夏热冬暖地区办公建筑节能设计探讨

夏热冬暖地区具有自身的特点,以深圳特区为例,分析夏热冬暖地区办公建筑的耗能现状,提出符合夏热冬暖地区气候、经济、环境条件的办公建筑设计的节能措施。     

Genetic Variation in ZmPAT7 Contributes to Tassel Branch Number in Maize

Tassel branch number (TBN) is one of the important agronomic traits that contribute to the efficiency of seed production and has been selected strongly during the modern maize breeding process. However, the genetic mechanisms of TBN in maize are not entirely clear. In this study, we used a B73 × CML247 recombination inbred lines (RILs) population to detect quantitative trait loci (QTLs) for TBN. A total of four QTLs (qTBN2a, qTBN2b, qTBN4, and qTBN6) and six candidate genes were identified through expression analysis. Further, one of the candidates (GRMZM2G010011, ZmPAT7) encoding an S-acyltransferase was selected to validate its function by CRISPR-Cas9 technology, and its loss-of-function lines showed a significant increase in TBN. A key SNP(−101) variation in the promoter of ZmPAT7 was significantly associated with TBN. A total of 17 distant eQTLs associated with the expression of ZmPAT7 were identified in expression quantitative trait loci (eQTL) analysis, and ZmNAC3 may be a major factor involved in regulating ZmPAT7. These findings of the present study promote our understanding of the genetic basis of tassel architecture and provide new gene resources for maize breeding improvement.     

Low Light Increases the Abundance of Light Reaction Proteins: Proteomics Analysis of Maize (Zea mays L.) Grown at High Planting Density

Maize (Zea mays L.) is usually planted at high density, so most of its leaves grow in low light. Certain morphological and physiological traits improve leaf photosynthetic capacity under low light, but how light absorption, transmission, and transport respond at the proteomic level remains unclear. Here, we used tandem mass tag (TMT) quantitative proteomics to investigate maize photosynthesis-related proteins under low light due to dense planting, finding increased levels of proteins related to photosystem II (PSII), PSI, and cytochrome b₆f. These increases likely promote intersystem electron transport and increased PSI end electron acceptor abundance. OJIP transient curves revealed increases in some fluorescence parameters under low light: quantum yield for electron transport (φE_o), probability that an electron moves beyond the primary acceptor Q_A⁻ (ψ_o), efficiency/probability of electron transfer from intersystem electron carriers to reduction end electron acceptors at the PSI acceptor side (δR_o), quantum yield for reduction of end electron acceptors at the PSI acceptor side (φR_o), and overall performance up to the PSI end electron acceptors (PI_total). Thus, densely planted maize shows elevated light utilization through increased electron transport efficiency, which promotes coordination between PSII and PSI, as reflected by higher apparent quantum efficiency (AQE), lower light compensation point (LCP), and lower dark respiration rate (R_d).     

Nutritional deterioration of stored Zea mays L. along supply chain in southwestern Ethiopia: Implication for unseen dietary hunger

Maize plays a key role in household food security in southwestern Ethiopia, but its benefits have been negated by high post-harvest losses. Previous loss assessment and management studies have focused mainly on quantity losses. This study was therefore designed to assess nutritional quality losses of stored maize along the supply chain in Jimma Zone, southwestern Ethiopia. Three districts representing potential maize producers and different agro-ecological regimes for maize production were selected for analyses. Sample collection started at harvest and continued for six months at two-month intervals from 21 selected actors along the supply chain. The experiment was conducted for two seasons, and a total of 72 samples were collected during each season. Both nutritional and anti-nutritional analyses were carried out following the international standards of the Association of Official Analytical Chemists. Data were analysed using SAS software (version 9.2) using a general linear model (GLM). The result revealed that moisture content significantly decreases (P < 0.05) as storage duration increases under different actors and agro-ecological conditions. But, showed increment during the final months under farmers' storage conditions. In addition, moisture content at the loading stage was not optimal for safe storage. Crude protein, crude fat, carbohydrate, and calorific value content significantly decreased (P < 0.05) as the storage duration increased, but fibre, ash, and major mineral (Ca, Zn, and Fe) content increased significantly over the storage period. Phytate and tannin content varied with storage duration and agro-ecological setting. Storing maize under traditional conditions along the supply chain resulted in substantial quality losses. This has great implications for nutrition insecurity and unrecognized undernourishment in the society. Additionally, substantial increases in fibre content above the optimum have important effects on nutrient absorption. There is thus a need to develop and disseminate appropriate storage technologies that minimize quality loss in maize stores.     

Delivery systems for biological control agents to manage aflatoxin contamination of pre-harvest maize

While soil application of a competitive non-toxigenic Aspergillus flavus strains is successful in reducing aflatoxin contamination in certain crops, direct application to aerial reproductive structures could be more effective for maize. A sprayable, clay-based water-dispersible granule formulation was developed to deliver non-toxigenic A. flavus strain K49 directly to maize ears. The efficacy of the K49 water-dispersible granule in mitigating aflatoxin in maize (Zea mays L.) was evaluated. Field studies were conducted to compare K49 colonization and effectiveness in reducing aflatoxin contamination when applied either as a soil inoculant or as a directed spray in plots infested with toxigenic strain F3W4. Fifty percent of non-toxigenic A. flavus was recovered from non-treated controls and from plots soil inoculated with K49 on wheat. In spray treatments with formulated or unformulated K49 conidia, over 90% of A. flavus recovered was non-toxigenic. Soil-applied K49 reduced aflatoxin contamination by 65% and spray applications reduced contamination by 97%. These findings suggest direct spray application of non-toxigenic A. flavus strains may be better than soil inoculation at controlling maize aflatoxin contamination and that a water-dispersible granule is a viable delivery system for maintaining viability and efficacy of the biological control agent, K49.     

Sub-Saharan African Maize-Based Foods - Processing Practices,Challenges and Opportunities

ABSTRACT

In vast swathes of Sub-Saharan Africa, maize is the staple food with consumption of up to 450 g/person/day. Additionally, maize is used as a weaning food for infants as well as for special ceremonies, caring for the sick, aged and pregnant women. Malnutrition persists in regions with heavy maize consumption, partly due to compositional maize characteristics, nutrient loss during processing and consumer preferences. This paper reviews the traditional uses and processing of maize, opportunities and necessary improvements to ensure (micro)nutrient security. Better use of maize can enhance its contribution to meeting the dietary needs and livelihood of Africa’s growing populace.     

Suitability of some selected maize hybrids from Serbia for the production of bioethanol and dried distillers' grains with solubles

BACKGROUND: Bioethanol is mostly produced from starchy parts of the corn grain kernel leaving significant amounts of valuable by‐products such as dried distillers' grains with solubles (DDGS) which can be used as a substitute for traditional feedstuff. The suitability of six maize hybrids from Serbia was investigated for bioethanol and DDGS production. The correlation between physical and chemical characteristics of the grain, bioethanol yield and quality of the corresponding DDGS was assessed. RESULTS: All hybrids had very different chemical composition and physical characteristics which could allow various applications. The highest bioethanol yield (94.5% of theoretical) and volumetric productivity (2.01 g l^?1 h^?1) were obtained with hybrid ZP 434 and the lowest with ZP 611k. Regarding chemical composition, all DDGS samples manifested good properties as feed components. Their protein content was higher compared to the kernel. In addition, the samples showed high digestibility and high mineral content, especially of calcium and phosphorus. CONCLUSION: A hybrid ZP 434 was selected as the most promising bioethanol producer. This property is attributed to the highest level of soft endosperm which is more susceptible to starch‐hydrolysing enzymes. A high yield potential per hectare makes it the best candidate for commercial bioethanol production. © 2012 Society of Chemical Industry     

The influence of flaxseed gum on the retrogradation of maize starch

The influence of flaxseed gum (FG) on the retrogradation of maize starch (MS) was investigated in this study. Based on the results of rapid visco‐analyzer (RVA), differential scanning calorimetry (DSC), X‐ray diffraction (XRD), Low field nuclear magnetic resonance (LF‐NMR) and scanning electron microscopy (SEM), FG has a retardation effect on the retrogradation of MS. With the addition increasing, the more significant the retardation effect was observed (P < 0.05). However, when the concentration of FG was up to 0.4%, the change of retrogradation ratio showed no significant difference (P > 0.05). FG could wrap around starch granules, suppress the recrystallisation of amylose and amylopectin, increase the water mobility and decrease the water loss. In summary, the overall results suggested that FG could be used as a natural inhibitor of the retrogradation of starch in food industry.     

夏季最大负荷发生时间的预测

夏季最大负荷发生时间的预测是电力部门十分关注的问题,它关系到该地区的负荷调整方案以及购电计划制定。北京近年来夏季用电需求增长尤为突出。准确地估计夏季最大负荷发生时间,十分必要且迫切。为此,收集了北京市1990~2002年的夏季最大负荷发生时间数据,发现它是一个波动的、含有灰信息量的序列,故采用灰色系统理论进行预测建模分析。但常规的GM(1,1)模型在适应波动的数据方面,预测精度未能达到要求,故采用GM(1,1)残差周期修正预测模型来解决。经过计算发现,该模型不仅可以提高原始数据的拟合精度,而且用于预测时,与2003年夏季最大负荷发生时间的实际值进行比较,预测偏差也在允许的范围内。