Analysis of the radiation Resistance and Gain of Full-Wave Dipole Antenna for Different Feeding Design

This paper demonstrates the analysis of antenna pattern and gain for different designs of full-wave dipole antenna feeding techniques. Seven such techniques were studied and analyzed;symmetrical dual feeding in phase, symmetrical dual feeding out of phase, asymmetrical dual feeding in phase, asymmetrical dual feeding out of phase, symmetrical triple feeding in phase and symmetrical triple feeding out of phase. Symmetrical dual feeding in phase produced high gain as compared to the single and center-fed antennas. An improvement of about 3 to 3.5 dB was achieved comparing to center tap fed and off center fed. It was found that an asymmetrical dual feeding in-phase provides good performance, considering the directivity, pattern, and input impedance. A 2.46 dB gain has been attained. It was found that a symmetrical triple feeding provides an overall best performance with respect to gain, radiation pattern, beam width and input impedance.

Intoxication Induced by Urea Containing Diets in Broiler Chickens: Effect on Weight Gain, Feed Conversion Ratio, Hematological and Biochemical Profiles

Urea as a source of cheap non-protein nitrogen is used to adulterate fish and meat meals which are basic components of broiler diets. The present study was carried out to elucidate the effects of urea on weight gain, and hematological and biochemical profiles. A total of 48 broiler chicks were randomly allotted into 4 groups, designated Groups 1, 2, 3 and 4 of 12 birds each. Birds in Groups 2, 3 and 4 were fed on diets containing urea at the levels of 1%, 2.5% and 4%, respectively. Birds in Group 1 served as control and were not exposed to urea. Experimentation period was for 3 weeks and experiment was terminated when birds were 42 days of age. Body weight of all intoxicated birds at the various intervals was significantly decreased in comparison with that of the untreated control. Compared with control, all intoxicated broilers manifested significant (P ≤ 0.05) decrease in all hematological parameters involving erythrocytic and total leucocytic counts, Hemoglobin (Hb) and Packed Cell Volume (PCV) on a dose- and time-pattern. In comparison with the control levels, biochemical profile of the intoxicated birds disclosed significant decrease in blood glucose level and significant increase in serum uric acid, urea, Alkaline Phosphatase (ALP) and Lactate Dehydrogenase (LDH) levels. Based upon the present data, it was concluded that the addition of urea to broiler diets bears serious sequences concerning the general health condition, performance, weight gain, and hematological and biochemical profiles.

Effects of Clenbuterol,Genotype,and Feeding Method on Bodyweight Gain of Meat Rabbits

Four-factor and three-level orthogonal experimental design(L9(34))was used in the experiment.The effects of three genotypes:Germany SAB three-bred-cross rabbits(S2),New Zealand purebred(N),and crossbred rabbits(ON);three levels of Clenbuterol treatment: 1 ng.g-1,2 ng.g-1and 3 ng.g-1,and three feeding methods:5-day,7-day and 10-day withdrawal period after two weeks of feeding Clenbuterol(CL)on bodyweight gain were evaluated.CL apparently improved average daily gain(ADG)of rabbits.70-day ADG of 5-day and 10-day withdrawal were higher than that of 7-day withdrawal,70-day ADG of S2 genotype was significantly higher than that of the control and N genotype was significant.Genotype,additive dose and feeding method had significant effects on overall-stage ADG.ON genotype,2 ng.g-1 dose and 5-day withdrawal feeding method was the best.Responses of different genotype to Clenbuterol appeared different at experimental prophase or whole experimental period.

Identification of feeding stimulants for shrimp

Two experiments were conducted to screen 5’ inosine monophosphate,betaine,fish hydrolysate,TMA O and DMPT as feeding stimulants for shrimp.Feeding stimulants carrier was non attractive diet.The first experiment was conducted to observe the attractant response.The maximum attractant response was attained when the diet contained DMPT.The second experiment was to observe the effect of attractant on growth and FCR of shrimp.The maximum weight gain rate and the minimum FCR was attained when the diet contained DMPT.

Effect of Enteromorpha from Qingdao Coasts on Weight Gain Perform ance of Broilers

This study was to investigate the effect of enteromorpha from Qingdao coasts on weight gain of Arbor Acres broilers. Four thousands of 1-day-old Arbor Acres broilers were randomly divided into four groups （1 000 for each）, i. e., one group was fed with basal diet as the control, and the other three were fed with basal diet added with 1.0%, 2.0% or 3.0% of enteromorpha as treatment groups. After 42 days of feeding trial, broilers in three treatment groups all gave a significantly increased average daily weight gain and feed to gain ratio in comparison with the control group （P 〈0. O1 ） ; within treatment groups, those added with 3.0% enteromorpha assumed a significantly higher average daily gain and feed to gain than with 3.0% enteromorpha （P 〈0.05）, while an insignificantly difference with 2.0% enteromorpha group （ P 〉 0.05 ）. The results indicated that adding appropriate amount of enteromorpha can facilitate the improvement of broiler performance.

Optimal Supplement Dosage of Double-Low Rapeseed Meal in Concentrated Feed of Fattening Lambs

[ Objective] To determine the optimal supplement dosage of double-low rapeseed meal in concentrated feed of fattening lambs. [ Method] A total of 120 Tibetan lambs at the age of 50 d were selected and divided randomly into four groups. The lambs in these four groups were fed with diets respectively supplemented the double-low rapeseed meal of 50,100,150 and 200 g/kg. Their diets had the same nutritional levels of energy and protein. The experimental period was 120 d. [ Result] Daily gain, feed conservation ratio and economic benefits were largely increased in the lambs fed with the diets supplemented the double-low rapeseed meal of 150 g/kg （Daily gain, P 〈 0.01 ）. However, the daily gain and feed conservation ratio were largely decreased in the lambs fed with the diets supplemented the double-low rapeseed meal of 200 g/kg. Moreover, serum levels of transaminase and thyroxine were not significantly different between the four groups. [ Conclusion] The optimal supplement dosage of the double-low rapeseed meal is 150 g/kg in fattening lambs.

Design of a High-Gain 2 × 1 Array Antenna for S-Band Applications

Antennas are an indispensable element in wireless networks. For long-distance wireless communication, antenna gains need to be very strong (highly directive) because the signal from the antenna loses a lot of strength as it travels over long distances. This is true in the military with missile, radar, and satellite systems, etc. Antenna arrays are commonly employed to focus electromagnetic waves in a certain direction that cannot be achieved perfectly with a single-element antenna. The goal of this study is to design a rectangular microstrip high-gain 2 × 1 array antenna using ADS Momentum. This microstrip patch array design makes use of the RT-DUROID 5880 as a substrate with a dielectric constant of 2.2, substrate height of 1.588 mm, and tangent loss of 0.001. To achieve efficient gain and return loss characteristics for the proposed array antenna, RT-Duroid is a good choice of dielectric material. The designed array antenna is made up of two rectangular patches, which have a resonance frequency of 3.3 GHz. These rectangular patches are excited by microstrip feed lines with 13 mm lengths and 4.8 mm widths. The impedance of the patches is perfectly matched by these transmission lines, which helps to get better antenna characteristics. At a resonance frequency of 3.3 GHz, the suggested antenna array has a directivity of 10.50 dB and a maximum gain of 9.90 dB in the S-band. The S parameters, 3D radiation pattern, directivity, gain, and efficiency of the constructed array antenna are all available in ADS Momentum.

Comparative Analysis on Antenna Balun and Feeding Techniques of Step Constant Tapered Slot Antenna

This paper represents the performance analysis of the different shapes of antenna balun and feeding techniques for step constant tapered slot antenna. This work also addresses the benefits of antenna balun (circular and rectangular) along with two types of feeding techniques (Microstrip line L-shape and Microstrip line I-shape). The performance of the antenna for each technique is thoroughly investigated using Computer Simulation Technology (CST) Microwave Studio software simulation under the resonant frequency of 5.9 GHz. Results demonstrate that the proposed model is an effective tool for improving antenna performance. Moreover, an extensive comparison has been carried out between the two different shapes, with and without antenna balun and between two feeding techniques focusing on return losses, gain, directivity, and voltage standing wave ratio (VSWR).

The Effect of Quantitative Feed Restriction Duration on Growth Performance and Carcass Characteristics of Broiler Chickens

The growth productivity of broilers is influenced by improving growth performance through improving body weight, average daily gain, and feed conversion rate. The objective of the study was to determine the effect of quantitative feed restriction duration on growth performance and carcass characteristics of broilers. A total of 144 day-old broiler chicks were reared in a deep litter system until slaughter at 42 days. Chicks were randomly allocated to three treatments which were replicated three times with 16 birds per replicate. The three treatments were the control (T1), one week of feed restriction (T2), and two weeks of feed restriction (T3). Birds were fed with starter, grower and finisher diets. The average daily gain (ADG), average daily feed intake (ADFI), and the feed conversion ratio (FCR) were computed for each week. Carcass weight and internal organs weights were measured. The body weight gained by the birds in T1 was similar to the birds that were restricted for a week. The treatments had a significant effect on the average daily gain in weeks 4, 5, and 6. The ADG for T2 was higher (P < 0.05) at week 5 after 1 week of restriction, than T1 and T3. The feed conversion ratio was significantly higher in T3 after 2 weeks of restriction. In T2 and T3, feed intake was significantly lower than in birds fed ad libitum at week 4 at the start of the treatment. There was no significant effect on the relative weights of heart weights, liver, gizzard, feet, and heads among the treatment groups except for intestine weight which was lower (P < 0.05) in T1 than T2 and T3. It was concluded that broilers that were restricted for one week had a positive result in growth performance. Feed restriction had minimal effect on the organ weights of broiler chickens.

妊娠期糖尿病、孕期增重和喂养方式对其子代神经发育迟缓的影响

目的 探讨妊娠期糖尿病、孕期增重和喂养方式对其子代神经发育迟缓的影响。方法 采用回顾性队列研究,对纳入队列的8 023例产妇及其子代的基本信息进行描述性分析,在调整协变量后分析妊娠期糖尿病、孕期增重和喂养方式和其子代神经发育迟缓的关联。结果 研究对象妊娠年龄为(29.46±4.57)岁,孕前体质量指数(BMI)为(21.38±3.09)kg/m2。纳入子代中,男性4 450例(55.5%),采用母乳喂养4 351例(54.2%),出生时有735例(9.2%)为低体重新生儿。在校正了协变量后的logistic模型中,人工喂养与神经行为发育迟缓呈正相关[OR=1.70,95%CI:1.24~2.33]。在校正了协变量的多元线性回归模型中,妊娠期糖尿病、孕期增重不足,人工喂养与总发育商呈负相关(β=-0.44,95%CI:-0.87~-0.008;β=-0.73,95%CI:-1.25~-0.22;β=-0.80,95%CI:-1.34~-0.26)。母体妊娠糖尿病对其子代大运动和社交能力发育迟缓有明确影响(P <0.05);产妇增重不足对其子代五大能区的神经迟缓的影响均有统计学意义(P <0.05);人工喂养对其子代五大能区的神经迟缓有明确影响(P <0.05)。结论 产妇妊娠期增重不足以及采用人工喂养的方式是子代神经发育迟缓的危险因素,母体妊娠糖尿病是其子代大运动和社交能力发育迟缓的危险因素。

不同体位鼻饲喂养早产儿对生长发育的影响

目的:探讨早产儿应用不同体位鼻饲喂养对生长发育的影响。方法:选取2020年1月~2021年10月粤北人民医院195例早产儿作为本次研究对象,按照不同体位鼻饲喂养方式分为左侧卧位组以及右侧卧位组、俯卧位组,每组各65例,分别对三组早产儿实施左右卧位以及俯卧位,对三组早产儿生长发育情况进行详细记录。结果:俯卧位组头围增长以及身高增长、体重增长情况优于左侧卧位组与右侧卧位组,差异有统计学意义(P<0.05);俯卧位组腹胀次数、胃残奶次数、呕吐次数以及血氧下降次数(5.00%、5.00%、7.50%、5.00%)低于左侧卧位组(22.50%、25.00、27.50%、25.00%)与右侧卧位组(20.00%、20.00、22.50%、22.50%),差异有统计学意义(P<0.05);俯卧位组光疗时间及黄疸持续时间短于左侧卧位组与右侧卧位组,差异有统计学意义(P<0.05)。结论:早产儿采用俯卧位鼻饲喂养能够进一步促进身高增长、体重增长情况,缩短光疗时间及黄疸持续时间,避免腹胀、胃残奶、呕吐以及血氧下降等情况发生。

不同蛋白水平全价颗粒饲料对育肥公羊育肥效果对比研究

本研究主要探讨不同蛋白水平全价颗粒饲料对育肥公羊育肥效果对比。选择体重20 kg左右公羊共计120只(湖羊、澳湖杂交羊、欧拉羊、湖藏杂交羊、萨湖杂交羊各24只),每一个品种公羊随机平均分为3组,分别饲喂蛋白含量12.96%(LP组)、15.04%(MP组)、17.04%(HP组)的全价颗粒饲料,饲喂105 d,研究体重、养殖效益、体尺相关性等指标。结果显示:湖羊、澳湖、萨湖MP组和HP组羊日增重显著高于LP组(P<0.01),湖藏杂交羊3组间差异不显著(P>0.05),欧拉羊日增重HP组显著高于其他2组(P<0.05),澳湖、萨湖羊增重速度最快,日增重达到300 g以上;湖羊、澳湖、萨湖、湖藏MP组和HP组羊料重比显著低于LP组(P<0.01),欧拉羊3组差异均显著(P>0.05),不同品种羊MP组日养殖效益均优于HP组;湖羊、澳湖、萨湖、湖藏羊体重与各体尺之间呈极显著正相关(P<0.01),欧拉羊体重与体长呈极显著相关(P<0.01),体重与胸围、体长呈显著相关(P<0.05)。

两种配合饲料对比格幼犬饲喂效果的比对

为筛选出适用于比格幼犬生长的配合饲料,该试验采用两种配合饲料对16只12周龄幼犬进行三周的饲养试验。结果表明,A、B组幼犬的总平均日增重分别为33 g/d和43 g/d,B组比A组提高10 g/d;A、B组幼犬的相对生长率分别为13.30%和17.78%,B组比A组提高4.48%,B组增重效果优于A组(P<0.05);此外,B组幼犬粪便评分高于A组,提示B组配合饲料对于幼犬更易消化。因此,B组配合饲料更适于比格幼犬生长。

全价配合饲料对断奶犊牛增重的影响

对犊牛而言,更早地采食饲料,有助于断奶后提高采食量和日增重。使用颗粒状全价配合饲料,能最大限度降低犊牛因日粮变化而带来的胀气及营养性腹泻现象。本试验结合市面上常用的犊牛颗粒料饲料产品,搭配全混合日粮技术,制造断奶犊牛全价配合饲料。全价配合饲料保证犊牛日粮的稳定性的同时,该产品更易使用,在断奶犊牛饲养中推广使用还需进行推广试验。试验结果表明:针对断奶犊牛使用颗粒状的全价配合饲料是完全可行的。蛋白含量与淀粉含量分别为20%和24.1%的全价混合饲料组,平均日增重860 g/头/d,略低于对照组断奶犊牛平均日增重低49 g/头/d。

全混合日粮与传统方式饲喂肉牛增重效果的对比

为挖掘酒泉市肉牛产业发展潜力,筛选可提高饲草料利用率的科学饲喂方式,通过在养殖规模、软硬件设施和饲养管理水平各不相同的3个肉牛养殖场,分别采用机械加工全混合日粮、人工混合日粮和传统饲喂三种方式,连续饲喂肉牛200 d,分析对比各种饲喂方式增重效果。结果显示,饲喂机械加工全混合日粮较人工混合饲料和传统方式肉牛日增重分别提高9%和18%以上;差异均显著(P<0.05)和极显著(P<0.01)。试验表明,全混合日粮饲喂技术可显著提高肉牛日增重量,是一项可提高饲草料利用率,降低养殖成本,促进肉牛产业高质量发展的先进技术。

不同水平的益生菌制剂对杂交鲟生长性能的影响

试验旨在研究不同水平的益生菌(probiotics)制剂对杂交鲟(西伯利亚鲟Acipenser baerii♂×施氏鲟Acipenser schrenckii♀)生长性能的影响,确定益生菌制剂在杂交鲟养殖中的最适添加水平。试验选择健康、体重约为75 g的杂交鲟400尾,随机分成4组,每组4个重复,每个重复25尾。对照组杂交鲟投喂基础饲料,益生菌制剂组的杂交鲟分别投喂含有0.2%、0.4%和0.8%的益生菌制剂。饲养期56 d。试验结束后,检测各组杂交鲟的生长性能。结果显示,试验2组的杂交鲟试验末重、增重率显著高于对照组(P<0.05),而饲料系数显著低于对照组(P<0.05)。益生菌制剂对杂交鲟的成活率有所提高,均为100%。益生菌制剂对杂交鲟的肝体比和脏体比无显著影响(P>0.05)。研究表明,杂交鲟养殖饲料中添加0.4%的益生菌制剂可以有效改善杂交鲟的生长性能。

饲料中添加不同水平的核苷酸对草鱼生长性能的影响

试验旨在研究饲料中不同水平的核苷酸(Nucleotide)对草鱼(Ctenopharyngodon idella)生长性能的影响,为核苷酸在草鱼养殖生产中的高效应用提供参考。试验选择560尾体重约为10g的健康的草鱼,按照单因素试验设计,将其均分4组,每组5个重复,每组重复28尾草鱼。对照组草鱼投喂基础饲料,核苷酸组草鱼分别投喂含有0.2%、0.4%和0.6%的核苷酸的试验饲料。投喂60 d后,检测各组草鱼的生长性能。结果显示,与对照组比较,草鱼投喂0.4%的核苷酸可以使试验末重增加(P<0.05),增重率增加17.28%(P<0.05),可以使饲料系数显著降低(P<0.05)。而核苷酸对草鱼的特定生长率、成活率、脏体比和肝体比无显著影响(P>0.05)。研究表明,适量的核苷酸可以促进草鱼生长,且核苷酸添加量为0.4%时,生长性能效果最好。

白牦牛舍饲育肥试验研究

在全舍饲饲养条件下,对3~4岁白牦牛和8~10岁淘汰白牦牛进行全舍饲育肥试验,测定白牦牛的日增重、采食量和屠宰率。结果表明,两个试验的试验组日增重显著高于其对照组,在90 d的同期饲养情况下,日增重分别高174.7%和111.2%,增重效果明显,饲料报酬高,经济效益明显。

低成本隧道双向天线的研究

文中提出了一种低成本隧道双向天线,其中4个集合线组成两个背对的共用反射板的对数周期天线,沿反射板天线辐射臂与辐射臂间距减小,集合线末端接同轴线缆,通过PCB功分板与同轴线缆对天线进行等幅同相馈电,实现了在低成本方案下的前后双向馈电。该天线具有低驻波、高增益、波束集中、方向图稳定、制作方便、成本低廉等优点,具有较高的应用价值。

金针菇菌渣对草鱼生长性能的影响

为探讨不同水平的金针菇(Flammulina velutiper)菌渣对草鱼(Ctenopharyngodon idella)生长性能的影响,评估金针菇菌渣在草鱼养殖中的最适使用水平。试验选择体况健康、体重约为20g的草鱼600尾,随机分成4组,每组3个重复,每个重复50尾。各组草鱼分别投喂含有0%(对照组)、4%、8%和16%金针菇菌渣的试验饲料。试验草鱼驯养2周,正式试验期8周。试验结束,统计分析各组草鱼的生长性能指标。试验结果显示,草鱼采食含有8%的金针菇菌渣饲料,可以显著提高试验末重(P<0.05)、增重率(P<0.05),并显著降低饲料系数(P<0.05),其中试验末重显著提高了6.6%、增重率提高了8.96%,饲料系数降低了6.76%。而不同水平的金针菇菌渣对草鱼的特定生长率、肝体比、脏体比等数据未产生显著性影响(P>0.05)。研究表明,在配合饲料中添加适量的金针菇菌渣可以改善草鱼的生长性能,提高饲料利用率,且金针菇菌渣的最适添加水平为8%。