMTS phones. Data presented clearly indicate the necessity of collecting band‐selective exposure data in epidemiological studies related to electromagnetic fields. Bioelectromagnetics 34:366–374, 2013. © 2012 Wiley Periodicals, Inc.  相似文献   

3.
In situ radiofrequency (RF) exposure of the different RF sources is characterized in Reading, United Kingdom, and an extrapolation method to estimate worst-case long-term evolution (LTE) exposure is proposed. All electric field levels satisfy the International Commission on Non-Ionizing Radiation Protection (ICNIRP) reference levels with a maximal total electric field value of 4.5 V/m. The total values are dominated by frequency modulation (FM). Exposure levels for LTE of 0.2 V/m on average and 0.5 V/m maximally are obtained. Contributions of LTE to the total exposure are limited to 0.4% on average. Exposure ratios from 0.8% (LTE) to 12.5% (FM) are obtained. An extrapolation method is proposed and validated to assess the worst-case LTE exposure. For this method, the reference signal (RS) and secondary synchronization signal (S-SYNC) are measured and extrapolated to the worst-case value using an extrapolation factor. The influence of the traffic load and output power of the base station on in situ RS and S-SYNC signals are lower than 1 dB for all power and traffic load settings, showing that these signals can be used for the extrapolation method. The maximal extrapolated field value for LTE exposure equals 1.9 V/m, which is 32 times below the ICNIRP reference levels for electric fields.  相似文献   

4.
The development and analysis of three waveguides for the exposure of small biological in vitro samples to mobile communication signals at 900 MHz (GSM, Global System for Mobile Communications), 1.8 GHz (GSM), and 2 GHz (UMTS, Universal Mobile Telecommunications System) is presented. The waveguides were based on a fin‐line concept and the chamber containing the samples bathed in extracellular solution was placed onto two fins with a slot in between, where the exposure field concentrates. Measures were taken to allow for patch clamp recordings during radiofrequency (RF) exposure. The necessary power for the achievement of the maximum desired specific absorption rate (SAR) of 20 W/kg (average over the mass of the solution) was approximately Pin = 50 mW, Pin = 19 mW, and Pin = 18 mW for the 900 MHz, 1800 MHz, and 2 GHz devices, respectively. At 20 W/kg, a slight RF‐induced temperature elevation in the solution of no more than 0.3 °C was detected, while no thermal offsets due to the electromagnetic exposure could be detected at the lower SAR settings (2, 0.2, and 0.02 W/kg). A deviation of 10% from the intended solution volume yielded a calculated SAR deviation of 8% from the desired value. A maximum ±10% variation in the local SAR could occur when the position of the patch clamp electrode was altered within the area where the cells to be investigated were located. Bioelectromagnetics 32:102–112, 2011. © 2010 Wiley‐Liss, Inc.  相似文献   

5.
Individuals who report sensitivity to electromagnetic fields often report cognitive impairments that they believe are due to exposure to mobile phone technology. Previous research in this area has revealed mixed results, however, with the majority of research only testing control individuals. Two studies using control and self‐reported sensitive participants found inconsistent effects of mobile phone base stations on cognitive functioning. The aim of the present study was to clarify whether short‐term (50 min) exposure at 10 mW/m2 to typical Global System for Mobile Communication (GSM) and Universal Mobile Telecommunications System (UMTS) base station signals affects attention, memory, and physiological endpoints in sensitive and control participants. Data from 44 sensitive and 44 matched‐control participants who performed the digit symbol substitution task (DSST), digit span task (DS), and a mental arithmetic task (MA), while being exposed to GSM, UMTS, and sham signals under double‐blind conditions were analyzed. Overall, cognitive functioning was not affected by short‐term exposure to either GSM or UMTS signals in the current study. Nor did exposure affect the physiological measurements of blood volume pulse (BVP), heart rate (HR), and skin conductance (SC) that were taken while participants performed the cognitive tasks. Bioelectromagnetics 30:556–563, 2009. © 2009 Wiley‐Liss, Inc.  相似文献   

6.
This study intends to discuss enclosed a realistic approach to determine and analyze the effects of radio frequency on human exposure inside a cylindrical enclosure. A scenario in which a mobile phone with inverted-F antenna (IFA) operating in the Global System for Mobile Communication (GSM) band (900 MHz) is used inside a cylindrical enclosure. Metallic enclosures are known to have resonance and reflection effects, thereby increasing electric field strength and hence resulting in a change of the human exposure to electromagnetic absorptions. So, this study examines and compares the levels of absorption in terms of specific absorption rate (SAR) values under various conditions. In this study, a human phantom with dielectric properties is designed and its interaction is studied with IFA inside fully enclosed cylindrical enclosures. The results show that SAR values are increased inside cylindrical enclosures compared with those in free space. The method of computation uses method of moments. Simulations are done in FEKO software.  相似文献   

7.
Modern mobile phones emit electromagnetic fields (EMF) ranging from 900 to 2000 MHz which are suggested to have an influence on well-being, attention and neurological parameters in mobile phone users. Until now most studies have investigated Global System for Mobile Communications (GSM)-EMF and only very few studies have focused on Universal Mobile Telecommunications System (UMTS)-EMF. Therefore, we tested the effects of both types of unilaterally presented EMF, 1950 UMTS (0.1 and 1 W/kg) and pulsed 900 MHz GSM (1 W/kg), on visually evoked occipital P100, the P300 of a continuous performance test, auditory evoked central N100 and the P300 during an oddball task as well as on the respective behavioral parameters, reaction time and false reactions, in 15 healthy, right handed subjects. A double-blind, randomized, crossover application of the test procedure was used. Neither the UMTS- nor the GSM-EMF produced any significant changes in the measured parameters compared to sham exposure. The results do not give any evidence for a deleterious effect of the EMF on normal healthy mobile phone users.  相似文献   

8.
Results of studies on the possible effects of electromagnetic fields emitted by mobile phones on cognitive functions are contradictory, therefore, possible effects of long‐term (7 h 15 min) electromagnetic field (EMF) exposure to handset‐like signals of Global System for Mobile Communications (GSM) 900 and Wideband Code‐Division Multiple Access (WCDMA) on attention and working memory were studied. The sample comprised 30 healthy male subjects (mean ± SD: 25.3 ± 2.6 years), who were tested on nine study days in which they were exposed to three exposure conditions (sham, GSM 900 and WCDMA) in a randomly assigned and balanced order. All tests were presented twice (morning and afternoon) on each study day within a fixed timeframe. Univariate comparisons revealed significant changes when subjects were exposed to GSM 900 compared to sham, only in the vigilance test. In the WCDMA exposure condition, one parameter in the vigilance and one in the test on divided attention were altered compared to sham. Performance in the selective attention test and the n‐back task was not affected by GSM 900 or WCDMA exposure. Time‐of‐day effects were evident for the tests on divided and selective attention, as well as for working memory. After correction for multiple testing, only time‐of‐day effects remained significant in two tests, resulting in faster reactions in the afternoon trials. The results of the present study do not provide any evidence of an EMF effect on human cognition, but they underline the necessity to control for time of day. Bioelectromagnetics 32:179–190, 2011. © 2010 Wiley‐Liss, Inc.  相似文献   

9.
Modern mobile phones emit electromagnetic fields (EMFs) ranging from 900 to 2000 MHz which are suggested to have an influence on well-being, attention and neurological parameters in mobile phone users. To date most studies have investigated Global System for Mobile Communications (GSM)-EMF and only very few studies were concerned with Universal Mobile Telecommunications System (UMTS)-EMF. Consequently, we tested the effects of both types of EMF, 1950 MHz UMTS (SAR 0.1 and 1 W/kg) and pulsed 900 MHz GSM (1 W/kg), on well-being and vigilance-controlled resting electroencephalogram (eyes closed) in 15 healthy, right-handed subjects. A double-blind, randomised, crossover application of the test procedure was used. Neither the UMTS- nor the GSM-EMF produced any significant changes in the measured parameters compared to sham exposure. The results do not give any evidence for a deleterious effect of the EMF on normal healthy mobile phone users.  相似文献   

10.
Pulsed radio frequency, (RF), electromagnetic radiation from common GSM mobile phones, (Global System for Mobile Telecommunications) with a carrier frequency at 900 MHz, “modulated” by human voice, (speaking emission) decreases the reproductive capacity of the insect Drosophila melanogaster by 50%–60%, whereas the corresponding “nonmodulated” field (nonspeaking emission) decreases the reproductive capacity by 15%–20%. The insects were exposed to the near field of the mobile phone antenna for 6 min per day during the first 2–5 days of their adult lives. The GSM field is found to affect both females and males. Our results suggest that this field-radiation decreases the rate of cellular processes during gonad development in insects.  相似文献   

11.
Low level radio-frequency (RF) signals may produce disorientation, headache and nausea. This double blind study tested nine case-subjects, who complained of various symptoms after prolonged mobile telephone use and 21 control subjects. Each subject underwent a series of trials, in which a dummy mobile telephone exposure system was held to each ear for 30 min in (a) pulsed, (b) continuous RF emission or, (c) no emission test modes. In the active pulsed and continuous modes the same mean power as the output of a typical handset was delivered at a carrier frequency of 882 MHz and at a maximum specific absorption rate (SAR) value of 1.3 W kg(-1) (+/- 30%). In Experiment I (auditory), transient evoked otoacoustic emissions (TEOAE), which assess the outer hair cells in the inner ear, were conducted. In Experiment II (vestibular) the vestibulo-ocular reflex was recorded by video-oculography (VOG), at baseline and immediately post exposure. There were no significant TEOAE changes from baseline to post-exposure recording for any of the exposures and no significant differences in the TEOAEs' change from baseline to post exposure between cases and controls. The VOG did not identify any effect of the exposure on the vestibular end organ in either cases or controls. In conclusion, 30 min exposure to mobile phone RF did not show any immediate effects on vestibulocochlear function as measured by TEOAE and the VOR.  相似文献   

12.
Among the toxic chemicals present in the ambient air of urban centres, benzene raises particular concern due to its haematoxicity and leukaemogenic hazards, probably related to clastogenic factors. However, little is known about the health risks associated with environmental--rather than industrial--exposure to benzene. We analysed micronucleus (MN) frequencies in peripheral lymphocytes by use of the cytokinesis-block technique, and haematological parameters among 49 traffic police and 36 indoor workers (controls) in the city of Bologna. The analysis of urban air provided by a municipal air-quality monitoring station indicated that the levels of environmental benzene were often above the recommended threshold level (10 microg/m3) whereas other pollutants--nitrogen oxides, polycyclic aromatic hydrocarbon compounds, total suspended particulate matter, carbon monoxide, sulfur dioxide--did not exceed the maximum atmospheric concentration established for air-quality standards. Mean levels of individual airborne benzene exposure--as measured by personal devices worn during 4-h morning work-shifts--were six-fold higher in the traffic police than in controls (P=0.001). While no significant difference in haematological parameters was found between the two groups, MN frequency was significantly higher among the traffic police than in indoor workers (P=0.001). Among the study population, MN frequency was found to increase with age, but no influence was observed for gender or smoking. Although it cannot be excluded that the increase of MN frequency observed in traffic police could also depend, apart from benzene, on the complex mixture of pollutants encountered in urban air, our data indicate that elevated personal benzene exposure could represent a genetic risk. The analysis of biomarkers of genetic damage in subjects particularly exposed to environmental benzene deserves careful study.  相似文献   

13.
The maximum spatial peak exposure of each commercial mobile phone determined in compliance with the relevant safety and product standards is publicly available. However, this information is not sufficient for epidemiological studies aiming to correlate the use of mobile phones with specific cancers or to behavioral alterations, as the dominant location of the exposure may be anywhere in the head between the chin to above the ear, depending on the phone design. The objective of this study was to develop a methodology to determine tissue-specific exposure by expanding the post-processing of the measured surface or volume scans using standardized compliance testing equipment, that is, specific absorption rate (SAR) scanners. The transformation matrix was developed using the results from generic dipoles to evaluate the relation between the SAR in many brain regions of the Virtual Family anatomical phantoms and in virtual brain regions mapped onto the homogeneous SAM head. A set of transformation factors was derived to correlate the SAR induced in the SAM head to the SAR in the anatomical heads. The evaluation included the uncertainty associated with each factor, arising from the anatomical differences between the phantoms (typically less than 6 dB (4×)). The applicability of these factors was validated by performing simulations of four head models exposed to four realistic mobile phone models. The new methodology enables the reliable determination of the maximum and averaged exposure of specific tissues and functional brain regions to mobile phones when combined with mobile phone power control data, and therefore greatly strengthens epidemiological evaluations and improves information for the consumer.  相似文献   

14.
Grigoriev  Y. G.  Grigoriev  O. A.  Ivanov  A. A.  Lyaginskaya  A. M.  Merkulov  A. V.  Stepanov  V. S.  Shagina  N. B. 《Biophysics》2010,55(6):1041-1045
Mobile communications provides a new source of electromagnetic exposure for almost the whole population of Russia. For the first time in the history of civilization, the brain of mobile phone users is exposed to localized radiofrequency (RF) electromagnetic fields (EMF). Base stations are a factor in the exposure of the population. Existing standards for limiting exposure do not account for the role of base stations as a source of EMF and cannot guarantee the absence of adverse health effects. It has become necessary to obtain reliable information to expand databases for the development of new standards. As recommended by the World Health Organization, an additional experiment is performed under the supervision of foreign experts, which shows changes in autoimmune status in rats after long-term low-level RF EMF exposure with an incident power of 500 μW/cm2.  相似文献   

15.
The extensive use of mobile phone communication has raised public concerns about adverse health effects of radiofrequency (RF) electromagnetic fields (EMFs) in recent years. A central issue in this discussion is the question whether EMFs enhance the permeability of the blood-brain barrier (BBB). Here we report an investigation on the influence of a generic UMTS (Universal Mobile Telecommunications System) signal on barrier tightness, transport processes and the morphology of porcine brain microvascular endothelial cell cultures (PBEC) serving as an in vitro model of the BBB. An exposure device with integrated online monitoring system was developed for simultaneous exposure and measuring of transendothelial electrical resistance (TEER) to determine the tightness of the BBB. PBEC were exposed continuously for up to 84 h at an average electric-field strength of 3.4-34 V/m (maximum 1.8 W/kg) ensuring athermal conditions. We did not find any evidence of RF-field-induced disturbance of the function of the BBB. After and during exposure, the tightness of the BBB quantified by 14C-sucrose and serum albumin permeation as well as by TEER remained unchanged compared to sham-exposed cultures. Permeation of transporter substrates at the BBB as well as the localization and integrity of the tight-junction proteins occludin and ZO1 were not affected either.  相似文献   

16.
17.
Goal, Scope and Background Goal of this study is an evaluation of the environmental sustainability of the UMTS mobile communication system in Switzerland by means of a Life Cycle Assessment (LCA). A baseline environmental impact profile across the full life cycle of the UMTS (Universal Mobile Telecommunication System) and its predecessor, the GSM (Global System for Mobile Communication) is presented. The baseline assessment was a necessary first step to evaluate the environmental impacts of the mobile communication systems use and growth, thus permitting the evaluation of its environmental sustainability. Main Features Two functional units are defined: a data set of 1 Gbit (1.000.000 kbit), and the yearly mobile communication of an average customer. In the UMTS, both data packages and calls can be conveyed. In order to be able to standardize the results, an equivalence between these two kinds of transmission is formed. Two different options are defined, which represent different ways of transferring the data: mobile phone to mobile phone, and mobile phone to fixed network. All components of the UMTS network like the mobile phones, base stations, antennae, switching systems and the components of the landline like cable system and switching centers, are assessed. The environmental impacts are assessed taking into account all major life cycle phases like raw material extraction, manufacturing, use, disassembly and disposal of the product and the needed infrastructure. Electronic components like printed wiring boards and integrated circuits are assessed using a simple model based on the size (for IC) or number of layers (for PWB), respectively. Mining of precious metals (gold, silver) is included. The study was carried out by ESU-services, Motorola, Swisscom and Deutsche Telekom. Thanks to the industrial partners it can rely on primary data for the production of mobile phone and base station, and for the operation of the networks. As the UMTS network is still being built, no actual data of network operation is available. Data from the GSM (Global System for Mobile Communication) were used in case of data gaps. Results and Conclusions About 25 kg CO2 are emitted and 800 MJ-eq (non-renewable) primary energy are required for the transfer of 1 Gbit information from mobile phone to mobile phone in the UMTS network. For a transfer from mobile to fixed network, these values are 20 kg CO2 and 640 MJ-eq, respectively. On the other hand, the fixed network requires more resources like copper (0.07 kg for the mobile to mobile option vs. 0.12 kg for mobile to fixed network). From an environmental point of view, the mobile telephone is the most important element of the mobile communication network (UMTS and GSM). The short service life of the mobile phone plays a substantial role. Increasing the utilization period of the mobile phone (e.g. by leasing, re-use, extension of the innovation cycles, etc.) could thus represent a large potential for its improvement. The second most important components are the base stations. In the assessment mainly the use phase proved to be important. The lower environmental impact (per Gbit data transfer) as compared to the mobile phone can be explained by the longer service life (around factor 8). Main impacts are caused by the electricity consumption, in particular the energy needed for cooling the base stations. By choosing an environmentally benign electricity mix and/or by increasing the portion of renewable sources of energy, the network operators have a substantial potential of lower the environmental impacts (in particular the greenhouse gas emissions) of mobile telecommunication. Furthermore, the manufacturing of electronic components, the life time of the appliances and energy consumption are key parameters influencing the environmental profile of the networks most. Given its larger data transfer rate, the UMTS is ecologically more favorable in terms of data transfer rate than its predecessor, the GSM system. The higher energy consumption and the more complex production of the devices in the UMTS system are compensated by the faster data transmission rate. Per customer, the result is inverse, however, since the higher efficiency is compensated by the higher data communication per user in the UMTS system. The UMTS network in its state of 2004 according to the 2001 planning and with the accordingly calculated number of customers and data transfer causes 2.1 times more CO2 emissions and requires 2.4 times more (non-renewable) primary energy per customer than for the GSM system in its current state. It must be noted, however, that the UMTS technology supports other services than the GSM system. The development of the UMTS is accompanied with an increased consumption of resources and emissions of pollutants and greenhouse gases regarding the entire system for mobile telephone communication. The GSM system is a mature technology, while the UMTS is still at the beginning of its learning curve. Thus, it can be safely assumed that large improvement potentials are still present for the UMTS network components concerning expenditures and emissions both at production and by the use of the devices. This study provides the necessary information where such improvements are most effective in environmental terms.  相似文献   

18.
Both actively growing and resting cells of the yeast Saccharomyces cerevisiae were exposed to 900-MHz fields that closely matched the Global System for Mobile Communication (GSM) pulsed modulation format signals for mobile phones at specific absorption rates (SAR) of 0.13 and 1.3 W/kg. Two identical anechoic test chambers were constructed to perform concurrent control and test experiments under well-controlled exposure conditions. Using specific test strains, we examined the genotoxic potential of mobile phone fields, alone and in combination, with a known genotoxic compound, the alkylating agent methyl methansulfonate. Mutation rates were monitored by two test systems, a widely used gene-specific forward mutation assay at CAN1 and a wide-range assay measuring the induction of respiration-deficient (petite) clones that have lost their mitochondrial function. In addition, two further assays measured the recombinogenic effect of mobile phone fields to detect possible effects on genomic stability: First, an intrachromosomal, deletion-formation assay previously developed for genotoxic screening; and second, an intragenic recombination assay in the ADE2 gene. Fluctuation tests failed to detect any significant effect of mobile phone fields on forward mutation rates at CAN1, on the frequency of petite formation, on rates of intrachromosomal deletion formation, or on rates of intragenic recombination in the absence or presence of the genotoxic agent methyl methansulfonate.  相似文献   

19.
A potential association between socioeconomic status (SES) and self‐reported use of mobile phones has been investigated in a few studies. If measured exposure to mobile phone networks differs by SES in children, it has not yet been studied. Interview data of 1,481 children and 1,505 adolescents on participants' mobile phone use, socio‐demographic characteristics and potential confounders were taken from the German MobilEe‐study. Sociodemographic data was used to stratify participants into three “status groups” (low, middle, high). Using a personal dosimeter, we obtained an exposure profile over 24 h for each of the participants. Exposure levels during waking hours were expressed as mean percentage of the reference level. Children with a low SES were more likely to own a mobile phone (OR 2.1; 95% CI: 1.1–3.9) and also reported to use their mobile phone longer per day (OR 2.4; 95% CI: 1.1–5.4) than children with a high SES. For adolescents, self‐reported duration of mobile phone use per day was also higher with a low SES (OR: 3.4; 95% CI: 1.4–8.4) compared with a high SES. No association between SES and measured exposure to mobile telecommunication networks was seen for children or adolescents. Mobile phone use may differ between status groups with higher use among disadvantaged groups. However, this does not result in higher overall exposure to mobile telecommunication networks. Whether short duration of own mobile phone use or the small numbers of participants with a low SES are causal, have to be investigated in further studies. Bioelectromagnetics 31:20–27, 2010. © 2009 Wiley‐Liss, Inc.  相似文献   

20.
A head exposure setup for efficient and precisely defined exposure of human subjects equipped with a near‐infrared imaging (NIRI) sensor is presented. In a partially shielded anechoic chamber the subjects were exposed to Universal Mobile Telecommunications System (UMTS)‐like electromagnetic fields (EMF) by using a patch antenna at a distance of 4 cm from the head. The non‐contact design of the exposure setup enabled NIRI sensors to easily attach to the head. Moreover, different regions of the head were chosen for localised exposure and simultaneous NIRI investigation. The control software enabled the simple adaptation of the test parameters during exploratory testing as well as the performance of controlled, randomised, crossover and double‐blind provocation studies. Four different signals with a carrier frequency of 1900 MHz were chosen for the exposure: a simple continuous wave signal and three different UMTS signals. Furthermore, three exposure doses were available: sham, low (spatial peak specific absorption rate (SAR) = 0.18 W/kg averaged over 10 g) and high (spatial peak SAR = 1.8 W/kg averaged over 10 g). The SAR assessment was performed by measurement and simulation. Direct comparison of measurement and numerical results showed good agreement in terms of spatial peak SAR and SAR distribution. The variability analysis of the spatial peak SAR over 10 g was assessed by numerical simulations. Maximal deviations of ?22% and +32% from the nominal situation were observed. Compared to other exposure setups, the present setup allows for low exposure uncertainty, combined with high SAR efficiency, easy access for the NIRI sensor and minimal impairment of test subjects. Bioelectromagnetics 33:124–133, 2012. © 2011 Wiley Periodicals, Inc.  相似文献   

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