镁肥的施用

1　我国土壤缺镁状况地壳中镁的平均含量为 2 3 5 % ,而土壤中镁的平均含量只有0 6% ,这是由于镁易被淋溶的结果 ,我国北方土壤平均含镁量 1% ,南方土壤平均含镁量为 0 5 % ,所以南方土壤比北方土壤更加缺镁。全国土壤普查结果表明 ,我国土壤缺镁严重 ,缺镁土壤面积达5 5 3 3万hm2 ,占全国耕地总面积约 6%。2　镁肥的需求全国缺镁土壤每公顷施用镁肥 15 0kg ,则年需求量为 80 0kt,其它喜镁作物需镁肥 5 0 0kt,则年需镁肥 13 0 0kt。3　镁肥资源及品种( 1)　我国镁资源情况我国镁资源十分丰富 ,菱镁矿储量 10亿t,白云石储量几十亿吨 ,水…     

稀土抗旱剂研制成功

硫和镁是作物增产提质所必须的营养元素,由于常年使用氮磷钾化肥、作物高产和循环耕作不断携出土壤中的镁和硫,加之含硫化肥用量锐减,含硫农药限用或禁用以及烟气治理项目的实施,硫的来源几乎断绝。同时又缺乏必要的补救措施,致使中国部分地区特别是南方诸省份出现缺硫缺镁现象,有些地区情况比较严重。     

世界硫需求及硫肥状况

阐述世界硫肥的需求状况:到2012年世界农业缺硫量预计每年将达1 100万t,而亚洲和美洲将成为全球最严重的缺硫地区。环境污染控制、集约化农业生产以及低硫高浓度肥料的使用,加剧了全球范围内土壤缺硫状况。缺硫日益成为农业可持续发展和提高肥料利用率的限制因素之一,但也刺激农用硫肥的需求,为肥料工业开发新技术和新产品、开拓市场提供了契机。有3种硫肥,分别是:(1)硫酸盐基;(2)硫磺基;(3)液态硫基,其中硫酸盐基占绝大部分,其具有较好的理化特性,可直接、均衡为作物提供多种养分。本文介绍含硫肥料的种类、各种肥料的性能及目前世界上开发多种新型含硫肥料产品来适应和满足不同作物、土壤的需要。     

复混肥料必须注意硫素

我国土壤缺硫趋向,提出复混肥料须注意加入硫素.列举土壤缺硫给作物造成的危害和施硫的良好效果.推荐诊断作物缺硫症状的方法和补硫措施,并介绍我国硫素来源和复混肥料可选的含硫矿物和含硫化肥.     

硫镁肥及硫镁钾肥

硫镁肥及硫镁钾肥郭如新（天津碱厂总工办）硫与镁均为二级营养元素，由于近１０年来化肥结构的巨大变化，氮肥施用量大幅度增长，致使土壤中硫镁养分日趋减少。我国部分地区特别是南方诸省份已呈现缺硫缺镁的趋势，有些地区情况比较严重。如何适时地增加土壤中硫镁养分，...     

中国南方土壤硫的状况和对硫肥的需求

目前世界广泛缺硫的主要原因是普遍使用高浓度化肥，随化肥带入土壤的硫减少。从１９６０年至１９８５年中国化肥中的氮、硫比逐渐增大（由１增加至１０），据南方１０省８６４个县６７００个土壤样品测定，缺硫样品占总数的２６．５％，估算的缺硫面积为６６０万公顷。中国目前已有１４个省报导旅硫肥有增产效果，增产作物有２０种。据１９９０年南方１０省耕地硫素平衡估算，要维持当年土壤硫的收支平衡，需要补充的硫为１０１．３万吨。随着高浓度化肥的发展，中国含硫肥料的生产和使用将提到议事日程。     

镁肥在荔枝和柑橘上的施用效应

土壤镁素已逐渐成为提高广东水果产量和品质的重要障碍因子。本文研究了镁肥对荔枝和柑橘类水果的施用效应。田间试验结果表明:在土壤缺镁的情况下,配施适量镁肥可使荔枝增产11.4%~33.3%,增收10.8%~37.5%;在土壤镁硫均缺乏的条件下,荔枝施用硫钾镁肥增产增收效果优于氯化镁。柑适施镁肥比不施镁肥处理显著提高产量,果实品质提高,增收效果好。沙田柚配施不同种类镁肥,以硫酸镁的增产增收作用最好,碳酸镁增产作用次之,但由于成本较高,增收效果不及硫钾镁肥。     

作物镁素营养与镁肥应用前景

本文论述作物的镁素营养作用，以及镁肥对作物产量和品质的影响，作物的缺镁症状与诊断方法，包括土壤代换性镁和植株叶片含镁量的缺乏临界值，镁肥种类，施用方法及其应用前景。     

河南省耕地土壤硫素现状、硫肥增产效应及土壤硫素平衡概况

对河南省几种主要土壤全硫和有效硫含量进行了测定 ,结果表明全省耕地有 1/ 2面积属缺硫或潜在性缺硫。主要作物硫肥田间小区试验结果表明增产效果显著 :施硫使小麦增产 3.5 %～ 13.4 % ,玉米增产 3.5 %～11.7% ,大豆增产 7.1%～ 13.5 %。在施硫量相同情况下 ,小麦、玉米施硫磺增产效果大于施石膏 ,而大豆施石膏增产效果则大于施硫磺。如果维持当前土壤硫素水平 ,每年需补充硫 4 8～ 85 kg/ hm2。     

镁对小麦产量及生长发育的影响

镁是小麦体内叶绿素的重要组成成分,在小麦生长发育中起重要作用。植物体内的镁主要来源于土壤。近年来,随着作物产量不断提高,植物从土壤中携走镁的数量也不断增加,植物缺镁现象在各地陆续出现。目前关于土壤镁及镁肥效应的研究大多集中在南方红壤,关于北方土壤中镁素丰缺状况及镁肥效应的研究极为少见,对小麦影响的研究就更少。     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况。按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、环氧树脂、不饱和聚酯树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍。     

ICP-MS法测定地球化学样品中As、Cr、Ge、V等18种微量痕量元素的研究

建立了测定地球化学样品中包括As、Cr、Ge、V等18种微量、痕量元素的ICP-MS方法。地化试样用HF-HNO3混酸分解后,以1 1 HNO3溶解干渣。由于制样不使用盐酸,避免了Cl对As、Cr、Ge、V的质谱干扰。用国家一级地球化学标准物质GBW 07309制备溶液优化仪器工作参数,并用于校准。方法测定限(6s)为:0.007~6.4μg/g,精密度(RSD%,n=12)为:29%~9.4%,经过国家一级地球化学标准物质的分析验证,结果与标准值吻合。方法已应用于国土资源调查的试样分析。     

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.     

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.     

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.