浇筑式钢桥面铺装层推挤变形病害机理分析

以贵州省北盘江大桥钢桥面铺装层推挤变形病害为研究背景,采用凝胶渗透色谱法(GPC)和傅里叶变换红外光谱法(FTIR),从沥青分子尺度分析钢桥面铺装产生推挤变形的原因。分析结果表明:沥青老化并不是造成钢桥面铺装层推挤变形的主要原因;从现场调查可知,第2层粘层粘结能力的降低是造成钢桥面铺装层推挤变形病害的次要原因;通过级配分析发现,造成钢桥面铺装层推挤变形的主要原因是浇筑式沥青混合料(GA)级配偏细以及GA中集料颗粒的棱角性较差所致。     

硫铝水泥和胶乳对水泥乳化沥青砂浆低温硬化性能的影响

通过分析水泥乳化沥青砂浆（CA砂浆）冬季低温病害的产生原因,研究了硫铝酸盐水泥、胶乳对CA砂浆低温凝结和灌注质量的影响。结果表明,低温导致CA砂浆超长缓凝,使体系稳定性变差,并引起泌水和揭板起皮等病害;掺入硫铝水泥能加快CA砂浆的低温凝结过程,随替代量增加,凝结时间逐渐缩短;随温度升高,胶乳水泥流态体系可搅拌时间呈降低趋势,选用低温稠化性能合适的的胶乳,可改善新拌CA砂浆的低温均匀稳定性;复掺10%硫铝水泥和8%胶乳的CA砂浆在24 h的强度和膨胀率符合要求,在实测0.5~7.7 ℃的低温环境中,揭板检查CA砂浆断面均匀、表面平整无起皮,符合上道要求。     

自制硅酸盐对传统糯米灰浆性能的影响

采用灰浆性能表征和扫描电镜（SEM）、X射线衍射（XRD）、红外光谱（FTIR）等技术手段,探讨了自制硅酸盐对糯米灰浆的影响及作用机理。结果表明：自制硅酸盐对糯米灰浆的表面硬度、抗压强度、耐冻融性和耐水性均有一定程度的改善。6%自制硅酸盐糯米灰浆的综合性能最佳,其66 d抗压强度高达1.41 MPa,耐冻融性较之空白样品提高了133%,耐水性能提高了43.8%。改性糯米灰浆耐水性等性能的提高,可能与灰浆中水化硅酸钙的生成有关。     

刍议种价高位运行对种业发展的影响

<种子法>的实施,促进了我国种业快速发展.在政府的宏观调控下,以企业为经营主体,对种子科研、生产、经营、使用进行市场化运作的新型种子产业化体系已见雏形,种子市场结构发生了显著变化:种子公司由原来的2700家增加到7800家,种子销售单位达到67000多家.种子行业销售额前50名企业中,国有独资种子企业的种子销售额由1997年的17亿元下降到2002年的15亿元,而有限责任种子公司的种子销售额则由5亿元上升到35亿元,这标志着我国种业多元化市场竞争格局正在形成.与此同时,一个现象应引起广泛的关注,即种子价格明显上升,部分企业或产品利润率相对偏高.去年以来,一些杂交种子的价格上涨幅度达到1倍以上,大田作物常规种子的毛利率平均为15%～25%,转基因棉花种子和蔬菜种子的毛利率更是高不可测.不仅如此,种子流通环节的毛利率也十分可观,有的甚至达到40%以上.是什么原因促使种子价格在短短几年内上涨幅度如此之大?种价高位运行对种业发展会有什么影响呢?     

The influence of photoperiod genes on the adaptability of European winter wheats

Photoperiod response genes play a major role in determining the climatic adaptability of European wheat varieties. Photoperiod insensitivity, in the vast majority of photoperiod insensitive European wheat varieties, is probably determined by a Ppd1 allele originally derived from the old Japanese variety Akakomugi. Analysis of the pleiotropic effects of a Ppd1 allele from the Italian variety Mara shows that, besides accelerating ear emergence time, Ppd1 also reduces plant height, tillering, and spikelet numbers. Increases in spikelet fertilities more than compensate for reduced spikelet numbers, producing increased numbers of grains per ear. In southern Europe, early flowering Ppd1 genotypes produce larger grain and greater yields. In England and Germany, pleiotropic effects of Ppd1 on yield vary annually, depending on prevailing weather conditions, from +9% to -16%, over a 10 year period in the United Kingdom. A possible alternative Ppd1 allele from the CIMMYT variety Ciano 67 was compared to that from Mara. Differences associated with complete substituted chromosomes were found to be due to linked genes rather than different Ppd1 alleles. Examination of an alternative weaker gene for photoperiod insensitivity, Ppd2, shows this to exert similar but less significant pleiotropic effects to Ppd1. In the UK, in each of three years of trialing, Ppd2 increased yield 6% more than Ppd1. Results of 10 years trialing show that in Central European countries, between areas where photoperiod sensitive or photoperiod insensitive varieties have a clear adaptive significance, the annual variations in climate make it extremely difficult for breeders to produce varieties with good adaptability to changing environmental conditions. This revised version was published online in August 2006 with corrections to the Cover Date.     

The influence of ammonium-nitrogen on the specific activity of pelletized methanogenic sludge

The influence of ammonium-nitrogen concentrations in the range 680–2601 mg litre⁻¹ on the specific activity of pelletized methanogenic sludge was investigated in batch experiments. A discontinuous linear negative correlation was found between ammonium-nitrogen concentration and methane production rate. The slope of the discontinuous correlation changed sharply at an ammonium-nitrogen concentration in the range 1600–1700 mg litre⁻¹. The reversibility of the effect of ammonium-nitrogen was shown in a continuously fed experiment using an Upflow Anaerobic Sludge Blanket (UASB) reactor.Some proof was gathered for the hypothesis that acetate-consuming methanogenic bacteria are more strongly affected by ammonium-nitrogen than hydrogen-consuming methanogenic bacteria. In gradually increasing ammonium-nitrogen concentration the methanogenic sludge can adapt to ammonium-nitrogen concentrations above 1700 mg litre⁻¹ without the occurrence of a lag-phase.     

收入对中国城镇居民奶类消费的影响分析

本文在总结现阶段城镇居民奶类消费特点的基础上,研究了收入对城镇居民奶类消费的影响。研究结果表明,收入是影响城镇居民奶类消费的主要因素,随着收入的增加,城镇居民奶类消费逐步增长;同时,奶类消费支出随着人均可支配收入的增加而增加;在动物性食物中,奶类是需求收入弹性最高的食品。     

The effect of T-DNA on the agronomic performance of transgenic flax plants

Summary Registration and commercial release of crop cultivars improved using recombinant DNA technologies will require extensive field testing of the transgenic lines. In addition to testing the efficacy of the transferred gene(s), regulatory bodies and farmers need data from large scale agronomic studies to provide assurance that the foreign DNA does not adversely affect normal agronomic productivity or quality of the crop. Here, five transgenic sulfonylurea resistant flax (Linum usitatissimum) lines were included in a multiple location cultivar registration trial, evaluated and compared with four standard commercial cultivars and 24 other (conventionally produced) breeding lines. The transgenic lines did not appear to be affected by T-DNA for any quality or agronomic parameter tested, including yield.     

The influence of sward-age and management on the type of timothy and cocksfoot

Summary Cocksfoot and timothy were collected from a number of Dutch grasslands. The populations obtained in this way were investigated to see whether there might be a correlation between age and management of the fields, and heading time and growthhabit type of the plants in them. It appeared that old grasslands contain a type of timothy quite different from that of young grasslands, the plants of which closely resembled the hay types from commercial strains. Such extreme hay types were not encountered in old grasslands. One old meadow developed intermediate types which collectively might be considered to represent an indigenous hay form.The difference between old and young grasslands was less clear in the case of cocksfoot; the populations from young pastures had rather more plants with slightly more erect growth-habit.An evident influence of management on the plant type, as was found in perennial ryegrass from Dutch grasslands by Jonker (8), could not be established in the case of cocksfoot and timothy.Choke (Epichloë typhina) appears to be a fairly extensively distributed disease in timothy, especially along the borders of the large rivers of the Netherlands..

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收刈时间对玉米秸秆营养物质产量的影响

【目的】从玉米植株秸秆的总可消化养分产量考虑，确定植株的适宜收刈时间可有效利用秸秆饲料资源，【方法】为此本试验大田试验种植4个早中熟玉米品种，包括农大108、高油298、冀丰58、郑单958，在生长期的92d、96d、100d和104d收刈秸秆，研究收刈时间对秸秆营养物质产量的影响，【结果】试验结果表明，收刈时间明显影响玉米秸秆的有机物、蛋白质、纤维性物质和可消化有机物产量，【结论】所选种的玉米品种秸秆蛋白质和可消化有机物产量在100d达到峰值     

早龄期约束水泥砂浆环开裂预测模型分析

采用约束圆环试验研究了早龄期水泥砂浆的应力变化规律与开裂趋势。应用早龄期砂浆水化热模型、收缩与徐变等预测分析模型,建立了考虑温度、干缩与自收缩、徐变及硬化等多种效应综合作用下的约束水泥砂浆环早龄期时变应力分析模型,讨论了约束钢环与砂浆环的相对约束刚度对钢环约束效应的影响,提出了圆环开裂预测因子以分析约束水泥砂浆环的开裂趋势,与实际观察结果和数值分析结果的对比表明,上述理论分析与预测模型是合理并适用的。     

贮存时间对玉米秸秆营养物质损失的影响

确定玉米秸秆贮存时间与营养成分变化关系可有效利用秸秆饲料资源,以农大108玉米秸秆收刈后在棚舍内保存1-125d,分析研究不同时间点的粗蛋白、NDF、ADF总量和可消化有机物量,结果表明不同时间点干物质、粗蛋白的量差异不显著,NDF、ADF量随贮存时间延长而增加（p〈0．05）,可消化有机物量减少,秸秆的水分量显著减少,贮存时间改变了秸秆的营养物质含量（浓度）,主要是由于秸秆水分的损失。     

The influence of modifier genes on the intensity and stability of self-incompatibility in cabbage

Summary Four inbred cabbage lines have been derived from a single parental plant through several generations of selfing. Two inbreds have been found homozygous for an S ₁ allele while the other two are each homozygous for S ₂. Each inbred is self-incompatible, cross-incompatible with the inbred carrying the same S allele, and fully cross-compatible with inbreds carrying the other S allele. The S ₁ and S ₂ pairs of inbreds were each found to consist of one inbred with very high self-incompatibility (mean seed set of 0.15–0.25 seeds per pod) and one inbred with less intense self-incompatibility (mean seed set of 1.25–1.70 seeds per pod). For the S ₁ pair, flower to flower and plant to plant variation in seed set per pod was much larger for the less incompatible inbred that for the highly incompatible inbred. Further, incompatibility expression of the less incompatible inbred was influenced by temperature variation while that of the highly incompatible inbred was stable under different temperature regimes. The F₁ between the two inbreds of high and low incompatibility with the common S ₁ allele behaved like the less incompatible parent. F₂ plants showed intermediate intensities of selfincompatibility as well as variation for both lesser and greater intensities than those exhibited by the parents. The variations of self-compatibility and the sensitivity to environmental differences are considered to be conditioned by genes which modify incompatibility expression of the S alleles.     

The influence of Elymus sibiricus L. genome on the diploidization system of wheat

Summary The meiotic behaviour of five tetraploid wheat strains x Elytricum fertile (2n=42 chromosomes, AABBD(SH) genomes) F₁ hybrids has been analysed. Multivalent associations were observed in the hybrids which could be attributed to Elymus sibiricus L. gene (s) somewhat suppressing the activity of the wheat homoelogous pairing control system. This interaction depends on the wheat genotype. The effect was particularly notable when Triticum turgidum var. salomonis was the wheat parent. The possibility of gene transfer from Elymus to wheat is discussed.     

The impact of foreign influence on exporting through open innovation

Foreign direct investment brings both increased competitive pressures and opportunities for domestic Small and Medium Sized Enterprises (SMEs). Competition may force them to seek new international markets, but also provide access to international customers. However, as economies become more knowledge-based in order to access international markets, SMEs must seek to innovate. This study examines how foreign firm presence and innovation influence the exporting activities of SMEs. It contributes to the existing literature by dividing innovation into product/process innovation and in-house/open innovation. With open innovation, products are more likely to be novel and productivity boosted to a larger degree. We interact different types of innovation with foreign influence to examine whether there is a moderating influence on the relationship. The individual firm level data and foreign influence data are from the Longitudinal Small Business Survey and Office for National Statistics. Whether firms are active exporters is explored using multilevel logit regressions. Both innovative activities and the foreign influence increase the likelihood of exporting. In-house product innovation boosts export propensity to a lesser degree in areas with higher levels of foreign influence. The hypothesis that open innovation has more impact on exporting activities when foreign influence is greater is not supported for either type of innovation.     

不同的预处理方式对甜高粱秸杆纤维素酶降解效率的影响

本文对甜高粱秸杆进行了各种预处理,包括机械处理、高温处理、超声波处理、无机溶剂处理、有机溶剂处理等,比较了不同的预处理方式对甜高粱秸杆纤维素酶降解效率的影响,得出其影响程度顺序是：高温＞超声波＞有机溶剂＞粉碎度＞稀酸/碱。温度影响中干燥高温效果最佳,每0.1克秸秆粉末可产生还原糖8.3116 mg。超声波处理在无溶剂（无水）条件下,在相同的时间产生还原糖的量是有溶剂（有水）时的5倍。有机溶剂方面,丙酮的作用最为显著,在30分钟内每0.1克秸秆粉末可以产生还原糖4.3736mg。在机械处理中还原糖的量随着粉碎目数的增大而增加。此结果对工业生产提供了有价值的建议。     

响应面法不确定性参数对行星架静强度的影响

不确定性参数对行星架静强度的影响,取行星架强度最薄弱的部位-前轴承支座挖根(清根处)为研究对象,采用参数方差分析法从不确定性参数中挑选显著参数,并利用D最优抽样法选取样本点组合,计算精细有限元模型清根处应力响应值,继而基于最小二乘估计建立多项式回归响应面模型。基于快速响应面模型,利用蒙特卡洛模拟法和统计分析法研究显著性参数过盈量、铸造圆角和腹板公差对清根处第一主应力的影响,并从可靠度角度对清根处静强度进行评估。研究发现过盈量和前后腹板偏差的离散性对清根处静强度影响明显,同时行星架可靠度达到99.3%,表明在考虑了GL和IEC安全系数后,行星架可靠度仍然非常高。     

淘汰猪瘟抗体不合格种猪对母猪繁殖性能和仔猪生长性能的影响研究

应用Herdchek猪瘟抗体检测试剂盒对3个规模化猪场送检的1865份血清样品进行猪瘟抗体的测定,淘汰加强免疫后猪瘟抗体不合格（阻断率＜50%）的种猪,观察并记录淘汰猪瘟抗体不合格种猪后猪场种猪繁殖性能和小猪生产性能指标的变化情况。结果显示：3个猪场（A、B、C）淘汰加强免疫后猪瘟抗体不合格种猪后,平均窝产仔数分别提高了0.29头（P<0.05）、0.40头（P<0.01）、0.39头（P<0.01）;平均窝产活仔数分别提高了0.54头（P<0.01）、0.35头（P<0.01）、0.62头（P<0.01）;平均窝产断奶仔猪数分别增加了0.65头（P<0.01）、0.71头（P<0.01）、0.81头（P<0.01）;3个猪场（A、B、C ）30-60日龄小猪增重差异均极显著（P<0.01）;3个猪场（A、B、C）的母猪受胎率、仔猪断奶成活率和30-60日龄小猪成活率均有不同程度的提高,但差异均不显著（P＞0.05）。由此表明：淘汰加强免疫后猪瘟抗体不合格种猪后可以显著提高猪场母猪繁殖性能和小猪的生产性能。