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Engineering personalized neural tissue using functionalized transcription factors
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作者 stephanie m.willerth 《Neural Regeneration Research》 SCIE CAS CSCD 2016年第10期1570-1571,共2页
Diseases and disorders of the central nervous system often require significant interventions to restore lost function due to their com- plexity. Examples of such disorders include Parkinson's disease, Alzheimer's di... Diseases and disorders of the central nervous system often require significant interventions to restore lost function due to their com- plexity. Examples of such disorders include Parkinson's disease, Alzheimer's disease, multiple sclerosis, traumatic brain injury, and spinal cord in)ury. These diseases and disorders result trom healthy cells being destroyed, which in turn causes dysfunction in the cen- tral nervous system, The death of these cells can trigger a cascade of events that affect the rest of the body, causing symptoms that become progressively worse over time. Developing strategies for repairing the damage to the central nervous system remains chal- lenging, in part due to its inability to regenerate. 展开更多
关键词 CELL Engineering personalized neural tissue using functionalized transcription factors
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Evaluation of the Effects of Cypermethrin on Female Reproductive Function by Using Rabbit Model and of the Protective Role of Chinese Propolis 被引量:3
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作者 AE Khatab NM Hashem +2 位作者 LM El-Kodary FM Lotfy GA Hassan 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2016年第10期762-766,共5页
The prophylactic effects of Chinese propolis against cypermethrin toxicity were evaluated by performing ovary and uterus histopathology, as well as by characterizing ovarian function, embryos, and litters. Cypermethri... The prophylactic effects of Chinese propolis against cypermethrin toxicity were evaluated by performing ovary and uterus histopathology, as well as by characterizing ovarian function, embryos, and litters. Cypermethrin induced atypia in the ovary and uterus, and decreased the ovulation sites and the number of embryos. Cypermethrin-induced oxidative stress during pregnancy, decreased the parturition rate as well as the number and weight of offspring and increased the incidence of morphological malformations in the offspring. Administration of propolis to cypermethrin-treated animals mitigated cypermethrin-induced reproductive toxicity. 展开更多
关键词 Evaluation of the Effects of Cypermethrin on Female Reproductive function by using Rabbit Model and of the Protective Role of Chinese Propolis Pro GPX
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THE SIGNIFICANCE OF TESTING PREOPERATIVE VISUAL FUNCTION IN CATARACT USING LASER INTERFEROMETRIC VISUAL ACUITY AND ERG 被引量:2
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作者 De-Zheng Wu Lezheng Wu Xijing Xu Hui Chen Taiqing Luo Zhongshan Ophthalmic Center Sun Yat-sen University of Medical Sciences Guangzhou 510060, China 《眼科学报》 1991年第1期21-24,共4页
Tests of preoperative visual function and prediction of postoperative E chart visual acuity(ECVA) using laser interferometric visual acuity(LIVA) and electroretinogram(ERG) were performed in 16 cases(19 eyes) of catar... Tests of preoperative visual function and prediction of postoperative E chart visual acuity(ECVA) using laser interferometric visual acuity(LIVA) and electroretinogram(ERG) were performed in 16 cases(19 eyes) of cataract. The results showed that the coincident rate between preoperative LIVA and postoperative ECVA was 63.2%, and there was a parallel correlation between preoperative amplitude of photopic ERG b-wave and postoperative ECVA in 79.0% of the eyes. Comparing these two methods, the test of LIVA ... 展开更多
关键词 THE SIGNIFICANCE OF TESTING PREOPERATIVE VISUAL function IN CATARACT using LASER INTERFEROMETRIC VISUAL ACUITY AND ERG
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Functional evaluation using several evoked spinal cord potentials in elderly patients with cervical spondylotic myelopathy
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作者 Zhenglin Li 《Neural Regeneration Research》 SCIE CAS CSCD 2006年第3期244-247,共4页
BACKGROUND : The recordings of evoked spinal cord potentials following epidural spinal cord stimulation are thought to be generated by volleys traversing the dorsal column pathway, and it may not directly reflect con... BACKGROUND : The recordings of evoked spinal cord potentials following epidural spinal cord stimulation are thought to be generated by volleys traversing the dorsal column pathway, and it may not directly reflect conduction defects in corticospinat tracts of cervical spinal cord. To our knowledge there has been few report using several evoked spinal cord potentials in function evaluation of the cervical spinal cord in eldedy patients with cervical spondylotic myelopathy (CSM). OBJECTIVE: To investigate the function states of the cervical spinal cord in elderly patients with CSM and explore its pathophysictogic mechanism. DESIGN: Case observation SETTING : Department of Orthopedics for the aged, Shenzhen Pingle Hospital of Orthopedics. Department of Orthopedic Surgery, Yamaguchi University School of Medicine. PARTICIPANTS : A total of 23 eldedy patients with CSM who received treatment in the Department of Orthopedic Surgery, Yamaguchi University School of Medicine of Japan from January 2003 to February 2004 were enrolled in this study. Inclusive criteria: ① Multiple intervertebral levels of cervical spinal cord compression confirmed by MRI, e.g. 3 or more than 3 levels of compressin. ② Age ≥ 70 years old. ③ Numbness and sensory disturbance in the upper limbs and showed hyperreflexia in the lower limbs. Exclusive criteria: Patients with abnormal motor and sensory nerve conduction velocities in both upper and lower limbs were excluded. METHODS: Evoked spinal cord potentials (ESCPs) following transcranial electric stimulation (TCE-ESCPs), epidural spinal cord stimulation (SpinaI-ESCPs) and median nerve stimulation (MN-ESCPs) were recorded in 23 patients from posterior epidural space intreoperatively. The abnormalities of TCE-ESCPs were defined as attenuation of amplitude of the D wave. The most cranial intervertebral level showing abnormal TCE-ESCPs with a marked reduction in size of the negative peak (reduction of over 50%) was considered as the upper level of the spinal cord lesion with respect to the corticospinal tract in white matter. The abnormalities of SpinaI-ESCPs were defined as marked reduction in the size of negative peak (reduction of over 50%). The most caudal intervertebral level showing abnormal SpinaI-ESCPs was considered as the lower level of the spinal cord lesion with respect to the dorsal column pathway in white matter. The abnormalities of MN-ESCPs were defined as attenuation of the N13 amplitude,which was considered as the lesion level of the spinal cord with respect to the dorsal horn in gray matter. Radiological investigation: Lateral view of plain X-ray films was obtained in flexion and extension of the cervical spine. Instability of the cervical intervertebral level was determined as horizontal displacement of the vertebral body of over 3 mm. MAIN OUTCOME MEASURES : The results of examination of TCE-ESCPs, SpinaI-ESCPs and MN-ESCPs in el- dedy patients with CSM. RESULTS: The 23 eldedy patients with CSM were participated in the result analysis. ①TCE-ESCPs: The impairment of the corticospinal tract in white matter at single intervertebral level was revealed in 18 of 23 patients by recordings of TCE-ESCPs (sensitivity 78%). In the 18 patients, the lesion level was shown at the up- per cervical segment in 14 patients (C3-4n=10 and C4-5n=4), and at the lower cervical segment in 4 patients (C5-6n=4). ②Spinal-ESCPs: The impairment of the dorsal column pathway of white matter at single intervertebral level was revealed in 17 of 23 patients, by recordings of Spinal-ESCPs (sensitivity 74%). In the 17 patients, the lesion level was presented at the upper cervical segment in 14 patients (C3-4n=10 and C4-5n=4), and at the lower cervical segment in 3 patients (C5-6 n=3). ③MN-ESCPs: All patients revealed abnormal MN-ESCPs at one or more intervertebral levels (sensitivity 100%). The impairment at single intervertebral level was demonstrated in 17 patients, and the impairment at multiple intervertebral levels was shown in 4 patients (3 patients at the C3-4, C4-4, and C5-4~6, and one patient at the C4-5, C5-6, and C6-7). ④Radiological findings: The Instability of the intervertebral level at the C3-4 or C4-5 motion segment was seen in 15 patients, with a total of 20 levels, and where 10 were at the C3-4 intervertebral level and 5 were at the C3-4, C4-5 intervertebral level. CONCLUSION : The results suggest that in most elderly patients with CSM who have multiple intervertebral level compressions of the cervical spinal cord on MRI, white matter is impaired at the single cervical intervertebral level, and not only the dorsal column pathway, but also the corticospinal tract can be affected. Combined the findings of radiography, the excessive motion and instability of the C3-4 or C4-5 intervertebral level plays an important role in inducing the long tract lesion in elderly patients with CSM. 展开更多
关键词 functional evaluation using several evoked spinal cord potentials in elderly patients with cervical spondylotic myelopathy CSM TCE
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ON VECTOR VALUED FUNCTION APPROXIMATION USING A PEAK NORM
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作者 G.A.Watson 《Analysis in Theory and Applications》 1996年第2期1-12,共12页
A peak norm is defined for Lp spaces of E-valued Bochner integrable functions, where E is a Banach space, and best approximations from a sun to elements of the space are characterized. Applications are given to some f... A peak norm is defined for Lp spaces of E-valued Bochner integrable functions, where E is a Banach space, and best approximations from a sun to elements of the space are characterized. Applications are given to some families of simultaneous best approximation problems. 展开更多
关键词 ON VECTOR VALUED function APPROXIMATION using A PEAK NORM 任气
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SYNTHESIS OF FUNCTIONAL UNSATURATED POLYESTER BY USING RARE EARTH CATALYSTS 2.TERPOLYMERIZATION OF EPICHLOROHYDRINMALEIC ANHYDRIDE-CARBON DIOXIDE WITH Y(P_(204))_3-Al(i-Bu)_3
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作者 Xian Hai CHEN Yi Feng ZHANG Zhi Quan SHENDepartment of Chemistry,Zhejiang University,Hangzhou 310027 《Chinese Chemical Letters》 SCIE CAS CSCD 1992年第5期359-360,共2页
Teroolymerization of enichlorohydrin(ECH)-maleic anhydride(MAn)-carbon dioxide(CO;) was carried out by using Y(P;);-Al(i-Bu);as catalyst for the first time.The terpolymersobtained were characterized by IR and;... Teroolymerization of enichlorohydrin(ECH)-maleic anhydride(MAn)-carbon dioxide(CO;) was carried out by using Y(P;);-Al(i-Bu);as catalyst for the first time.The terpolymersobtained were characterized by IR and;H-NMR.It was foundthat the composition of the teroolymer was influenced by theaddition mode,initial monomer charge ratio,etc. 展开更多
关键词 Al i-Bu SYNTHESIS OF functionAL UNSATURATED POLYESTER BY using RARE EARTH CATALYSTS 2.TERPOLYMERIZATION OF EPICHLOROHYDRINMALEIC ANHYDRIDE-CARBON DIOXIDE WITH Y
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Detecting the nerve function of fibril in patients with cervicalspondylotic radiculopathy using quantitative sensory testing
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作者 Lang He Ying Zhao 《Neural Regeneration Research》 SCIE CAS CSCD 2006年第8期729-732,共4页
BACKGROUND: Pain and sensory disability are greatly affected by subjective factors, there are no quantitative indexes to evaluate cervical spondylotic radiculopathy(CSR). The judgment on clinical body examination and ... BACKGROUND: Pain and sensory disability are greatly affected by subjective factors, there are no quantitative indexes to evaluate cervical spondylotic radiculopathy(CSR). The judgment on clinical body examination and chief complaint always causes nonobjective results with great individual differences. Quantitative sensory testing (QST) can be used to judge the nerve function of fibril. The application of QST for the quantitative evaluation of peripheral nervous system disease needs to be further studied. OBJECTIVE: The cold-thermal sensation and pain of patients with CSR are quantitatively analyzed by using QST technology in order to evaluate the nerve function of fibril in patients with CSR. DESIGN: Case-control observation. SETTING: Pain Center of Beijing Hospital of Ministry of Health. PARTICIPANTS: Twenty patients with CSR, including 8 males and 12 females, aged from 33 to 70 years, who received treatment between January and April 2005 in Pain Center of Beijing Hospital of Ministry of Health were involved in CSR group. All the involved patients presented symptoms in unilateral upper extremity (left side 10 patients, right side 10 patients). They did not undergo physical therapy or nerve block therapy in 1 week before examination. Eight non-CSR patients who received treatment in Pain Center concurrently were involved in the control group (2 patients with trigeminal neuralgia, 4 with osteoarthrosis of knee joint and 2 with lumbar intervertebral disc protrusion), and another 12 healthy volunteers were involved. Four non-CSR patients and 12 healthy volunteers, 8 male and 12 female, were aged from 23 to 75 years. The informed consents were obtained from all the involved subjects. METHODS: The volar thresholds of cold sensation, thermal sensation, cryalgesia of thenar eminence of both upper extremities of all the subjects were examined separately by limit method with type TSA-Ⅱ temperature sensation analysator made by Medco Company (Israel). The subjects were pre-examined to be familiar with the method for sensory discrimination and affirmation. Thenar eminence vola of bilateral upper extremities were detected. The infrared detector of a semiconductor was contacted with skin. The infrared detector could be used to heat and cool skin. A group of cold-heat water circulation device was given electric current to produce temperature gradient, which was higher or lower than skin temperature. The initial temperature of infrared detector was 32 ℃, stimulation temperature was increased or decreased progressively at 1 ℃/s, and temperature change range was 0 to 50 ℃. In the first step, subjects pressed down the button to stop the stimulation when the temperature of infrared detector was decreased progressively until the subjects felt, and the threshold of cold sensation was obtained; In the second step, the threshold of thermal sensation was obtained when the temperature of infrared detector was increased progressively until the subjects felt; In the third step, the threshold of cryalgesia was obtained when the temperature of infrared detector was decreased progressively until subjects felt; and in the fourth step, the threshold of thermalgesia was obtained when the temperature of infrared detector was increased progressively until subjects felt. Each step was conducted 4 times and the mean threshold was obtained. Before each measurement, the temperature was made to rebound to the initial temperature and kept for 10 s. MAIN OUTCOME MEASURES: The thresholds of cold sensation, thermal sensation and cryalgesia, thermalgesia of thenar eminence vola of bilateral upper extremities of all the subjects. RESULTS: Twenty patients with CSR and 20 healthy subjects participated in the final results. ① In the CSR group, the threshold of cold sensation of affected side was lower than that of intact side [(29.00±1.26) ℃ vs.(30.00±1.06) ℃, P < 0.05], and the threshold of thermal sensation of affected side was higher than that of intact side [(35.04±0.87) ℃ vs. (34.14±0.99) ℃, P < 0.05]. There were no significant differences in the thresholds of cold and thermal sensation between affected side and intact side (P > 0.05). ②In the CSR group, the difference of threshold of cold sensation, thermal sensation, cryalgesia and thermalgesia between affected side and intact side was (-1.01±0.57), (0.89±0.39), (2.49±1.10) and (-1.62±0.86) ℃, respectively , the absolute value of which was higher than that of control group, respectively [(0.04±0.28),(0.05±0.26),(0.28±1.79),(0.17±1.10) ℃,P < 0.01]. In the CSR group, the threshold of cold sensation and thermalgesia of affected side was lower than that of intact side, respectively; and the threshold of thermal sensation and cryalgesia of affected side was higher than that of intact side, respectively. CONCLUSION: The superficial sensation of affected extremity of patients with CSR is lessened as compared with that of intact extremity. There are dysfunctions of small myelinated fiber (Aδ fiber) and demyelinated fiber (C fiber) in the affected-side extremity. QST, as a mean for quantitatively evaluating the function of Aδ fiber and C fiber, plays an objective evaluative role in the diagnosis and therapeutic effect observation of CSR. 展开更多
关键词 CSR Detecting the nerve function of fibril in patients with cervicalspondylotic radiculopathy using quantitative sensory testing
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Spatiotemporal mismatch of land use functions and land use efficiencies and their influencing factors:A case study in the Middle Reaches of the Yangtze River,China 被引量:1
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作者 GAO Yunxiao WANG Zhanqi +1 位作者 CHAI Ji ZHANG Hongwei 《Journal of Geographical Sciences》 SCIE CSCD 2024年第1期62-88,共27页
Identification of the spatial mismatch between land use functions(LUFs)and land use efficiencies(LUEs)is essential to regional land use policies.However,previous studies about LUF-LUE mismatch and its driving factors ... Identification of the spatial mismatch between land use functions(LUFs)and land use efficiencies(LUEs)is essential to regional land use policies.However,previous studies about LUF-LUE mismatch and its driving factors have been insufficient.In this study,we explored the spatiotemporal mismatch of LUFs and LUEs and their influencing factors from 2000 to 2018 in the Middle Reaches of the Yangtze River(MRYR).Specifically,we used Spearman correlation analysis to reveal the trade-off relationship between LUFs and LUEs and determine the direction of the influencing factors on the LUF-LUE mismatch,adopted spatial mismatch analysis to measure the imbalance between LUFs and LUEs,and used the geographical detector model to analyze the factors influencing this spatial mismatch.The results showed that production function(PDF),living function(LVF),ecological function(ELF),agricultural production efficiency(APE),urban construction efficiency(UCE),and ecological services efficiency(ESE)all displayed significant spatial heterogeneity.The high trade-off areas were widely distributed and long-lasting in agricultural space and urban space,while gradually decreasing in ecological space.Wuhan and Changsha showed high spatial mismatch coefficients in urban space,but low spatial mismatch coefficients in agricultural space.Hunan generally presented high spatial mismatch coefficients in ecological space.Furthermore,the interaction of the proportion of cultivated area and transportation accessibility exacerbated the mismatch in agricultural space.The interaction effects of capital investment and technology innovation with other factors have the most intense impact on the mismatch in urban space.The internal factor for cultivated area interacts with other external factors to drastically affect ecological spatial mismatch. 展开更多
关键词 land use function land use efficiency spatial mismatch analysis influencing factors Middle Reaches of the Yangtze River
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Study on the proposed environmental guidelines for Cd, Hg, Pb and As in soil of China 被引量:7
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作者 Wu Yanyu, Tian Junliang Zhou QixingInstitute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110015, ChinaNorthwest Institute of Water and Soil Conservation, Chinese Academy of Sciences, Shaanxi 712100, China 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 1992年第1期66-73,共8页
This paper deals with the soil-environmental standard. According to the current situation of researching on the soil-environmental quality guideline at home and abroad, and on the basis of the foundations and principl... This paper deals with the soil-environmental standard. According to the current situation of researching on the soil-environmental quality guideline at home and abroad, and on the basis of the foundations and principles of enacting the soil-environmental standard, the soil environment quality guideline values of Hg, Cd, Pb and As were suggested. 展开更多
关键词 soil-environmental standard soil guideline heavy metal functional land use soil background content.
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A Collocation Method for Initial Value Problems of Second-Order ODEs by Using Laguerre Functions 被引量:4
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作者 Jian-Ping Yan Ben-Yu Guo 《Numerical Mathematics(Theory,Methods and Applications)》 SCIE 2011年第2期283-295,共13页
We propose a collocation method for solving initial value problems of secondorder ODEs by using modified Laguerre functions.This new process provides global numerical solutions.Numerical results demonstrate the effici... We propose a collocation method for solving initial value problems of secondorder ODEs by using modified Laguerre functions.This new process provides global numerical solutions.Numerical results demonstrate the efficiency of the proposed algorithm. 展开更多
关键词 Laguerre-Gauss collocation method using modified Laguerre functions initial value problems of second-order ODEs
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Time lag characteristics of sap flow in seed-maize and their implications for modeling transpiration in an arid region of Northwest China 被引量:4
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作者 BO Xiaodong DU Taisheng +1 位作者 DING Risheng Louise COMAS 《Journal of Arid Land》 SCIE CSCD 2017年第4期515-529,共15页
Plant capacity for water storage leads to time lags between basal stem sap flow and transpiration in various woody plants. Internal water storage depends on the sizes of woody plants. However, the changes and its infl... Plant capacity for water storage leads to time lags between basal stem sap flow and transpiration in various woody plants. Internal water storage depends on the sizes of woody plants. However, the changes and its influencing factors in time lags of basal stem flow during the development of herbaceous plants including crops remain unclear. A field experiment was conducted in an arid region of Northwest China to examine the time lag characteristics of sap flow in seed-maize and to calibrate the transpiration modeling. Cross-correlation analysis was used to estimate the time lags between stem sap flow and meteorological driving factors including solar radiation(R_s) and vapor pressure deficit of the air(VPD_(air)). Results indicate that the changes in seed-maize stem sap flow consistently lagged behind the changes in R_s and preceded the changes in VPD_(air) both on hourly and daily scales, suggesting that light-mediated stomatal closures drove sap flow responses. The time lag in the maize's sap flow differed significantly during different growth stages and the difference was potentially due to developmental changes in capacitance tissue and/or xylem during ontogenesis. The time lags between stem sap flow and R_s in both female plants and male plants corresponded to plant use of stored water and were independent of total plant water use. Time lags of sap flow were always longer in male plants than in female plants. Theoretically, dry soil may decrease the speed by which sap flow adjusts ahead of shifts in VPD_(air) in comparison with wet soil and also increase the speed by which sap flow adjusts to R_s. However, sap flow lags that were associated with R_s before irrigation and after irrigation in female plants did not shift. Time series analysis method provided better results for simulating seed-maize sap flow with advantages of allowing for fewer variables to be included. This approach would be helpful in improving the accuracy of estimation for canopy transpiration and conductance using meteorological measurements. 展开更多
关键词 seed-maize sap flow capacitance transfer function model time lag stored water use
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Quantitative identification and the evolution characteristics of production–living–ecological space in the mountainous area:From the perspective of multifunctional land 被引量:1
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作者 JI Zhengxin LIU Chao +6 位作者 XU Yueqing SUN Minxuan WEI Hejie SUN Danfeng LI Yaoyao ZHANG Ping SUN Qiangqiang 《Journal of Geographical Sciences》 SCIE CSCD 2023年第4期779-800,共22页
Developed here is an integrated framework for identifying production–living–ecological space(PLES)quantitatively at grid scale from the perspective of multifunction land use,and 25 compound space types are classifie... Developed here is an integrated framework for identifying production–living–ecological space(PLES)quantitatively at grid scale from the perspective of multifunction land use,and 25 compound space types are classified to highlight the multiple functions of PLES.As a typical mountainous city in northern Hebei province,Zhangjiakou is used as a case study,and the results show that more than 80%of the land space in Zhangjiakou has remarkable triple functionality.The living-dominated space and the production-dominated space are distributed mainly in the valleys of the Yanghe,Sanggan,and Huliu rivers and have obvious spatial consistency,while the ecological-dominated space is concentrated mostly at the eastern Yanshan Mountains and southern Taihang Mountains and complements the other two types of space.The former two are spatially fragmented,while the latter has been expanding to the periphery over time.From 1990 to 2015,the ecological-dominated space has increased the most by 1555.02 km^(2),while the living-dominated space has increased the least by 816.79 km^(2).The types of PLES are more diverse in the medium and low mountains and the areas with gentle slope,and the influencing factors include natural ecological environment,socioeconomic development,human consumption demand,and institutional policies.Therefore,these findings can mitigate conflicts among PLES in mountainous and similar areas,and promote the balanced development of land space. 展开更多
关键词 land use function value evaluation production-living-ecological space spatial and temporal varia-tion Zhangjiakou
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Reliable iris localization using integral projection function and 2D-shape properties
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作者 Farmanullah Jan Imran Usman Shahrukh Agha 《Chinese Optics Letters》 SCIE EI CAS CSCD 2012年第11期50-55,共6页
Iris recognition technology recognizes a human based on his/her iris pattern. However, the accuracy of the iris recognition technology depends on accurate iris localization. Localizing a pupil region in the presence o... Iris recognition technology recognizes a human based on his/her iris pattern. However, the accuracy of the iris recognition technology depends on accurate iris localization. Localizing a pupil region in the presence of other low-intensity regions, such as hairs, eyebrows, and eyelashes, is a challenging task. This study proposes an iris localization technique that includes a localizing pupillary boundary in a sub-image by using an integral projection function and two-dimensional shape properties (e.g., area, geometry, and circularity). The limbic boundary is localized using gradients and an error distance transform, and the boundary is regularized with active contours. Experimental results obtained from public databases show the superiority of the Drooosed techniaue over contemporary methods. 展开更多
关键词 Reliable iris localization using integral projection function and 2D-shape properties ROI
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Using the system function to analyze the performance of transducer's impedance measurement method
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作者 LI Haifeng ZENG Juan +3 位作者 GAO Tianfu LIU Haijun PENG Dayong ZHAO Wenyao 《Chinese Journal of Acoustics》 2013年第3期211-221,共11页
Prom investigation of the advantages and disadvantages of conventional tri-voltage method,a method for the measurement of the transmitting transducer's impedance was presented to solve the difficult problem of examin... Prom investigation of the advantages and disadvantages of conventional tri-voltage method,a method for the measurement of the transmitting transducer's impedance was presented to solve the difficult problem of examining the consistency of the transmitting phased array on the single-mode excitation sea spot.In the method based on the system function, the circuit structure of tri-voltage method was used but new parameters were measured.The principle of the method was given first.Then when resistors with different nominal values were used in the circuit,the measured results for the impedance of transducers were reported.The results were compared with the higher precision impedance analyzer.Finally,the error analysis was performed according to the impedance formula and the equivalent circuit parameters were fitted.Under the condition of guaranteeing the sampling precision,by performance analyzing, the resistor value in series was chosen relatively smaller than the impedance of transducer,the measurement of impedance could achieve the same precision as the higher precision impedance analyzer.Finally,the least squares curve-fitting of measured curves indicated that the transducer equivalent electrical parameters could be extracted accurately and used to design the matching network. 展开更多
关键词 using the system function to analyze the performance of transducer’s impedance measurement method
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1Chinese human geography and its contributions 被引量:4
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作者 FAN Jie 《Journal of Geographical Sciences》 SCIE CSCD 2016年第8期987-1000,共14页
The aim of this paper is to sift through examples of outstanding contributions made by Chinese human geography in terms of social applications and explain the basic concepts and theoretical methods explored by human g... The aim of this paper is to sift through examples of outstanding contributions made by Chinese human geography in terms of social applications and explain the basic concepts and theoretical methods explored by human geography that are behind the applications of results with major social influence, so as to be able to summarize the main school that represents developments in contemporary Chinese human geography. Chinese human geography upholds the subject's designation as being integrated and interdisciplinary. Research focuses on interactions between the natural and human spheres of the Earth's surface, and it is guided by the understanding and effects of the processes of regional sustainable development at different spatial scales. Chinese human geography has innovatively established the following development paradigm: "To be guided by application requirements, refine key issues of the discipline in the course of solving major issues of human geography in national and regional development, and by solving those key issues, to enhance its ability to provide scientific and technological support to serve national and local needs while promoting its own development." Results from early Chinese human geography studies on land use and agricultural zoning, recent research results on point-axis system models and T-shaped national spatial development patterns, and current research results on territorial function theory and major function oriented zones have all continued and strengthened the mainstream school of Chinese human geography and have avoided the global tendency for human geography to become rapidly human-oriented, while results have been applied at the highest level of decision-making management. Chinese human geography can provide lessons for developing countries and may play a leading role in the future development of global human geography. 展开更多
关键词 Chinese human geography main school social contribution land use agricultural zoning point-axis system T-shaped land development structure territorial function major function oriented zone
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城市用地功能混合测度方法的比较研究
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作者 赵广英 宋聚生 +2 位作者 刘淑娟 Qian Fang(Translated) Tang Yan(Proofread) 《China City Planning Review》 CSCD 2022年第3期58-71,共14页
The study aims at exploring the applicability and limitations of domestic and foreign methods for measuring the function mixing of urban land use,and sorting out various classic measurement methods according to the lo... The study aims at exploring the applicability and limitations of domestic and foreign methods for measuring the function mixing of urban land use,and sorting out various classic measurement methods according to the logic of “conceptual reflection–characteristics comparison–limitation analysis.” The study shows that:① the connotation and types of mixed land use functions are still controversial at home and abroad;② there is a lack of research on measurement methods in China;③ for medium and micro-scale planning,current measurement methods cannot fully reflect the differences in the degree of mixing caused by the planar and three-dimensional layout of building functions within the grid;④ the measurement methods for refined planning governance should improve the measurement model in terms of the number of functional types and the mixed layout of various functions in the horizontal and vertical directions at the medium and micro-scales,and improve its accuracy of the measurement results of a single grid and the whole area. 展开更多
关键词 urban planning function mixing of land use MEASUREMENT model LIMITATION IMPROVEMENT
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