无胶烟秆刨花板喷蒸热压自胶合

为了研究无胶烟秆刨花板喷蒸热压自胶合机理,通过喷蒸热压工艺制备无胶烟秆刨花板。采用傅里叶红外光谱分析(FTIR)、热重分析(TG)、高效液相色谱分析(HPLC)以及比表面积分析(BET)等分析手段,分析了无胶烟秆刨花板自胶合机制。结果表明：喷蒸热压过程的水、热协同作用使纤维素分子的活性羟基数量增加,活性羟基间可以形成氢键(O-H…H),在烟秆刨花间可以形成范德华力;喷蒸热压过程的水、热协同作用使烟秆刨花中的部分半纤维素水解,水解产物可以进行缩聚反应,生成类似于胶黏剂的缩聚呋喃树脂,也可以直接与具有酚羟基结构的木素发生缩聚反应,形成类似于酚醛树脂胶黏剂的缩合物。另外,烟秆刨花中的木质素受水热作用而充分流展并均匀分布在烟秆刨花间,一定程度上也改善了无胶烟秆刨花板物理力学性能。     

IMPROVING ULTRA-HIGH MOLECULAR WEIGHT POLYETHYENE(UHMW-PE)FIBRE SURFACE ADHESION BY PLASMA TREATMENT

It's very difficult to study high-strenth compositesbecause of the poor adhesion of polyethylene fibres caused by its specialstructural qualities.This paper reports a study of changing the surfacequalities of ultra high molecular weight polyethyene(UHMW-PE)fibres of different draw ratios by plasma and acid treatment.It alsodevotes to the experiments of measuring the fibre resin adhesion bythe pull out technigue,and studies the mechanism of the interface failureby SEM.The experimental results show that there's a significant impr-ovement in the adhesion between the UHMW-PE fibres and the resinafter the plasma treatment and it can be four times stronger,dependingupon the draw ratios of fibres and plasma parameters,The interfacefailure in the pull-out test involved developes along the fibre-resininterface within the fibre,and the skin of the fibre is peeled off.Theadhesion can be improved by combining the plasma etching technique andother methods of treating the surface of UHMW-PE fibre.     

甜菜种,肥分层机播技术研究

本文讨论了甜菜的种、肥分层机播技术.在同等条件下使用该项技术,甜菜生育前期的生长势显著增强,与种、肥混播的耧种甜菜相比,株高、叶片数、叶面积和叶面积指数等四项指标均有较大幅度提高,定植时株距的变异系数明显小于耧播;甜菜块根产量增加15%以上,含糖率略有提高.     

小麦黄色花叶病毒RNA2自然缺失突变体的筛选和定位分析

许多真菌介体传播的病毒在机械接种过程中易于发生自然缺失。利用在小麦上连续机械接种WYMV的方法,自第27代起,利用RT-PCR和Northern blot方法在感病小麦中检测到一个WYMV RNA2的缺失突变株,序列分析发现缺失区域位于RNA2的214~2 808 nt,共计2 595 nt,并在缺失区域的两端存在7个碱基的反向互补序列。缺失区域上游紧邻这7个碱基双链区存在一富含AU的短序列,并据此对此D-RNA2的缺失机制进行了讨论。     

Experimental Study for the Movement of Liquid Droplets on the Surface with Gradient Surface Energy

By using the chemical vapor deposition (CVD), a surface with gradient surface energy is fabricated based on the treated silicon chip. The dodecyltrichlorosilane (C_(12)H_(25)Cl_3Si) and Octrytrichlorosilane (C_(8)H_(17)Cl_3Si) are used as the source of silanization. By using the measurement of sessile drop method, the surface with gradient surface energy was characterized by measuring the contact angle of small water which lied on the surface of the treated silicon chip. The experiment shows the liquid droplets are driven to move from hydrophobic to hydrophilic zone on the gradient surface which is placed horizontally, the diameter of the droplets are 1~3 mm, and the single droplet reached the maximum velocity of up to 0.9 m/s. Based on the experimental results, the mechanical of the movement of the liquid droplet on the gradient surface is researched.     

速生人工林桉树木材高温热处理力学性能研究

广西速生人工林桉树资源丰富,对其进行高温热处理能够改善其极易端裂、尺寸稳定性和耐久性差等缺陷;同时,其力学性能受到一定影响。为此,采用单因素试验方法对高温热处理桉树木材的力学性能进行研究。主要探讨了热处理温度对速生桉树木材力学性能的影响。结果表明：热处理温度在180~230℃范围内,随着热处理温度的升高,木材的静曲强度、弹性模量随之降低,经220℃处理的桉木试件的静曲强度(MOR)、弹性模量(MOE)分别比未处理的降低了43.18%和35.94%。高温热处理对速生人工林桉树木材的改性效果显著,同时其力学性能有所降低。     

Analysis on Longitudinal Cracks and Deflection of the Pre-stressed V-shape Slab Roof Structure

In this paper, the finite element method is used to analyze the behavior of the prestressed V-shape Slab Roof structure, especially the effect of temperature change on the stress of slab. The calculated results indicate that when the temperature changes, the tensile stress at the lower extreme fibers of the flange plate near rib exceeds the tensile strength of concrete subjected to the combined action of triaxial stresses and results in the longitudinal cracks of the flange plate. The deflection analysis is based on the mechanical model of the prestressed V shape slab with the longitudinal cracks. The calculated results are in general agreement with the field observations.     

施肥对蕹菜生长及品质的影响

在褐土上采用盆栽试验研究了鸡粪、包衣尿素、素、硝铵4种肥料对蕹菜硝酸盐累积以及其他品质指标的影响，结果表明，在低量施氮下，鸡粪处理表现缺氮症状，长势不及等氮量的尿素处理，在中量施氮情况下，蕹菜长势为：鸡粪，包衣尿素＞硝铵＞尿素。在硝酸盐指标上，施用等量鸡粪可以明显降低其含量；在中量施氮情况下，植株的硝酸盐含量为：尿素＞硝铵、包衣尿素＞鸡粪；随着施氮量的增加，植株硝酸盐呈增加趋势，以尿素处理增加更为明显。鸡粪的施用量增加有利于提高蕹菜的Vc有可溶糖含量，但尿素素处理没有表现出类似的结果：在中量氮素投入情况下，硝铵及包衣尿素处理的Vc含量相对较高、中、高量化学氮肥施用显著地促进了土壤无机氮累积，其中又以尿不处理累积为甚，包衣尿素累积量较少，因此在生产中鸡粪或化学氮施肥用量的合理控制是蔬菜施肥中一项非常重要的工作。     

超临界CO2为快挥发溶剂丙烯酸清漆喷涂研究Ⅰ——超临界CO2对成膜物质物性影响、涂料配方选择

本文用FT-IR及粘均分子量法对超临界CO2作用前后的丙烯酸树脂进行表征。用气相色谱测定了超临界CO2作用前后的醋酸正丁酯、二丁酯溶液浓度的变化,并在不同压力下测定了65℃时醋酸正丁酯在超临界CO2中的偏摩尔体积。结果表明：超临界CO2不会改变丙烯酸清漆的成膜物质丙烯酸树脂及其它成分的性质,选择醋酸正丁酯为清漆的活性溶剂,可促进超临界CO2对涂料中丙烯酸树脂的溶胀,更有效地降低涂料液的粘度;选择二丁酯作为增塑剂是可行的。     

酶法制备紫甘薯花色苷色素的研究

采用α-淀粉酶水解提取紫甘薯花色苷色素,研究了反应温度、时间、pH值以及酶与底物比对提取效果的影响,结果表明最佳提取条件为:反应温度60℃,pH值5.5,反应时间70 min,酶与底物比400 U/mL。采用大孔树脂吸附法对色素提取液进行纯化,比较发现4种大孔树脂中AB-8型大孔树脂的吸附效果最好,并进一步研究了紫甘薯花色苷色素在AB-8型大孔树脂上的动态吸附及解吸过程。     

高压静电场对南瓜种子萌发及幼苗生长的生物学效应

南瓜种子经不同电场强度处理一定时间,研究其萌发状况并测定了12项生理生化指标.实验结果表明:经电场处理后,与对照相比,种子发芽率提高了3.2%～9.7%,电解质外渗率、呼吸强度均有不同程度的改善,可溶性蛋白的含量明显提高,静电处理还提高了种子中CAT、SOD等清除自由基的酶的活性,起到了提前打破种子休眠、提高种子活力、促进种子代谢水平的作用.各项指标显示:以H、I、J效果最为显著,可视为高压静电场处理南瓜种子的最佳剂量.     

等离子体对干旱胁迫下小麦种子萌发的生物学效应

用80~240 W射频等离子体处理小麦种子,在聚乙二醇（PEG-6000）模拟干旱胁迫条件下,研究了不同功率等离子体对小麦幼苗生长及抗旱性的影响。试验结果表明：不同功率的等离子体处理对干旱胁迫条件下小麦幼苗生长的影响效果不同,80~200 W处理对幼苗生长有不同程度的促进作用,根数、根长、株高、幼苗干重和根冠比各项指标均比对照有不同程度的提高,而240 W处理对小麦幼苗生长产生了抑制效应。其中160 W处理小麦种子在干旱胁迫下小麦幼苗根数、根长及干重分别比对照增加14.29%、16.94%和9.76%;丙二醛（MOD）含量及质膜透性比对照明显降低,防止或降低了膜质过氧化作用对膜的伤害;SOD、POD活性及脯氨酸含量均比对照高,表明保护性酶系统增强,一定程度上缓减了干旱胁迫对小麦幼苗的伤害,提高了其抗旱性。     

热处理对人工林杉木尺寸稳定性的影响

以人工林杉木为试材,对分别用热油和热空气为介质,在温度为180、200和220 ℃分别热处理1、3和5 h后试件的抗吸水率、抗胀率和表面接触角进行了测定,并用化学法分析了处理材主要成分的变化。结果表明：热处理后试件的尺寸稳定性能均显著高于未处理对照材（p﹤0.05）,且随温度的升高、处理时间的延长,木材的尺寸稳定性明显增加;在隔氧的油介质中进行热处理,试件的尺寸稳定性明显高于空气热处理材。对处理材主要化学成分的分析表明热处理使木材尺寸稳定的机理是处理过程中木材细胞壁组分尤其是半纤维素和少量的纤维素发生了化学降解。     

微生物预处理秸秆纤维浆结构、形态及成膜性研究

为研究生物预处理对秸秆纤维解离作用,促进制浆过程纤维分丝帚化及成膜性,采用实验室模拟发酵法,探讨微生物接种量及发酵时间对秸秆纤维化学组分、纤维形态及膜力学性质的影响。结果表明,与对照相比,接种1%外源菌处理稻秸14天时降解率达到20%,纤维降解适中,细小纤维占比仅59.63%~67.91%,纤维间交织力增强,纤维的疏解与拆分效应提升,打浆能耗降低71.54%。且随发酵时间的延长,纤维膜的抗张强度先升高再降低,第7和14天时分别提高7.6%和4.64%;3%接菌量处理14天时,浆料重均和质量加权增幅最大至28.57%和49.36%,膜撕裂度最高达240.9 mN。抗张强度与纤维质量间无明显相关性,耐破强度与纤维质量加权长度间呈负相关,撕裂强度与纤维数均长度、重均及纤维长宽比间呈显著正相关。该研究为生物降解秸秆纤维地膜的开发应用可行性提供技术支撑。     

等离子体处理大豆对化肥利用率的影响

为探索等离子体处理大豆对化肥利用率的影响、最佳方法和增产机理，进行了等离子体处理大豆对化肥利用率的试验。试验采用5种剂量、7个处理三次重复随机排列。苗期调查处理根数比CK1多1.8~2.9条。处理间株高变化不明显。结荚期、成熟期干物质的化验分析和测产，结果表明处理1.0A×2和1.5A×2的剂量能促进大豆吸收养分，(N＋P2O5＋K2O)总量比CK1提高10%以上；比CK1提高化肥利用率，提高氮、磷、钾肥利用率为25.2%~32.9%、3.0%~6.7%和 7.5%~13.5%。明确处理1.0A×2的剂量，比CK1增产11.0%，效果显著。     

Review on the Research of High-strength Wrought Magnesium Alloy ZK60

ZK60 magnesium alloy is one of high-strength wrought magnesium alloys. Owing to its high strength and low density, it has nearly the highest strength to density ratio among existing materials. Because its strength approximates to high-strength aluminum alloy 7075, it has promising application future. The history of magnesium alloy ZK60 and researches on its microstructure, mechanical properties, surface treatment, and the effects of alloy elements and microelements are reviewed . Further more, the authors put forward methods to improve its microstructure and mechanical properties and prospected the development future of this alloy in the aspects of surface treatment and application.     

Forest Landscape Change and Driving Forces in Nanling National Nature Reserve,Guangdong

Landscape change and its driving forces are always one of the major issues in landscape ecology. In this paper,we investigated the landscape pattern of Nanling National Nature Reserve using TM data and forest stand map. The paper aims at exploring how and why the landscape changed form 1988 to 2009. The results indicated that: the major landscape types are evergreen broad-leaved forest and coniferous forests,the area ratio of both total more than 80%; area ratio of other landscape types is less than 10%,including mainly mixed coniferous and broad-leaved forest,deciduous forest,shrub,other woodland,cultivated land,other land,construction land and water. During the 20 years,evergreen broad-leaved forest landscape has become a large-scale substrate,coniferous forests are interspersed,a small area of mixed coniferous and broad-leaved mixed forest patches expands; forest area in the study area changes slightly,the number of blocks increases,the degree of landscape fragmentation increases; forest landscapes change,and are less affected by human activities,which is closely related to the establishment,management and protection of protected areas.     

改性核桃壳固定化猪肉内源性脂肪酶及其对鸡肉风味的影响

脂肪酶作为一种绿色生物催化剂,在食品工业中有着广泛的应用。但其结构容易破坏,稳定性差,固定化脂肪酶是提高其稳定性的关键。采用微球酶、改性核桃壳固定化脂肪酶和LX-1000HA树脂固定化脂肪酶3种固定化方法,固定化猪肉内源性脂肪酶,利用顶空固相微萃取-气相色谱-质谱联用技术（HS-SPME-GC-MS）和电子鼻检测鸡肉经固定化猪肉内源性脂肪酶处理前后的风味变化,并分析鸡肉样品中挥发性成分的变化情况。结果表明：在同一条件下,3种脂肪酶固定化方法中以改性核桃壳固定化脂肪酶的活力最高,达169.8 U/mL;电子鼻结合HS-SPME-GC-MS技术共检测出53种挥发性成分,主要包括醛类、烯烃类、芳香族类、酯类、醇类和含硫化合物等,脂肪酶经固定化后可以有效改善鸡肉的风味。     

1-MCP controls ripening induced by impact injury on apricots by affecting SOD and POX activities

The influence of 1-MCP on the response of apricots to mechanical injury (impact) and the potential involvement of oxidative stress was investigated. Apricots (Prunus armeniaca L. cv. Marietta) picked at an early ripening (commercial harvest) stage (11–11.5 °Brix) were dropped from 30 cm onto a flat, hard surface to simulate an impact injury; fruit were treated with 500 nl 1⁻¹ 1-MCP for 20 h at 20 °C before or after the impact injury. Injured fruit showed a substantial rise in ethylene production after 4 days, while in fruit treated with 1-MCP, this increase started after 6 days, with a production rate lower than that of injured fruit. Increase in the respiration rate was delayed for 1-MCP-treated injured fruit in comparison with untreated injured ones. Tissue softening was reduced by 1-MCP treatment, showing less tissue deformability. Scanning EM analysis of injured tissue revealed healthier cells in 1-MCP treated apricots. 1-MCP-treated the increase of superoxide dismutase activity (SOD) due to mechanical injury in the first 4 days and this behaviour was related to ethylene production. Peroxidase activity (POX) increased in injured tissue immediately but then remained stable; 1-MCP, particularly when applied before the impact, increased POX activity. These results indicate that using 1-MCP can control ripening acceleration of apricots induced by mechanical injury. SOD, POX, and ethylene relationships are discussed.     

不同机械中耕处理对人工栽培甘草生长特性的影响研究

为有效改善多年生人工栽培甘草地表生长环境,降低成本投入,提高甘草产量和经济效益,分别以播种机地表耖土、推土机地表耖土、刀具地表耖土等机械中耕为试验处理,以大田未挠动处理为对照,对比分析不同处理对甘草农田土壤水分、紧实度、地表根系呼吸、植株光合能力,以及机械中耕后对甘草株高、产量等主要特征的影响。结果表明,播种机地表耖土和刀具地表耖土均可适度改善甘草农田土壤环境、增加产量,特别是播种机地表耖土处理增产7.43%,应结合早春田间追肥、机械除草等在5月中下旬进行,推土机地表松土作业对田间甘草苗破坏严重,不提倡应用。