Estimating parameters of hyperbolic modulation frequency signal based on cascade dictionary

为降低水下通信中出现的多径和多普勒效应,提高水下目标探测精度,采用双曲调频信号作为探测信号,利用双曲调频信号(hyperbolic modulation frequency,HFM)时频变化具有双曲线的特征,通过建立HFM信号时间-尺度级联原子库模型,在原子库中寻找最优解,进而对HFM信号的两个频率变化因子进行估计。计算机仿真和水池实验的结果均证明,相较于现在常用的小波-拉东变换(wavelet-Radon)估计方法,本方法的均方根误差小于1%,因此在水下目标探测中有较大的应用价值。To reduce the multi-path and Doppler effects occurring in underwater communications and to increase the precision of underwater target detection,we employ a modulation frequency signal as the detection signal. A hyperbolic modulation frequency( HFM) signal is hyperbolic in the time-frequency domain. In view of this feature,we establish a time-scale cascade dictionary model to find the optimal solution; furthermore,two frequency variation factors of the HFM signal are estimated. The simulation results and the pool trials show that the proposed algorithm performs well,and its accuracy is superior to that of the commonly used wavelet-Radon transform. The root mean square error of the frequency variation factors is 1% lower than that achieved using the wavelet Radon transform.This demonstrates the potential of the suggested algorithm for underwater target detection.国家自然科学基金项目(61471309,61107023);; 国家教育部博士点基金项目(20110121120020);; 福建省自然科学基金项目(2013J01258);福建省自然科学基金项目(2010J01344);; 福建省重点基金项目(2012H1012

Studies on Energy of Casuarina equisetifolia Plantation on Degraded Coastal Sand

应用GR-3500型氧弹式热值仪测定福建沿海中部惠安县崇武林场1989年造的海岸沙地木麻黄人工林热值和能量现存量。结果表明:现存生物量为152·60t·hm-2,净生产力为10·17t·hm-2a-1,凋落物的年归还量为14·17t·hm-2a-1。木麻黄各组分干质量热值为19·26~20·53kJ·g-1,平均为19·70kJ·g-1,灰分含量为1·20%~11·92%,平均5·23%。整个林分能量现存量为2986·92GJ·hm-2,各组分的分布为干(43·30%)>根(24·10%)>枝(13·60%)>皮(10%)>小枝(6·60%)>枯枝(1·60%)>果(0·80%)。能量的归还量为294·56GJ·hm-2,净固定量为196·80GJ·hm-2,整个林分对林地有效太阳辐射能转化率为0·90%。木麻黄在东南沿海地区有较高的太阳能利用率和生长适应性,是很好的造林树种。By burning samples in a GR-3500 Oxygen Bomb Calorimeter, the caloric values and the total amounts of energy of Casuarina equisetifolia plantation planted in 1989 were determined at Chongwu forestry centre of Hui'an county, central coastline of Fujian Province. The standing crop of biomass, net productivity and litter production of the C. equisetifolia plantation were 152.60 t·hm~ -2 , 10.17 and 14.17 t·hm~ -2 a~ -1 , respectively. The gross caloric values of various components varied from 19.26 kJ·g~ -1 to 20.53 kJ·g~ -1 , with the weighted average of 19.70 kJ·g~ -1 . Ash content ranged from 1.20% to 11.92%, and averaged 5.23%. Total amounts of energy of plantation was 2 986.92 GJ·hm~ -2 , the rank order of various components was stem (43.30%) > root (24.10%) > branch (13.60%) > bark (10%) > foliage (6.60%) > dead branch (1.60%) > fruit (0.80%). Energy return through litter and net energy fixation were 294.56 and 196.80 GJ·hm~ -2 , respectively. The energy conversion efficiency of the photosynthetic active radiation was 0.90% on the whole stand. These results demonstrated that C. equisetifolia is a good tree species for silviculture in east-south coastlines of China because of its high energy conversion efficiency and ecological adaptation.国家“十五”科技攻关项目(2002BA516A16-15)“海岸带防护林优化配置模式和可持续经营技术研究”

Dynamic Caloric Value of Casuarina equisetifolia Litter Fall During Decomposition on Coast Sandy Land

采用氧弹式热值仪测定福建惠安滨海沙地木麻黄凋落物分解过程中的热值,揭示凋落物分解过程中干物质热值、去灰分热值、灰分含量的变化规律,结果表明:凋落物起始干物质热值为21.67kJ·g-1,经过3个月平缓下降后其值为21.40kJ·g-1,到第10个月干物质热值为20.48kJ·g-1,达到最低点,与起始值相差1.19kJ·g-1,随后干物质热值开始回升,第12个月的干物质热值为20.83kJ·g-1,年平均每月降低0.07kJ·g-1;去灰分热值与干物质热值有相同的变化趋势,从开始的22.78kJ·g-1,到第9个月的最小值21.89kJ·g-1,与起始值相差0.89kJ·g-1,随后的回升速度较干物质热值快,到第12个月时达22.41kJ·g-1,但是12个月总体平均每月降低0.03kJ·g-1;凋落物灰分含量的变化与热值呈相反的变化趋势,随着时间的延长灰分含量增加,但和热值一样反映了凋落物分解的规律,开始的灰分含量为4.88%,到3个月时为4.90%,随后进入线性增长的趋势,到第12个月时达7.09%,平均每月增加0.184个百分点。不论热值还是灰分含量与气温和不同层次土壤温度都显著相关,温度,特别是气温是影响凋落物分解的重要因素。The Casuarina equisetifolia litter decomposition experiment site locates at Huian county in Fujian province, south of China. Caloric value were tested by oxygenic bomb caloric-meter. The aim was to expose the law of gross caloric value, ash free caloric value and ash content of litter during decomposition. The result showed the dynamic of the gross caloric value, ash free caloric value and ash content of Casuarina equisetifolia litter during decomposing. The decomposation lasted for three months with the caloric 21.40 kJ·g -1, to which decreased from the beginning gross caloric 21.67 kJ·g -1. At the tenth month, the gross caloric value was decreased to rock bottom, 20.48 kJ·g -1, with the range 1.19 kJ·g -1 to the begin value. After ten months of decomposation, the gross caloric value began to increase, then gross caloric value increased to 20.83 kJ·g -1 at the twelfth month, while with average decreasing ratio 0.07 kJ·g -1 per month; As to ash free caloric value, which the beginning ash free caloric 22.78 kJ·g -1, decreased to nadir, 21.89 kJ·g -1 at the ninth month, with the range 0.89 kJ·g -1 to the begin value. Then it increased faster than gross caloric did, up to 22.41 kJ·g -1 at the twelfth month. While it had average decreasing ratio 0.03 kJ·g -1 per month; The ash content, which had the contrary tendency to caloric, increased with time go by. But as the gross caloric, they all reflected the law of litter decomposition. It increased slowly from 4.88% to 4.90% in the beginning three months, then increased sharply. At the twelfth month, the ash content was up to 7.09%,and with average increasing ratio 0.184 point of percentage per month, in twelve months. While both caloric and ash content related obviously with temperature and soil temperature, especial the air temperature, so temperature was an important factor effecting the litter decomposition.国家“十五”科技攻关项目:“海岸带防护林优化配置模式和可持续经营技术研究”(2002BA516A1615

Study on Dynamic of Casuarina equisetifolia Plantation Litter and Its Caloric Value on Coastal Sands

2002年11月至2003年10月在福建沿海中部惠安县崇武镇赤湖林场用收集筐法收集木麻黄凋落物,分析了凋落物各组分的归还量;应用GR-3500型氧弹式热值仪测定木麻黄凋落物的热值,并测定分析了凋落物各组分的灰分含量。结果表明:木麻黄人工林的凋落物归还量为14.18 t.hm-2.a-1,其中小枝占72.21%,枝条占23.41%,球果占2.68%,其余部分占1.69%。归还分布情况是:4—9月为归还高峰期,占总归还量的68.48%,其它月份占总归还量的31.52%。凋落物各组分灰分含量平均值顺序为:花(5.32%)>小枝(4.90%)>枝(4.69%)>球果(3.20%);凋落物干物质热值平均值顺序为:小枝>(21.11 kJ.g-1)>花(20.96 kJ.g-1)>球果(19.91 kJ.g-1)>枝条(19.89 kJ.g-1);凋落物去灰分热值的顺序为:小枝(22.19 kJ.g-1)>花(22.18 kJ.g-1)>枝条(20.87 kJ.g-1)>球果(20.63 kJ.g-1)。整个林分的能量归还量为294.55 G J.hm-2.a-1,其中小枝占主体,归还量为215.79 G J.hm-2.a-1,其次是枝条66.07 G J.hm-2.a-1,再次是果7.66 G J.hm-2.a-1,花最小5.02 G J.hm-2.a-1,各月的能流变化与凋落物生物量相似。By burning samples in a GR-3500 Oxygen Bomb Calorimeter,the caloric value of Casurina equisetifolia litter collected by traps from Nov.2002 to Oct.2003 at Chihu forestry centre in Huian county in the middle of Fujian coast was analyzed,and the ash content and ash free caloric value of every components were tested.Result showed that Casuarina equisetifolia plantation litter was 14.18 t·hm~(-2)·a~(-1),foliage twig occupied 72.21% of total,branch,cone,flower were 23.41%,2.68%,1.69%,respectively.The monthly dynamic variance was that the fastigium was from April to September,occupied 68.48% of total litter,and that in the other months occupied 31.52%.The average ash content order of components were flower(5.32%)>foliage twig(4.90%)>twig(4.69%)>cone(3.20%).The average gross caloric value order of components were foliage twig(21.11 kJ·g~(-1))>flower(20.96 kJ·g~(-1))>cone(19.91 kJ·g~(-1))>twig(19.89 kJ·g~(-1)).The average ash free caloric value order were foliage twig(22.19 kJ·g~(-1))>flower(22.18 kJ·g~(-1))>twig(20.87 kJ·g~(-1))>cone(20.63 kJ·g~(-1)).The C.equisetifolia plantation had high returning energy in a year,the amount of total plant was 294.55 GJ·hm~(-2)·a~(-1).The distribution among the components are as follows: foliage twig was 215.79 GJ·hm~(-2)·a~(-1) while twig,cone,flower were 66.07 GJ·hm~(-2)·a~(-1),7.66 GJ·hm~(-2)·a~(-1),5.02 GJ·hm~(-2)·a~(-1),respectively,with same dynamic tendency as the litter biomass variance.国家“十五”科技攻关项目:“海岸带防护林优化配置模式和可持续经营技术研究”(2002BA516A16-15

Study on Biomass and Energy of Main Species Plantation on the Coast Sandy in the South East of China

应用GR-3500型氧弹式热值仪测定了福建省东山县赤山林场木麻黄林、厚荚相思林和湿地松林的能量现存量,结果表明:木麻黄林现存生物量为156.82 t/hm2,各组分热值(总能量与总生物量的比值)处于19.84~21.70 kJ/g,整个林分平均热值为20.26 kJ/g,能量现存量为3 177.95 GJ/hm2,干的能量最大占总量38.09%,果的能量最小占总量0.77%;厚荚相思林现存生物量为149.51 t/hm2,各组分干重热值为19.98~23.48 kJ/g,整个林分平均热值为20.59 kJ/g,能量现存量3 079.16 GJ/hm2,干的能量最大占总量57.67%,果的能量最小占总量3.06%;湿地松林现存生物量142.22 t/hm2,各组分干重热值处于20.53~21.54 kJ/g,整个林分平均热值为21.00 kJ/g,能量现存量为2 986.28 GJ/hm2,其中干的能量最大占总量35.08%,枯枝的最小。3树种林分具有较高的现存生物量、能量现存量、各组分热值和整体平均热值,体现出较高的太阳能利用率。可见从热值与生物量的角度看,木麻黄、厚荚相思和湿地松是海岸沙地造林的良好树种。By burning samples in a GR-3500 Oxygen Bomb Calorimeter,the caloric values of plant samples were tested and then calculated the total amounts of energy of Casuarina equisetifolia plantation,Pinus elliottii plantation and Acasia crassicarpa plantation at Chishan forestry centre in Dong shan county Fujian province.The results were showed as follows: The standing biomass and energy were 156.82 t/hm2 and 3 177.95 GJ/hm2 in C.equisetifolia plantation,and the gross caloric values were between 19.84 kJ/g and 21.70 kJ/g,with total average 20.26 kJ/g(The ratio of total energy to total biomass).The energy distribution among components were: trunk occupied 38.09% of total,the largest ratio of components,while fruit on the other hand,was 0.77%;While in the A.crassicarpa plant,the standing biomass and energy were 149.51 t/hm2 and 3 079.16 GJ/hm2,respectively.The caloric were from 19.98 kJ/g to 23.48 kJ/g with total average 20.59 kJ/g.The components energy structure were as follows: Truck occupied 57.67% of total,while dead branch only 3.06% in the other side.In the P.elliottii plantation,standing biomass was 142.22 t/hm2.Caloricvalue of components range from 20.53 kJ/g to 21.54 kJ/g,with total average 21.00 kJ/g.While standing energy was 2 986.28 GJ/hm2.From all the above,three species of plantation with higher standing biomass,standing energy,high caloric values of components and total average values,showed that they had higher ratio of solar energy utilization.So C.equisetifolia,A.crassicarpa and P.elliottii were very suitable species to coastal sandy cultivation.国家“十五”科技攻关项目(2002BA516A16-15

Enrichment of Heavy Metals by Casuarina equisetifolia of Different Stand Ages

为认识木麻黄(Casuarina equisetifolia)防护林带重金属消减效应,利用电感耦合等离子体质谱(ICP-MS)测定了福建省平潭国有防护林场林龄分别为5,15,20,30年的木麻黄小枝、细根、凋落物及林地土壤中5种重金属(Cr、Cu、Zn、Cd和Pb)的含量.结果表明:平潭木麻黄林地土壤重金属Cr、Cu、Zn、Pb、Cd含量均低于福建省土壤和福建海岸带土壤的重金属含量背景值,未发现重金属污染;木麻黄Cr、Cd和Zn的平均含量高出普通植物的正常值范围,木麻黄中重金属含量依Zn>Cr>Pb>Cu>Cd顺序降低;木麻黄细根中的重金属含量最高,且细根对重金属的富集系数也最高;木麻黄对Cr、Cu、Zn、Cd的富集系数均大于1;木麻黄细根中Zn、Cu元素含量显著正相关;小枝对Cr、Cd和Pb,细根对Zn的富集系数均与林龄极显著正相关;木麻黄现存生物量中,Cr、Cu、Zn、Cd和Pb的现存储量分别为3.06~3.46 kg/hm2,1.14~1.57kg/hm2,11.67~12.57 kg/hm2,0.05~0.09 kg/hm2和0.45~1.84 kg/hm2,且主要存在于根和树干中;随着林龄的增加,木麻黄积累大量的重金属,并达到其峰值.综上所述,木麻黄防护林在防风固沙的同时,能够吸收富集大量的重金属,对海岸带的重金属污染具有明显的消减作用.Casuarina equisetifolia is the key species in the seashore shelter belt in Fujian Province.It is necessary to assess enrichment of heavy metals by C. equisetifolia.Concentrations of heavy metals,including Cr,Cu,Zn,Cd and Pb,in branchlet,fine root,litter and soil of C.equisetifolia in 4 ages( 5,15,20,30 a) were determined.There was no heavy metal pollution in the shelter belt soil. The results showed that the content of the heavy metals in C. equisetifolia could be ranked from high to low as Zn>Cr>Pb>Cu>Cd.The heavy metal content of the fine root was significantly higher than the other parts,and the concentration coefficient of the fine root was also the highest in C. equisetifolia.There was a significant positive correlation between the content of Zn and Cu in the fine root. The concentration coefficients of Cr,Cd,Pb in branchlet,and the concentration coefficient of Zn in the fine root were significantly correlated with stand age.Existing reserves of Cr,Cu,Zn,Cd and Pb were 3. 06-3. 46 kg / hm2,1. 14-1. 57 kg/hm2,11. 67-12. 57 kg/hm2,0. 05-0. 09 kg/hm2,0. 45-1. 84 kg/hm2. Heavy metals mainly existed in the root and trunk.C. equisetifolia had the capability of accumulating heavy metals during growth,and the potential to reduce heavy metal pollution.国家自然科学基金(41176090);; 国家科技支撑计划(2009BADB2B0302

Strategies of Prior-Fractionation for the Graded Utilization of Lignocellulose

木质生物质是地球上最丰富的一类生物质资源,主要由碳水化合物高分子(纤维素、半纤维素)和芳族聚合物(木质素)组成。木质纤维组分的清洁高效分离,是实; 现多元化、高值化生物精炼的重要基础。本文首先讨论了基于分级利用的组分分离技术与基于制备纤维素乙醇的预处理技术的不同之处;其次,梳理归纳了五种木质; 纤维组分优先分级分离策略:纤维素优先分离,木质素优先分离,半纤维素优先分离,木质素和半纤维素优先分离以及纤维素和半纤维素优先分离;再次,基于半纤; 维素优先分离策略,对国内相关的产业化应用进行了评述;最后,对木质生物质组分分离技术的当下定位和发展前景进行了总结与展望,以期对木质生物质的三大组; 分有较全面的价值观念和利用思路,并对木质生物质精炼技术的发展提供借鉴与参考。Lignocellulosic materials contributing the large proportion to the biomass resource are mainly composed of carbohydrate polymers (cellulose, hemicellulose), and aromatic macromolecules (lignin). Pre-fractionating lignocellulose is considered as the foundational step to establish an economical and sustainable lignocellulosic biorefinery. Firstly, the distinction between lignocellulose fractionation technologies and pretreatment methods for cellulosic ethanol production is discussed. Afterwards, five prior-fractionating strategies of lignocellulose for the biorefinery process are elaborated, including cellulose-first processing, lignin-first processing, hemicellulose-first processing, lignin & hemicellulose-first processing, and cellulose & hemicellulose-first processing. And then industrial applications of hemicellulose-first processing in our country are reviewed. Ultimately, the future perspective on lignocellulose fractionation technologies are given. The aim of this review is to provide new insights into the lignocellulosic biorefinery based on the fractionating of lignocellulose.National Natural Science Foundation of China [21676223, 21506177];; Fujian Provincial Development and Reform Commission, China [2015489];; Fundamental Research Funds for the Central Universities [20720160087,; 20720160077, 20720170062]; Natural Science Foundation of Fujian Province; of China [2016J01077, 2015J05034]; Education Department of Fujian; Province [JZ160398

Litter and Caloric Value of Casuarina equisetifolia Plantation in Coastal Sandy Area

采用定位研究的方法,在福建惠安赤湖防护林场定期收集木麻黄林分的凋落物,开展凋落物的归还量和热值的研究.结果表明,木麻黄林凋落物年归还量为14.17thm-2a-1,小枝占总归还量的72.19%,其他各组分占27.81%.凋落物灰分含量小枝4.39%~5.65%,枝条3.52%~5.65%,球果2.63%~4.23%;凋落物干重热值为小枝20.51~21.68kJ/g,枝条19.63~20.21kJ/g,球果18.27~20.63kJ/g;凋落物去灰分热值为小枝21.48~22.69kJ/g,枝条21.48~22.69kJ/g,球果18.91~21.49kJ/g.图1表8参26The litter of Casuarina equisitiforia plantation in Hui′an County, Fujian was regularly collected, and its return amount and caloric value were studied. Result showed that the return amount of litter was 14.17 t hm-2 a-1, with leaf accounting for 72.19% and the others for 27.81%. The litter ash contents of leaf, branch and cone ranged between 4.39%~5.65%, 3.52%~5.65% and 2.63%~4.23%, respectively. The litter gross caloric values of leaf, branch and cone were 20.51~21.68 kJ/g, 19.63~20.21 kJ/g and 18.27~20.63 kJ/g, and the ash free caloric values of them were 21.48~22.69 kJ/g, 21.48~22.69 kJ/g and 18.91~21.49 kJ/g, respectively. Fig 1, Tab 8, Ref 26国家"十一五"科技支撑计划“沿海防护林体系构建技术”项目;; 福建省森林培育与林产品加工利用重点实验室和国家林业局南方山地用材林培育重点实验室资助(2004BA516A13-15)~

滨海沙地主要造林树种纯林与混交林叶片热值特征

对福建东南沿海防护林4种主要树种纯林及混交林共8个林分类型成熟和衰老叶片的热值进行了研究。结果表明,在4种纯林中,厚荚相思叶片中热值最高,湿地松次之,都高于木麻黄和桉树;木麻黄纯林、木麻黄-厚荚相思混交林、木麻黄-湿地松混交林中木麻黄小枝热值差别不显著,都高于与桉树混交的木麻黄小枝;厚荚相思纯林和混交林成熟叶及衰老叶热值都高于湿地松和桉树;在所有的林分类型中,衰老叶中的热值都高于成熟叶或差别不显著。国家“十一五”科技支撑计划项目(2006BAD03A14-01);; 福建省重大科技专项(2006NZ0001-2);; 福建省森林培育与林产品加工利用重点实验室资助项

Nitrogen and phosphorus concentrations,N∶P ratio and resorption efficiency of leaves in different forest types

以福建东山沿海防护林中木麻黄、厚荚相思、刚果桉和湿地松4种主要树种为研究对象,探讨了纯林和混交林成熟叶与衰老叶中的养分状况、氮磷比、养分内吸收率以及它们之间的关系。结果表明:叶片中的养分浓度和内吸收率一般表现为纯林高于混交林、固氮树种高于非固氮树种。这是由于混交林和固氮树种改善了立地条件,林木能够从土壤中吸收较多的养分,从而降低了二者叶片中的养分内吸收率。各林分类型成熟叶片中的氮磷比都大于14,表明这些立地条件都存在不同程度的磷限制,导致大部分林分叶片磷内吸收率(rEP)大于氮内吸收率(rEn),因而衰老叶中的氮磷比大于成熟叶,但成熟叶和衰老叶氮磷比之间依然存在显著的正相关关系。不同林分类型成熟叶和衰老叶养分浓度、内吸收率和氮磷比在固氮树种和非固氮树种中存在互补性,表明固氮树种和非固氮树种在养分利用方面存在差异。不同树种的营养利用策略不同,在选择造林树种时,应优先考虑叶片养分含量低而内吸收率高的“营养保存型“树种。Nitrogen and phosphorus concentrations,N∶P ratio,nutrient resorption efficiency and their relationship in mature and senescent leaves in pure and mixed protection forest of Casuarina equisetifolia,Acacia crassicarpa,Eucalyptus ABL 12 W5 and Pinus elliottii were discussed in this paper.The results showed that nutrient concentration and resorption efficiency of leaves were higher in pure forest and N fixing species than in mixed forest and non-N-fixing species,respectively.This indicated that soil nutrient availability increased in mixed forest and N-fixing species,so the trees could absorb more nutrients from soil and depended less on nutrient resorption from senescent leaves.The N∶P ratios of mature leaves were all above 14,nitrogen was less limiting than phosphorus,and accordingly phosphorus resorption efficiency(RE_P)was higher than nitrogen resorption efficiency(RE_N).N∶P ratio was increased with leaf senescence.There was significant positive relationship between N∶P ratio in mature and in senescent leaves.Inter-and intraspecific correlations among nutrient concentrations,nutrient resorption and N∶P ratio of mature and senescent leaves in various forest types were different in N-fixing and non-N-fixing species.Due to the difference of nutrient use strategy for various life-forms,there was a significant correlation in N-fixing species,but no correlation in non-N-fixing species,and vice versa."Nutrient conservation" species,such as P.elliottii,with low leaf nutrient and high nutrient resorption efficiency should be prior selected for afforestation.“十一五”国家科技支撑计划项目(2006BAD03A14-01);福建省科技重大项目(2006NZ0001-2);国家林业局南方山地用材林培育重点实验室项