期刊文献+
共找到5,258篇文章
< 1 2 250 >
每页显示 20 50 100
Activity Data and Emission Factor for Forestry and Other Land Use Change Subsector to Enhance Carbon Market Policy and Action in Malawi
1
作者 Edward Missanjo Henry Kadzuwa 《Journal of Environmental Protection》 2024年第4期401-414,共14页
Activity data and emission factors are critical for estimating greenhouse gas emissions and devising effective climate change mitigation strategies. This study developed the activity data and emission factor in the Fo... Activity data and emission factors are critical for estimating greenhouse gas emissions and devising effective climate change mitigation strategies. This study developed the activity data and emission factor in the Forestry and Other Land Use Change (FOLU) subsector in Malawi. The results indicate that “forestland to cropland,” and “wetland to cropland,” were the major land use changes from the year 2000 to the year 2022. The forestland steadily declined at a rate of 13,591 ha (0.5%) per annum. Similarly, grassland declined at the rate of 1651 ha (0.5%) per annum. On the other hand, cropland, wetland, and settlements steadily increased at the rate of 8228 ha (0.14%);5257 ha (0.17%);and 1941 ha (8.1%) per annum, respectively. Furthermore, the results indicate that the “grassland to forestland” changes were higher than the “forestland to grassland” changes, suggesting that forest regrowth was occurring. On the emission factor, the results interestingly indicate that there was a significant increase in carbon sequestration in the FOLU subsector from the year 2011 to 2022. Carbon sequestration increased annually by 13.66 ± 0.17 tCO<sub>2</sub> e/ha/yr (4.6%), with an uncertainty of 2.44%. Therefore, it can be concluded that there is potential for a Carbon market in Malawi. 展开更多
关键词 Activity Data emission factor Climate Change Forestland Carbon Market
下载PDF
Spontaneous emission fromΛ-type three-level atom driven by bichromatic field in anisotropic double-band photonic crystals
2
作者 凌凯 姜丽 +1 位作者 万仁刚 姚治海 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第4期389-396,共8页
The spontaneous emission property ofΛ-type three-level atom driven by the bichromatic field in the anisotropic double-band photonic crystal is calculated by n-times iteration method.The influence of different paramet... The spontaneous emission property ofΛ-type three-level atom driven by the bichromatic field in the anisotropic double-band photonic crystal is calculated by n-times iteration method.The influence of different parameters on atomic spontaneous emission is studied,and the phenomena of atomic spontaneous emission are explained in the dressed state representation.It is found that the spontaneous emission spectra of the atom driven by the bichromatic field presents a multi-peak comb structure.The position of the emission peak is determined by the initial state of the atom,and the interval between the neighboring emission peaks is the detuningδof the bichromatic field.When the ratio between Rabi frequency intensity and the detuningδof the bichromatic field remains unchanged,the intensity of each emitted peak remains invariant.The spontaneously emitted peak can be annihilated in the band gap and enhanced near the band edge in the anisotropic photonic crystals.Meanwhile,we also observe the fluorescence quenching phenomenon in the spontaneous emission spectra.The research in this paper provides the theoretical guidance for the control of atomic spontaneous emission. 展开更多
关键词 photonic crystal bichromatic field spontaneous emission spectra dressed state
原文传递
Spontaneous emission of a moving atom in a waveguide of rectangular cross section
3
作者 曾静 卢竞 周兰 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第2期92-96,共5页
We study the spontaneous emission(SE) of an excited nonrelativistic two-level system(TLS) interacting with the vacuum in a waveguide of rectangular cross section. All TLS’s transitions and the center-of-mass motion o... We study the spontaneous emission(SE) of an excited nonrelativistic two-level system(TLS) interacting with the vacuum in a waveguide of rectangular cross section. All TLS’s transitions and the center-of-mass motion of the TLS are taken into account. The SE rate and the carried frequency of the emitted photon for the TLS initially being at rest are obtained, it is found that in the first order of the mass M, the frequency of the emitted photon is smaller than the transition frequency of the TLS and the SE rate is smaller than the SE rate Γfof the TLS fixed in the same waveguide. The SE rate for the TLS initially being moving is obtained in the second order of the mass M. The SE rate is smaller than Γfbut it is dependent not only on the atomic mass but also on the initial momentum. The carried frequency of the emitted photon is decreased when it travels along the direction of the initial momentum, whereas it is increased when it travels in the opposite direction of the initial momentum. 展开更多
关键词 spontaneous emission moving atom waveguide of rectangular cross section
原文传递
Impact of amplified spontaneous emission noise on the SRS threshold of high-power fiber amplifiers
4
作者 刘伟 任帅 +1 位作者 马鹏飞 周朴 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第3期234-238,共5页
Impact of amplified spontaneous emission(ASE)noise on the stimulated Raman scattering(SRS)threshold of highpower fiber amplifiers is demonstrated numerically through a spectral evolution approach.The simulation result... Impact of amplified spontaneous emission(ASE)noise on the stimulated Raman scattering(SRS)threshold of highpower fiber amplifiers is demonstrated numerically through a spectral evolution approach.The simulation results confirm that ASE noise in the Raman wavelength band could reduce the SRS threshold of high-power fiber amplifiers significantly.As for ASE noise originated the main amplifier,it becomes stronger and reduces the SRS threshold at shorter operation wavelength below 1052 nm.As for ASE noise originated from the seed laser,it reduces the SRS threshold at different operation wavelength under the condition that the Raman ratio is over-90 dB in the seed laser.The theoretical method and results in this work could provide a well reference to extend the operation wavelength of high-power fiber lasers. 展开更多
关键词 high-power fiber amplifiers amplified spontaneous emission stimulated Raman scattering
原文传递
Assessment of the crucial factors influencing the responses of ammonia and nitrous oxide emissions to controlled release nitrogen fertilizer: A meta-analysis
5
作者 Lü Hui-dan WANG Xi-ya +1 位作者 PAN Zhao-long ZHAO Shi-cheng 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2023年第11期3549-3559,共11页
Reducing ammonia(NH3) and nitrous oxide(N2O) emissions have great effects on mitigating nitrogen(N) nutrient loss and greenhouse gas emissions. Controlled release urea(CRU) can control the N release rate, which reduce... Reducing ammonia(NH3) and nitrous oxide(N2O) emissions have great effects on mitigating nitrogen(N) nutrient loss and greenhouse gas emissions. Controlled release urea(CRU) can control the N release rate, which reduces reactive N loss and increases nitrogen use efficiency relative to conventional urea(CU). However, the crucial factors influencing the responses of NH3and N2O emissions to CRU relative to CU are still unclear. In this study, we evaluated the responses of NH3and N2O emissions to CRU based on collected field data with a meta-analysis. CRU reduced the NH3and N2O emissions by 32.7 and 25.0% compared with CU, respectively. According to subgroup analysis, CRU presented better mitigation of NH3and N2O emissions in soils with pH 6.5–7.5(–47.9 and –23.7%) relative to either pH<6.5(–28.5and –21.4%) or pH>7.5(–29.3 and –17.3%), and in the rice season(–34.8 and –29.1%) relative to the wheat season(–19.8 and –22.8%). The responses of NH3and N2O emissions to CRU increased from rainfed(–30.5 and –17.0%) to irrigated(–32.5 and –22.9%), and then to paddy(–34.8 and –29.1%) systems. In addition, the response of N2O emission mitigation increased with increases in soil total nitrogen(TN);however, soil TN did not significantly affect the response of NH3volatilization. The reduction in NH3emission was greater in sandy-textured soil(–57.7%) relative to loam-textured(–32.9%) and clay-textured(–32.3%) soils, whereas soil texture did not affect N2O emission. Overall, CRU was a good option for reducing the NH3and N2O emissions relative to CU in agricultural production. This analysis improves our understanding of the crucial environmental and management factors influencing the mitigation of NH3and N2O emissions under CRU application, and these site-specific factors should be considered when applying CRU to reduce reactive N loss and increase NUE. 展开更多
关键词 controlled release urea NH VOLATILIZATION N O emission environmental factor management practice
下载PDF
Enhanced spontaneous emission factor for microcavity lasers
6
作者 张晓霞 潘炜 《Chinese Optics Letters》 SCIE EI CAS CSCD 2008年第6期411-414,共4页
The microcavity and the influence of nonradiative recombination can control spontaneous emission.An analytic resolution of rate equation is studied for microcavity lasers.The relationship between output prop- erties a... The microcavity and the influence of nonradiative recombination can control spontaneous emission.An analytic resolution of rate equation is studied for microcavity lasers.The relationship between output prop- erties and structural parameters of multi-quantum wells(MQWs)is obtained.One of the most important consequences of the increased spontaneous emission factor is the reduction of laser threshold.It is found that the characteristic curve of a'thresholdless'laser is strongly nonradiative depopulation-dependent. The light output is increased by the enhanced well number and the reduced width.In particular,there is an optimal well number corresponding to the lowest threshold current density for MQW structure in the microcavity lasers. 展开更多
关键词 电子学 无辐射复合 自发发射 激光器
原文传递
Tumor necrosis factor-α and interleukin-6 in cirrhotic patients with spontaneous bacterial peritonitis 被引量:39
7
作者 Muhammed AM Suliman Fawzy MH Khalil +3 位作者 Salam SA Alkindi Anil V Pathare Ali AA Almadhani Neveen AAI Soliman 《World Journal of Gastrointestinal Pathophysiology》 CAS 2012年第5期92-98,共7页
AIM:To evaluate the role of tumor necrosis factor-α(TNF-α) and interleukin-6(IL-6) in cirrhotic patients who have hepatic and renal impairment with spontaneous bacterial peritonitis(SBP).METHODS:We prospectively stu... AIM:To evaluate the role of tumor necrosis factor-α(TNF-α) and interleukin-6(IL-6) in cirrhotic patients who have hepatic and renal impairment with spontaneous bacterial peritonitis(SBP).METHODS:We prospectively studied 120 cirrhotic patients with SBP and 80 cirrhotic patients with sterile ascitic fluid.They included 144 males and 56 females with ages ranging between 34 and 62 years.The diagnosis of cirrhosis was established by clinical and laboratory criteria that did not require histological confirmation.The severity of underlying liver disease was evaluated using Pugh's modification of Child's criteria(Child-Pugh scores).Ascitic fluid was sent to the laboratory for cell count,culture,sensitivity testing,and measurement of chemical elements(i.e.,albumin,glucose).Specimens were inoculated into aerobic and anaerobic blood culture bottles.Serum and ascitic fluid were also collected in sterile tubes at study entry(before the initiation of antibiotic treatment) and 48 h later.Assays for TNF-α and IL-6 in the serum and ascitic fluid were performed with an immunoenzymometric assay using manufacture's instructions.RESULTS:Cytokine levels in serum and ascitic fluid were significantly higher in the patients with SBP.(plasma TNF-α:135.35 ng/mL ± 11.21 ng/mL vs 92.86 ng/mL ± 17.56 ng/mL,P < 0.001;plasma IL-6:32.30 pg/mL ± 7.07 pg/mL vs 12.11 pg/mL ± 6.53 pg/mL,P < 0.001;ascitic fluid TNF-α:647.54 ± 107.11 ng/mL vs 238.43 ng/mL ± 65.42 ng/mL,P < 0.001);ascitic fluid IL-6:132.84 ng/mL ± 34.13 vs 40.41 ± 12.85 pg/mL,P < 0.001).About 48(40%) cirrhotic patients with SBP developed renal and hepatic impairment and showed significantly higher plasma and ascitic fluid cytokine levels at diagnosis of infection.[(plasma TNF-α:176.58 ± 17.84 vs 135.35 ± 11.21 ng/mL)(P < 0.001) and(IL-6:57.83 ± 7.85 vs 32.30 ± 7.07 pg/mL)(P < 0.001);ascitic fluid TNF-α:958.39 ± 135.72 vs 647.54 ± 107.11 ng/mL,(P < 0.001),ascitic fluid IL-6:654.74 ± 97.43 vs 132.84 ± 34.13 pg/mL,(P < 0.001)].Twenty nine patients(60.4%) with SBP and renal impairment died whereas,only four patients(5.55%) with SBP but without renal impairment died from gastrointestinal hemorrhage(P < 0.0005).CONCLUSION:It appears that TNF-α production may enhance liver cell injury and lead to renal impairment.This correlated well with the poor prognosis and significantly increased mortality associated with SBP in cirrhotic patients. 展开更多
关键词 Tumor NECROSIS factor INTERLEUKIN-6 spontaneous BACTERIAL PERITONITIS CIRRHOSIS
下载PDF
Fibroblast Growth Factor-2 Counteracts the Effect of Ciliary Neurotrophic Factor on Spontaneous Differentiation in Adult Hippocampal Progenitor Cells 被引量:3
8
作者 贺致礼 丁君 +4 位作者 张建芳 刘颖 龚成新 孙圣刚 陈红辉 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2012年第6期867-871,共5页
Neural stem/progenitor cells (NSCs) can spontaneously differentiate into neurons and glial cells in the absence of mitogen fibroblast growth factor-2 (FGF-2) or epidermal growth factor (EGF) in medium and the spontane... Neural stem/progenitor cells (NSCs) can spontaneously differentiate into neurons and glial cells in the absence of mitogen fibroblast growth factor-2 (FGF-2) or epidermal growth factor (EGF) in medium and the spontaneous differentiation of NSCs is mediated partially by endogenous ciliary neuro-trophic factor (CNTF). This study examined the relationship of FGF-2 and CNTF in the spontaneous differentiation of adult hippocampal progenitor cells (AHPs). AHPs were cultured in the medium containing different concentration of FGF-2 (1-100 ng/mL). Western blotting and immunofluorescence staining were applied to detect the expression of the astrocytic marker GFAP, the neuronal marker Tuj1, the oligodendrocytic marker CNPase and, Nestin, the marker of AHPs. The expression of endogenous CNTF in AHPs at early (passage 4) and late stage (passage 22) was also measured by Western blotting. The results showed that FGF-2 increased the expression of Nestin, dramatically inhibited the expression of GFAP and Tuj1 and slightly suppressed the expression of CNPase. FGF-2 down-regulated the expression of endogenous CNTF in AHPs at both early (passage 4) and late stage (passage 22). These results suggested that FGF-2 could inhibit the spontaneous differentiation of cultured AHPs by negatively regulating the expression of endogenous CNTF in AHPs. 展开更多
关键词 spontaneous DIFFERENTIATION neural PROGENITOR cells basic FIBROBLAST growth factor neuro-genesis
下载PDF
Risk factors, clinical features, and short-term prognosis of spontaneous fungal peritonitis in cirrhosis: A matched case-control study 被引量:3
9
作者 Chun-Hong Huang Lan-Tian Pang +3 位作者 Li-Chen Xu Tian-Tian Ge Qiao-Mai Xu Zhi Chen 《World Journal of Clinical Cases》 SCIE 2019年第17期2438-2449,共12页
BACKGROUND Spontaneous peritonitis is one of the most common infectious complications in cirrhotic patients with ascites.Spontaneous fungal peritonitis (SFP) is a type of spontaneous peritonitis that is a less recogni... BACKGROUND Spontaneous peritonitis is one of the most common infectious complications in cirrhotic patients with ascites.Spontaneous fungal peritonitis (SFP) is a type of spontaneous peritonitis that is a less recognized but devastating complication in end-stage cirrhosis.Although high mortality was previously noted,scant data are available to fully define the factors responsible for the occurrence of SFP and its mortality.AIM To illustrate the differences between SFP and spontaneous bacterial peritonitis (SBP) and discuss the risk factors for the occurrence of SFP and its short-term mortality.METHODS We performed a matched case-control study between January 1,2007 and December 30,2018.Patients with SFP were included in a case group.Sex-,age-,and time-matched patients with SBP were included in a control group and were further divided into control-1 group (positive bacterial culture) and control-2 group (negative bacterial culture).The clinical features and laboratory parameters,severity models,and prognosis were compared between the case and control groups.Logistic regression analysis was used to determine the risk factors for occurrence,and the Cox regression model was used to identify the predictive factors for short-term mortality of SFP.RESULTS Patients with SFP exhibited more severe systemic inflammation,higher ascites albumin and polymorphonuclear neutrophils,and a worsened 15-d mortality than patients in the control groups.Antibiotic administration (case vs control-1: OR = 1.063,95%CI: 1.012-1.115,P = 0.014;case vs control-2: OR = 1.054,95%CI: 1.014-1.095,P = 0.008) remarkably increased the occurrence of SFP or fungiascites.Hepatorenal syndrome (HR = 5.328,95%CI: 1.050-18.900) and total bilirubin (μmol/L;HR = 1.005,95%CI: 1.002-1.008) represented independent predictors of SFP-related early mortality.CONCLUSION Long-term antibiotic administration increases the incidence of SFP,and hepatorenal syndrome and total bilirubin are closely related to short-term mortality. 展开更多
关键词 spontaneous FUNGAL PERITONITIS Risk factor CIRRHOSIS
下载PDF
Spatial-temporal Evolution Characteristics and Decoupling Analysis of Influencing Factors of China’s Aviation Carbon Emissions 被引量:7
10
作者 HAN Ruiling LI Lingling +2 位作者 ZHANG Xiaoyan LU Zi ZHU Shaohua 《Chinese Geographical Science》 SCIE CSCD 2022年第2期218-236,共19页
The aviation industry has become one of the top ten greenhouse gas emission industries in the world. China’s aviation carbon emissions continue to increase, but the analysis of its influencing factors at the provinci... The aviation industry has become one of the top ten greenhouse gas emission industries in the world. China’s aviation carbon emissions continue to increase, but the analysis of its influencing factors at the provincial level is still incomplete. This paper firstly uses Stochastic Impacts by Regression on Population, Affluence and Technology model(STIRPAT) model to analyze the time series evolution of China’s aviation carbon emissions from 2000 to 2019. Secondly, it uses the Logarithmic Mean Divisia Index(LDMI) model to analyze the influencing characteristics and degree of four factors on China’s aviation carbon emissions, which are air transportation revenue, aviation route structure, air transportation intensity and aviation energy intensity. Thirdly, it determines the various factors’ influencing direction and evolution trend of 31 provinces’ aviation carbon emissions in China(not including Hong Kong, Macao, Taiwan of China due to incomplete data). Finally, it derives the decoupling effort model and analyzes the decoupling relationship and decoupling effort degree between air carbon emissions and air transportation revenue in different provinces. The study found that from 2000 to2019, China’s total aviation carbon emissions continued to grow, while the growth rate of aviation carbon emissions showed a fluctuating downward trend. Air transportation revenue and aviation route structure promote the growth of total aviation carbon emissions, and air transportation intensity and aviation energy intensity have a restraining effect on the growth of total aviation carbon emissions. The scope of negative driving effect of air transportation revenue and air transportation intensity on total aviation carbon emissions in various provinces has increased. While the scope of positive driving influence of aviation route structure on total aviation carbon emissions of various provinces has increased, aviation energy intensity mainly has negative driving influence on total aviation carbon emissions of each province. Overall, the emission reduction trend in the areas to the west and north of the Qinling-Huaihe River Line is obvious. The decoupling mode between air carbon emissions and air transportation revenue in 31 provinces is mainly expansion negative decoupling.The air transportation intensity effect shows strong decoupling efforts in most provinces, the decoupling effort of aviation route structure effect and aviation energy intensity effect is not prominent. 展开更多
关键词 aviation carbon emissions influencing factors spatial and temporal analysis DECOUPLING China
下载PDF
Effect of spatially nonlocal versus local optical response of a gold nanorod on modification of the spontaneous emission 被引量:4
11
作者 文莎莎 田锰 +8 位作者 杨红 谢素君 王小云 李芸 刘杰 彭金璋 邓科 赵鹤平 黄勇刚 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第2期520-528,共9页
The spontaneous emission rate of a two-level quantum emitter(QE)near a gold nanorod is numerically investigated.Three different optical response models for the free-electron gas are adopted,including the classical Dru... The spontaneous emission rate of a two-level quantum emitter(QE)near a gold nanorod is numerically investigated.Three different optical response models for the free-electron gas are adopted,including the classical Drude local response approximation,the nonlocal hydrodynamic model,and the generalized nonlocal optical response model.Nonlocal optical response leads to a blueshift and a reduction in the enhancement of the spontaneous emission rate.Within all the three models,the resonance frequency is largely determined by the aspect ratio(the ratio of the nanorod length to the radius)and increases sharply with decreasing aspect ratio.For nanorod with a fixed length,it is found that the larger the radius is,the higher the resonance frequency is,and the smaller the enhancement is.However,if the length of the nanorod increases,the peak frequency falls sharply,while the spontaneous emission enhancement grows rapidly.For nanorod with a fixed aspect ratio,the peak frequency decreases slowly with increasing nanorod size.Larger nanorod shows smaller nonlocal effect.At a certain frequency,there is an optimal size to maximize the enhancement of the spontaneous emission rate.Higher order modes are more affected by the nonlocal smearing of the induced charges,leading to larger blueshift and greater reduction in the enhancement.These results should be significant for investigating the spontaneous emission rate of a QE around a gold nanorod. 展开更多
关键词 spatially nonlocal response HYDRODYNAMICS spontaneous emission rate gold nanorod
原文传递
Granulocyte colony-stimulating factor-producing squamous cell carcinoma of the tongue exhibiting characteristic fluorine-18 deoxyglucose accumulation on positron emission tomography–computed tomography: A case report 被引量:2
12
作者 Hiroaki Shimamoto Yuka Hirota +4 位作者 Yoshihisa Kashima Naoya Kinoshita Misaki Yokokawa Tohru Ikeda Hiroyuki Harada 《World Journal of Clinical Cases》 SCIE 2020年第9期1666-1673,共8页
BACKGROUND Granulocyte colony-stimulating factor(G-CSF)is a cytokine produced in inflammatory environments that induces differentiation and proliferation of neutrophils in bone marrow.We report a rare case of aggressi... BACKGROUND Granulocyte colony-stimulating factor(G-CSF)is a cytokine produced in inflammatory environments that induces differentiation and proliferation of neutrophils in bone marrow.We report a rare case of aggressive G-CSFproducing squamous cell carcinoma of the tongue exhibiting fluorine-18 deoxyglucose(FDG)accumulation in primary lesion,metastatic lymph nodes,spleen,and bone marrow on positron emission tomography–computed tomography(PET/CT).CASE SUMMARY We report a 58-year-old female with a rapid enlarged lingual mass with partial necrosis.Blood test results from the initial examination revealed a leukocyte count of 21380/μL.On PET/CT,extensive FDG accumulation was observed in the tongue and bilateral cervical lymph nodes,with elevated FDG accumulation in the spleen and bone marrow although no distant metastases were observed.We performed partial glossectomy and bilateral neck dissection.Immunohistochemical staining with G-CSF antibodies on biopsy specimen and resected samples revealed that both specimens were G-CSF positive.This is a rare case of G-CSF producing tongue carcinoma with elevated FDG accumulation in the spleen and bone marrow.CONCLUSION In patients with the tongue cancer and hyperleukocytosis,where FDG accumulations in the spleen and bone marrow are observed using PET/CT and when these accumulations are not caused by metastasis,G-CSF-producing tumors,with associated poor prognosis,should be considered. 展开更多
关键词 TONGUE cancer GRANULOCYTE colony-stimulating factor Hyperlukocytosis POSITRON emission tomograph Case report
下载PDF
Characterization of spontaneous otoacoustic emissions in 2–4 day old neonates with respect to gender and ear 被引量:8
13
作者 Jinfeng Liu Baoyu Shi Ningyu Wang Jinlan Li 《Neural Regeneration Research》 SCIE CAS CSCD 2009年第1期67-71,共5页
BACKGROUND: Spontaneous otoacoustic emissions (SOAEs) are regarded as a valuable audio- metric parameter that objectively reflects the function of outer hair cells (OHCs). Many studies have reported that the incidence... BACKGROUND: Spontaneous otoacoustic emissions (SOAEs) are regarded as a valuable audio- metric parameter that objectively reflects the function of outer hair cells (OHCs). Many studies have reported that the incidence of SOAEs in adults is less than 50%. Therefore, measurement of SOAEs may be of little value to clinical examinations. However, the incidence of SOAEs in infants and neonates is higher than in adults. OBJECTIVE: To analyze the basic characteristics of SOAEs in 2–4 day old neonates, and to dem- onstrate the difference in OHC function between sexes and ears. DESIGN, TIME AND SETTING: Neurophysiological contrast study, performed in the Department of Neonates, Beijing Chaoyang Hospital, Capital Medical University, between December 2007 and August 2008. PARTICIPANTS: A total of 112 newborns (224 ears) consisting of 59 females and 53 males were included in this study. METHODS: The probe was adapted and embedded in the neonate external auditory canal with a foam rubber earplug after checking and clearing up the outer ear canal. The presence of SOAEs was determined when the signal amplitude had a clear peak exceeding –30 dB, or was 3 dB above the noise floor. MAIN OUTCOME MEASURES: The incidence of SOAEs, the number of SOAE signal peaks, and the maximal tension of SOAEs. RESULTS: The incidence in females (79.7%) was higher than males (76.4%) (P > 0.05), and the incidence in right ears (86.6%) was higher than in left ears (69.6%) (P < 0.05). There were no sig- nificant difference in the number of SOAE peaks between females and males (4.49 vs. 4.28), or between right ears and left ears (4.62 vs. 4.12) (P > 0.05). The mean maximum SOAE level per ear in females (–3.29 ± 9.28) dB sound pressure level (SPL) was slightly higher than that in males (–3.91 ± 9.14) dB SPL (P > 0.05). Also, the mean maximum SOAE level in right ears (–2.03 ± 9.11) dB SPL was higher than in left ears (–5.50 ± 9.65) dB SPL (P < 0.05). The maximum SOAE level showed a positive correlation with maximum SOAE number in emitting ears (r = 0.55, P < 0.01). CONCLUSION: The incidence of SOAEs in neonates is high (78.1%) within 4 days of birth. The in-cidence of SOAEs and the maximum SOAE level exhibited a significant difference between right and left ears, but the difference between sexes was insignificant. Both the strongest SOAE signal peak and number of SOAEs per ear are representative of the function OHCs. 展开更多
关键词 自发性耳声发射 新生儿 耳朵 日龄 SOAE A型 表征 性别
下载PDF
Silicon cuboid nanoantenna with simultaneous large Purcell factor for electric dipole,magnetic dipole and electric quadrupole emission 被引量:1
14
作者 Qiurong Deng Jianfeng Chen +3 位作者 Li Long Baoqin Chen Huakang Yu Zhiyuan Li 《Opto-Electronic Advances》 SCIE EI 2022年第2期13-21,共9页
The Purcell effect is commonly used to increase the spontaneous emission rate by modifying the local environment of a light emitter.Here,we propose a silicon dielectric cuboid nanoantenna for simultaneously enhancing ... The Purcell effect is commonly used to increase the spontaneous emission rate by modifying the local environment of a light emitter.Here,we propose a silicon dielectric cuboid nanoantenna for simultaneously enhancing electric dipole(ED),magnetic dipole(MD)and electric quadrupole(EQ)emission.We study the scattering cross section,polarization charge distribution,and electromagnetic field distribution for electromagnetic plane wave illuminating the silicon dielectric cuboid nanoantenna,from which we have identified simultaneous existence of ED,MD and EQ resonance modes in this nanoantenna.We have calculated the Purcell factor of ED,MD and EQ emitters with different moment orientations as a function of radiation wavelength by placing these point radiation source within the nanoantenna,respectively.We find that the resonances wavelengths of the Purcell factor spectrum are matching with the resonance modes in the nanoan-tenna.Moreover,the maximum Purcell factor of these ED,MD and EQ emitters is 18,150 and 118 respectively,occur-ring at the resonance wavelength of 475,750,and 562 nm,respectively,all within the visible range.The polarization charge distribution features allow us to clarify the excitation and radiation of these resonance modes as the physical ori-gin of large Purcell factor simultaneously occurring in this silicon cuboid nanoantenna.Our theoretical results might help to deeply explore and design the dielectric nanoantenna as an ideal candidate to enhance ED,MD and EQ emission simultaneously with very small loss in the visible range,which is superior than the more popular scheme of plasmonic nanoantenna. 展开更多
关键词 dielectric nanostructure spontaneous emission RESONANCE Purcell effect
下载PDF
Investigation on emission factors of particulate matter and gaseous pollutants from crop residue burning 被引量:61
15
作者 CAO Guoliang ZHANG Xiaoye +1 位作者 GONG Sunling ZHENG Fangcheng 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2008年第1期50-55,共6页
微粒物质(下午)的排放因素,元素碳( EC ),器官的碳( OC ), SO2 , NOx ,公司, CO2 ,和十个离子(Na+,NH4+,K+,Mg2+,Ca2+, F ?, Cl ?, NO2 ?, NO3 ?, SO42 ?)从在农村中国的通常生产的罪残茬的四种类型的国内烧被估计:稻... 微粒物质(下午)的排放因素,元素碳( EC ),器官的碳( OC ), SO2 , NOx ,公司, CO2 ,和十个离子(Na+,NH4+,K+,Mg2+,Ca2+, F ?, Cl ?, NO2 ?, NO3 ?, SO42 ?)从在农村中国的通常生产的罪残茬的四种类型的国内烧被估计:稻秸,麦秸,玉米 stover,和棉花越过中国搜索区域,它从代表是镇定的。一个燃烧塔被设计模仿农民在农村中国在下面烧了他们的罪残茬的煮的条件,到措施排放因素。,结果证明那麦秸在四罪残茬之中有最高的排放因素彻底的下午(8.75 g/kg ) 玉米 stover 和麦秸分别地为 EC (0.95 g/kg ) 和 OC (3.46 g/kg ) 有最高的排放因素。玉米 stover 也作为有最高的排放因素介绍没有, NOx,和 CO2,麦秸,稻秸,和棉花梗分别地有 NO2, SO2,和公司的最高的排放因素。水溶性的离子, K+ 和 Cl ? ,从所有庄稼有最高的排放因素。麦秸有阳离子种类和 F 的一个相对更高的排放因素 ? , Cl ? , NO2 吗?比另外的残余。 展开更多
关键词 中国 农村 农作物燃烧 气体污染物 发射因数
下载PDF
Clinical feature and predictive factor analysis for spontaneous regression of retinopathy of prematurity in a Chinese population 被引量:1
16
作者 Yi-An Li Xiao-Hong Zhou +1 位作者 Xiao-Jing Cai Chen-Hao Yang 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2022年第12期1978-1984,共7页
AIM:To investigate the ratio of spontaneous regression of retinopathy of prematurity(ROP)and to explore the possible relevant predictive factors.METHODS:A retrospective review of 405 infants who were diagnosed with RO... AIM:To investigate the ratio of spontaneous regression of retinopathy of prematurity(ROP)and to explore the possible relevant predictive factors.METHODS:A retrospective review of 405 infants who were diagnosed with ROP and mother during pregnancy were collected.Stage,zone,and duration of ROP were recorded.Statistical analysis was performed on 51 possible predictive factors.RESULTS:Totally 356 infants showed spontaneous regression.The incidence was 100%,95.3%,and 22.7%in stage 1,2,and 3,respectively.The 13.4%of the ROP with plus disease eventually resolved spontaneously.All affected eyes of aggressive posterior retinopathy of prematurity(APROP)failed to spontaneously regress.The mean duration of ROP was 7.2wk in patients with spontaneous resolution of ROP.Days of mechanical ventilation(OR=0.981,95%CI,0.965-0.997,P=0.021),retinal hemorrhage(OR=0.173,95%CI,0.064-0.470,P=0.001),delivery pattern(OR=2.750,95%CI,1.132-6.681,P=0.025),maternal anemia in pregnancy(OR=0.142,95%CI,0.036-0.563,P=0.005),the stages(at initial diagnosis OR=0.183,95%CI,0.041-0.816,P=0.026;at final diagnosis OR=0.031,95%CI,0.006-0.167,P<0.001),and with plus disease or not(OR=0.005,95%CI,0.001-0.031,P<0.001)were independent predictive factors of the spontaneous regression of ROP.CONCLUSION:Most mild ROP can spontaneously resolve.Active treatment is still recommended for stage 3 ROP,zone I ROP,AP-ROP,and ROP with plus disease.Prolonged mechanical ventilation and concurrent retinal hemorrhage reduce the likelihood of spontaneous ROP resolution.The pattern of delivery and the mother's anemia during pregnancy can also affect the prognosis of ROP. 展开更多
关键词 retinopathy of prematurity predictive factors spontaneous regression anemia during pregnancy mechanical ventilation pattern of delivery retinal hemorrhage
原文传递
The Effects of Naoxintong Capsule on the Vascular Endothelial Function and Inflammatory Factors in Spontaneously Hypertensive Rats 被引量:1
17
作者 Yimin Wang Tao Zhao 《Journal of Health Science》 2018年第6期420-426,共7页
Objective:To investigate the effects of Naoxintong(NXT)capsule on vascular endothelial function and inflammatory mechanism in spontaneously hypertensive rats.Methods:A total of 100 spontaneously hypertensive rats were... Objective:To investigate the effects of Naoxintong(NXT)capsule on vascular endothelial function and inflammatory mechanism in spontaneously hypertensive rats.Methods:A total of 100 spontaneously hypertensive rats were divided into model group,positive control group,NXT low-dose group,NXT medium-dose group and NXT high-dose group.Rats in the model group were given an equal dose of normal saline once a day;the positive control group was given telmisartan 50 mg/(kg·d)once a day;the low,middle and high dose groups were given the NTX 0.5,1.0,2.0 mg/(kg·d)once a day,respectively.Rats in each group were continuously intragastrically administered for 12 weeks.The vascular endothelial function index,inflammation index and blood pressure of each group were observed at the end of 8 weeks.Results:Endothelin(ET),interleukin-6(IL-6),tumor necrosis factor-α(TNF-α),C-reactive protein(CRP)and systolic blood pressure levels were lower in the positive control group and NXT group compared with model group.In the model group,the NO level was lower than the positive control group and NXT group;the levels of ET,IL-6,TNF-α,CRP and systolic blood pressure in the middle-dose group and the high-dose group were lower than those in the positive control group and NXT low-dose group.Furthermore,the level of NO was higher in positive control group and NXT middle and high dose group compared with model group.The levels of ET,IL-6,TNF-α,CRP and systolic pressure in NXT high dose group were lower than in NXT middle dose group,while the level of NO was higher in NXT high group than in NXT middle dose group and the difference was statistically significant(p<0.05).Conclusions:NXT has obviously antihypertensive effect on spontaneously hypertensive rats,and its mechanism may be related to the improvement of vascular endothelial function and inflammatory factors. 展开更多
关键词 NAOXINTONG CAPSULE spontaneous hypertension VASCULAR ENDOTHELIAL function inflammatory factor.
下载PDF
A study on the factor market distortion and the carbon emission scale effect of two-way FDI 被引量:1
18
作者 Mengqi Gong Haiyun Liu +1 位作者 Rao Muhammad Atif Xu Jiang 《Chinese Journal of Population,Resources and Environment》 2019年第2期145-153,共9页
Based on the data of 30 Chinese provinces for the period from 2004 to 2015,this paper expounds the carbon emissions effect of two-way foreign direct investment (FDI) from the perspective of scale effect and factor mar... Based on the data of 30 Chinese provinces for the period from 2004 to 2015,this paper expounds the carbon emissions effect of two-way foreign direct investment (FDI) from the perspective of scale effect and factor market distortions.This study uses Kaya identity to decompose carbon emission and construct simultaneous equations model to empirically examine the factor market distortion and the carbon emission scale effect of two-way FDI.The results show that the inward foreign direct investment (IFDI) increase regional carbon emission through scale effect and also exacerbates factor market distortion in China,whereas the outward FDI trends reduce carbon emission and reduces factor market distortions in China.The study also shows that human capital,research and development (R&D),trade openness,and capital accumulation are important determinants of two-way FDI.Therefore,the study proposes that IFDI policies should focus on acquiring green technologies.In addition,the domestic enterprises should be encouraged to participate in global business. 展开更多
关键词 factor market DISTORTIONS INWARD FOREIGN DIRECT INVESTMENT (IFDI) outward FOREIGN DIRECT INVESTMENT (OFDI) scale effect carbon emissionS
下载PDF
Three-body entanglement induced by spontaneous emission in a three two-level atoms system 被引量:1
19
作者 廖湘萍 方卯发 +1 位作者 郑小娟 蔡建武 《Chinese Physics B》 SCIE EI CAS CSCD 2006年第2期353-364,共12页
关键词 自发发射 双层原子 混乱张量 原子物理学
原文传递
Research on Spatial-Temporal Characteristics and Driving Factor of Agricultural Carbon Emissions in China 被引量:31
20
作者 TIAN Yun ZHANG Jun-biao HE Ya-ya 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2014年第6期1393-1403,共11页
Macroscopic grasp of agricultural carbon emissions status, spatial-temporal characteristics as well as driving factors are the basic premise in further research on China's agricultural carbon emissions. Based on 2... Macroscopic grasp of agricultural carbon emissions status, spatial-temporal characteristics as well as driving factors are the basic premise in further research on China's agricultural carbon emissions. Based on 23 kinds of major carbon emission sources including agricultural materials inputs, paddy field, soil and livestock breeding, this paper firstly calculated agricultural carbon emissions from 1995 to 2010, as well as 31 provinces and cities in 2010 in China. We then made a decomposed analysis to the driving factors of carbon emissions with logarithmic mean Divisia index(LMDI) model. The results show:(1) The amount of agricultural carbon emissions is 291.1691 million t in 2010. Compared with 249.5239 million t in 1995, it increased by 16.69%, in which, agricultural materials inputs, paddy field, soil, enteric fermentation, and manure management accounted for 33.59, 22.03, 7.46, 17.53 and 19.39% of total agricultural carbon emissions, respectively. Although the amount exist ups and downs, it shows an overall trend of cyclical rise;(2) There is an obvious difference among regions: the amount of agricultural carbon emissions from top ten zones account for 56.68%, while 9.84 % from last 10 zones. The traditional agricultural provinces, especially the major crop production areas are the main source regions. Based on the differences of carbon emission rations, 31 provinces and cities are divided into five types, namely agricultural materials dominant type, paddy field dominant type, enteric fermentation dominant type, composite factors dominant type and balanced type. The agricultural carbon emissions intensity in west of China is the highest, followed by the central region, and the east zone is the lowest;(3) Compared with 1995, efficiency, labor and structure factors cut down carbon emissions by 65.78, 27.51 and 3.19%, respectively; while economy factor increase carbon emissions by 113.16%. 展开更多
关键词 二氧化碳排放量 中国西部 农业 驱动因子 时空特征 驱动因素 碳排放强度 时空特性
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部