砂姜黑土区控释尿素与普通尿素掺混对小麦/玉米轮作的产量及氮肥利用率的影响

试验结果表明:控释尿素与普通尿素掺混处理的产量在小麦玉米轮作上均以控释尿素掺混30%普通尿素处理最好。小麦产量:新坡村与农科所农场的产量分别为8096kg/hm2,8211kg/hm2;比控释尿素单施处理增产5.4%和7.2%,比普通尿素单施处理增产21.0%和22.6%,比对照(CK)增产40.2%和44.2%,它们之间的差异达5%或1%显著水平。小麦氮肥利用率变化趋势与产量变化趋势基本一致,均以控释尿素掺混30%普通尿素处理最高,新坡村与农科所农场小麦氮肥利用率分别为54.5%和52.7%。玉米产量:新坡村与农科所农场的产量分别为8715kg/hm2,9020kg/hm2,比控释尿素单施处理增产6.1%,6.7%,比普通尿素单施处理增产16.2%,16.1%,比对照增产55.7%,56.6%,它们之间的差异达1%显著水平。     

南四湖水稻化肥减施对产量及氮素吸收的影响

为寻求南四湖水稻优化施肥模式,根据当地习惯施肥和水稻的需肥特性,设计了7种不同施肥模式,对不同施肥模式下水稻生长因子(水稻地上部干重、植株及籽粒中氮含量)、产量因子(水稻成熟区生物量、产量)、肥料利用率进行对比分析。试验结果显示:控释尿素比普通尿素更符合水稻生长特性,水稻地上部干重优于普通尿素,籽粒氮的吸收量较普通尿素增加15.83%;降低化肥施用量、增施有机肥可提高水稻对养分的吸收和养分向籽粒中的迁移;在等氮磷钾量情况下,控释尿素和20%减量控释尿素配施推荐磷钾肥的水稻产量较普通尿素分别提高8.75%和8.70%;控释尿素配施推荐磷钾肥显著提高了氮磷钾肥的利用率,20%减量控释尿素的氮肥利用率可提高21.40%。从降低施肥成本、提高肥料利用率和控制面源污染角度出发,20%减量控释尿素配施推荐磷钾肥为最优施肥模式。     

砂姜黑土区控释尿素与普通尿素掺混对小麦-玉米轮作定位产量及氮肥利用率的影响

在驻马店新坡村进行了小麦-玉米轮作制下的控释尿素与普通尿素掺混比例定位试验研究。结果表明:控释尿素与普通尿素掺混处理的小麦、玉米产量均以70%控释尿素+30%普通尿素处理最好,第1年和第2年的小麦产量分别比100%普通尿素处理增产17.0%和21.1%,玉米产量分别比普通尿素处理增产16.2%和16.2%;氮肥利用率与产量结果一致,均以70%控释尿素+30%普通尿素处理最高,分别为53.9%和54.5%。     

潮土区氮肥运筹对小麦产量和氮肥利用率的影响

研究了氮肥运筹对小麦产量和氮肥利用率的影响,结果表明:以控释BB肥处理最佳,达8070kg/hm2。控释尿素基肥处理和33.3%氮肥基肥+33.3%氮肥拔节+33.3%氮肥抽穗期处理产量分别为7796kg/hm2和7978kg/hm2,三处理之间没有达到1%极显著水平。在施用普通尿素的各个处理中,33.3%氮肥基肥+33.3%氮肥拔节+33.3%氮肥抽穗期处理的氮肥利用率最高,为36.8%,可见适当的施肥方式也能提高氮肥的利用率。控释尿素基肥处理和控释BB肥基肥处理的氮肥利用率分别为45.7%和47.3%,均高于施用普通尿素的各个处理,控释BB肥基肥处理的氮肥利用率高于控释尿素基肥处理的氮肥利用率。     

控释掺混肥对小麦产量、氮素利用率及土壤氮平衡的影响

利用不同类型和不同氮素水平的控释掺混肥与普通复合肥进行对比试验,研究了不同施氮水平对大田小麦产量、氮素利用率和土壤氮平衡的影响。结果表明,控释掺混肥既能够显著提高小麦产量和氮素利用率,又明显减少了氮素损失量,以比常规施氮量减少20%、控氮比75%的控释掺混肥(CRF4)效果最显著,产量增加10.08%,氮素利用率提高15.23百分点,氮素损失量减少75.26 kg/hm2。     

控释肥料基施及普通尿素不同基追比对夏玉米产量及氮肥利用率的影响

研究了控释尿素和控释BB肥一次性基施后的肥料效果,以及普通尿素不同基追比对玉米产量和氮肥利用率的影响.研究结果表明:以33.3％普通尿素基施+33.3％大喇叭口期追施+33.3％抽雄期追施的处理最佳,产量最高达8 700 kg/hm2,氮肥利用率为34.3％.控释尿素基施处理和控释BB肥基施处理的氮肥利用率分别为41....     

钙镁磷肥复式包膜尿素对冬小麦产量和氮肥效率的影响

通过连续 3年 ( 1999～ 2 0 0 0年 )大田试验 ,研究了钙镁磷肥复式包膜尿素对冬小麦产量、氮效率〔包括 :氮素效率比 ( NER) ,氮吸收效率 ( NUp E) ,氮素使用效率 ( NUE)和氮肥利用效率 ( Nf UE)〕的影响。结果表明 ,钙镁磷肥复式包膜尿素与普通尿素的生物量、籽粒和秸秆量均显著大于对照处理 ;氮素使用效率 ( NUE)和氮肥利用率均显著高于对照。包膜尿素处理的产量和氮效率最高 ,其籽粒、秸秆、生物量平均值比普通尿素处理分别高 9.0 9%～15 .0 6 %、13.11%～ 14 .96 %、11.73%～ 14 .99% ,氮肥利用率高 15～ 16个百分点。在本试验条件下 ,相对于通常氮肥施用量 ( 15 0 kg N/hm2 ) ,少量增加氮肥施用量 (氮肥用量增加 8% )对产量和氮效率 ( NE)没有显著影响 ;而大量增加氮肥施用量 (增加 2 0 % ) ,能明显增加小麦产量、吸氮量和氮肥利用率     

树脂包膜尿素与普通尿素配施及树脂包膜BB肥在玉米上增产效果研究

在驻马店市农科所进行了树脂包膜尿素与普通尿素配施试验。试验结果表明,树脂包膜尿素与普通尿素配施处理的产量以控释尿素70%+普通尿素30%处理最好,为7 665 kg/hm2,比100%金正大树脂包膜尿素增产465 kg/hm2,提高了6.5%,比普通复合肥处理增产1 125 kg/hm2,提高了19.0%,比对照增产了2 400 kg/hm2,提高45.6%。金正大控释专用BB肥处理比普通复合肥处理增产90 kg/hm2,提高1.5%。     

控释尿素与普通尿素配合施用对夏玉米的增产效果研究

对控释尿素与普通尿素配合施用进行试验,试验在驻马店市农科所农场进行。夏玉米试验结果表明,控释尿素与普通尿素配合施用的产量均以控释尿素70%+普通尿素30%处理最好。产量为8115kg/hm2,比控释尿素单施(处理1)增产390kg/hm2,提高5.0%;比普通尿素单施(处理5)增产1230kg/hm2,提高17.9%;比处理6(CK)增产2940kg/hm2,提高56.8%;它们之间的差异达1%显著水平。     

植物油包膜控释氮肥在间作玉米-大豆上的施用效果研究

为考察新型植物油包膜控释氮肥对间作玉米-大豆的产量、经济效益、肥料利用率等方面的影响,开展了田间小区试验。试验以不施氮肥(CK)、施用普通尿素(PU)处理为对照;植物油包膜控释氮肥施肥量为全量、减量20%、减量30%等3种,控释氮占总氮量为60%、40%等2种,共设置4个处理。结果表明,在玉米试验中,与PU处理相比,控释氮占总氮量60%的全量、减量20%处理的产量分别显著增产14.70%、7.49%,纯收入分别显著增加3 192.80、2 680.02元/hm²;控释氮肥处理的氮素利用率为50.14%～53.43%,差异显著。在大豆试验中,与PU处理相比,控释氮占总氮量60%的全量处理显著增产16.67%,纯收入显著增加2 725.80元/hm²;控释氮肥处理的氮素利用率为54.12%～57.98%,差异显著。对于玉米-大豆间作栽培,建议全量或减量20%施用控释氮占总氮量60%的植物油包膜控释氮肥。     

乙苯,苯乙烯的生产及合成乙苯,苯乙烯催化剂的研究进展

苯乙烯是重要的石油化工原料。本文介绍了国内外苯乙烯生产的发展概况，合成乙苯，苯乙烯所用的催化剂种类，并就苯乙烯生产及催化剂的发展趋势提出了自己的观点。     

Synthesis and characterization of homopolymers and copolymers of various acrylates and acrylonitrile

Various homopolymers and copolymers of methyl acrylate, ethyl acrylate, butyl acrylate, and acrylonitrile in different feed ratios were synthesized. These were characterized by IR, ¹³C-NMR, DSC, DTA, and TGA. Spectroscopic characterization helped in differentiating copolymers of different mol ratios. Thermal analysis revealed different degradation patterns for homopolymers and copolymers. The temperature and energy changes associated with various phase transitions were dependent on the chemical composition of homo- and copolymers, as expected. © 1993 John Wiley & Sons, Inc.     

生物质气化及生物质与煤共气化技术的研发与应用

总结了生物质原料的特点及生物质单独气化的缺点;介绍了国内外生物质气化技术及生物质与煤共气化技术的研发与应用现状;分析了在此领域国内外的发展趋势与前景;概括了开展生物质与煤共气化技术研发的意义。     

Comparison of the Adhesion and Cohesion of Triblock and Random Copolymers of Styrene and Butadiene

A substantially greater detachment energy is required to strip a polyethylene tereph-thalate (Mylar) film from a styrene-butadiene-styrene (SBS) triblock copolymer compared to that for peeling from a random styrene-butadiene (SBR) copolymer. This is true even though the intrinsic interaction between the Mylar and each elastomer is expected to be similar because of their virtually identical chemical composition. It is proposed that this difference in peel strength (between the SBS and SBR) is a consequence of the much higher dissipative capacity of the former elastomer. Another manifestation of this is the higher cohesive tear strength of the SBS compared to the SBR. Extents of energy dissipation within each elastomer during detachment of the Mylar adherend are consistent with the hypothesis that the average maximum stress experience before detachment is some similar fraction of each elastomer's tensile strength.     

Electronic structures and reactivities of monometallic and bimetallic clusters of Au and Cu

The variation of the Au 4f binding energy of Au clusters with the cluster size has been established by measuring the binding energies of clusters whose size distributions were independently determined by HREM and STM. The binding energy increases significantly when the cluster size is less than 2 nm. Au-Cu bimetallic clusters of the composition Cu₃Au have been deposited for the first time on carbon substrates. The shifts in the core level binding energies of the bimetallic clusters show the effect of alloying in the case of large clusters, but show effects of both alloying and cluster size in the case of the small clusters. The interaction of CO with Cu₃Au clusters is stronger than with a bulk Cu metal. The interaction of CO with small Cu clusters also seems to be stronger than with bulk Cu or with large Cu clusters.     

钾盐资源及钾肥供需情况分析及预测

阐述了国内外钾盐资源及钾肥生产现状,对国内外钾盐的供需形势进行了分析及预测,从资源、原材料、国际市场三方面提出了解决我国钾盐短缺的措施。     

Kinetics and Mechanism of Oxidation of Mono- and Polyacetals

Abstract

Kinetics and mechanisms of oxidation of 6 acetals by molecular oxygen and ozone in liquid phase have been studied. Reaction with molecular oxygen (70°C, 15–16 hr) leads to the formation monoethers of the corresponding glycols with 68–90% selectivity. Salts of metals and complexes with crown-ethers have increased the reaction rate significally. Ozone have reacted with acetals with formation similar products. The mechanisms of intermediate stages have been proposed.     

Wetting properties of homopolymers and copolymers of pentafluorostyrene and methylacrylate and homopolymer blends

Polypentafluorostyrene (PPFS), polymethylacrylate (PMA), and poly(pentafluorostyrene-co-methylacrylate), poly(PFS-co-MA) were prepared and the wetting characteristics of polymer blends of PPFS and PMA were compared with that of poly(PFS-co-MA) via contact angle measurements. The critical surface tension of polypentafluorostyrene was found to be 22.6 dyne/cm, which is comparable to the value reported for polytrifluoroethylene (22 dyne/cm). The critical surface tension of poly(PFS-co-MA) is not linearly related to its composition. The polymer blends of PPFS and PMA exhibit significant surface enrichment of the fluoropolymer. The harmonic-mean method¹ was employed to determine surface tensions of these polymers and many known polymers. It is found that the method produces useful surface tension data provided the contact angle values are derived from testing liquids of dissimilar polarity.     

泡沫起泡性、稳定性及评价方法

本文论述了泡沫的两个基本性质:起泡性和稳定性。对起泡性和提高泡沫稳定性的方法作了评价。