美国开发钻孔采脂技术

在美国东南部对树木边树木质部进行了钻孔采脂新方法的研究。用密闭容器收集松脂，１９９６－１９９７年又对２７５棵湿地松进行了钻孔采脂试验，调查了各种同处理方法对松脂得率的影响。     

国外采脂和松香生产近况

一、采脂和松脂生产全世界的松脂产量每年约675,000吨。近年来,松脂产量最多的国家是中国,其次是苏联、葡萄牙、西班牙、墨西哥和印度。再其次是美国、法国、波兰、民主德国和希腊。保加利亚、匈牙利、南斯拉夫、土耳其、日本、新西兰和其它一些国家也进行松树采脂。从采脂生产的技术装备和对采脂进行科学研究的情况来看,美国占首位。     

加强营林措施提高马尾松产脂力的试验报告

我国松香主要是脂松香,脂松香产量完成的如何,取决于松脂的多少而定,因而采割松脂这项生产,已引起人们重视。就世界采脂来说,由三十年代的常法采脂逐步发展到七十年代的化学采脂,其目的是促进和延长松脂的分泌,从而提高侧沟或单位面积产脂量。我们认为,一棵松树在一个采脂季节里,要想提高它的产脂量,采用先进的采脂技术只是一个方面,更重要的是松树还得有适应先进采脂技术的制造松脂补充量;换句话说,也就是松树在单位时间内,制造松脂能力的大小问题。在采割间隔期内,松树制造松脂能力大时,侧沟产脂量就上升;反之产脂量就下降,这是采脂人员在生产中经常     

亚硫酸造纸废液化学采脂试验报告

一、研究目的与意义马尾松是我国主要采脂树种,产脂量高,在全国总产量中占90%以上。目前松脂生产远不能满足国内外市场的需要。尤其是我国采脂劳动生产率低,大约每生产1.5吨松香要一个劳动力,每年在农村大忙季节,全国约需20方个劳动力进行采脂,与农业争劳力的矛盾突出。为了提高松脂产量和劳动生产率,节约采脂劳力,必需进行化学采脂才能充分利用松林资沅,实现松脂稳产高产。因此,研究马尾松中长期化学采脂具有广泛     

湿地松松脂生产经济效益分析

本文对湿地松松脂生产经济效益作出了分析,认为:湿地松进入采脂期,每人年采脂量达5吨以上;湿地松结合采脂经营,其综合经济效益提高38％;涅地松松脂生产的开发利用,对发展我国松香工业具有重要意义。     

我们是怎样开展造纸废液化学采脂试验的

在华主席为首的党中央领导下,高举毛主席的伟大旗帜,坚决执行国务院关于建立松脂林场,实现原料基地化的方针,认真贯彻全国化学采脂技术协作会议精神,在松脂林场内部物色有丰富采脂经验的脂农,开展了亚硫酸造纸废液化学采脂的生产性试验活动,试验结果,效果显著。一九七七年,荷塘、田南两个松脂林场有三个脂农,用了五个月的试验时间,共收割松脂二万三千二百八十七斤,与去年同期、同地、同树的常法采脂产量相比增产24%,迈开了采脂生产化学化的新步伐,闯出了松脂长流的新途径,稳产高产,大有希望。     

马尾松中长期化学采脂工艺试验初报

马尾松是我国主要采脂树种,产脂量占全国总产脂量的90%左右。据一九七四年统计,全世界松脂年产量约100万吨,中国年产量高达37.7万吨,居世界首位,但还远远满足不了实现我国四个现代化和外贸出口的需要,主要原因是劳动生产率低。我省大约生产一吨松脂需要一个劳动力。从全国来看,平均每个采脂工人或农民仅年产松脂2吨(美国20吨、墨西哥6吨、葡萄牙5吨、苏联4吨)。同时,每年在农业大忙季节,全国约需投入20万个劳动力进行采脂生产,与农业争劳力的矛盾较为突出。为了提高松脂产量和劳动生产率,实现采脂化学化,我们于一九七八年进行了“松针浸提液刺激采脂     

云南松化学采脂施用亚硫酸造纸废液和乙烯利试验报告

云南松是我省松脂生产的主要树种,也是全国三大采脂树种之一。为提高云南松立木产脂量和采脂劳动生产率,促进云南松松脂资源的充分利用。我们参考亚硫酸造纸废液、乙烯利在马尾松等树种上化学采脂试验的资料,于1980年7—12月在云南省石屏县大桥公社果腊村后山云南松纯林内进行了小区试验。     

钻孔施药法增脂剂增脂试验研究

利用钻孔法对思茅松进行施药。施入西林2#增脂剂6mL,用下降法采脂,采割面负荷率40%。30d施一次药,共5次。利用本底产量对比法计算增脂率。最高增脂率达35.7%。测定增脂剂对流脂时间及含油率的影响,并采集松针,测定松针中叶绿素含量的可溶性糖含量。证明叶绿素含量和可溶性糖含量与松脂产量呈正相关。     

辽宁省松脂资源现状及松脂生产发展前景

通过对辽宁省松脂资源现状的详细剖析,对松树采脂的可行性进行初步探讨,并就松脂开发中可能存在的问题及对策提出了自己的见解.     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Novel polyurethane coating technology through glycidyl carbamate chemistry

Glycidyl carbamate chemistry combines the excellent properties of polyurethanes with the crosslinking chemistry of epoxy resins. Glycidyl carbamate functional oligomers were synthesized by the reaction of polyfunctional isocyanate oligomers and glycidol. The oligomers were formulated into coatings with several amine functional crosslinkers at varying stoichiometric ratios and cured at different temperatures. Properties such as solvent resistance, hardness, and impact resistance were dependent on the composition and cure conditions. Most coatings had an excellent combination of properties. Studies were carried out to determine the kinetics of the curing reaction of the glycidyl carbamate functional oligomers with multifunctional and model amines. Detailed kinetic analysis of the curing reactions was also undertaken. The results indicated that the glycidyl carbamate functional group is more reactive than a glycidyl ether group. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago, IL.     

Highly moisture-proof polysilsesquioxane coating prepared via facile sol-gel process

A highly moisture-proof polysilsesquioxane coating was obtained from a new bis-silylated precursor, which was synthesized from 3-aminopropyltriethoxysilane (APTES) and m-xylylene diisocyanate (m-XDI) in tetrahydrofuran (THF) and verified by ¹H MAS NMR. For direct comparison purposes, an SiO₂ coating was also prepared by the Stöber method using tetraethoxysilane (TEOS) as the reactant. Interestingly, the coating obtained from the polysilsesquioxane sol exhibited a much higher moisture resistance capability than its counterpart, which was attributed to its more compact feature between nanoparticles as characterized by N₂ absorption experiment and transmission electron microscopy (TEM). Furthermore, its high transparency of about 92% showed potential for application in the protection of optical crystals.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.