规模化蛋鸡养殖场依靠先进技术赢得利润空间

一中国鸡蛋的市场占有量和发展方向 亚洲是全球最大的蛋品市场,全球养殖蛋鸡70亿只,中国蛋鸡数量13亿只,占全球蛋鸡养殖总量的18．5％,中国的鸡蛋产量占全球37．2％。可见中国是全球最重要的蛋品市场。中国大部分蛋鸡采用笼养的模式,美国93％的蛋鸡都采用笼养。从蛋品的消费量来看,中国位列世界第四,2011年人均消费鸡蛋295个（见表1）。     

禽舍自动化设施及节粮关键技术

鸡蛋生产和蛋品加工是全球化的技术,其相关知识具有通用性。当养殖场所有生产要素都达到平衡时,家禽生产必然收获成功,包括品种、营养（饲料和水）、保健、禽舍、设备和饲养员等。饲料成本占据禽类肉蛋生产成本的60％-80％。虽然设备投资仅占2％-3％,但对饲料成本的节约却起到决定性的作用。控制成本要跟踪记录盈利水平,主要参数有饲料、用水量、温度、能耗等相关费用。     

拉丁美洲家禽业概貌、特点与面临的挑战

一家禽业概况 拉丁美洲有25个国家,其中巴西和阿根廷是全球玉米、大豆的主产国和出口国,巴西和墨西哥分别是全球第三大和第五大鸡肉生产国,墨西哥是全球第三大鸡蛋生产国,人均鸡蛋消费量位居全球第一（人均365个）,鸡肉和鸡蛋是大多数拉丁美洲国家人们每天的主食。     

A concept to define a quantitative measure of mixture state

Mixing is a mechanical operation to distribute components evenly in a plane or a space. Composite molding and textile manufacturing industries are routinely taking advantage of mixing operations in order to distribute raw materials uniformly or in a specific way during composite molding or textile producing processes. Key issues to identify any mixed state are (1) the time needed to accomplish through mixing (the time scale) and (2) the extent of the homogeneity of the mixture in a plane (the length scale). In this paper, a new concept of mixture status is focused on the length scale. The goal to derive a new concept of mixture status is to establish a measure to describe the mixed extent of a mixture consisting of two components, derived from clump size and clump distribution. To verify the usefulness of the newly conceived “Mixedness Index”, the suggested definition was compared with the existing coefficient of variation (CV) method based on simulation and experiments. Results showed a reasonable relationship between the Mixedness Index and observation, demonstrating the feasibility of the proposed Mixedness Index for industrial applications.     

Synthesis and properties of Nylon 4/5 copolymers for hydrophilic fibers

Nylon 4, which can be synthesized by anionic ring-opening polymerization, has good mechanical properties and a very high affinity for water owing to its high polarity. On the other hand, despite its high melting temperature, the polymer has not been commercialized because of its low thermal stability. In this study, copolymerization of 2-pyrrolidone (C4) with 2-piperidone (C5) was performed to reduce the melting temperature of Nylon 4 homopolymer. The copolymerization reaction was controlled by changing the comonomer content, catalyst content, temperature, initiator content, and reaction time. The Nylon copolymers were characterized by ¹H-nuclear magnetic resonance (NMR) spectroscopy, differential scanning calorimetry, and thermogravimetric analysis. The hydrophilic properties of Nylon 4 and its copolymers were evaluated by surface free energy analysis and moisture regain measurement. The intrinsic viscosity and polymerization yield of Nylon 4 increased with increasing catalyst concentration until 5 mole% and decreased with further increases in catalyst loading. The proton NMR spectrum revealed the composition of the Nylon 4/5 copolymer to be 62.5 % C4 moiety at a 5:5 comonomer feed ratio. The melting temperature of the Nylon 4/5 copolymers decreased considerably according to the composition. The moisture regain of the Nylon 4/5 copolymer was higher than 6.4 % even at 77.3 % C4 in composition.     

Genetic evidence of stable northward extension of Pinus thunbergii Parl. forests in the Democratic People’s Republic of Korea

Genetic Resources and Crop Evolution - Japanese black pine (Pinus thunbergii Parl.) with high salt tolerance may be an important constitutive element sustaining terrestrial ecosystem by playing a...     

Ciguatoxin in moray eels raising the risk for seafood safety in Viet Nam

Fisheries Science - Recently, suspected ciguatera fish poisoning (CFP) cases caused by the consumption of moray eels, popular seafood for locals and tourists, have been reported in Viet Nam....     

七个突破性经营策略

每天,我们的收件箱和垃圾箱中充满了许诺重大效果的电子邮件,诸如“提高搜索引擎中的排名”以及“揭秘你的秘密销售力量”,更不必说那些“想要建立联系”或希望“只占用你15分钟”的名流了。而这只是上周收到的一小部分!     

Formation mechanism of p-methylacetophenone from citral via a tert-alkoxy radical intermediate

The aim of this study was to clarify the formation mechanism of a potent off-odorant, p-methylacetophenone, from citral under acidic aqueous conditions. An acidic aqueous solution (pH 3.0) containing 10 mg/L of citral was stored at 40 degrees C for 2 weeks. Among the compounds detected in the stored citral solution, 4-(2-hydroxy-2-propyl)benzaldehyde was identified for the first time as a degradation product from citral. The formation of p-methylacetophenone and 4-(2-hydroxy-2-propyl)benzaldehyde behaved the same when antioxidants were added to the citral solution. In addition, both compounds were formed by the Fe(2+)-induced decomposition of 8-hydroperoxy-p-cymene, another compound identified in the stored citral solution. These results suggested that both p-methylacetophenone and 4-(2-hydroxy-2-propyl)benzaldehyde can be formed via the same radical intermediate [p-CH3C6H4C(CH3)2O*] that can be derived from the O-O bond homolysis of 8-hydroperoxy-p-cymene. On the other hand, the degradation of 8-hydroperoxy-p-cymene without Fe2+ under acidic aqueous conditions did not yield p-methylacetophenone and 4-(2-hydroxy-2-propyl)benzaldehyde, but the degradation of citral without Fe2+ did. Therefore, other than the decomposition of 8-hydroperoxy-p-cymene, a mechanism to generate the tert-alkoxy radical intermediate was proposed for the formation of p-methylacetophenone and 4-(2-hydroxy-2-propyl)benzaldehyde in the citral solution.