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    题名 作者 年代 出处 被引量
1Widespread Whole Genome Duplications Contribute to Genome Complexity and Species Diversity in Angiosperms显示文摘基因复制为产生新奇功能提供进化潜力,当 polyploidization 或整个染色体复制(WGD ) 开始加倍染色体并且导致百~千个保留的副本时。WGD 被通常在优核质的许多充满种类的系发现的证据强烈支持,并且因此在种类多样化被看作一个主要驱动力。我们执行了 59 公共 genomes/transcriptomes 和盖住被子植物的主要的系的 46 最新定序的 transcriptomes 的比较 genomic 和 phylogenomic 分析 ? 由调查几万个基因家谱检测大规模基因复制事件。这些分析证实了大多数以前报导的 WGD 并且在许多系为新奇的提供了充分证据。检测 WGD 与约 2160 万年的估计的半衰期在进化期间支持了指数的基因损失的一个模型,并且与两个被相关有多样化的高度和全球气候的时期的系的出现变化。新数据集和分析 ? 检测了广泛地在支持被子植物放射并且提高他们的改编到环境变化为 WGD 的角色在被子植物进化,在必要细胞的新陈代谢的基因功能的揭开的优先的保留,和提供的线索期间散布的许多新奇 WGD。Ren Ren Haifeng Wang Chunce Guo Ning Zhang Liping Zeng Yamao Chen Hong Ma Ji Qi 2018Molecular Plant2018,11,3:35
2Impact of Grid Connection of Large-Scale Wind Farms on Power System Small-Signal Angular Stability显示文摘The grid connection of a large-scale wind farm could change the load flow/configuration of a power system and introduce dynamic interactions with the synchronous generators(SGs),thus affecting system small-signal angular stability.This paper proposes an approach for the separate examination of the impact of those affecting factors,i.e.,the change of load flow/configuration and dynamic interactions brought about by the grid connection of the wind farm,on power system smallsignal angular stability.Both cases of grid connection of the wind farm,either displacing synchronous generators or being directly added into the power system,are considered.By using the proposed approach,how much the effect of the change of load flow/configuration brought about by the wind farm can be examined,while the degree of impact of the dynamic interaction of the wind farm with the SGs can be investigated separately.Thus,a clearer picture and better understanding of the power system small-signal angular stability as affected by grid connection of the large-scale wind farm can be achieved.An example of the power system with grid connection of a wind farm is presented to demonstrate the proposed approach.Wenjuan Du Jingtian Bi Tong Wang Haifeng Wang 2015CSEE Journal of Power and Energy Systems2015,1,2:39
3Distribution and assessment of heavy metals in the surface sediment of Yellow River, China显示文摘Large amounts of heavy metals discharged by industrial cities that are located along the middle reach of Yellow River, China have detrimental impacts on both the ecological environment and human health. In this study, fourteen surface sediment samples were taken in the middle reach of the Yellow River. Contents of Zn, Pb, Ni, Cu, Cr, Cd, As were measured, and the pollution status was assessed using three widely used pollution assessment methods, including the single factor index method, Nemerow pollution index method and potential ecological risk index. The concentrations of the studied heavy metals followed the order: Zn > Cr > Cu > Ni > Pb > As > Cd. Nearly 50% of sites had Cu and Cr accumulation. The concentration of Cu at the Yiluo River exceeded the secondary standard value of the Environmental quality standard for soils. Comparison of heavy metal concentrations between this study and other selected rivers indicated that Cu and Cr may be the major pollutants in our case. The single factor index indicated that many samples were at high levels of pollution for Cu and Cd; the Nemerow pollution index indicated that the Yihe River, Luohe River, Yiluo River and Huayuankou were polluted. According to the results of potential ecological risk assessment, Cd in the tributaries of Luo River, Yihe River,and Yiluo River showed high risk toward the ecosystem and human health, Cd in Huanyuankou and Cu in Yiluo River showed a middle level of risk and other samples were at a low level of risk.Nan Yan Wenbin Liu Huiting Xie Lirong Gao Ying Han Mengjing Wang Haifeng Li 2016Journal of Environmental Sciences2016,28,1:33
4Modeling on Heat and Mass Transfer in Stored Wheat during Forced Cooling Ventilation显示文摘A mathematical model based on the theory of heat and mass transfer in porous media was developed to simulate the evolution of grain temperature and moisture content in a wheat storage bin during ventilation with cooling air at the constant temperature and humidity.Unlike the previous works on this aspect,the present work was not focused on cooling the stored grain by ventilation with ambient air,but with the refrigerated air.Validation was performed by comparing between predicted and measured grain temperature and grain moisture content for two cases.Predicted data were in reasonable good agreement with measured ones.The model and the parameter values used in the model are applicable for predicting temperature and moisture of stored grains under ventilation conditions.Yuancheng WANG,Haifeng DUAN,Hao ZHANG and Zhaohong FANG College of Thermal Energy Engineering,Shandong Jianzhu University,Jinan 250101,China 2010Journal of Thermal Science2010,19,2:27
5Atg7 is required for acrosome biogenesis during spermatogenesis in mice显示文摘acrosome 是盖住精子原子核的前面的部分并且在授精的过程起一个必要作用的一个专业化细胞器。位于这个 lysosome 相关的细胞器(LRO ) 的生物的续生说下面的分子的机制大部分仍然是未知的。这里,我们显示出房间特定的 Atg7 大美人老鼠是的那个细菌由于在 acrosome 生物的续生说的一个缺点不肥沃并且显示了类似于人的 globozoospermia 的显型;这个繁殖缺点被 intracytoplasmic 精子注射成功地救。而且,在细菌房间的 Atg7 的弄空没影响细菌房间的开发的早阶段,但是精子发生在以后上演,在 Golgi 期间没有通过到保险丝进一个单个 acrosomal 泡的 proacrosomal 泡分阶段执行,它最后导致了不规则或将近 round-headed 精子。Autophagic 流动在弄空 Atg7 的细菌房间被破坏,最后导致 LC3 变化形式的失败到 Golgi 导出仪器的泡。另外, Atg7 部分调整了另一 globozoospermia 相关的蛋白质,联系 Golgi 的 PDZ 卷和卷卷包含主题的蛋白质(GOPC ) ,在 acrosome 生物的续生说期间。最后,任何一个 autophagy 的注射或进睾丸的 lysosome 禁止者导致了类似的显型到细菌的房间特定的 Atg7 大美人老鼠。总的来说,我们的结果揭开为在 acrosome 的生物的续生说的 Atg7 的一个新角色,并且我们提供证据为 acrosome 支持 autolysosome 起源假设。Hongna Wang Haifeng Wan Xixia Li Weixiao Liu Qi Chen Yaqing Wang Lin Yang Hongmei Tang Xiujun Zhang Enkui Duan Xiaoyang Zhao Fei Gao Wei Li 2014Cell Research2014,24,7:25
6Lithium, an anti-psychotic drug, greatly enhances the generation of induced pluripotent stem cells显示文摘体的房间能由定义因素是进导致的 pluripotent 干细胞(iPSCs ) 的 reprogrammed。reprogramming 的低效率和 oncogenes 和病毒的向量的 genomic 集成限制了 iPSCs 的潜在的申请。这里,我们报导那锂(李) ,药过去常对待心情混乱,极大地从老鼠提高 iPSC 产生胚胎的成纤维细胞和人的脐的静脉 endothelial 房间。李与(Oct4 ) 或二个因素(OS 或好) 便于 iPSC 产生。支持 reprogramming 上的李的效果仅仅部分取决于它的主要目标 GSK3β。不同于另外的 GSK3β禁止者,李不仅增加 Nanog 的表示,而且提高 Nanog 的 transcriptional 活动。我们也发现李由经由 LSD1 的 downregulation 支持 epigenetic 修正施加它的效果, H3K4 特定的 histone demethylase。将 LSD1 击倒部分在提高 reprogramming 模仿李的效果。我们的结果不仅提供一个直接方法改进 iPSC 产生效率,而且为体的房间 reprogramming 作为一个批评调节的人识别了 histone demethylase。Quan Wang Xinxiu Xu Jun Li Jing Liu Haifeng Gu Ru Zhang Jiekai Chen Yin Kuang Jian Fei Cong Jiang Ping Wang Duanqing Pei Sheng Ding Xin Xie 2011Cell Research2011,21,10:23
7Nitrogen removal and simultaneous nitrification and denitrification in a fluidized bed step-feed process显示文摘For urban wastewater treatment,we conducted a novel four-stage step-feed wastewater treatment system combined with a fluidized bed laboratory experiment to investigate chemical oxygen demand(COD),NH4+-N,and total nitrogen(TN) removal performance.The removal rates of COD,NH4+-N and TN were 88.2%,95.7%,and 86.4% with e?uent concentrations of COD,NH4+-N and TN less than 50,8,and 10 mg/L,respectively.Biomass and bacterial activities were also measured,with results showing more nitrobacteria in the activated sludge than in the biofilm;however,bacterial activity of the biofilm biomass and the activated sludge were similar.Nitrogen concentrations during the process were also detected,with simultaneous nitrification and denitrification found to be obvious.BingWang Wei Wang Hongjun Han Hongbo Hu Haifeng Zhuang 2012Journal of Environmental Sciences2012,24,2:22
8Radix Astragali-induced differentiation of rat bone marrow-derived mesenchymal stem cells显示文摘BACKGROUND:Chemical induction has been shown to be effective at promoting the differentiation of bone marrow-derived mesenchymal stem cells(MSCs).However,these inductors have cytotoxicity side effects that may damage cells over time.Traditional Chinese medicines avoid this disadvantage while still producing effective induction. OBJECTIVE:To investigate the influence of Radix Astragali(Huangqi) on the differentiation of MSCs. DESIGN,TIME AND SETTING:In vitro study of traditional Chinese medicine in neural stem cell differentiation.The experiment was performed at the Central Laboratory of Hebei North University between April and June 2007. MATERIALS:Radix Astragali solution(lot No.060105;license No.Z53021585) was purchased from Dali Pharmaceutical Co.,Ltd.,China;rabbit anti-rat nestin,rabbit anti-rat neuron-specific enolase (NSE),mouse anti-rat microtubule-associated protein 2,and rabbit anti-rat glial fibrillary acidic protein were purchased from Wuhan Boster,China. METHODS:Whole bone marrow was isolated from the femur and tibia of 6-week-old male Wistar rats and subcultured.The fourth passage of MSCs were harvested and induced by different concentrations(50,100,200,400 g/L) of Radix Astragali. MAIN OUTCOME MEASURES:Hematoxylin-eosin staining was used to observe MSC morphology after 24 hours of induction.Immunocytochemistry was employed to observe the expression of NSE (specific neuronal marker),nestin(marker of neural stem cell),glial fibrillary acidic protein and microtubule-associated protein 2(markers of astrocytes). RESULTS:Following Radix Astragalitreatment,changes occurred in cell morphology including:cell body pyknosis;thin and long processes formed in some cells,with growth corresponding to drug concentration and induction time;and the formation of network-like connections between some cells. With increasing drug concentration and induction time,nestin expression was upregulated,and the number of positive cells increased;cells produced NSE,glial fibrillary acidic protein and microtubule-associated protein 2;nestin was expressed earlier than glial fibrillary acidic protein and microtubule-associated protein 2 expression.In addition,the number of NSE-positive cells was increased significantly more than glial fibrillary acidic protein-positive cells. CONCLUSION:Radix Astragali promoted process formation in stem cells.It may induce the differentiation of MSCs into neural stem cells,and subsequently into neuronal-and glial-like cells. Radix Astragali exhibits stronger inductive effect on neuronal differentiation than glial differentiation of MSCs.Xinsheng Wang Haifeng Li Ying Zhao Xiaoli Zhang Aihua Bo 2009Neural Regeneration Research2009,4,7:21
9Decision Tree Based Online Stability Assessment Scheme for Power Systems with Renewable Generations显示文摘The stochastic fluctuation of renewable energy resources has significant impact on the stability of the power system with renewable generations and results in change in stability.Therefore,it is necessary to track the changing stability of the power system with renewable generations,a task that can be performed online.This paper details the use of decision trees to predict multi-mode damping of power system integrating renewable generations with the help of wide-area measurements system(WAMS).Power systems with renewable source generation are complex with vast amounts of data being collected from WAMS.Decision trees(DTs)are employed as a means to handle vast quantities of wide-area information,which involves the mode damping information indicating the stability.A 16-generator,68-bus system with photovoltaic power generation and wind power generation is used as the test system.Remote signals obtained from phasor measurement units(PMUs)are employed as the input variables of DTs for predicting purposes.The simulation results demonstrate that the proposed predicting scheme is able to suggest the optimal course of action to remedy any near instability or unstable electromechanical oscillations even without prior knowledge of the varying output of the renewable source power.Tong Wang Tianshu Bi Haifeng Wang Jizhen Liu 2015CSEE Journal of Power and Energy Systems2015,1,2:21
10Formation and destruction processes of upper Sinian oil-gas pools in the Dingshan-Lintanchang structural belt, southeast Sichuan Basin, China显示文摘The lower Cambrian Niutitang Formation hydrocarbon source rocks at the Dingshan-Lintanchang structure in the southeast Sichuan Basin were of medium-good quality with two excellent hydrocarbon-generating centers developed in the periphery areas, with a possibility of forming a medium to large-sized oil-gas field. Good reservoir rocks were the upper Sinian (Dengying Formation) dolomites. The mudstone in the lower Cambrian Niutitang Formation with a good sealing capacity was the cap rock. The widely occurring bitumen in the Dengying Formation indicates that a paleo oil pool was once formed in the study area. The first stage of paleo oil pool formation was maturation of the lower Cambrian source rocks during the late Ordovician. Hydrocarbon generation from the lower Cambrian source rocks stopped due to the Devonian-Carboniferous uplifting. The lower Cambrian source rocks then restarted generation of large quantities of hydrocarbons after deposition of the middle Permian sediments. This was the second stage of the paleo oil pool formation. The oil in the paleo oil pool began to crack during the late Triassic and a paleo gas pool was formed. This paleo gas pool was destroyed during the Yanshan-Himalayan folding, uplifting and denudation. Bitumen can be widely seen in the Dengying Formation in wells and outcrops in the Sichuan Basin and its periphery areas. This provides strong evidence that the Dengying Formation in the Sichuan Basin and its periphery areas was once an ultra-large structural-lithologic oil-gas field, which was damaged during the Yanshan-Himalayan period.Liu Shugen Zhang Zhijing Huang Wenming Wang Guozhi Sun Wei Xu Guosheng Yuan Haifeng Zhang Changjun Deng Bin 2010Petroleum Science2010,7,3:20
11中国广域范围内大规模太阳能和风能各时间尺度下的时空互补特性研究显示文摘中国的风能和太阳能等可再生能源资源非常丰富。大规模具有波动性的电源接入电网将会给电网的安全稳定运行带来挑战。但是合理利用广域范围内风能和太阳能等资源的时空互补性可以有效降低其输出功率波动。基于中国气象局提供的大量气象站点实测小时级别风速和太阳辐射强度数据,分析和研究了不同组合场景下广域范围内的风电和太阳能资源之间的时空互补性。研究表明在不同时间尺度下(月,日,小时)中国大陆北部和东部沿海广域范围内风能和太阳能资源具有良好时空互补性,其中日时间尺度下互补性最强。同时,在各时间尺度下这两种可再生能源装机容量存在着使其时空互补性最强的组合比例。再者,分散区域越大,风电所占比重越大的组合场景小时时间尺度的时空互补性越强。刘怡 肖立业 Haifeng WANG 林良真 戴少涛 齐智平 2013中国电机工程学报2013,33,25:18
12A comparative study between Embosphere~ and conventional transcatheter arterial chemoembolization for treatment of unresectable liver metastasis from GIST显示文摘Objective:Transcatheter arterial chemoembolization(TACE) is a standard treatment for hepatocellular carcinoma(HCC) and/or some unresectable liver metastasis tumors.Hypervascular liver metastatic lesions such as metastasis from gastrointestinal stromal tumor(GIST) are an indication for transcatheter arterial embolization(TAE).The purpose of this study was to evaluate the efficacy and safety of Embosphere~-TAE(Embo-TAE) in comparison with conventional TACE(cTACE) for the treatment of liver metastasis from GIST.Methods:A total of 45 patients who underwent TACE between Aug 2008 and Feb 2013 were enrolled.Patients with GIST who underwent TAE with Embosphere~(n=19) were compared with controls who received cTACE(n=26).The primary end points were treatment response and treatment-related adverse events.The secondary end points were progression-free survival(PFS) and overall survival(OS).Results:The treatment response of Embo-TAE group was significantly higher than that of the cTACE group(P<0.001).The PFS was significantly better in the Embosphere~-group than in the cTACE group(56.6 and 42.1 weeks,respectively;P=0.003).However,there was no statistically significant difference in liver toxicity between the two groups(P>0.05).The median OS in the Embo-TAE group was longer than that in the cTACE group(74.0 weeks,95% CI:68.2-79.8 vs.61.7 weeks,95% CI:56.2-67.2 weeks)(unadjusted P=0.045).The use of Embo-TAE significantly reduced the risk of death in patients with GIST with liver metastases according to the Cox proportional hazards regression model [hazard ratio(HR):0.149;95% CI:0.064-0.475].Conclusions:TAE with Embosphere~ showed better treatment response and delayed tumor progression compared with cTACE.There was no significant difference in treatment-related hepatic toxicities.EmboTAE thus appears to be a feasible and promising approach in the treatment of liver metastasis from GIST.Guang Cao Xu Zhu Jian Li Lin Shen Renjie Yang Hui Chen Xiaodong Wang Song Gao Haifeng Xu Linzhong Zhu Peng Liu Jianhai Guo 2014Chinese Journal of Cancer Research2014,26,1:18
13Polysaccharides from Angelica sinensis alleviate neuronal cell injury caused by oxidative stress显示文摘Angelica sinensis has antioxidative and neuroprotective effects. In the present study, we aimed to determine the neuroprotective effect of polysaccharides isolated from Angelica sinensis. In a preliminary experiment, Angelica sinensis polysaccharides not only protected PC12 neuronal cells from H 2 O 2-induced cytotoxicity, but also reduced apoptosis and intracellular reactive oxygen species levels, and increased the mitochondrial membrane potential induced by H 2 O 2 treatment. In a rat model of local cerebral ischemia, we further demonstrated that Angelica sinensis polysaccharides enhanced the antioxidant activity in cerebral cortical neurons, increased the number of microvessels, and improved blood flow after ischemia. Our findings highlight the protective role of polysaccharides isolated from Angelica sinensis against nerve cell injury and impairment caused by oxidative stress.Tao Lei Haifeng Li Zhen Fang Junbin Lin Shanshan Wang Lingyun Xiao Fan Yang Xin Liu Junjian Zhang Zebo Huang Weijing Liao 2014Neural Regeneration Research2014,9,3:17
14Downstaging and resection of hepatocellular carcinoma in patients with extrahepatic metastases after stereotactic therapy显示文摘Background:A combination of tyrosine kinase inhibitors(TKIs)and anti-PD-1 antibodies with local regional therapy has elicited yield substantial clinical benefits in patients who have hepatocellular carcinoma(HCC)with extrahepatic metastases.Using this treatment strategy to convert HCC patients with extrahepatic metastases from unresectable to resectable has not yet been reported.Methods:Consecutive hepatocellular carcinoma patients with extrahepatic metastases who received first-line therapy with a combination of TKIs and anti-PD-1 antibodies and at least one local regional therapy were analysed.Results:Nine patients with localized disease who received first-line systemic therapy were enrolled.At baseline,all of them had oligometastatic disease,namely,Barcelona Clinic Liver Cancer stage C(or Chinese Liver Cancer stage IIIB).The most common treatment administered was lenvatinib plus anti-PD-1 antibody and transarterial chemoembolization,and the median time span from systemic therapy to surgery was 3.2(IQR,2.8-6.2)months.Three patients achieved a pathological complete response.Six patients underwent laparoscopic surgery,and the other 3 patients underwent open surgery.After a median follow-up of 10.2(IQR,8.6-20.0)months,7 patients survived without disease recurrence,and 2 experienced tumour recurrence.All patients had any-grade AEs,and 55.6%of the patients experienced grade 3 AEs.Fatigue was the most common AE,followed by elevated aminotransferase levels and hypertension.Conclusions:Stereotactic therapy is a feasible conversion therapy for HCC patients with extrahepatic metastases to become resectable.This is the first study to analyse therapeutic outcomes of patients receiving these therapies for HCC with extrahepatic metastases.Xiaobo Yang Haifeng Xu Bangyou Zuo Xu Yang Jin Bian Junyu Long Dongxu Wang Junwei Zhang Cong Ning Yanyu Wang Ziyu Xun Yunchao Wang Xin Lu Yilei Mao Xinting Sang Haitao Zhao 2021Hepatobiliary Surgery and Nutrition2021,10,4:17
15MdGSTF6,activated by MdMYB1,plays an essential role in anthocyanin accumulation in apple显示文摘Anthocyanins are biosynthesized on the cytosolic surface of the endoplasmic reticulum and then transported into the vacuole for storage.Glutathione S-transferases(GSTs)are considered to be responsible for the transport of anthocyanins into the vacuole.However,the regulatory mechanisms of GSTs in plants are still unclear.Here,we performed a genome-wide analysis and identified 69 GST genes in apple.The expression of MdGSTF6 was positively correlated with the anthocyanin content(r=0.949)during‘Yanfu 8’fruit development.The overexpression of MdGSTF6 in the Arabidopsis thaliana tt19 mutant resulted in seedlings of 35S::MdGSTF6-GFP/tt19 that could accumulate anthocyanin and rescue its phenotype,suggesting that MdGSTF6 was an anthocyanin transporter.The silencing of MdGSTF6 affected anthocyanin accumulation in apple fruit.Moreover,the knockdown of MdGSTF6 by RNA interference in cultured‘Gala’seedlings inhibited anthocyanin accumulation.The interaction experiments showed that MdMYB1 could bind directly to the MdGSTF6 promoter to transcriptionally activate its expression.Collectively,our results demonstrate that MdGSTF6 encodes an important GST transporter of anthocyanins in apple fruit and provide evidence for the associated regulatory mechanisms.Therefore,MdMYB1 can not only regulate anthocyanin synthesis,but also control the transport of anthocyanin in apples.This information may be useful for further clarifying the regulation of anthocyanin transport in apple.Shenghui Jiang Min Chen Naibo He Xiaoliu Chen Nan Wang Qingguo Sun Tianliang Zhang Haifeng Xu Hongcheng Fang Yicheng Wang Zongying Zhang Shujing Wu Xuesen Chen 2019Horticulture Research2019,6,1:16
16Birth of fertile bimaternal offspring following intracytoplasmic injection of parthenogenetic haploid embryonic stem cells显示文摘Zhikun Li Haifeng Wan Guihai Feng Leyun Wang Zhengquan He YukaiWang Xiu-Jie Wang Wei Li Qi Zhou Baoyang Hu 2016Cell Research2016,26,1:15
17China's Sponge City construction: A discussion on technical approaches显示文摘Haifeng Jia Zheng Wang Xiaoyue Zhen Mike Clar Shaw L. Yu 2017Frontiers of Environmental Science & Engineering2017,11,4:15
18Malus sieversii: the origin, flavonoid synthesis mechanism, and breeding of red-skinned and red-fleshed apples显示文摘Flavonoids play essential roles in human health.Apple(Malus domestica Borkh.),one of the most widely produced and economically important fruit crops in temperate regions,is a significant source of flavonoids in the human diet and is among the top nutritionally rated and most widely consumed fruits worldwide.Epidemiological studies have shown that the consumption of apples,which are rich in a variety of free and easily absorbable flavonoids,is associated with a decreased risk of various diseases.However,apple production is challenged by serious inbreeding problems.The narrowing of the hereditary base has resulted in apples with poor nutritional quality and low flavonoid contents.Recently,there have been advances in our understanding of the roles that Malus sieversii(Ledeb.)M.Roem has played in the process of apple domestication and breeding.In this study,we review the origin of cultivated apples and red-fleshed apples,and discuss the genetic diversity and construction of the core collections of M.sieversii.We also discuss current research progress and breeding programs on red-skinned and red-fleshed apples and summarize the exploitation and utilization of M.sieversii in the breeding of high-flavonoid,and red-fleshed apples.This study highlights a valuable pattern of horticultural crop breeding using wild germplasm resources.The future challenges and directions of research on the molecular mechanisms of flavonoid accumulation and high-flavonoid apple breeding are discussed.Nan Wang Shenghui Jiang Zongying Zhang Hongcheng Fang Haifeng Xu Yicheng Wang Xuesen Chen 2018Horticulture Research2018,5,1:15
19Comprehensive eco-environmental effects of the shelter-forest ecological engineering along the Tarim Desert Highway显示文摘In this work, we report a comprehensive study about the eco-environmental effects of the shelter forest along the Tarim Desert Highway, including the effects on aeolian environment, soil, micro-climate, biodiversity, and groundwater. The results show that: (1) The movement of windblown sand near the ground surface was affected by the shelter forest. The wind speed and sediment transport rate in the shelter forest decreased by 64%―80% and 87.45%―99.02%, respectively. In addition, there were also significant changes in the sand flux structure, the sand grain size, and the deflation and deposition on the ground surface. (2) Compared to the natural mobile sand, the soil bulk density in the forest area decreased while the total salt content, the total porosity, and the water content increased. In addition, the soil fertility was significantly improved in the forest area, and showed the 'first rapid, then slow' variation pattern. (3) The shelter forest showed positive effects on the micro-climate. Within the 6 m height above the ground, the air temperature in the shelter forest at different heights was lower than that in the mobile sand, while the air humidity was higher, while, the soil temperature was also lower in the shelter forest than mobile sand. (4) The number of soil microbial species increased significantly with the improvement of habitat in the shelterbelt. However, the population of different species was not distributed evenly across the surveyed area. (5) Currently, no significant effects of groundwater-pumping and forest-irrigation water have been found on the groundwater level and its salinity. The variation amplitude of both groundwater level and salinity was at the level of centimeters and 1g/L, respectively. No obvious variation trend has been observed.LEI JiaQiang LI ShengYu JIN ZhengZhong FAN JingLong WANG HaiFeng FAN DongDong ZHOU HongWei GU Feng QIU YongZhi XU Bo 2008Chinese Science Bulletin2008,53,S2:14
20Ablation and radar-wave transmission performances of the nitride ceramic matrix composites显示文摘The 2.5 dimensional silica fiber reinforced nitride matrix composites (2.5D SiO2f/Si3N4-BN) were prepared through the preceramic polymer impregnation pyro- lysis (PIP) method. The ablation and radar-wave transparent performances of the composite at high temperature were evaluated under arc jet. The composition and ablation surface microstructures were studied by X-ray diffraction (XRD) and scanning electron microscope (SEM). The results show that the 2.5D SiO2f/Si3N4-BN composites have a linear ablation rate of 0.33 mm/s and high radar-wave trans- parent ratio of 98.6%. The fused layer and the matrix are protected by each other, and no fused layer accumulates on the ablation surface. The nitride composite is a high-temperature ablation resistivity and microwave transparent material.JIANG YongGang ZHANG ChangRui CAO Feng WANG SiQing HU HaiFeng QI GongJin 2008Science China(Technological Sciences)2008,51,1:14
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