仓房自动堆包机的研制与设计

仓房自动堆包机是专门为粮食储藏和粮食加工企业研制的一款有限空间堆包设备。它不仅能在有限空间将粮包提升到目标高度、自动堆放,而且还能替代多人工作,设备操作简单、方便、灵活,可实现粮食储藏和食品加工企业有限仓房机械化作业。     

Rural land reforms and villagers' preferences for urban settlement: A case study of Shandong Province,China

Based on surveys conducted in Shandong Province, China, this paper examined the interests of rural residents to move to and settle in cities, as well as the factors that motivate or discourage their potential settlement changes. Results of the binary logistic regression analysis showed that villagers' urban settlement preference was related to sociodemographic factors such as gender, age, and occupation. Overall, the separation of the “three rights” (collective ownership, land contract right, and land use right) associated with rural land has strengthened the urban settlement preference of rural residents. Nevertheless, we did not find significant association between land transfer and the preference for urban settlement. For villagers who expressed interest in urban settlement, better job opportunities, education opportunities, and higher income are the leading “pull” factors that would attract them to cities. The attachment to rural life, high living costs, and high housing prices in cities were the top concerns for villagers who did not want to move. The study also found that villagers' desired urban destinations changed with the changing land parameters, indicating that the outcomes of China's rural land reforms may not be aligned well with the policy goals laid in the country's urbanization and rural development plans.     

TFSQ型高效环保组合式粮食杂质清理筛的研制

通过对振动筛理、垂直风选、旋风分离与沉降系统的研究,研制出集振动筛理、风选、旋风分离沉降、含尘气流循环再利用为一体的TFSQ型高效环保组合式粮食杂质清理筛。经应用测试和专家鉴定:该设备具有清理效率高、清理过程粉尘污染小,使用维护方便、可靠性强等优点,具有广阔的市场推广前景。     

亚洲棉GaPP2C24基因的克隆及表达分析

PP2C是一大类重要的蛋白磷酸酶,广泛参与不同的逆境胁迫响应。为了解PP2C基因在干旱响应中的功能,以亚洲棉石系亚1号为材料,利用RT-PCR方法从中克隆了GaPP2C24基因,并对该基因进行了生物信息学分析,荧光定量PCR研究了其在亚洲棉不同组织和干旱胁迫下的表达情况。结果表明,GaPP2C24基因CDS序列全长为1 251 bp,编码416个氨基酸。序列同源比对发现,GaPP2C24与其他植物的PP2C氨基酸序列有较高的相似性,其中与可可树(EOY33930.1)、黄麻(OMO91132.1)的相似性分别为85%,84%。进化分析表明,GaPP2C24与同属锦葵目的黄麻聚在一支,亲缘关系最近,与可可树的亲缘关系次之。实时荧光定量PCR结果表明,GaPP2C24基因在子叶、下胚轴、胚根、叶、茎和根均有表达,且在茎中的表达量最高,根中次之。GaPP2C24受干旱胁迫的诱导表达,其在根和叶片中的相对表达量在处理1 h后最高,分别达到对照的53.9,6.9倍,推测该基因在棉花干旱响应中有重要作用。     

Increasing selenium supply during the close-up dry period improves nutrient metabolism and attenuates inflammatory response after calving in dairy cows

The objective of this study was to investigate whether feeding selenium (Se)-replete cows a Se-yeast supplement in late pregnancy affects nutrient metabolism and inflammatory response during the periparturient period. Twenty cows were randomly assigned to two groups with 10 cows each. Cows in one group received Se-yeast at 0.3 mg Se/kg DM during the last 4 weeks before calving in addition to fed a TMR containing supplemented sodium selenite at 0.3 mg Se/kg DM (Se-yeast), while cows in another group were only fed a TMR containing supplemented sodium selenite at 0.3 mg Se/kg DM (Control). Blood samples were collected and analyzed for nonesterified fatty acids (NEFA), β-hydroxybutyrate (BHBA), glucose, insulin, tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, serum amyloid A (SAA), haptoglobin (Hp), and albumin. In control cows, plasma NEFA, IL-1β, IL-6, SAA, and Hp levels increased after calving, but glucose, insulin, and albumin levels decreased after parturition. Se-yeast supplemental cows had lower postpartum concentrations of NEFA, TNF-α, IL-1β, IL-6, SAA, and Hp, and higher postpartum levels of glucose, insulin, and albumin compared with control cows. The results indicate that feeding Se-replete cows a Se-yeast supplement in late pregnancy improves nutrient metabolism and attenuates the inflammatory response after calving.     

High-throughput screening reveals small molecule modulators inhibitory to Acidovorax citrulli

Acidovorax citrulli is a seed-transmitted gram-negative bacterium that can cause substantial economic yield loss in watermelon and melon production worldwide. Four small-molecule libraries containing 4,952 compounds were selected for high-throughput screening against A. citrulli wild-type strain Xu3-14 by evaluation of growth inhibition. One hundred and twenty-seven molecules (2.5% hit rate) were identified as bactericidal or bacteriostatic against A. citrulli at 100 μM. Secondary screens indicated that 27 candidate compounds were more effective against A. citrulli Group II strains than Group I strains (classified using repetitive element PCR). Several compounds were inhibitory to other pathogenic bacteria, including Clavibacter michiganensis subsp. michiganensis and Xanthomonas campestris pv. campestris, but did not affect the growth of plant beneficial bacteria Pseudomonas fluorescens and Bacillus subtilis. More than half of the compounds did not inhibit germination of Arabidopsis or watermelon seeds. The effect of small molecules on A. citrulli seed-to-seedling transmission was evaluated by applying each compound to inoculated watermelon seeds and assessing seedling infection. Nine compounds were chosen for further investigation based on their reduction of percentage seedling infection and compiling scores on their specificity, sensitivity, and phytotoxicity obtained in the secondary screens. The five best compounds were selected (thiamphenicol, nadifloxacin, pipemidic acid, ciclopirox, and zinc pyrithione) for greenhouse tests and were found to effectively reduce the seed-to-seedling transmission of A. citrulli in both artificially and naturally infested seeds. These top five compounds provide a basis for future development of an A. citrulli-specific bactericide.     

离地高度可调的减振式履带驱动机构设计

履带式农田作业车由于其优异的通过性与稳定的行驶性能,被广泛使用于南方丘陵地区。针对传统履带底盘采用刚性悬架,无法调节离地高度,行驶时乘坐舒适性较差的问题,设计了一种离地高度可调的减振式履带驱动机构。该机构采用分离式设计,将整个驱动机构分为上层承载架与下层行驶架,通过在上、下层之间设置液压缸与弹性元件,达到在一定区间内调节车辆离地高度与减少车身振动的目的。通过对关键部件进行重点设计,并对其工作过程进行简要分析,该机构在理论上能达到设计要求。     

齐齐哈尔市城市森林空气负离子浓度变化规律

于2015-2017年的5-10月份,采取定位观测研究方法,在齐齐哈尔市城市森林中选取6个固定观测区,包括16种林分类型,在每个林分类型中设置固定观测点,进行逐月连年观测空气负离子浓度、正离子浓度以及空气温度湿度等环境因子,获取有效观测数据18万个;对观测数据系统全面分析,探索城市森林负离子浓度日变化、月变化、季节变化规律及时空分布格局。结果表明:经3 a连续观测,齐齐哈尔市城市森林空气负离子浓度的日变化规律,一般是早晨(06:00-08:00)达到峰值,随后下降,至中午或下午最低,晚上18:00左右再次出现峰值;负离子浓度最高值可达2000个/cm^3左右、最低值在300个/cm^3左右。齐齐哈尔市城市森林中,空气负离子浓度一年中的变化规律,从5月份开始逐月上升,到9月份达到峰值,从10月份开始下降,负离子浓度5月份最低,9月份最高。齐齐哈尔市城市森林各季节空气负离子浓度水平有所不同,秋季空气负离子浓度水平最高,夏季略低于秋季,春季最低。     

黑木耳简单快速组织分离新法

利用酒精、镊子对黑木耳耳片进行组织分离,方法方便、快捷,分离成功率100%。