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135篇 您的检索式:作者名="Zhengfu"
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1Environmental issues from coal mining and their solutions显示文摘The environmental challenges from coal mining include coal mine accidents,land subsidence,damage to the water environment,mining waste disposal and air pollution.These are either environmental pollution or landscape change.A conceptual framework for solving mine environmental issues is proposed.Clean processes,or remediation measures,are designed to address environmental pollution.Restoration measures are proposed to handle landscape change.The total methane drainage from 56 Chinese high methane concentration coal mines is about 101.94 million cubic meters.Of this methane,19.32 million,35.58 million and 6.97 million cubic meters are utilized for electricity generation,civil fuel supplies and other industrial purposes,respectively.About 39% of the methane is emitted into the atmosphere.The production of coal mining wastes can be decreased 10% by reuse of mining wastes as underground fills,or by using the waste as fuel for power plants or for raw material to make bricks or other infrastructure materials.The proper use of mined land must be decided in terms of local physical and socio-economical conditions.In European countries more than 50% of previously mined lands are reclaimed as forest or grass lands.However,in China more than 70% of the mined lands are reclaimed for agricultural purposes because the large population and a shortage of farmlands make this necessary.Reconstruction of rural communities or native residential improvement is one environmental problem arising from mining.We suggest two ways to reconstruct a farmer's house in China.BIAN, Zhengfu INYANG, Hilary I DANIELS, John L OTTO, Frank STRUTHERS, Sue 2010Mining Science and Technology2010,20,2:47
2Field experiment on a robust hierarchical metropolitan quantum cryptography network显示文摘A hierarchical metropolitan quantum cryptography network upon the inner-city commercial telecom fiber cables is reported in this paper. The seven-user network contains a four-node backbone net with one node acting as the subnet gateway, a two-user subnet and a single-fiber access link, which is realized by the Faraday-Michelson interferometer set-ups. The techniques of the quantum router, optical switch and trusted relay are assembled here to guarantee the feasibility and expandability of the quantum cryptography network. Five nodes of the network are located in the government departments and the secure keys generated by the quantum key distribution network are utilized to encrypt the instant video, sound, text messages and confidential files transmitting between these bureaus. The whole implementation including the hierarchical quantum cryptographic communication network links and the corresponding application software shows a big step toward the practical user-oriented network with a high security level.XU FangXing CHEN Wei WANG Shuang YIN ZhenQiang ZHANG Yang LIU Yun ZHOU Zheng ZHAO YiBo LI HongWei LIU Dong HAN ZhengFu GUO GuangCan 2009Chinese Science Bulletin2009,54,17:40
3Active phase compensation of quantum key distribution system显示文摘Quantum key distribution (QKD) system must be robust enough in practical communication. Besides birefringence of fiber, system performance is notably affected by phase drift. The Faraday-Michelson QKD system can auto-compensate the birefringence of fiber, but phase shift is still a serious problem in its practical operation. In this paper, the major reason of phase drift and its effect on Faraday- Michel- son QKD system is analyzed and an effective active phase compensation scheme is proposed. By this means, we demonstrate a quantum key distribution system which can stably run over 37-km fiber in practical working condition with the long-time averaged quantum bit error rate of 1.59% and the stan- dard derivation of 0.46%. This result shows that the active phase compensation scheme is suitable to be used in practical QKD systems based on double asymmetric interferometers without additional de- vices and thermal controller.CHEN Wei HAN ZhengFu MO XiaoFan XU FangXing WEI Guo GUO GuangCan 2008Chinese Science Bulletin2008,53,9:24
4Spatio-temporal variation of vegetation in an arid and vulnerable coal mining region显示文摘Environmental assessment in an arid coal mining area requires an understanding of the influences of coal mining,the arid climate and ecological remediation.To that end,we selected vegetation as the key environmental factor to observe.Remote sensing approaches to monitoring the spatio-temporal variation of vegetation caused by mining activities,the arid climate and ecological remediation in the Shengdong coal mining area are described.Over a large regional scale it was found that the vegetation was improved as a result of ecological remediation activities.At the local scale,however,the vegetation coverage and soil moisture in the mined areas were slightly lower than those in un-mined areas due to mining subsidence.These differences are partly attributed to ground fissures that injure root systems and increase the depletion of soil moisture.It is recommended that fissures be reduced and filled to lessen their adverse effects on the environment.LEI Shaogang BIAN Zhengfu DANIELS John L HE Xiao 2010Mining Science and Technology2010,20,3:20
5Multiple stochastic paths scheme on partially-trusted relay quantum key distribution network显示文摘Quantum key distribution (QKD) technology provides proven unconditional point-to-point security based on fundamental quantum physics. A QKD network also holds promise for secure multi-user communications over long distances at high-speed transmission rates. Although many schemes have been proposed so far, the trusted relay QKD network is still the most practical and flexible scenario. In reality, the insecurity of certain relay sections cannot be ignored, so to solve the fatal security problems of partially-trusted relay networks we suggest a multiple stochastic paths scheme. Its features are: (i) a safe probability model that may be more practical for real applications; (ii) a multi-path scheme with an upper bound for the overall safe probability; (iii) an adaptive stochastic routing algorithm to generate sufficient different paths and hidden routes. Simulation results for a typical partially-trusted relay QKD network show that this generalized scheme is effective.WEN Hao HAN ZhengFu ZHAO YiBo GUO GuangCan HONG PeiLin 2009Science in China(Series F)2009,52,1:17
6Evolution of gp85 gene of subgroup J avian leukosis virus under the selective pressure of antibodies显示文摘Subgroup J Avian leucosis virus (ALV-J) strain NX0101 was inoculated into chicken embryo fibroblasts (CEF) monolayers in 6-well plates. The six wells of CEF inoculated with NX0101 were divided into groups A (without anti-ALV-J serum in the medium) and B (with anti-ALV-J serum in the medium), then viruses from each well of both groups were separately passed in CEF every 6 d and formed their independent passage lineages. For each lineage of both groups, gp85 genes of the viruses in the 10th, 20th and 30th passages were amplified, cloned and sequenced. The sequence data indicated that the homologies of gp85 at aa level between the primary virus and the passed viruses of different passages of 3 lineages in group A were 97.7%―99.7%; and the homologies of gp85 between the primary virus and the passed viruses of different passages of 3 lineages in group B were 93.8%―96.1%. Analysis of the ratios of nonsynonium (NS) vs synonium (S) mutations of nucleic acids demonstrated that NS/S in 3 highly variable (hr-) regions at aa#110―120, aa#141―151 and aa#189―194 of gp85 in 3 lineages of group A were 2 (8/4), 1(3/3) and 1.3 (4/3), however, NS/S in the same 3 hr-regions of group B were 4.1 (13/3), 4.7 (14/3) and 3.3 (11/3). This study is the first demonstration of influence of immune selective pressure on evolution of ALV-J gp85 by specific antibodies under the controlled in vitro experiments.WANG Zhengfu CUI Zhizhong 2006Science China(Life Sciences)2006,49,3:14
7Mechanism of formation of sliding ground fissure in loess hilly areas caused by underground mining显示文摘Based on a shallow-buried coal seam covered with thick loose layers in hilly loess areas of western China,we developed a mechanical model for a mining slope with slope stability analysis, and studied the mechanism of formation and development of a sliding ground fissure by the circular sliding slice method.Moreover, we established a prediction model of a sliding fissure based on a mechanical mechanism,and verified its reliability on face 52,304, an engineering example, situated at Daliuta coal mine of Shendong mining area in western China. The results show that the stress state of a mining slope is changed by its gravity and additional stress from the shallow-buried coal seam and gully terrain. The mining slope is found to be most unstable when the ratio of the down-sliding to anti-sliding force is the maximum, causing local fractures and sliding fissures. The predicted angles for the sliding fissure of face 52,304 on both sides of the slope are found to be 64.2° and 82.4°, which are in agreement with the experimental data.Liu Hui Deng Kazhong Lei Shaogang Bian Zhengfu 2015International Journal of Mining Science and Technology2015,25,4:10
8Effect of gas emissions from Tianchi volcano (NE China) on environment and its potential volcanic hazards显示文摘The Tianchi volcano in the Changbai Mountains is located on the boundary between China and North Korea. There are many times of eruptions of the Tianchi volcano during the Holocene. One of its large eruptions occurred around 1000 years ago dated by 14C method and historical records. Composition of products of the largest Tianchi volcanic eruption studied is characterized by comendi- tic Plinian fallout and unwelded ignimbrite, which are mainly distributed in China and North Korea. Caldera is about 4.4 km long and 3.4 km wide, which had filled with water (e.g. Tianchi Lake). The Tianchi volcanic cone is about 2700 m high above sea level. The Tianchi Lake is located on the summit of the volcanic cone, that is also highest peak of the Changbai Mountains in northeastern China. This study analyzed Cl, F, S and H2O concentrations of melt inclusions in the phenocryst min- erals (anorthoclase and quartz) and co-existing matrix glasses using the electron microprobe and estimated environmental effect of Tianchi volcanic gases. The authors proposed a new method to evaluate future eruption of active volcano and estimate potential volcanic hazards based on contents of volatile emissions. Using this method, we made a perspective of future volcanic hazard in this re- gion.GUO Zhengfu LIU Jiaqi HAN Jingtai HE Huaiyu DAI Guoliang YOU Haitao 2006Science China Earth Sciences2006,49,3:9
9KIF18B promotes tumor progression in osteosarcoma by activating β-catenin显示文摘Objective:Osteosarcoma is a common primary highly malignant bone tumor.Kinesin family member 18B(K1F18B)has been identified as a potential oncogene involved in the development and metastasis of several cancer types.While KIF18B overexpression in osteosarcoma tissue is clearly detected,its specific function in the disease process remains to be established.Methods:K IF18B expression was assessed in osteosarcoma tissues and cells.We additionally evaluated the effects of KIF18B on proliferation,migration,and invasion of osteosarcoma cells,both in vitro and in vivo.Results:Our results showed overexpression of KIF18B in osteosarcoma tissues and cells.Knockdown of K IF18B induced G1/S phase arrest and significantly inhibited proliferation,migration,and invasion of osteosarcoma cells,both in vitro and in vivo.K IF18B regulated P-catenin expression at the transcriptional level by controlling nuclear aggregation of ATF2 and at the post-transcriptional level by interacting with the adenomatous polyposis coli(APC)tumor suppressor gene in osteosarcoma cells.Conclusions:KIF18B plays a carcinogenic role in osteosarcoma by regulating expression ofβ-catenin transcriptionally via decreasing nuclear aggregation of ATF2 or post-transcriptionally through interactions with APC.Our collective findings support the potential utility of KIF18B as a novel prognostic biomarker for osteosarcoma.Tian Gao Ling Yu Zhiwei Fang Jiayong Liu Chujie Bai Shu Li Ruifeng Xue Lu Zhang Zhichao Tan Zhengfu Fan 2020Cancer Biology & Medicine2020,17,2:7
10Chelerythrine chloride from Macleaya cordata induces growth inhibition and apoptosis in human gastric cancer BGC-823 cells显示文摘This study aimed to investigate the ability of chelerythrine chloride(CHE),the main active ingredient of Macleaya cordata,to induce apoptosis in human gastric cancer BGC-823 cells.The results demonstrate that CHE inhibits cell proliferation in a time-and dose-dependent manner with accompanying S phase arrest.It also induces apoptosis by a mechanism involving a reduction in the mitochondrial mem brane potential,the release of cytochrome c,activation of caspase 3 and cleavage of poly-ADP-ribose polymerase.In addition,CHE-induced apoptosis is accompanied by down-regulation of Bcl-x1 and Bcl-2 proteins with no change in the levels of Bax proteins.Taken together,the results support the development of CHE as a potentially useful anticancer drug for the treatment of gastric cancer.Zhengfu Zhang Ying Guo Lingwei Zhang Jianbin Zhang Xionghui Wei 2012Acta Pharmaceutica Sinica B2012,2,5:7
11Monitoring on subsidence due to repeated excavation with DInSAR technology显示文摘DInSAR technology was used to monitor subsidence caused by underground coal mining activities in mountainous area, with multi source SAR data, including 8 EnviSAT C-band and 4 ALOS L-band, and 4 programmed TerraSAR-X dataset. The results revealed that 2-pass DInSAR technique sometimes failed to retrieve the mining-caused subsidence due to spatial and/or temporal de-correlation. We also noticed that there existed residual topographic phase after the compensation with SRTM DEM, which could almost overwhelm the subsidence information when the perpendicular baseline was relatively large. Based on the mining materials, analysis was made on the shape of subsidence area. For the well geocoded results from TerraSAR-X, confirmed by GPS surveying results of corner reflectors, we tried to extract the advance distance of influence besides the subsidence area. Due to the big deformation gradient over stopingfaces, the X-band SAR data could not capture the maximum value subsidence revealed by GPS survey in our preliminary results, the same as C-band EnviSAT data. This will turn to be our research subject in the next few months.Liu Zhenguo Bian Zhengfu Lü Fuxiang Dong Baoquan 2013International Journal of Mining Science and Technology2013,23,2:7
12Real-time compensation of phase drift for phase-encoded quantum key distribution systems显示文摘Phase drift is an inherent problem in phase-encoded quantum key distribution(QKD) systems.The current active phase trackingand compensation solutions cannot satisfy the requirements of a system with nonlinearity in phase modulation.This paper presents a four-phase scanning method,which is based on the quantitative analysis of the quantum bit error rate(QBER) from phasedrift and the performance requirements of phase compensation.By obtaining the four interference fringes and adjusting the codingmatrix of the system,this method automatically calculates the accurate driving voltages for the phase modulator.The implementation and experimental tests show that the proposed method can compensate phase drift caused by environmental changes and thesystem's nonlinearity,and is applicable to large-scale QKD networks.ZHANG LiJun WANG YongGang YIN ZhenQiang CHEN Wei YANG Yang ZHANG Tao HUANG DaJun WANG Shuang LI FangYi HAN ZhengFu 2011Chinese Science Bulletin2011,56,22:6
13Efficacy of vinorelbine combined with low-dose methotrexate for treatment of inoperable desmoid tumor and prognostic factor analysis显示文摘Objective: To assess the efficacy of conservative chemotherapy for inoperable desmoid tumor(DT) and analyze the prognostic factors.Methods:From November 2008 to April 2016,71 patients of inoperable DT were treated with vinorelbine and low-dose methotrexate in the Department of Bone and Soft Tissue Tumors,Peking University Cancer Hospital&Institute,and enrolled in this retrospective study.The chemotherapy duration is one year.The efficacy of chemotherapy and the prognosis were observed.Results:Of the 71 patients,55% were female.Age of onset varied from 1 to 47 years,and the median age was 14years.Only 11(15.5%)cases suffered primary tumor.The distribution of the site of tumors was:31(43.7%)in the trunk,36(50.7%)in the limbs,and 4(5.6%)in the peritoneal and pelvic cavity.The size of tumor(the maximum diameter)differed from 2 to 37 cm with a mean of 9.3 cm.The median follow-up duration was 28(range,6–87)months.Common side effects included:nausea and vomiting,liver injury,bone marrow suppression and oral ulcers.When the chemotherapy finished,1(1.4%)case achieved complete response,24(33.8%)achieved partial response,37(52.1%)achieved stable disease and 9(12.7%)had progressive disease.The overall response rate was 87.3%.The progression-free survival(PFS)of the participants were from 6 to 87 months,and the 2-,3-and 5-year PFS was 79.9%,68.4% and 36.3%,respectively.No significant difference was identified in PFS in subgroups of gender,age of onset,age of chemotherapy,tumor site and tumor size.Conclusions:For recurrent,inoperable and progressive DT,enough course of chemotherapy with vinorelbine combined with low-dose methotrexate was an optional choice for local control.Shu Li Zhengfu Fan Zhiwei Fang Jiayong Liu Chujie Bai Ruifeng Xue Lu Zhang Tian Gao 2017Chinese Journal of Cancer Research2017,29,5:6
14Investigating spatial and temporal variations of soil moisture content in an arid mining area using an improved thermal inertia model显示文摘Mining operations can usually lead to environmental deteriorations. Underground mining activities could cause an extensive decrease in groundwater level and thus a dramatic variation in soil moisture content(SMC). In this study, the spatial and temporal variations of SMC from 2001 to 2015 at two spatial scales(i.e., the Shendong coal mining area and the Daliuta Coal Mine) were analyzed using an improved thermal inertia model with a long-term series of Landsat TM/OLI(TM=Thematic Mapper and OLI=Operational Land Imager) data. Our results show that at large spatial scale(the Shendong coal mining area), underground mining activities had insignificant negative impacts on SMC and that at small spatial scale(the Daliuta Coal Mine), underground mining activities had significant negative impacts on SMC. Trend analysis of SMC demonstrated that areas with decreasing trend of SMC were mainly distributed in the mined area, indicating that underground mining is a primary cause for the drying trend in the mining region in this arid environment.WANG Yuchen BIAN Zhengfu LEI Shaogang ZHANG Yu 2017Journal of Arid Land2017,9,5:5
15Effect of Miocene basaltic volcanism in Shanwang (Shandong Province, China) on environmental changes显示文摘Miocene(16―10 Ma) basalts,together with significantly well-preserved fossils(including animal and plant fossils) in the contemporaneously tephra-rich Maar sediments,are located in Shanwang volcanic region,Shandong Province,China.Distribution area of the basaltic eruption products is about 240 km2.Detailed field observations indicate that most of basaltic rocks are fissure eruptive products and some are central eruptives constrained by linear faults.The well-preserved fossils in the lacustrine deposits have been considered to be a result of mass mortalities.Based on physically volcanologic modeling results,eruption column of the basaltic fissure activities in the Shanwang volcanic region is estimated to have entered the stratosphere.Petrographic observations indicate that the basalts have porphyritic textures with phenocrysts of olivine,pyroxene,plagioclase feldspar and alkali feldspar setting in groundmass of plagioclase feldspar,alkali feldspar,quartz,apatite and glass.Based on observations of tephra,tuff and tuffites collected in the Maar sediments of the Shanwang area,we determined major element oxide concentrations and volatile composition of melt inclusions in phenocrysts and matrix glasses by electron microprobe analysis.Volatile(including S,Cl,F and H2O) concentrations erupted into the stratosphere were estimated by comparing pre-and post-eruptive volatile concentrations.Our determination results show that contents of S,Cl,F and H2O emitted into the stratosphere were 0.18%― 0.24%,0.03%―0.05%,0.03%―0.05% and 0.4%―0.6%,respectively,which was characterized by high-S contents erupted.Amounts of volatiles emitted in the Shanwang volcanic region are much higher than those in eruptions which had a substantial effect on climate and environment.According to the com-positions and amounts of the volatiles erupted from the Miocene basaltic volcanism in Shanwang,we propose a hypothesis that volatile-rich basaltic volcanism could result in the mass mortalities by in-jecting volatiles(e.g.,SO2,H2S,HCl,HF and H2O) into the stratosphere that would have triggered abrupt environmental changes(including formation of acid rain,temperature decline,ozone depletion,etc.) and altered lake chemistry,and subsequently volcanic ash fall buried and covered the dead animals and plants,forming well-preserved fossils in Shanwang Maar sediments.GUO ZhengFu LIU JiaQi CHEN XiaoYu 2007Science China Earth Sciences2007,50,12:4
16Cholesterol homeostasis regulated by ABCA1 is critical for retinal ganglion cell survival显示文摘Genome-wide association studies have suggested a link between primary open-angle glaucoma and the function of ABCA1.ABCA1 is a key regulator of cholesterol efflux and the biogenesis of high-density lipoprotein(HDL) particles. Here, we showed that the POAG risk allele near ABCA1 attenuated ABCA1 expression in cultured cells. Consistently, POAG patients exhibited lower ABCA1 expression, reduced HDL, and higher cholesterol in white blood cells. Ablation of Abca1 in mice failed to form HDL, leading to elevated cholesterol levels in the retina. Counting retinal ganglion cells(RGCs) by using an artificial intelligence(AI) program revealed that Abca1-deficient mice progressively lost RGCs with age. Single-cell RNA sequencing(scRNA-seq) revealed aberrant oxidative phosphorylation in the Abca1-/-retina, as well as activation of the mTORC1 signaling pathway and suppression of autophagy. Treatment of Abca1-/-mice using atorvastatin reduced the cholesterol level in the retina,thereby improving metabolism and protecting RGCs from death. Collectively, we show that lower ABCA1 expression and lower HDL are risk factors for POAG. Accumulated cholesterol in the Abca1-/-retina causes profound aberrant metabolism, leading to a POAG-like phenotype that can be prevented by atorvastatin. Our findings establish statin use as a preventive treatment for POAG associated with lower ABCA1 expression.Jialiang Yang Yuhong Chen Tongdan Zou Bai Xue Fang Yang Xiangzhou Wang Yibo Huo Boyun Yan Yuxia Xu Shiyu He Yi Yin Jing Wang Xiong Zhu Lin Zhang Yu Zhou Zhengfu Tai Ping Shuai Man Yu Qian Luo Yilian Cheng Bo Gong Xianjun Zhu Jing Zhang Xinghuai Sun Ying Lin Houbin Zhang Zhenglin Yang 2023Science China(Life Sciences)2023,66,2:2
17ANTI-DIFFUSIVE FINITE DIFFERENCE WENO METHODS FOR SHALLOW WATER WITH TRANSPORT OF POLLUTANT显示文摘在我们进一步探索并且适用的这篇论文,我们的最近的反散开的流动改正了有限差别 WENO 策划让能量守恒定律与污染物质繁殖计算浅水方程的 theSaint-Venant 系统的高顺序,它被一个运输方程描述。动机是高度命令当在答案的光滑的区域为近似把高顺序作为精确性时,为能量守恒定律的反散开的 WENO 计划生产接触断绝的锋利的分辨率。到有污染物质的运输的浅水方程的 Saint-Venant 系统的 theanti 散开的高顺序 WENOZhengfu Xu Chi-Wang Shu 2006Journal of Computational Mathematics2006,24,3:2
18Mathematical modeling on hot air drying of thin layer apple pomace显示文摘Zhengfu Wang Junhong Sun Xiaojun Liao Fang Chen Guanghua Zhao Jihong Wu Xiaosong Hu 2006Food Research International2006,,1:2
19Chronological dating and tectonic implications of late Cenozoic volcanic rocks and lacustrine sequence in Oiyug Basin of southern Tibet显示文摘Reconstruction of uplift history of the Tibetan Plateau is crucial for understanding its environmental impacts. The Oiyug Basin in southern Tibet contains multiple periods of sedimentary sequences and volcanic rocks that span much of the Cenozoic and has great potential for further studying this issue. However, these strata were poorly dated. This paper presents a chronological study of the 145 m thick and horizontally-distributed lacustrine sequence using paleomagnetic method as well as a K-Ar dating of the underlying volcanic rocks. Based on these dating results, a chronostratigraphic framework and the basin-developmental history have been established for the past 15 Ma, during which three tectonic stages are identified. The period of 15-8.1 Ma is characterized by intense volcanic activities involving at least three major eruptions. Subsequently, the basin came into a tectonically quiescent period and a lacustrine sedimentary sequence was developed. Around 2.5 Ma, an N-S fault occurred across the southern margin of the basin, leading to the disappearance of the lake environment and the development of the Oiyug River. The Gyirong basin on northern slope of the Himalayas shows a similar basin developmental history and thus there is a good agreement in tectonic activities between the Himalayan and Gangdise orogenic belts. Therefore, the tectonic evolution stages experienced by the Oiyug Basin during the past 15 Ma could have a regional significance for southern Tibet. The chronological data obtained from this study may provide some constraints for further studies with regard to the tectonic processes and environmental changes in southern Tibetan Plateau.CHEN HeHai HAN JingTai DING ZhongLi SUN HuiGuo GUO ZhengFu 2008Science China Earth Sciences2008,51,2:2
20One-dimensional finite-difference modeling on temperature history and freezing time of individual food显示文摘Zhengfu Wang Han Wu Guanghua Zhao 2007Journal of Food Engineering2007,,79:1
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