基于Cocks-Ashby模型的多轴蠕变设计准则的局限性及其修正

多轴应力状态下结构的蠕变变形分析是高温装备强度设计的理论基础。经典的Cocks-Ashby多轴蠕变孔洞长大模型及其简化模型存在着严苛的适用条件及局限性,仅适用于描述高温低应力环境下以晶间蠕变孔洞长大过程为材料蠕变损伤主要形式的蠕变变形行为。根据其简化解得到的用于单-多轴蠕变延性换算的多轴蠕变因子则存在着在低三轴应力度段给出的计算值较试验值偏小的问题。在基于WITCHMANN对该问题修正工作的基础上,通过合理的进一步优化,一个新的多轴蠕变因子被得出。将新修正因子应用在一个处于简化恒定应力场中的发动机热端叶片算例上,计算出恒载下叶片的等效多轴蠕变应变分布。有限元计算结果表明在叶片模型的叶根中部区域存在着较大的三轴应力度及较小的多轴蠕变因子,使得叶根中部原本应变不太明显的区域也产生了较大的等效多轴蠕变应变,导致叶片计算出的潜在失效面积较未经多轴蠕变因子修正前显著增加。

基于Cocks身份密码体制的高效签密方案

现有的基于身份签密方案多是基于双(多)线性对构造的,针对其复杂的对运算导致签密效率低下的问题,基于Cocks的身份密码体制提出了一种新的高效签密方案。首先,形式化所提方案的安全模型,给出了保密性和不可伪造性的定义;然后,利用二次剩余难解问题实现了所提方案的具体构造,进一步结合雅可比符号运算巧妙地在一个逻辑步骤内实现了签密算法设计;最后,在随机预言模型下,给出了所提方案满足保密性和不可伪造性的安全性证明。效率分析表明,相对于已有的基于身份签密的方案,所提方案较大幅度地提升了运算效率,同时具备基于身份密码的良好特性。

Use of factor scores for determining the relationship between body measurements and semen traits of cocks

Semen evaluation is required to predict fertility. In most rural African communities, facilities for microscopic evaluation of semen are not available. Therefore, an indirect method of predicting semen traits of cocks is required by poultry farmers. The objective of this study was to use factor scores derived from factor analysis of body measurements to predict some semen traits of cocks. Correlation matrix was obtained by calculating the correlations between body measurements and semen traits of cocks. Kais-er-Meyer-Olkin (KMO) measure of sampling adequacy and Bartletts test of sphericity were used to test the appropriateness of factor analysis on the data. The extraction of the factors was done by calculating the eigenvalues of the correlation matrix. Variance maximizing rotation of the transformation matrix was done to facilitate the interpretation of the factor loadings. Two factors with eigenvalues greater than 1 were extracted which accounted for 76.96% of the variations present in the original variables. The two factors were used to obtain the factor score coefficients. When utilized as independent variables in multiple regression analysis, the two factors explained 53.20% and 40.80% of the variations in sperm motility and sperm concentration respectively. Factor 1 had more impact on sperm motility than factor 2 as it was significantly related to it. Factor 2 was significantly more related to sperm concentration than factor 1. The relationship between body measurements and semen volume, live sperm and abnormal sperm were weak and mostly negative. Therefore, they were not predicted using factor scores.

Cock年话“鸡”

根据十二生肖,1993年出生的人属“Cock鸡”,1993年为鸡年。汉语有“呆若木鸡;鸡飞蛋打;鹤立鸡群;鸡犬之声相闻,者死不相往来;鸡犬升天;杀鸡焉用宰牛刀”等之说。那么,英语有关“鸡”的说法又有哪些呢?本文将就此作如下探讨。一、与“鸡”有关的常用英语词语: cock/rooster 公鸡,hen 母鸡,chicken 小鸡,鸡肉,chick

Methods and Effects of Hongshan Cock Spermatozoa Cryopreservation

The survival rates, acrosomic integrity rates of frozen semen from Hongshan cock and fertilities of the frozen-thawed spermatozoa in both pellets and straws were studied. The result shows that the average survival rate of spermatozoa in straws was 0, 451±0, 056, and 0. 390±0. 040 in pellets, the former was significantly higher than the later （n=20, p〈0, 01）, The average acrosomic integrity rate of the sperms was 0, 613±0. 049 in straws, and 0. 476±0. 057 in pellets. The former was significantly higher than the later （n= 20, p〈0.05）. The fertility rates （%） of sperms in pellets, straws and freshly colleered semen at the third day after artificial insemination （AI） were 85.32±2. 32, 87. 73±1.00 and 90.77±1.68, respectively. The fertility rate,s of the three types of semen at the fourth and fifth days were lower than the third day＇s. Variance analysts shows that the fertilities of the spermatozoa in pellets and straws were significantly lower than freshly collected semen （n=3, p〈0.01）, and the fertilities of the spermatozoa in straws were significantly higher than those in pellets （n= 3, p〈0.01）.

The Effect of Different Levels of Salinity and Potassium Nitrate on the Germination of Cocks Comb (<i>Celosia cristata</i>)

Cocks Comb (Celosia cristata) is a hot-season annual species which is grown from seeds. A study was carried out in the horticulture laboratory of Gorgan University of Agriculture Science and Natural Resources of February 2013 to evaluate the impact of salinity and potassium nitrate on the germination of cockscomb with five salinity levels (0, &minus;2, &minus;4, &minus;6, and &minus;8 bars) and three potassium nitrate levels (0%, 0.2%, and 0.4%) at 25&deg;C on the basis of a Randomized Complete Block Design. Analysis of variance showed significant differences among salinity levels in germination percentage, radicle length, plumule length, and seed vigor at the 1% probability level. Mean comparison for germination percentage revealed that higher salinity reduced seed germination percentage so that it was decreased from 80% in no salinity to 15% in &minus;8 dS&sdot;m&minus;1. The highest percentage of germination was related to zero percent salt and potassium nitrate 0.2%. Also, the highest radicle length of 2.48 cm was related to no salinity and the lowest one (0.61 cm) to &minus;6 dS salinity. The highest radicle length and seed vigor were also observed in no salinity. Potassium nitrate by itself had no impact on the measured traits. Among interactions between salinity and potassium nitrate, the highest germination percentage was observed under 0 salinity × 0.2% potassium nitrate.

Comparison of the Anthelmintic Efficacy of Three Commercial Products against Ascarids and Capillaria SPP. in Fighting Cocks

The aim of the present study was to evaluate the anthelmintic efficacy of three commercial compounds against ascarids and Capillaria spp. in naturally infected fighting cocks from Mexico. First experiment.- Forty cocks were selected on the basis of eggs per gram (EPG) counts quantified by the McMaster method. On day 0 the birds were divided into four groups of 10 cocks, each subjected to the treatments. Group 1 received a single oral dose of 1 mg of ivermectin, 25 mg of praziquantel and 40 mg of fenbendazole given in tablets according to body weight (b.w). Group 2 was treated with a single oral dose of 1 mg of ivermectin, 25 mg of praziquantel and 40 mg of fenbendazole given in tablets/b.w. but formulated with a different excipient. Group 3 received a single tablet containing 0.2 mg of abamectin and 30 mg of albendazole. Group 4 served as a non-treated control. Fecal analyses were carried out on days 0 (day of treatment), 7, 14, 21 and 28, being collected from the floor where the cocks were individually caged. Efficacy was measured on the percentage of egg reduction from day 0 with respect the EPG counts from the control group. In a second experiment the study was similarly performed using another cock-farm located at approximately 300 km away from the first one. Results indicated an overall efficacy of 100%, 94.0% and 100% for groups 1, 2 and 3 in the first experiment and 100%, 100%, 100% for groups 1, 2 and 3 of the 2nd experiment, respectively. It is concluded that all drugs used exerted high efficacy in fighting cocks naturally infected with helminths.

Some Remarks on Cocks'Identity-Based Encryption Scheme

The theory of quadratic residues plays an important role in cryptography.In 2001,Cocks developed an identity-based encryption(IBE)scheme based on quadratic residues,resolving Shamir’s 17-year-old open problem.However,a notable drawback of Cocks’scheme is the significant expansion of the ciphertext,and some of its limitations have been addressed in subsequent research.Recently,Cotan and Teşeleanu highlighted that previous studies on Cocks’scheme relied on a trial-and-error method based on Jacobi symbols to generate the necessary parameters for the encryption process.They enhanced the encryption speed of Cocks’scheme by eliminating this trialand-error method.Based on security analysis,this study concludes that the security of Cotan-Teşeleanu’s proposal cannot be directly derived from the security of the original Cocks’scheme.Furthermore,by adopting the Cotan-Teşeleanu method and introducing an additional variable as a public element,this study develops a similar enhancement scheme that not only accelerates the encryption speed but also provides security equivalent to the original Cocks’scheme.

种公鸡精液品质性状与表型性状相关性研究进展

在现代家禽生产中,种公鸡的选择和高效利用对于鸡产业的发展和良种品系的建立至关重要。精液品质是种公鸡重要的繁殖性状,是选择良种公鸡的重要指标。精液品质的测定费时费力,研究精液品质与表型性状的相关性,可为精液品质的间接选择提供理论依据。文章综述了家禽精液品质与表型性状相关性的研究进展,并对其实际应用进行了展望,以期为家禽生产需要和遗传改良提供参考。

Habitat selection of the Tibetan Snow Cock Tetraogallus tibetanus in the spring in Lhasa

The habitat selection of Tibetan Snow Cocks in shrub vegetation was investigated in Lhasa,Tibet,China,between March and April,2005.Fourteen parameters were measured.These include altitude,slope,slope aspect,slope position,vegetation cover,plant type and other environmental parameters.Results show that Snow Cocks favor foraging in areas where vegetation cover was small and close to the residents’houses.Supplementary food supplied by humans has caused Snow Cocks to decrease their foraging range.Snow Cocks also favor roosting in areas with low vegetation,sparse grass,short grass,large rocks and close to houses.The Snow Cocks’activity in the study areas show a close relationship with human activities.

空气制动隔离不缓解故障分析及方案优化

针对地铁车辆空气制动隔离不缓解故障,从制动系统的气路原理和控制逻辑进行了分析,根本原因是切除制动隔离塞门时,制动控制单元中排风阀打开,缓解制动缸压力,在缓解过程中,排风阀先导控制压力和制动缸压力同时下降,在接近结束时,由于排风阀先导控制压力不足会将排风阀自动关闭,导致制动缸中存在残余压力且大于25kPa时,制动系统会发出制动不缓解故障信号。为解决此问题,通过对切除制动隔离塞门后整个制动气路原理的分析,发现控制制动隔离塞门排风流量,实现制动控制单元中排风阀先导控制压力和闭合弹簧压力的合理匹配,可消除制动缸内的残余压力。AMESim软件搭建车辆架控气路仿真模型,模拟车辆切除制动隔离塞门的排风过程,监测该过程中紧急制动和最大常用制动时制动缸压力随时间的变化,确定能消除制动缸残余压力时隔离塞门排风口通径,将仿真确认的排风口通径进行试验验证,结果能有效解决地铁车辆空气制动隔离不缓解故障的问题。为其他车型架控制动系统存在空气制动隔离不缓解故障提供了解决问题的方向。

基于改进YOLOV5m的列车风管与折角塞门检测

由于操作环境复杂,风管和折角塞门尺寸小,原始YOLOV5m算法的检测精度有待提高。为此,在YOLOV5m的检测头输出部分增加了一个大尺寸特征图,用于提升小尺寸目标的检测能力。首先在主干网络中增加1个含有多卷积、短连接的类残差分流模块,以丰富浅层网络的梯度流信息,并将新增模块的输出作为新增的大尺寸特征图。然后在Neck部分使用特征金字塔模型FPN和路径聚合模型PAN进行多尺寸特征融合,最终在检测头部分得到了4种不同尺寸的特征图。结果显示,改进YOLOV5m的检测帧率约为每秒100帧,比原始YOLOV5m在平均精度mAP上提升了1.3%,表明改进YOLOV5m可作为可见光辅助模型提升列车摘钩机器人多模态识别系统的性能。

基于多尺度特征的货运列车风管与折角塞门检测

针对小尺寸列车风管与折角塞门的检测问题,提出一种多尺度特征增强的YOLOv5s检测算法。首先在主干网络Backbone增加了一个大尺寸特征图输出分支,使用C2f(CSP bottleneck with 2 convolution and forward)模块丰富新增特征图的梯度流信息;然后在Neck部分使用自适应空间特征融合增强特征金字塔模型FPN (Feature Pyramid Network)的多尺度特征融合能力,并使用路径聚合模型PAN(Path Aggregation Network)提高目标定位能力;检测头Head拥有4种尺度的特征图,其中新增特征图的尺寸最大,用于增强小尺寸目标的检测能力。实验结果表明,多尺度特征增强的YOLOv5s比原来的YOLOv5s在平均精度mAP(mean Average Precision)上提升了1.5%,优于其他检测器,提升了小尺寸风管和折角塞门的检测能力。

神丹6号绿壳蛋鸡公鸡早期屠宰性能与肉品质研究

研究旨在探明神丹6号绿壳蛋鸡公鸡早期屠宰性能与肉品质,为该配套系的公雏利用提供理论依据。以神丹6号绿壳蛋鸡出雏公鸡为素材,饲养至15周龄,每周测量屠宰性状,15周龄时,以母鸡为对照,测量屠体重、全净膛重,计算屠宰率、全净膛率,测量常规肉品质、肉营养成分,进行全净膛品尝评价。结果显示,神丹6号绿壳蛋鸡公鸡0~15周龄屠宰性能在中上等水平,消化系统发育良好,免疫系统发育良好;15周龄屠体重、全净膛重显著大于母鸡,肉品质比母鸡略差,但与其它多数鸡种相当,风味、口感较好。综合分析表明,神丹6号绿壳蛋鸡公鸡早期屠宰性能良好,肉品质良好,综合性能优于多数绿壳蛋鸡品种。

利用WGCNA挖掘种公鸡睾丸和附睾中影响精子活力的核心基因

种公鸡的精子活力对养禽业的可持续发展至关重要,通过加权基因共表达网络(WGCNA)分析法挖掘种公鸡睾丸、附睾中调控精子活力的基因共表达模块和核心基因,并构建与种公鸡精子活力相关的调控网络。基于团队前期对不同精子活力种公鸡睾丸、附睾组织转录组测序数据的分析,用WGCNA方法构建基因共表达网络,识别与表型性状显著相关的基因模块,并对关键模块基因进行GO功能注释、KEGG通路富集分析。用Cytoscape软件筛选每个关键模块的核心基因并构建可视化共表达网络。结果表明,14227个基因聚类到11个模块,以决定系数(R2)≥0.6、P<0.05为标准挖掘出青绿色(Turquoise)模块、黄色(Yellow)模块、红色(Red)模块与表型显著相关。对3个关键模块的基因进行功能分析,发现这些基因显著富集在核苷酸切除修复、同源重组、细胞色素P450对异类物质代谢、MAPK信号通路和细胞凋亡等通路上。选出的IFT家族基因与HMOX2、CYP4B1、ANG、ITGB2基因是与种公鸡精子活力相关的核心基因,可作为提高精子活力的潜在基因。

不同坐姿对背部形态与臀压的影响

目的探讨不同坐姿对脊柱和骨盆代偿特征的影响,为寻找出一个理想的坐姿姿势提供理论依据,减少不良坐姿给人体带来的姿势代偿。方法使用Diers formetric及Pedscan模块进行20名健康青年直立坐、跷腿坐、盘腿坐坐姿下表面形态学参数和臀压参数测量。结果相对直立坐姿,跷腿坐导致骨盆后倾、侧倾和相对扭转(P<0.05),跷腿侧臀压面积减少(P<0.05),最大压力和平均压力显著增加(P<0.05)。双臀最大压力比、平均压力比(P<0.05)及臀压面积(P<0.05)的对称性降低;相对直立坐姿,盘腿坐姿下矢状面偏移角度增加(P<0.05),躯干前屈、腰椎后凸(P<0.05)的同时伴随骨盆后倾(P<0.05),臀压面积减少(P<0.05)。结论3种坐姿中,直立坐姿下臀两侧受力均匀,背部表形态学参数最优,腰椎和骨盆代偿最少,可认为是理想的坐姿。

武定彝族纳苏支系公鸡帽中的文化意蕴研究

民族服饰作为一种文化符号,是民族文化的载体之一。彝族人口分布广泛,支系繁多,其保持了数千年传统和文化的服饰更是丰厚博大、魅力无穷。作为彝族传统服饰文化的重要组成部分,云南省武定县彝族纳苏支系公鸡帽仍然保留着古老的传统,其以构图之巧妙,造型之生动,用色之和谐,工艺之精湛,寓意之丰富,作为彝族手工艺和民族智慧的象征,被代代传承至今,具有很高的审美价值和收藏价值。

不同絮凝剂处理焦化废水的研究

相同条件下用 3种常用的聚硅酸盐类絮凝剂 (PASS,PZSS,PFSC)和高铁酸钠 (Na2 Fe O4 )处理焦化废水 ,实验结果表明 ,除聚硅酸铝在去浊方面优于高铁酸钠外 ,高铁酸钠无论在 CODCr。

鸡、鸭消化道pH和消化酶活的比较研究

为阐明鸡、鸭对营养物质利用率差异的原因,比较了8只公鸡和8只公鸭消化道内容物酸碱性及体内主要蛋白质消化酶、碳水化合物水解酶和脂肪水解酶活性的差异。结果表明:(1)鸭消化道前段除口腔pH比鸡的高(P<0.01),食管膨大部、腺胃和肌胃的pH均比鸡低(P<0.05或P<0.01),而后段消化道从空肠开始到直肠,鸭的pH均比鸡高(P<0.05)。(2)鸡和鸭消化道内主要蛋白酶活性存在差异。鸭肌胃内容物中胃蛋白酶的相对活性和总量都极显著高于鸡的(P<0.01);鸭十二指肠、空回肠和盲肠内容物以及胰腺组织中胰蛋白酶的相对活性和总量高于鸡(P<0.05或P<0.01);鸭空回肠内容物中糜蛋白酶的活性显著高于鸡(P<0.05)。(3)鸭胰腺组织中脂肪酶相对活性极显著高于鸡(P<0.01),脂肪酶总量显著高于鸡(P<0.05);肠道内容物中脂肪酶的活性也大多数高于鸡。(4)鸡和鸭消化道内可溶性碳水化合物水解酶活性差异没有很强的规律性,但鸭空回肠内容物中纤维素酶的相对活性高于鸡(P<0.01),盲肠内容物中纤维素酶的总量显著高于鸡(P<0.05)。消化道中消化酶活性差异是鸡鸭对饲料养分消化利用差异的原因之一。