维普中文期刊产品整合服务
54篇 您的检索式:作者名="Shen Yanping"
    题名 作者 年代 出处 被引量
1Component analysis of Chinese medicine and advances in fuming-washing therapy for knee osteoarthritis via unsupervised data mining methods显示文摘OBJECTIVE: To analyze the component law of Chinese medicines in fuming-washing therapy for knee osteoarthritis(KOA), and develop new fuming-washing prescriptions for KOA through unsupervised data mining methods.METHODS: Chinese medicine recipes for fuming-washing therapy for KOA were collected and recorded in a database. The correlation coefficient among herbs, core combinations of herbs, andnew prescriptions were analyzed using modified mutual information, complex system entropy cluster, and unsupervised hierarchical clustering, respectively.RESULTS: Based on analysis of 345 Chinese medicine recipes for fuming-washing therapy, 68 herbs occurred frequently, 33 herb pairs occurred frequently, and 12 core combinations were found.Five new fuming-washing recipes for KOA were developed.CONCLUSION: Chinese medicines for fuming-washing therapy of KOA mainly consist of wind-dampness-dispelling and cold-dispersing herbs, blood-activating and stasis-resolving herbs,and wind-dampness-dispelling and heat-clearing herbs. The treatment of fuming-washing therapy for KOA also includes dispelling wind-dampness and dispersing cold, activating blood and resolving stasis, and dispelling wind-dampness and clearing heat. Zhenzhutougucao(Herba Speranskiae Tuberculatae), Honghua(Flos Carthami), Niuxi(Radix Achyranthis Bidentatae), Shenjincao(Herba Lycopodii Japonici), Weilingxian(Radix et Rhizoma Clematidis Chinensis), Chuanwu(Radix Aconiti), Haitongpi(Cortex Erythrinae Variegatae), Ruxiang(Olibanum),Danggui(Radix Angelicae Sinensis), Caowu(Radix Aconiti Kusnezoffii), Moyao(Myrrha), and Aiye(Folium Artemisiae Argyi) are the main herbs used in the fuming-washing treatment for KOA.Jun Liu Jianke Pan Yanping Wang Dingkun Lin Dan Shen Hongjun Yang Xiang Li Minghui Luo Xuewei Cao 2013Journal of Traditional Chinese Medicine2013,33,5:32
2Active catalysts based on cobalt oxide@cobalt/N-C nanocomposites for oxygen reduction reaction in alkaline solutions显示文摘Dekang Huang Yanping Luo Shaohui Li Bingyan Zhang Yan Shen Mingkui Wang 2014Nano Research2014,7,7:8
3Hypoxia-stressed cardiomyocytes promote early cardiac differentiation of cardiac stem cells through HIF-1α/Jagged1/Notch1 signaling显示文摘Hypoxia is beneficial for the differentiation of stem cells transplanted for myocardial injury,but mechanisms underlying this benefit remain unsolved. Here, we report the impact of hypoxia-induced Jagged1 expression in cardiomyocytes(CMs) for driving the differentiation of cardiac stem cells(CSCs).Forced hypoxia-inducible factor 1α(HIF-1α) expression and physical hypoxia(5% O_2) treatment could induce Jagged1 expression in neonatal rat CMs. Pharmacological inhibition of HIF-1α by YC-1 attenuated hypoxia-promoted Jagged1 expression in CMs. An ERK inhibitor(PD98059), but not inhibitors of JNK(SP600125), Notch(DAPT), NF-κB(PTDC), JAK(AG490), or STAT3(Stattic) suppressed hypoxiainduced Jagged1 protein expression in CMs. c-Kit^+ CSCs isolated from neonatal rat hearts using a magnetic-activated cell sorting method expressed GATA4, SM22α or vWF, but not Nkx2.5 and cTnI.Moreover, 87.3% of freshly isolated CSCs displayed Notch1 receptor expression. Direct co-culture of CMs with BrdU-labeled CSCs enhanced CSCs differentiation, as evidenced by an increased number of BrdU^+/Nkx2.5^+ cells, while intermittent hypoxia for 21 days promoted co-culture-triggered differentiation of CSCs into CM-like cells. Notably, YC-1 and DAPT attenuated hypoxia-induced differentiation.Our results suggest that hypoxia induces Jagged1 expression in CMs primarily through ERK signaling,and facilitates early cardiac lineage differentiation of CSCs in CM/CSC co-cultures via HIF-1α/Jagged1/Notch signaling.Keke Wang Ranran Ding Yanping Ha Yanan Jia Xiaomin Liao Sisi Wang Rujia Li Zhihua Shen Hui Xiong Junli Guo Wei Jie 2018Acta Pharmaceutica Sinica B2018,8,5:7
4Multi-task Joint Sparse Representation Classification Based on Fisher Discrimination Dictionary Learning显示文摘Recently,sparse representation classification(SRC)and fisher discrimination dictionary learning(FDDL)methods have emerged as important methods for vehicle classification.In this paper,inspired by recent breakthroughs of discrimination dictionary learning approach and multi-task joint covariate selection,we focus on the problem of vehicle classification in real-world applications by formulating it as a multi-task joint sparse representation model based on fisher discrimination dictionary learning to merge the strength of multiple features among multiple sensors.To improve the classification accuracy in complex scenes,we develop a new method,called multi-task joint sparse representation classification based on fisher discrimination dictionary learning,for vehicle classification.In our proposed method,the acoustic and seismic sensor data sets are captured to measure the same physical event simultaneously by multiple heterogeneous sensors and the multi-dimensional frequency spectrum features of sensors data are extracted using Mel frequency cepstral coefficients(MFCC).Moreover,we extend our model to handle sparse environmental noise.We experimentally demonstrate the benefits of joint information fusion based on fisher discrimination dictionary learning from different sensors in vehicle classification tasks.Rui Wang Miaomiao Shen Yanping Li Samuel Gomes 2018Computers, Materials & Continua2018,,10:6
5Research Progress of Active Ingredients and Pharmacological Action of Honeysuckle显示文摘Honeysuckle,the dry flower bud or with open flower of Lonicera japonica in caprifoliaceae,has been touted as a cure-all for heat-clearing and detoxifying effect.Honeysuckle contains abundant components such as volatile oil,flavonoids and organic acids,playing the role of antibiosis,antivirus,antiphlogosis,immunopotentiation and antioxidation.The active ingredients and pharmacological action of honeysuckle are reviewed in the paper,so as to lay the foundation for further application of honeysuckle in veterinary clinic.Zhang Zhimei Guo Shijin Fu Shijun Xu Qianqian Yang Limei Zhang Ying Wang Yanping Ma Li Wang Jianjun Shen Zhiqiang 2014Animal Husbandry and Feed Science2014,6,1:4
6Effects of Shuanghuanglian Propolis Oral Liquid on Growth Performance,Slaughter Performance and Meat Quality of Broilers显示文摘[Objective] The paper was to investigate the effects of adding Shuanghuanglian propolis oral liquid in drinking water on growth performance,slaughter performance and meat quality of broilers. [Method]Ninety one-day-old broilers were randomly divided into three groups( group Ⅰ,group Ⅱ and group Ⅲ) : group Ⅰ was the control group,and groups Ⅱ and Ⅲ were added 0. 5 and 1. 0 mL / L Shuanghuanglian propolis oral liquid in drinking water,respectively.[Result] Compared with broilers in group I,the average daily feed intakes of broilers in group Ⅱ and group Ⅲ were increased by 0. 86%( P > 0. 05) and 1. 10%( P > 0. 05),respectively; the average daily gains were increased by 2. 33%( P < 0. 05) and 4. 43%( P < 0. 05),respectively; the feed gain ratios were decreased by 1. 05%( P >0. 05) and 2. 63%( P <0. 05),respectively; the slaughter rates were increased by 0. 94%( P >0. 05) and 1. 70%( P <0. 05),respectively; the eviscerated rates were increased by 0. 52%( P > 0. 05) and 1. 15%( P > 0. 05),respectively; the semi-eviscerated rates were increased by 1. 51%( P < 0. 05) and 2.23%( P < 0. 05),respectively; the breast muscle rates were increased by 3. 77%( P < 0. 05) and 5. 51%( P < 0. 05),respectively; the leg muscle rates were increased by 1. 96%( P > 0. 05) and 4. 09%( P < 0. 05),respectively; the lightness( L*) were decreased by 0. 96%( P > 0. 05) and 1. 47%( P > 0. 05),respectively; the redness( a*) were increased by 1. 24%( P < 0. 05) and 1. 86%( P < 0. 05),respectively; the yellowness( b*) were decreased by 0. 44%( P >0. 05) and 1. 03%( P <0. 05),respectively; the drip losses were decreased by 1. 22%( P <0. 05) and 1. 56%( P <0. 05),respectively; the cooking losses were decreased by 1. 76%( P > 0. 05) and 2. 89%( P < 0. 05),respectively. [Conclusion]Adding 0. 5 and 1. 0 mL / L Shuanghuanglian propolis oral liquid in drinking water could improve growth performance,slaughter performance,meat quality of broilers,and the dose of 1. 0 mL / L is recommended in clinical application.Ma Li Yang Limei Shen Zhiqiang Wang Yanping Xu Qianqian Zhang Ying Guo Shijin 2016Animal Husbandry and Feed Science2016,8,4:4
7A New Understanding of Channel Patterns and Facies Models of the Shallow Lake Delta Facies of Fuyu Oil Reservoir in Songliao Basin,China显示文摘摘要:在 Songliao 盆的 Fuyu 水库,在那里发生一系列开发得好的古怪的浅湖三角洲外形,它能被划分到象上面的三角洲平原 subfacies,更低的三角洲平原 subfacies,和三角洲前面 subfacies 的如此的三。在他们之中,上面的三角洲平原 subfacies 主要种近似支流隧道;更低的三角洲平原 subfacies 主要增长远侧的。全部 Fuyu 水库主要开发了 7 种支流隧道模式:proximal/ 远侧的蜿蜒地流类型支流隧道,近似 / 远侧的低蜿蜒的类型支流隧道,近似 / 远侧的直类型支流隧道,和水下的支流隧道。在这些模式之中,近似、远侧的蜿蜒地流的类型支流隧道有点酒吧并且更好的排序和泥的低内容的更大的厚度;而且,他们是主要水库并且发生在 Quan-4th 的底部成员。水下的支流隧道的沙洲有更高的泥内容,并且用作更差的水库,并且主要发生在 Quan-4th 成员的顶。LI Yanping CHEN Shumin SONG Yongzhong ZHANG Erhua SHEN Jiagang ZHENG Jianbin 2008Acta Geologica Sinica(English Edition)2008,82,3:3
8Neurological function following intra-neural injection of fluorescent neuronal tracers in rats显示文摘Fluorescent neuronal tracers should not be toxic to the nervous system when used in long-term labeling.Previous studies have addressed tracer toxicity,but whether tracers injected into an intact nerve result in functional impairment remains to be elucidated.In the present study,we examined the functions of motor,sensory and autonomic nerves following the application of 5% Fluoro-Gold,4% True Blue and 10% Fluoro-Ruby (5μL) to rat tibial nerves via pressure injection.A set of evaluation methods including walking track analysis,plantar test and laser Doppler perfusion imaging was used to determine the action of the fluorescent neuronal tracers.Additionally,nerve pathology and ratio of muscle wet weight were also observed.Results showed that injection of Fluoro-Gold significantly resulted in loss of motor nerve function,lower plantar sensibility,increasing blood flow volume and higher neurogenic vasodilatation.Myelinated nerve fiber degeneration,unclear boundaries in nerve fibers and high retrograde labeling efficacy were observed in the Fluoro-Gold group.The True Blue group also showed obvious neurogenic vasodilatation,but less severe loss of motor function and degeneration,and fewer labeled motor neurons were found compared with the Fluoro-Gold group.No anomalies of motor and sensory nerve function and no myelinated nerve fiber degeneration were observed in the Fluoro-Ruby group.Experimental findings indicate that Fluoro-Gold tracing could lead to significant functional impairment of motor,sensory and autonomic nerves,while functional impairment was less severe following True Blue tracing.Fluoro-Ruby injection appears to have no effect on neurological function.Wen Hu Dan Liu Yanping Zhang Zhongyi Shen Tianwen Gu Xiaosong Gu Jianhui Gu 2013Neural Regeneration Research2013,8,14:3
9Three-dimensional reconstruction of Picea wilsonii Mast. pollen grains using automated electron microscopy显示文摘Three-dimensional electron microscopy(3 D-EM) has attracted considerable attention because of its ability to provide detailed information with respect to developmental analysis. However, large-scale high-resolution 3 D reconstruction of biological samples remains challenging. Herein, we present a 3 D view of a Picea wilsonii Mast. pollen grain with 100 nm axial and38.57 nm lateral resolution using AutoCUTS-SEM(automatic collector of ultrathin sections-scanning electron microscopy). We established a library of 3,127 100 nm thick serial sections of pollen grains for preservation and observation, demonstrating that the protocol can be used to analyze large-volume samples. After obtaining the SEM images, we reconstructed an entire pollen grain comprising 734 serial sections. The images produced by 3D reconstruction clearly revealed the main components of the P.wilsonii pollen grain, i.e., two sacci and pollen corpus, tube cell, generative cell, and two degenerated prothallial cells, and their internal organization. In addition, we performed a quantitative analysis of the different pollen grain cells, including sacci, and found that there were 202 connections within a saccus SEM image. Thus, for the first time, this study provided a global 3D view of the entire pollen grain, which will be useful for analyzing pollen development and growth.Weiwei Shen Lingyu Ma Xi Zhang Xixia Li Yuanyuan Zhao Yanping Jing Yun Feng Xueke Tan Fei Sun Jinxing Lin 2020Science China(Life Sciences)2020,63,2:3
10Fiber-tip polymer clamped-beam probe for high-sensitivity nanoforce measurements显示文摘Micromanipulation and biological,material science,and medical applications often require to control or measure the forces asserted on small objects.Here,we demonstrate for the first time the microprinting of a novel fiber-tip-polymer clamped-beam probe micro-force sensor for the examination of biological samples.The proposed sensor consists of two bases,a clamped beam,and a force-sensing probe,which were developed using a femtosecond-laser-induced two-photon polymerization(TPP)technique.Based on the finite element method(FEM),the static performance of the structure was simulated to provide the basis for the structural design.A miniature all-fiber micro-force sensor of this type exhibited an ultrahigh force sensitivity of 1.51 nmμN−1,a detection limit of 54.9 nN,and an unambiguous sensor measurement range of~2.9 mN.The Young’s modulus of polydimethylsiloxane,a butterfly feeler,and human hair were successfully measured with the proposed sensor.To the best of our knowledge,this fiber sensor has the smallest force-detection limit in direct contact mode reported to date,comparable to that of an atomic force microscope(AFM).This approach opens new avenues towards the realization of small-footprint AFMs that could be easily adapted for use in outside specialized laboratories.As such,we believe that this device will be beneficial for high-precision biomedical and material science examination,and the proposed fabrication method provides a new route for the next generation of research on complex fiber-integrated polymer devices.Mengqiang Zou Changrui Liao Shen Liu Cong Xiong Cong Zhao Jinlai Zhao Zongsong Gan Yanping Chen Kaiming Yang Dan Liu Ying Wang Yiping Wang 2021Light(Science & Applications)2021,10,9:3
11Plant multiscale networks:charting plant connectivity by multi-level analysis and imaging techniques显示文摘In multicellular and even single-celled organisms,individual components are interconnected at multiscale levels to produce enormously complex biological networks that help these systems maintain homeostasis for development and environmental adaptation.Systems biology studies initially adopted network analysis to explore how relationships between individual components give rise to complex biological processes.Network analysis has been applied to dissect the complex connectivity of mammalian brains across different scales in time and space in The Human Brain Project.In plant science,network analysis has similarly been applied to study the connectivity of plant components at the molecular,subcellular,cellular,organic,and organism levels.Analysis of these multiscale networks contributes to our understanding of how genotype determines phenotype.In this review,we summarized the theoretical framework of plant multiscale networks and introduced studies investigating plant networks by various experimental and computational modalities.We next discussed the currently available analytic methodologies and multi-level imaging techniques used to map multiscale networks in plants.Finally,we highlighted some of the technical challenges and key questions remaining to be addressed in this emerging field.Xi Zhang Yi Man Xiaohong Zhuang Jinbo Shen Yi Zhang Yaning Cui Meng Yu Jingjing Xing Guangchao Wang Na Lian Zijian Hu Lingyu Ma Weiwei Shen Shunyao Yang Huimin Xu Jiahui Bian Yanping Jing Xiaojuan Li Ruili Li Tonglin Mao Yuling Jiao Sodmergen Haiyun Ren Jinxing Lin 2021Science China(Life Sciences)2021,64,9:3
12Thermoelectric properties of p-type (Bi_(0.15)Sb_(0.85))_2Te_3-PbTe graded thermoelectric materials with different barriers显示文摘The p-type (Bi0.15Sb0.85)2Te3 and PbTe are typical thermoelectric materials used for low and middle temperature range and functional graded materials (FGM) is an inevitable way to widen the working temperature range. Here two segments graded thermoelectric materials (GTM) consisting of (Bi0.15Sb0.85)2Te3, PbTe and different barriers were fabricated by the common hot pressure method. Metals Fe, Mg and Ni were used as barriers between the two segments. The diffusion of different barriers between the barriers and bases were analyzed by electron microprobe analysis (EMA). The phase and crystal structures were determined by X-ray diffraction analysis (XRD). The thermoelectric properties were measured at 303 K along the direction parallel to the pressing direction. The results show that the compositional diffusion occurs when there is no barrier at the interface of the two segments, and the diffusion of Pb is most obvious; as the barrier material, the diffusion of metals Fe, Mg and Ni between different bases is not very obvious, and the thermoelectric properties of GTM is much better than that of the original segment.Guiying Xu Yanping Gao Changchun Ge Weiping Shen 2005Journal of University of Science and Technology Beijing2005,12,4:3
13Direct demonstration of carrier distribution and recombination within step-bunched UV-LEDs显示文摘AlGaN-based solid state UV emitters have many advantages over conventional UV sources. However, UV-LEDs still suffer from numerous challenges, including low quantum efficiency compared to their blue LED counterparts. One of the inherent reasons is a lack of carrier localization effect inside fully miscible AlGaN alloys. In the pursuit of phase separation and carrier localization inside the active region of AlGaN UV-LED, utilization of highly misoriented substrates proves to be useful, yet the carrier distribution and recombination mechanism in such structures has seldom been reported. In this paper, a UV-LED with step-bunched surface morphology was designed and fabricated, and the internal mechanism of high internal quantum efficiency was studied in detail. The correlation between microscale current distribution and surface morphology was provided, directly demonstrating that current prefers to flow through the step edges of the epitaxial layers. Experimental results were further supported by numerical simulation. It was found that efficient radiative recombination centers were formed in the inclined quantum well regions. A schematic three-dimensional energy band structure of the multiple quantum wells(MQWs) across the step was proposed and helps in further understanding the luminescence behavior of LEDs grown on misoriented substrates. Finally, a general principle to achieve carrier localization was proposed, which is valid for most ternary Ⅲ-Ⅴ semiconductors exhibiting phase separation.HOUQIANG XU JIEAN JIANG LI CHEN JASON HOO LONG YAN SHIPING GUO CAI SHEN YANPING WEI HUA SHAO ZI-HUI ZHANG WEI GUO JICHUN YE 2021Photonics Research2021,9,5:2
14External application of a Nocardia rubra cell wall skeleton in the treatment of diabetic foot ulcers显示文摘Diabetic foot ulcers are one of the most severe complications of diabetes that have imposed great financial and psychological burdens on diabetic patients.A Nocardia rubra cell wall skeleton(Nr-CWS)can be externally applied to accelerate wound healing.However,its clinical application has not yet been reported.Herein,we report two patients with diabetic foot ulcers treated with Nr-CWS.After wound debridement,the wound was covered with a sterile cotton ball infiltrated with an Nr-CWS that was diluted with 2.0 mL of saline.The covers were changed every two days until complete wound healing occurred.The two wounds healed after 3 and 12 weeks,respectively.This article aims to provide a new treatment for diabetic foot ulcers,with the hope that physicians may consider an Nr-CWS as a complementary method for the treatment of chronic wounds.Caiqi Shen Wuhan Wei Aijun Zhang Changbo Tao Xueyang Li Yanping Guo Hanxiao Wei Qiang Li Peisheng Jin 2022Chinese Journal Of Plastic and Reconstructive Surgery2022,4,1:2
15Determination of Berberine Hydrochloride Content in Qingwen Baidu Granule by HPLC显示文摘The paper was to establish a simple and sensitive HPLC method for determination of berberine hydrochloride content in Qingwen Baidu granule.The HPLC system consisted of Stable Bond- C18 column(4.6×150 mm,5μm) and with a mobile phase of acetonitrile- 0.05mol / L potassium dihydrogen phosphate solution(50∶50,v∶v) mixture.Berberine hydrochloride was detected at the wavelength of 345 nm,with a flow rate of 1.0 mL / min and a column temperature of30 ℃.The excipients and solvents in the granule could be well separated from the drug under such a designated chromatogram condition and did not interfere with the assay.A good linear relationship was found between peak area and the concentration of berberine hydrochloride in the range of 16.0- 48.0 μg / mL.The average recovery of berberine hydrochloride was 99.09%.The established approach was specific,accurate,reliable,prompt,sensitive and applicable,and could be used to control the quality of Qingwen Baidu granule.Guo Shijin Wang Yanping Fu Shijun Zhang Zhimei Xu Qianqian Shen Zhiqiang 2014Animal Husbandry and Feed Science2014,6,1:2
163D printed fiber-optic nanomechanical bioprobe显示文摘Ultrasensitive nanomechanical instruments,e.g.atomic force microscopy(AFM),can be used to perform delicate biomechanical measurements and reveal the complex mechanical environment of biological processes.However,these instruments are limited because of their size and complex feedback system.In this study,we demonstrate a miniature fiber optical nanomechanical probe(FONP)that can be used to detect the mechanical properties of single cells and in vivo tissue measurements.A FONP that can operate in air and in liquids was developed by programming a microcantilever probe on the end face of a single-mode fiber using femtosecond laser two-photon polymerization nanolithography.To realize stiffness matching of the FONP and sample,a strategy of customizing the microcantilever’s spring constant according to the sample was proposed based on structure-correlated mechanics.As a proof-of concept,three FONPs with spring constants varying from 0.421 N m^(−1)to 52.6 N m^(−1)by more than two orders of magnitude were prepared.The highest microforce sensitivity was 54.5 nmμN^(−1)and the detection limit was 2.1 nN.The Young’s modulus of heterogeneous soft materials,such as polydimethylsiloxane,muscle tissue of living mice,onion cells,and MCF-7 cells,were successfully measured,which validating the broad applicability of this method.Our strategy provides a universal protocol for directly programming fiber-optic AFMs.Moreover,this method has no special requirements for the size and shape of living biological samples,which is infeasible when using commercial AFMs.FONP has made substantial progress in realizing basic biological discoveries,which may create new biomedical applications that cannot be realized by current AFMs.Mengqiang Zou Changrui Liao Yanping Chen Lei Xu Shuo Tang Gaixia Xu Ke Ma Jiangtao Zhou Zhihao Cai Bozhe Li Cong Zhao Zhourui Xu Yuanyuan Shen Shen Liu Ying Wang Zongsong Gan Hao Wang Xuming Zhang Sandor Kasas Yiping Wang 2023International Journal of Extreme Manufacturing2023,5,1:1
17Continuous wavelet grey moment approach for vibration analysis of rotating machinery显示文摘Zhang YanPing Huang ShuHong Hou JingHong Shen Tao Liu Wei 2005Mechanical Systems and Signal Processing2005,,5:1
18Patient derived hurrmn turnout tissue xenografts in immunodeficient mice:a systematic review显示文摘In Ketao Teng Lisong Shen Yanping 2010Clini- cal & Translational Ontology2010,12,7:1
19Thiolated nano- structured lipid carriers as a potential ocular drug delivery sys- tem for cyclosporine A: Improving in vivo ocular distribution 显示文摘Shen Jie Deng Yanping Jin Xuefeng 2010Int JPharm2010,402,12:1
20Continuous Wavelet Gray Moment Approach for Vibration Analysis of Rotating Machinery显示文摘Zhang Yanping Huang Shuhong Hou Jinghong Shen Tao Liu Wei 2006Mechanical Systems and Signal Processing2006,20,5:1
返回顶部 每页显示:
共3页 首页 上一页 第1页 下一页 末页 /3 跳转

网站首页 | 关于我们 | 联系我们 | 产品服务 | 客服中心 | 广告服务 | 版权声明 | 网站联盟 | 友情链接 | 售卡网点

版权所有© 渝B2-20050021-1 渝公网安备 50019002500403号 违法和不良信息举报中心

互联网出版许可证 新出网证(渝)字10号 全国400电话 - 免长途话费