维普中文期刊产品整合服务
113篇 您的检索式:作者名="WU Pingping"
    题名 作者 年代 出处 被引量
1Generation of iPSCs from mouse fibroblasts with a single gene, Oct4, and small molecules显示文摘由病毒的 transduction 的四抄写因素 Oct4, Klf4, Sox2 和 c-Myc 的介绍能导致体的房间的 reprogramming 进导致的 pluripotent 干细胞(iPSCs ) ,但是 iPSCs 的使用被病毒的交货系统的使用妨碍。导致化学药品的 reprogramming 把一条新奇途径提供给没有任何病毒的基于向量的基因修正,产生 iPSCs。尽管,以前的报告证明几个小分子能代替一些 reprogramming 因素至少二个抄写因素, Oct4 和 Klf4,仍然被要求从老鼠产生 iPSCs 胚胎的成纤维细胞。这里,我们识别特定的化学联合,它是足够的面对一个单个抄写因素从胚胎的老鼠和成年成纤维细胞允许 reprogramming, Oct4 在 20 天以内,代替 Sox2, Klf4 和 c-Myc。用这个处理产生的 iPSCs 类似于胚胎的干细胞以全球基因表示介绍的老鼠,在 vitro 并且在 vivo 的 epigenetic 地位和 pluripotency。我们也发现那 8 天 Oct4 正式就职是足够的面对小分子启用导致 Oct4 的 reprogramming,它建议 reprogramming 在开始的 8 天以内被开始并且独立于连续外长的 Oct4 表示。没有基因修正,这些发现将帮助 iPSCs 的未来产生,以及阐明位于 reprogramming 过程下面的分子的机制。Yanqin Li Qiang Zhang Xiaolei Yin Weifeng Yang Yuanyuan Du Pingping Hou Jian Ge Chun Liu Weiqi Zhang Xu Zhang Yetao Wu Honggang Li Kang Liu Chen Wu Zhihua Song Yang Zhao Yan Shi Hongkui Deng 2011Cell Research2011,21,1:51
2Prevalence of HIV Indeterminate Western Blot Tests and Follow-up of HIV Antibody Sero-Conversion in Southeastern China显示文摘HIV-indeterminate Western blotting(WB)results are typically obtained in WB confirmatory assays,and the number of indeterminate samples may increase with the detection of HIV infections,which will present considerable challenges for the management of HIV/AIDS.Nucleic acid detection has been used as a laboratory test for screening suspected or indeterminate samples.However,the effectiveness of these assays for the differential diagnosis of HIV-indeterminate WB samples remained undetermined.In this study,210 subjects with HIV-indeterminate WB results were detected from 6360 positive HIV screening samples between 2015 and 2016 in southeastern China,in which HIV-indeterminate WB results accounted for 3.30%.The highest proportion of indeterminate results was observed in pregnant and lying-in women receiving physical examinations(16.67%),followed by that in voluntary blood donors(8.82%).The most common WB band patterns were p24,gpl60 and p24,and gpl60.The follow-up study revealed that the highest negative and positive conversion rates of HIV antibodies were in samples with a single p24 band(80.28%),and with gpl60 and p24 bands(86.21%),respectively.Among the Env,Gag,and Pol antibodies,samples with a Gag band showed the highest negative conversion rate(81.25%),whereas the highest positive conversion rate was observed in samples with an Env band(56.76%).In addition,quantitative and qualitative HIV nucleic acid testing exhibited the highest sensitivity(96.3%)and specificity(97.85%),respectively.Our results indicate a lower proportion of HIV indeterminate WB results in southeastern China compared to previous reports,and the follow-up re-examination of patients with HIV indeterminate results should be performed.Nucleic acid testing facilitates the identification of HIV infections.Shouli Wu Min Gao Jian Zheng Pingping Yan Wei Wang Xiaoli Lu Yuefeng Qiu Yansheng Yan 2019Virologica Sinica2019,34,4:15
3Joint Inversion of the 3D P Wave Velocity Structure of the Crust and Upper Mantle under the Southeastern Margin of the Tibetan Plateau Using Regional Earthquake and Teleseismic Data显示文摘The special seismic tectonic environment and frequent seismicity in the southeastern margin of the Qinghai–Tibet Plateau show that this area is an ideal location to study the present tectonic movement and background of strong earthquakes in China's Mainland and to predict future strong earthquake risk zones. Studies of the structural environment and physical characteristics of the deep structure in this area are helpful to explore deep dynamic effects and deformation field characteristics, to strengthen our understanding of the roles of anisotropy and tectonic deformation and to study the deep tectonic background of the seismic origin of the block's interior. In this paper, the three-dimensional(3D) P-wave velocity structure of the crust and upper mantle under the southeastern margin of the Qinghai–Tibet Plateau is obtained via observational data from 224 permanent seismic stations in the regional digital seismic network of Yunnan and Sichuan Provinces and from 356 mobile China seismic arrays in the southern section of the north–south seismic belt using a joint inversion method of the regional earthquake and teleseismic data. The results indicate that the spatial distribution of the P-wave velocity anomalies in the shallow upper crust is closely related to the surface geological structure, terrain and lithology. Baoxing and Kangding, with their basic volcanic rocks and volcanic clastic rocks, present obvious high-velocity anomalies. The Chengdu Basin shows low-velocity anomalies associated with the Quaternary sediments. The Xichang Mesozoic Basin and the Butuo Basin are characterised by lowvelocity anomalies related to very thick sedimentary layers. The upper and middle crust beneath the Chuan–Dian and Songpan–Ganzi Blocks has apparent lateral heterogeneities, including low-velocity zones of different sizes. There is a large range of low-velocity layers in the Songpan–Ganzi Block and the sub–block northwest of Sichuan Province, showing that the middle and lower crust is relatively weak. The Sichuan Basin, which is located in the western margin of the Yangtze platform, shows high-velocity characteristics. The results also reveal that there are continuous low-velocity layer distributions in the middle and lower crust of the Daliangshan Block and that the distribution direction of the low-velocity anomaly is nearly SN, which is consistent with the trend of the Daliangshan fault. The existence of the low-velocity layer in the crust also provides a deep source for the deep dynamic deformation and seismic activity of the Daliangshan Block and its boundary faults. The results of the 3D P-wave velocity structure show that an anomalous distribution of high-density, strong-magnetic and high-wave velocity exists inside the crust in the Panxi region. This is likely related to late Paleozoic mantle plume activity that led to a large number of mafic and ultra-mafic intrusions into the crust. In the crustal doming process, the massive intrusion of mantle-derived material enhanced the mechanical strength of the crustal medium. The P-wave velocity structure also revealed that the upper mantle contains a low-velocity layer at a depth of 80–120 km in the Panxi region. The existence of deep faults in the Panxi region, which provide conditions for transporting mantle thermal material into the crust, is the deep tectonic background forthe area's strong earthquake activity.LI Dahu LIAO Hua DING Zhifeng ZHAN Yan WU Pingping XU Xiaoming ZHENG Chen 2018Acta Geologica Sinica(English Edition)2018,92,1:12
4Prognostic evaluation of postoperative adjuvant therapy for operable cervical cancer:10 years'experience of National Cancer Center in China显示文摘Objective: The aim of this study was to investigate the prognostic factors and to evaluate the impact of adjuvant therapy on clinical outcome for early-stage cervical cancer.Methods: The clinical-pathological data of all 1,335 patients with the International Federation of Gynecology and Obstetrics(FIGO) Ib–IIa cervical cancer treated with primary radical surgery at the Chinese National Cancer Center between May 2007 and Dec 2013 were retrospectively reviewed.The median follow-up was 70 months.Results: Of all the patients,61.6% of the cases received adjuvant therapy,with 5-year disease-free survival(DFS)of 92.1% and 5-year overall survival(OS) of 95.0%.In multivariate analysis,differentiation of G3(P<0.05),lymph node metastasis(LNM,P<0.05) and lymphovascular space invasion(LVSI,P<0.05) were independent predictors for OS,while LNM(P<0.05),deep stroma invasion(DSI,P<0.05) and LVSI(P<0.05) were independent factors for DFS.The samples were stratified by histologic type,and cervical squamous cell carcinoma(SCC) was found to share the same independent factors except for differentiation of OS.As to patients with cervical adenocarcinoma/adenosquamous carcinoma(AC/ASC),differentiation was the independent predictor of OS(P<0.05); and LVSI of DFS(P<0.05).Of 236 patients with high-risk factors,there was no significant difference in survival between concurrent chemoradiotherapy(CCRT,n=195),radiotherapy(RT,n=24),and chemotherapy(CT,n=17).Among the 190 patients with LNM who underwent CCRT,124 cases showed improved DFS after sequential CT(P=0.118),with a recurrence rate decrease of 14%,though the difference was not statistically significant.Patients with single intermediate-risk factors like DSI or LVSI were found to partially benefit from adjuvant therapy,but the difference was not statistically significant.Conclusions: LNM,LVSI,DSI and differentiation were found to be independent prognostic factors for operable cervical cancer.Aggressive postoperative adjuvant therapy based on single risk factors in Chinese National Cancer Center could benefit survival.CCRT+CT outperformed CCRT in high-risk patients.For patients with single non-high-risk factor,the role of adjuvant therapy needs to be further discussed.Tong Shu Dan Zhao Bin Li Yating Wang Shuanghuan Liu Pingping Li Jing Zuo Ping Ba i RongZhang Lingying Wu 2017Chinese Journal of Cancer Research2017,29,6:12
5Combined model based on optimized multi-variable grey model and multiple linear regression显示文摘The construction method of background value is improved in the original multi-variable grey model (MGM(1,m)) from its source of construction errors.The MGM(1,m) with optimized background value is used to eliminate the random fluctuations or errors of the observational data of all variables,and the combined prediction model together with the multiple linear regression is established in order to improve the simulation and prediction accuracy of the combined model.Finally,a combined model of the MGM(1,2) with optimized background value and the binary linear regression is constructed by an example.The results show that the model has good effects for simulation and prediction.Pingping Xiong Yaoguo Dang Xianghua wu Xuemei Li 2011Journal of Systems Engineering and Electronics2011,22,4:10
6Glutamate and aspartate alleviate testicular/epididymal oxidative stress by supporting antioxidant enzymes and immune defense systems in boars显示文摘Several potential oxidative agents have damaging effects on mammalian reproductive systems.This study was conducted to investigate the effects of glutamate(Glu)and aspartate(Asp)supplementation on antioxidant enzymes and immune defense systems in the outer scrotum of boars injected with H2O2.A total of 24 healthy boars were randomly divided into 4 treatment groups:control(basal diet,saline-treated),H2O2(basal diet,H2O2-challenged outer scrotum(1 m L kg^–1 BW)),Glu(basal diet+2%Glu,H2O2-challenged),and Asp(basal diet+2%Asp,H2O2-challenged).Our results showed that both Glu and Asp supplementation improved testicular morphology and decreased the genital index in the H2O2-treated boars.Glu and Asp administration increased the antioxidant enzyme activities and affected the testicular inflammatory cytokine secretion but had no effect on sex hormone levels.Furthermore,the m RNA expression of CAT,Cu Zn SOD,and GPx4 was altered in the testes and epididymis of boars treated with Asp and Glu.Glu and Asp supplementation also modulated the expression of TGF-β1,IL-10,TNF-α,IL-6 and IL-1βin the testis and epididymis.These results indicate that dietary Glu and Asp supplementation might enhance antioxidant capacity and regulate the secretion and expression of inflammatory cytokines to protect the testes and epididymis of boars against oxidative stress.Wenjie Tang Jian Wu Shunshun Jin Liuqin He Qinlu Lin Feijun Luo Xingguo He Yanzhong Feng Binsheng He Pingping Bing Tiejun Li Yulong Yin 2020Science China(Life Sciences)2020,63,1:9
7Gut microbiota drives macrophage-dependent self-renewal of intestinal stem cells via niche enteric serotonergic neurons显示文摘Lgr5+intestinal stem cells(ISCs)reside within specialized niches at the crypt base and harbor self-renewal and differentiation capacities.ISCs in the crypt base are sustained by their surrounding niche for precise modulation of self-renewal and differentiation.However,how intestinal cells in the crypt niche and microbiota in enteric cavity coordinately regulate ISC stemness remains unclear.Here,we show that ISCs are regulated by microbiota and niche enteric serotonergic neurons.The gut microbiota metabolite valeric acid promotes Tph2 expression in enteric serotonergic neurons via blocking the recruitment of the NuRD complex onto Tph2 promoter.5-hydroxytryptamine(5-HT)in turn activates PGE2 production in a PGE2+macrophage subset through its receptors HTR2A/3 A;and PGE2 via binding its receptors EP1/EP4,promotes Wnt/β-catenin signaling in ISCs to promote their self-renewal.Our findings illustrate a complex crosstalk among microbiota,intestinal nerve cells,intestinal immune cells and ISCs,revealing a new layer of ISC regulation by niche cells and microbiota.Pingping Zhu Tiankun Lu Jiayi Wu Dongdong Fan Benyu Liu Xiaoxiao Zhu Hui Guo Ying Du Feng Liu Yong Tian Zusen Fan 2022Cell Research2022,32,6:8
8Parkin promotes proteasomal degradation of p62: implication of selective vulnerability of neuronal cells in the pathogenesis of Parkinson's disease显示文摘Pingping Song Shanshan Li Hao Wu Ruize Gao Guanhua Rao Dongmei Wang Ziheng Chen Biao Ma Hongxia Wang Nan Sui Haiteng Deng Zhuohua Zhang Tieshan Tang Zheng Tan Zehan Han Tieyuan Lu Yushan Zhu Quan Chen 2016Protein & Cell2016,7,2:8
9Wogonoside inhibits tumor growth and metastasis in endometrial cancer via ER stress-Hippo signaling axis显示文摘Wogonoside,a bioactive flavonoid component derived from Scutellaria baicalensis Georgi,has been reported to inhibit tumor growth in mice bearing various types of cancer cells such as breast cancer,lung cancer,and leukemia cells.However,whether wogonoside could inhibit tumor growth of endometrial cancer has not been elucidated.In this study,we explored the function of wogonoside on tumor growth and the underlying mechanism on endometrial cancer.Firstly,we investigated the effect of wogonoside on endometrial cancer cells and found that wogonoside could significantly decrease cell proliferation and metastasis.Mechanistically,wogonoside could aggravate the extent of ER stress and upregulate the phosphorylation level of Mammalian Ste20-like kinase 1,leading to the activation of the Hippo signaling pathway.Taken together,in vitro and in vivo data demonstrated that wogonoside could be a potent inducer of ER stress and could be further developed into a promising therapy for endometrial cancer.Shaorong Chen Zhuna Wu Yumin Ke Pingping Shu Caihong Chen Ruying Lin Qirong Shi 2019Acta Biochimica et Biophysica Sinica2019,51,11:8
10Efficient Image Transmission Schemes over Zigbee-Based Image Sensor Networks显示文摘Image transmission is one of the biggest challenges in wireless sensor networks because of the limited resource on sensor nodes. We proposed two image transmission schemes driven by reliability and real time considerations in order to transfer JPEG images over Zigbee-based sensor networks. By adding two bytes counter in the header of data packet, we can easily solve the repeated data reception problem caused by retransmission mechanism in traditional Zigbees network layer. We proposed an efficient retransmission and acknowledgment mechanism in Zigbees application layer. By classifying different data reception response events, we can provide data packets with differential responses and ensure that image packets can be transferred quickly even with large maximum number of retransmission. Practical results show the effectiveness of our solutions to make image transmission over Zigbee-based sensor networks efficient.TAO Dan YANG Guangwei CHEN Houjin WU Hao LIU Pingping 2016Chinese Journal of Electronics2016,25,2:5
11Upper crustal velocity and seismogenic environment of the M7.0 Jiuzhaigou earthquake region in Sichuan, China显示文摘On August 8,2017,a magnitude 7.0 earthquake occurred in Jiuzhaigou County,Sichuan Province,China.The deep seismogenic environment and potential seismic risk in the eastern margin of Tibetan Plateau have once again attracted the close attention of seismologists and scholars at home and abroad.The post-earthquake scientific investigation could not identify noticeable surface rupture zones in the affected area;the complex tectonic background and the reason(s)for the frequent seismicity in the Jiuzhaigou earthquake region are unclear.In order to reveal the characteristics of the deep medium and the seismogenic environment of the M7.0 Jiuzhaigou earthquake region,and to interpret the tectonic background and genesis of the seismicity comprehensively,in this paper,we have reviewed all available observation data recorded by the regional digital seismic networks and large-scale,dense mobile seismic array(China Array)for the northern section of the North-South Seismic Belt around Jiuzhaigou earthquake region.Using double-difference seismic tomography method to invert the three-dimensional P-wave velocity structure characteristics of the upper crust around the Jiuzhaigou earthquake region,we have analyzed and discussed such scientific questions as the relationship between the velocity structure characteristics and seismicity in the Jiuzhaigou earthquake region,its deep tectonic environment,and the ongoing seismic risk in this region.We report that:the P-wave velocity structure of the upper crust around the Jiuzhaigoug earthquake region exhibits obvious lateral inhomogeneity;the distribution characteristics of the shallow P-wave velocity structure are closely related to surface geological structure and formation lithology;the M7.0 Jiuzhaigou earthquake sequence is closely related to the velocity structure of the upper crust;the mainshock of the M7.0 earthquake occurred in the upper crust;the inhomogeneous variation of the velocity structure of the Jiuzhaigou earthquake area and its surrounding medium appears to be the deep structural factor controlling the spatial distribution of the mainshock and its sequence.The 3D P-wave velocity structure also suggests that the crustal low-velocity layer of northeastern SGB(Songpan-GarzêBlock)stretches into MSM(Minshan Mountain),and migrates to the northeast,but the tendency to emerge as a shallow layer is impeded by the high-velocity zone of Nanping Nappe tectonics and the Bikou Block.Our results reveal an uneven distribution of high-and low-velocity structures around the Tazang segment of the East Kunlun fault zone.Given that the rupture caused by the Jiuzhaigou earthquake has enhanced the stress fields at both ends of the seismogenic fault,it is very important to stay vigilant to possible seismic hazards in the large seismic gap at the Maqu-Maqên segment of the East Kunlun fault zone.DaHu Li ZhiFeng Ding Yan Zhan PingPing Wu LiJun Chang XiangYu Sun 2021Earth and Planetary Physics2021,5,4:4
12Deep Seismogenic Environment in the Southern Section of the Longmenshan Fault Zone on the Eastern Margin of the Tibetan Plateau and Lushan M_s 7.0 Earthquake显示文摘The 2,026 earthquake events registered by the Sichuan regional digital seismic network and mobile seismic array after the April 20 th,2013 Lushan earthquake and 28,188 pieces of data were selected to determine direct P waves arrival times. We applied the tomographic method to inverse the characteristics of the velocity structure for the three-dimensional(3D) P wave in the mid-upper crust of the seismic source region of the Lushan earthquake. The imaging results were combined with the apparent magnetization inversion and magnetotelluric(MT) sounding retest data to comprehensively study the causes of the deep seismogenic environment in the southern section of the Longmenshan fault zone and explore the formation of the Lushan earthquake. Research has shown that there are obvious differences in velocity structure and magnetic distribution between the southern and northern sections of the Longmenshan fault zone. The epicenter of the Lushan earthquake is located near the boundary of the high and low-velocity anomalies and favorable for a high-velocity section. Moreover,at the epicenter of the Lushan earthquake located on the magnetic dome boundary of Ya'an,the development of high velocity and magnetic solid medium favors the accumulation and release of strain energy. Lowvelocity anomalies are distributed underneath the are of seismogenic origin,The inversion results of the MT retest data after the April 20 th Lushan earthquake also indicate that there a high-conductor anomaly occurs under the area of seismogenic origin of the Lushan earthquake,Therefore,we speculated that the presence of a high-conductivity anomaly and low-velocity anomaly underneath the seismogenic body of the Lushan earthquake could be related to the existence of fluids. The role of fluids caused the weakening of the seismogenic layer inside the mid-upper crust and resulted in a seismogenic fault that was prone to rupture and played a triggering role in the Lushan earthquake.LI Dahu DING Zhifeng ZHAN Yan WU Pingping YE Qingdong 2015Acta Geologica Sinica(English Edition)2015,89,2:4
13Spacecraft angular velocity estimation method using optical flow of stars显示文摘Angular velocity is a crucial parameter for spacecraft navigation, which, at present, is mainly obtained by using gyroscopes. Several studies have been performed on angular velocity estimation using star sensors when data from gyroscopes are not available. Most of the previous angular velocity estimation methods using star sensors are based on information on the attitude or star vector measurements. In this paper,an angular velocity estimation method using the optical flow(OF) directly from the star images is proposed,which, unlike the previous methods, requires star coordinates in two consecutive images only. Because the procedure of star identification is eliminated, the corresponding high computation requirement is reduced.Simulations demonstrate that the proposed method has a robust performance in terms of computational cost and the number of stars in the field of view(FOV) compared with the previous methods. Finally, certain affecting factors are analyzed, including lens distortion, star senor instantaneous FOV(IFOV), star number,and accuracy of the star sensor.Xiaolin NING Zonghe DING Pingping CHEN Weiren WU Jiancheng FANG Gang LIU 2018Science China(Information Sciences)2018,61,11:3
14Direct Ink Writing of Highly Conductive MXene Frames for Tunable Electromagnetic Interference Shielding and Electromagnetic Wave-Induced Thermochromism显示文摘The highly integrated and miniaturized next-generation electronic products call for high-performance electromagnetic interference(EMI)shielding materials to assure the normal operation of their closely assembled components.However,the most current techniques are not adequate for the fabrication of shielding materials with programmable structure and controllable shielding efficiency.Herein,we demonstrate the direct ink writing of robust and highly conductive Ti3C2Tx MXene frames with customizable structures by using MXene/AlOOH inks for tunable EMI shielding and electromagnetic wave-induced thermochromism applications.The as-printed frames are reinforced by immersing in AlCl_(3)/HCl solution to remove the electrically insulating AlOOH nanoparticles,as well as cross-link the MXene sheets and fuse the filament interfaces with aluminum ions.After freeze-drying,the resultant robust and porous MXene frames exhibit tunable EMI shielding efficiencies in the range of 25-80 dB with the highest electrical conductivity of 5323 S m−1.Furthermore,an electromagnetic wave-induced thermochromic MXene pattern is assembled by coating and curing with thermochromic polydimethylsiloxane on a printed MXene pattern,and its color can be changed from blue to red under the high-intensity electromagnetic irradiation.This work demonstrates a direct ink printing of customizable EMI frames and patterns for tuning EMI shielding efficiency and visualizing electromagnetic waves.Xinyu Wu Tingxiang Tu Yang Dai Pingping Tang Yu Zhang Zhiming Deng Lulu Li Hao-Bin Zhang Zhong-Zhen Yu 2021Nano-Micro Letters2021,13,10:3
15Association of serum lipids and severity of epithelial ovarian cancer:an observational cohort study of 349 Chinese patients显示文摘While obesity and fat intake have been associated with the risk and prognosis of epithelial ovarian cancer, the association between the lipid levels and epithelial ovarian cancer phenotype remains controversial. We conducted a retrospective study of 349 epithelial ovarian cancer patients who received treatment at Jiangsu Cancer Hospital, China between 2011 and 2017. We analyzed age at diagnosis, blood pressure, plasma glucose content, body mass index(BMI), lipid levels and clinical parameters. Severity of epithelial ovarian cancer was classified according to the International Federation of Gynecology and Obstetrics(FIGO) grading system. Univariate analysis of the clinical factors according to the severity of epithelial ovarian cancer was followed by logistic regression analysis to identify clinical factors significantly associated with epithelial ovarian cancer severity. Univariate analysis indicated that age,BMI, triglyceride(TG), and high density lipoproteins(HDL) differed significantly among different stages of epithelial ovarian cancer(P<0.05). In the logistic regression model, elevated TG(OR: 1.883; 95% CI= 1.207-2.937), and low HDL(OR: 0.497; 95% CI = 0.298-0.829) levels were significantly associated with the high severity epithelial ovarian cancer. Our data indicate that high TG and low HDL levels correlate with a high severity of epithelial ovarian cancer. These data provide important insight into the potential relationship between the lipid pathway and epithelial ovarian cancer phenotype and development.Yi Zhang Jing Wu Junya Liang Xing Huang Lei Xia Dawei Ma Xinyu Xu Pingping Wu 2018The Journal of Biomedical Research2018,32,5:3
16Characteristics of plant calcium fractions for 25 species in Tengger Desert显示文摘Little attention has been paid to plant calcium fractions in the desert.To address the characteristic of the calcium fractions of desert plants,we collected 25 plant species in Tengger Desert,observed the calcium crystals using an optical microscope and determined water soluble calcium,acetic acid soluble calcium,and hydrochloric acid soluble calcium.To do so,we used sequential fractionation procedures to probe the relationships among different functional groups,different growth forms,or different successional stages.The results showed that the psammophyte,the late successional plants,and the drought-resistant shrub and semi-shrub all held considerable calcium oxalate crystal compared to the grassland plants,the early successional plants,and the perennial herb.With the proceeding succession,the acetic acid soluble calcium decreased gradually,and the hydrochloric acid soluble calcium increased gradually.The perennial herb had more water soluble calcium,while shrub held greater hydrochloric acid soluble calcium.The grassland plants held more water soluble calcium,while psammophyte had greater hydrochloric acid soluble calcium.This implies that the plants that are relatively sensitive to drought hold more calcium ion,while the drought-resistance plants hold more calcium oxalate.Thus,the plant calcium components are in close relation to plant drought-resistance,and of important significance in plant physiology of the desert.HuaCong Ci XingDong lie Rong Li Wei Wu PingPing Xue YuBao Gao HaLin Zhao 2010Research in Cold and Arid Regions2010,2,2:3
17Optimal design of wind machine impeller for frost protection based on CFD and its field test on airflow disturbance显示文摘Wind machines have been increasingly applied to prevent frost damage through airflow disturbance in tea fields and orchards.An impeller is the most important component of the machine.However,there are few studies on customized impeller design or airflow disturbance performance.The objective of this study was to design a new impeller for frost protection wind machines based on reverse engineering and CFD simulation.The characteristic parameters of an impeller include blade cross-section shape,installation angle,sweep angle,hub ratio and blade number.The optimal combination of the above parameters was obtained through the simulation of the impeller’s aerodynamic performance.Field tests were conducted in a tea field to evaluate airflow disturbance performance of the designed impeller.The result shows that at a certain rotation speed and rotation diameter,the optimal combination of impeller parameters was:single arc cross-section ofϕ2400 mm,installation angle of 15°,sweep angle of 87°,hub ratio of 0.3 and blade number of 4,of which the impeller could achieve the highest usage of 0.56,the least consumed power of 1.363 kW and more uniform distribution of surface pressure on the windward side.Compared with other commercial frost protection wind machines,the maximum airflow velocity of the developed impeller was higher at 12 m in front of it.The probability of airflow velocity above 3.0 m/s within 30 min was the highest(71.7%),indicating its improvement of airflow stability.Without swing the new impeller could cover an effective area of 300 m2,which was similar to that of the commercial ones.Wu Wenye Hu Yongguang Yang Shuo Mao Kangqian Zhu Xiaoyong Li Pingping 2015International Journal of Agricultural and Biological Engineering2015,8,5:3
18Effects of soil stoichiometry of the CaCO_3/available phosphorus ratio on plant density in Artemisia ordosica communities显示文摘In soil, CaCO3 can reduce the availability of phosphorus in arid and semi-arid regions, thereby influencing plant growth. However, the effects of soil stoichiometry of the CaCO3/available phosphorus ratio (CaCO3/AP ratio) on plant density are unknown. In this study, we examined 4 Artemisia ordosica communities located in arid and semi-arid regions, and performed a pot experiment with an orthogonal design to examine the relationships between the soil CaCO3/AP ratio and plant density. The results showed that the soil stoichiometry of the CaCO3/AP ratio had a greater effect on growth of A. ordosica than either CaCO3 or AP as single factor. The influence of the soil CaCO3/AP ratio on density of A. ordosica was related to the climatic zone and the types and/or amplitudes of increases in the soil CaCO3/AP ratio. When the soil CaCO3/AP ratio was within the same amplitude and was less than 2.5, the A. ordosica density increased in the semi-arid region, whereas the density decreased with increasing soil CaCO3/AP ratios in the arid region. In the semi-arid region, when the soil CaCO3/AP ratio was within the same amplitude and the increase in the soil CaCO3 content was greater than the increase in soil AP, the A. ordosica density increased with increasing soil CaCO3/AP ratios. This means that the relationship between the soil CaCO3/AP ratio and the A. ordosica density remained the same. In the arid region, an increase in the soil CaCO3/AP ratio as a result of increased soil CaCO3 content and decreased soil AP resulted in increased density of A. ordosica. Therefore, the relationship between soil CaCO3/AP ratios and density of A. ordosica was altered by these changes in soil chemistry. Thus, the soil stoichiometry of the CaCO3/AP ratio is an important factor affecting the density of A. ordosica in arid and semi-arid regions.ZHAO XueLai HE XingDong XUE PingPing ZHANG Ning WU Wei LI Rong CI HuaCong XU JingJing GAO YuBao ZHAO HaLin 2012Chinese Science Bulletin2012,57,5:2
19Preparation and characterization of graphite nanosheets from ultrasonic powdering technique显示文摘Guohua Chen Wengui Weng Dajun Wu Cuiling Wu Jinrong Lu Pingping Wang Xiangfeng Chen 2004Carbon2004,,4:2
20Research progress in interface modification and thermal conduction behavior of diamond/metal composites显示文摘Diamond/metal composites are widely used in aerospace and electronic packaging fields due to their outstanding high thermal conductivity and low expansion.However,the difference in chemical properties leads to interface incompatibility between diamond and metal,which has a considerable impact on the performance of the composites.To improve the interface compatibility between diamond and metal,it is necessary to modify the interface of composites.This paper reviews the experimental research on interface modification and the application of computational simulation in diamond/metal composites.Combining computational simulation with experimental methods is a promising way to promote diamond/metal composite interface modification research.Ping Zhu Pingping Wang Puzhen Shao Xiu Lin Ziyang Xiu Qiang Zhang Equo Kobayashi Gaohui Wu 2022International Journal of Minerals,Metallurgy and Materials2022,29,2:2
返回顶部 每页显示:
共6页 首页 上一页 第1页 下一页 末页 /6 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