柜式喂料机电子秤系统防堵料改进

为解决柜式喂料机电子秤这一定量喂料系统频繁堵料问题,通过对设备结构及控制匹配进行研究,分析了堵料 原因。堵料主要发生在尾料阶段的柜式喂料机出口处,这是由松料辊反转导致出料的楔形空间过小所致;爬坡输送带与 计量管间的落料口处堵料,这是由计量管料位光电管与喂料机底带和爬坡带的匹配不当,以及高料位光电管与落料缩口 间的缓冲空间不足导致。通过重新调整松料辊轴承座位置、设定新的喂料机底带、爬坡带调速模型,以及调整高料位光 电管位置等方法进行了改进。应用效果表明,改进后定量喂料系统较好地解决了堵料问题,堵料频次由原来的18.7次／ 月减少到0.3次／月,保证了物料流量稳定性。     

我国生猪生产效率及补贴政策评价

文章采用数据包络分析方法（DEA）分别对我国生猪生产效率进行了区域差异和规模比较。研究表明,生猪生产效率呈现出明显的地区差异,与西部地区比较,东部更有效率,但呈现规模不经济的状况;规模养殖比散养有较高的经济效率,但散养生猪仍具有较灵活的成本优势。根据研究结论,认为中国实施区域差别化的生猪补贴扶持政策有一定的合理性,但应有侧重,东部应侧重效率导向,中西部地区应以规模导向为主;同时在发展规模化养殖过程中也应注意差异化,对不同规模养殖户实行差别的补贴政策;生猪补贴政策还应充分考虑生产和消费布局等。     

Mothers’ attitudes and beliefs about infant feeding highlight barriers to exclusive breastfeeding in American Samoa

BackgroundIn American Samoa, initiation of breastfeeding is almost universal but exclusive breastfeeding, a promising target for obesity prevention, is short in duration.Aims(1) To examine American Samoan mothers’ feeding experiences and attitudes and beliefs about infant feeding and (2) to identify potential barriers to exclusive breastfeeding.MethodsEighteen semi-structured interviews were conducted with American Samoan mothers at 16–32 days postpartum. Interviews focused on mother's knowledge and beliefs about infant feeding, how their infants were fed, why the mother had chosen this mode of infant feeding, and how decisions about feeding were made within her social surroundings. A thematic qualitative analysis was conducted to identify salient themes in the data.FindingsIntention to exclusively breastfeed did not predict practice; most women supplemented with formula despite intending to exclusively breastfeed. The benefits of breastfeeding were well-recognized, but the importance of exclusivity was missed. Formula-use was not preferred but considered an innocuous “back-up option” where breastfeeding was not possible or not sufficient for infant satiety. Identified barriers to exclusive breastfeeding included: the convenience of formula; perceptions among mothers that they were not producing enough breast milk; and pain while breastfeeding. The important support role of family for infant feeding could be utilized in intervention design.ConclusionThis study identified barriers to exclusive breastfeeding that can be immediately addressed by providers of breastfeeding support services. Further research is needed to address the common perception of insufficient milk in this setting.     

Birth of a very low birth weight preterm infant and the intention to breastfeed 'naturally'

An interpretive phenomenological study involving 17 Australian parents was undertaken to explore parents' experiences of breastfeeding very low birth weight (VLBW) preterm infants from birth to 12 months of age. Data were collected from 45 individual interviews held with both mothers and fathers, which were then transcribed verbatim and analysed using thematic analysis. From this study, the analysis identified the following themes: the intention to breastfeed naturally; breast milk as connection; the maternal role of breast milk producer; breastmilk as the object of attention; breastfeeding and parenting the hospitalised baby and the demise of breastfeeding. The discussion presented here presents the theme of the intention to breastfeed 'naturally'. This study found that all of the participant women decided to breastfeed well before the preterm birth, and despite the birth of a VLBW preterm infant continued to expect the breastfeeding experience to be normal regardless of the difference of the postpartum experience. It is without doubt that for these parents the pro-breastfeeding rhetoric is powerfully influential and thus successful in promoting breastfeeding. Furthermore, all participants expected breastfeeding to be 'natural' and satisfying. There is disparity between parents' expectations of breastfeeding 'naturally' and the commonplace reality of long-term breast expression and uncertain at-breast feeding outcomes. How the parents came to make the decision to breastfeed their unborn child -- including the situations and experiences that have influenced their decision making -- and how the preterm birth and the dominant cultures subsequently affected that decision will be discussed. The findings have implications for midwifery education and maternity care professionals who support parents making feeding decisions early in pregnancy and those striving to breastfeed preterm infants.     

“It Makes My Skin Crawl”: Women’s experience of breastfeeding aversion response (BAR)

ProblemSome women who intend to breastfeed experience a breastfeeding aversion response (BAR) while breastfeeding.BackgroundLittle is known about the experience of those who have feelings of aversion while breastfeeding.AimThis study aimed to investigate the experiences of women who have an aversion response to breastfeeding while their infant is latched at the breast. This is the first study that aims to understand this breastfeeding aversion response (BAR) as described by women who experience this phenomenon.MethodsInterpretative phenomenological analysis (IPA) was used to conduct and analyse ten semi-structured in-depth interviews with women who self-identified as experiencing BAR.FindingsFour overarching themes were identified: (1) Involuntary, strong sensations of aversion in response to the act of breastfeeding, (2) Internal conflict and effects on maternal identity, (3) The connection between BAR and relationships with others, and (4) Reflections on coping with BAR and building resilience.DiscussionSome women who intend to breastfeed can experience BAR, and this negative sensation conflicts with their desire to breastfeed. BAR can impact on maternal wellbeing. Those who experience BAR may benefit from person-centred support that directly addresses the challenges associated with BAR to achieve their personal breastfeeding goals.ConclusionThe experience of BAR is unexpected and difficult for mothers. If support is not available, BAR can have detrimental effects on maternal identity, mother–child bonds, and intimate family relationships.     

辽宁生猪生产：30年波动分析与发展建议

辽宁省生猪养殖业作为畜牧业的重要组成部分，已经发展成为农业和农村的支柱产业。依据辽宁省30年生猪生产的历史数据，以生产波动的相关理论，运用回归分析对猪肉产量进行时间趋势拟合，得出辽宁生猪生产波动特征：长期表现为总量增长，短期呈明显周期性波动。生猪价格、利润周期、疫病发生的不确定性和农户饲养规模是产生短期波动的主要因素。结合周期波动分析，提出建立生猪期货市场，实现生猪规模化饲养，健全完善生猪疫病防控体系，加强宏观政策引导等辽宁生猪生产发展建议。     

数控铣削加工沟槽方法与控制

本文主要介绍在数控铣削加工沟槽时,如何利用刀具半径补偿功能,使刀具偏离工件沟槽轮廓一定距离,实现利用一个程序完成沟槽内、外轮廓粗、精加工,以及选用合适的下刀方式进行沟槽加工质量控制,并用宏指令进行编程。     

Cost–benefit analysis of a PMTCT program in Mozambique

The costs and benefits of a HIV/AIDS PMTCT program in a Mozambican city were calculated. The provision and non-provision of infant feeding formula were considered, along with voluntary counselling and testing, and anti-retroviral treatment with Nevirapine. Costs were calculated in monetary units and benefits as deaths averted and disability-adjusted life years. The UNAIDS cost-effectiveness tool for evaluating ARV drug and substitute feeding interventions was used. The costs of the program were compared with the costs of treating HIV-infected children. With no infant feeding formula, there would be a total savings of US$5242 and a negative cost per DALY of US$1.53 without infant feeding formula. With formula, net annual costs would be US$141,268 and cost per DALY US$38.69. Citywide, each year 132 infant deaths would be averted by use of Nevirapine and eight averted by the breastmilk replacement program. All program options have reasonable cost-effectiveness ratios.     

抚州地区农田两栖动物食性分析

本文对抚州地区１２种农田两栖动物进行了食性分析，对泽蛙胃内容物的检查表明；其捕食种类达４门７纲１６目３３种以上，且以膜翅目，鞘翅目，鳞翅目的昆虫和蜘蛛为主，有益多数达６０．１４％，其他１１种多以农业害虫为食，其中饰纹姬蛙，小弧斑姬蛙以蚂蚁为主食，这些结果表明，这１２种两栖类是农业的效益，应加保护。     

Dose-Response Model for 13 Strains of Salmonella

Data from a human feeding trial with healthy men were used to develop a dose-response model for 13 strains of Salmonella and to determine the effects of strain variation on the shape of the dose-response curve. Dose-response data for individual strains were fit to a three-phase linear model to determine minimum, median, and maximum illness doses, which were used to define Pert distributions in a computer simulation model. Pert distributions for illness dose of individual strains were combined in an Excel spreadsheet using a discrete distribution to model strain prevalence. In addition, a discrete distribution was used to model dose groups and thus create a model that simulated human feeding trials. During simulation of the model with @Risk, an illness dose and a dose consumed were randomly assigned to each consumption event in the simulated feeding trial and if the illness dose was greater than the dose consumed then the model predicted no illness, otherwise the model predicted that an illness would occur. To verify the dose-response model predictions, the original feeding trial was simulated. The dose-response model predicted a median of 69 (range of 43-101) illnesses compared to 74 in the original trial. Thus, its predictions were in agreement with the data used to develop it. However, predictions of the model are only valid for eggnog, healthy men, and the strains and doses of Salmonella used to develop it. When multiple strains of Salmonella were simulated together, the predicted dose-response curves were irregular in shape. Thus, the sigmoid shape of dose-response curves in feeding trials with one strain of Salmonella may not accurately reflect dose response in naturally contaminated food where multiple strains may be present.