“火罐”柿减压处理、低乙烯MA贮藏技术研究

利用减压贮藏的原理,提出了减压处理低乙烯ＭＡ贮藏技术,并利用该技术对陕西优良柿子品种－－火罐柿进行了室温条件下的保鲜贮藏研究。结果表明,减压处理低乙烯ＭＡ贮藏技术甬地抑制火罐柿硬度的下降,延长果实贮藏期。保硬期为４３ｄ,比对照长２４ｄ;贮藏期达９７ｄ,比对照长６７ｄ。     

苹果低氧气调新组合贮后效应的利用研究

利用0.12mm聚乙烯薄膜大帐进行低氧气调新组合的较大规模应用试验,对2394kg玫瑰红苹果进行低氧处理,帐内O2浓度可下调至约2%,CO2浓度可自动维持在5%～8%的较理想状态,处理结束后很易转为MA自发气调。低氧处理后再MA贮藏的苹果,虎皮病果率低、症状轻,腐烂果少,果柄和果皮新鲜,叶绿素保持效果好,果肉硬度明显高于小包装气调和冷藏对照。说明利用塑膜大帐进行前期低氧新组合处理与后期自发气调、实现低氧气调新组合贮后效应的利用是可行的。     

TDRSS Communication Services AndSignal Schemes

Tracking and Data Relay Satellite System studying and constructing is an important sustaining system in China. The signal designing of TDRSSis systematically introduced in this paper. According to various services, KSA, SSA, MA, UQPSK are selected in the up link, data spreaded spectrum is transferred in I section and ranging code is transferredin Q section. According to the different data groups and modes, spreading spectrum or not is selected and QPSK is used. The signal equations and system designing notes are presentedin detail.     

叶用莴苣耐热品种筛选

为快速、有效地筛选出耐热优质叶用莴苣品种,实现夏季耐热栽培,搜集国内外36个叶用莴苣品种进行人工模拟高温栽培试验,测定各品种的热害指数、根系活力、叶片相对电导率及氧自由基含量等指标。初步筛选出卡斯特奶油生菜、苦细叶、西班牙、双子结球生菜、美国结球生菜等5个较耐高温叶用莴苣品种。     

绵羊痒病在国内的首次报告

1982年7月四川省凉山彝族自治州从苏格兰购回2岁左右的边区莱塔特(简称边莱)种羊115只。1983年4～5月和12月,先后发现其中有2只母羊和3只一岁龄的纯种后代羔羊出现明显的搔痒与神经症状,经检查未见螨和虱等外寄生虫。一只母羊因迅速失重,后躯瘫痪,躺卧不起,于濒死期剖杀。尸体剖检无明显病变。病理组织学切片观察,在中枢神经系统的脑干(延髓、脑桥、丘脑和纹状体)呈两侧对称性的损害,出现特征的空泡性神经元(所谓“气球样细胞”)、灰质不同程度的海绵状变性和星形胶质细胞的肥大与增生等病变。取脑和脾作细菌培养为阴性,以病羊脑悬浮液接种家兔未发病。诊断是以呈现典型的痒病症状和脑内的组织损害为依据。     

包装材料与气体组分对磨盘柿贮藏的影响

采用ＭＡ贮藏法，对脆柿在长期贮藏过程中自行脱涩保脆状况进行了观测。对柿果包装材料及方法、气体组分最佳比例、氧与乙烯吸收剂的作用以及柿果褐变进行了分析探讨。结果表明：柿果贮藏以０．１０ｍｍ聚乙烯为包装材料，采用四果小包装，加入适量氧吸收剂和乙烯吸收剂，包装袋内ＣＯ_２与Ｏ_２比例尽快达到２：１以上，可使磨盘柿贮藏期达８０ｄ以上，硬果率为９０％，无涩味，无污染，色泽鲜艳，风味纯正，商品率达９８％。     

气调袋保鲜青菜头(茎瘤芥)的研究

检测青菜头贮藏过程中MA袋内气体指标变化和贮藏后的品质指标,并进一步探讨贮藏效果最佳MA袋的袋装量和硅窗面积对青菜头贮藏保鲜效果的影响。结果表明,PE硅窗袋、PVC硅窗袋和SCA袋内气体指标在一定时间后达到相对平衡,定期换气袋内气体呈不稳定周期性变化。PVC硅窗袋贮藏效果较好,PE硅窗袋和SCA袋次之,定期换气袋较差。当袋装量15 kg,硅窗面积为110 mm×75 mm时,PVC硅窗袋贮藏保鲜效果达到最好。     

Causes of maize density loss in farmers' fields in Northeast China

Increasing plant density is an effective and important way to reduce maize yield gaps in Northeast China. However, the fact is that a significant plant density gap exists between optimum plant density and actual plant density in farmers' fields.To quantify the density gap between planned planting density and final harvest plant density(HPD), we studied 60 farmers' fields on three types of soil for three crop seasons from 2015 to 2017 by measuring their plant-plant distance, actual seedlings density(ASD), final HPD and yield. We also explored the potential causes of density loss by digging the places where the seedlings were missing for two consecutive years in 2016–2017. Results show that the three-year average HPD in farmers' fields was 59 699 plants ha~(–1), which was significantly lower than the planned density, including both the machine setting density(MSD; 67 962 plants ha~(–1)) and theoretical plant density(TPD; 67 467 plants ha~(–1)). No significant difference was found in HPD between years and soil types. However, for MSD and TPD, the average value in 2015 was significantly higher than that in 2016 and 2017. No significant difference between soil types was observed. Furthermore,the results from 2016 till 2017 indicated that a lack of seeds in the soil, a failure to germinate due to low-quality seeds,and a lack of seedlings breaking out of the soil due to environmental problems explained approximately 60.88, 10.33 and 28.80% of density loss, respectively. According to our survey, 63% of farmers did not know their own TPD and HPD, and 54% of farmers did not know the density loss. Therefore, we argue that farmers' limited knowledge of density and density loss is an urgent problem that needs to be solved in maize production. These observations will be useful for determining best management practices for maize production and for providing helpful suggestions for machine improvement.     

Effect of Different Rearing Conditions of Indoor and Outdoor in Winter and Summer on Growth Performance and Immune Function of Heijiao MA Chicken

This experiment was conducted to study the effect of different rearing conditions of indoor and outdoor in winter and summer on growth performance and immune function of Heijiao MA chicken.In the winter and summer, 180 Heijiao MA chicken with the age of 35-day-old were chosen and randomly divided into two groups with three replicates per group and 30 chickens per replicate.The Heijiao MA chicken were reared at outdoor and indoor, respectively, and at 49, 63, 77, 91 days the immune organ indexes, serum antibody titers and growth performance were measured.The results showed that:①Whether it was winter or summer, the body weight of Heijiao MA chicken rearing at indoor were higher than that of outdoor, and the difference was significant at experimental stages in winter (P<0.05).There was significant difference only at 77 days old of Heijiao MA chicken in summer (P<0.05), the rest were not significant (P>0.05);②The ADG of outdoor group in summer was higher than that in winter, while the F/G of outdoor group in summer were significantly lower than that in winter (P<0.05).The ADFI and ADG of indoor group were not significantly different between winter and summer (P>0.05).③On immune function, immune organ indexes and ND antibody titer of Heijiao MA chicken of indoor group in winter were higher than outdoor group, while part of immune organ indexes, AI (H5) and ND antibody titers of outdoor group in summer were higher than that of indoor group;And ND and AI (H5) antibody titers in winter were higher than summer.In conclusion, The climate and season were major factors to influence the growth performance and immune function of Heijiao MA chicken.     

CLINICAL,DIAGNOSTIC, AND PATHOLOGICAL FEATURES OF 2 CASES OF METASTATIC IRIDOPHOROMA IN A VEILED CHAMELEON (CHAMAELEO CALYPTRATUS) AND A RED-BARRED DRAGON (CTENOPHORUS VADNAPPA)

Iridophores are iridescent cutaneous pigment cells found in reptiles, fish, and amphibians. Neoplasms of iridophores are rarely reported, and little is known about their behaviour, metastatic potential, and prognostic indicators. This paper reports details of the clinical course and pathological findings of metastatic iridophoroma in a veiled chameleon (Chamaeleo calyptratus) and red-barred dragon (Ctenophorus vadnappa). The veiled chameleon presented with a subcutaneous mass on the right lateral elbow and was diagnosed as an iridophoroma on fine needle aspiration. It was otherwise clinically normal. Within 35 days of excision, multiple secondary skin masses developed which were often non-pigmented and required microscopic examination to identify them as iridophoroma metastases. There were in total 54 days between the first detection of the primary mass and end stage, extensive cutaneous and visceral metastatic disease, and there had been no detectable primary mass during routine clinical examination 128 days prior to death. The red-barred dragon presented with a white sub-mandibular mass. While undergoing an excisional biopsy the animal expired, post-mortem examination revealed a cutaneous malignant iridophoroma with tumour cell clusters seen in pulmonary arterial vessels, suggesting that surgical handling of iridophoroma could precipitate the release of circulating tumour cell clusters. This is the first iridophoroma described in a red-barred dragon and the second report of a malignant iridophoroma in a veiled chameleon. Timely detection and careful excision of lizard iridophoroma may be an important factor in clinical outcome.