荧光增白剂对颜色复制影响的研究

在纸张抄造过程中添加荧光增白剂来提高纸张白度的方法,在现代造纸工业中得到广泛应用。由于目前关于印刷复制的国际标准,如ISO、ICC的数据是建立在不含荧光增白剂纸张基础之上的,因此它的存在造成了印刷工艺中颜色复制效果的差异,从而导致实际印刷结果不符合国际标准。本论文通过对不同配比浆料原纸、不同荧光增白剂含量的纸张的ISO白度(蓝光漫反射因数)和色度的比对,以及对不同荧光增白剂含量的样本纸张光谱数据和对印刷复制中阶调还原的分析,得出荧光增白剂添加量对纸张色度与白度的影响规律和光谱特征表现,以及在印刷复制过程中对颜色复制的影响,为纸张生产过程中荧光增白剂的添加提供一定的借鉴依据。     

Stomata‐Inspired Photomechanical Ion Nanochannels Modified by Azobenzene Composites

A low‐powered and highly selective photomechanical sensor system mimicking stomata in the epidermis of leaves harvested from nature is demonstrated. This device uses a light‐responsive composite consisting of 4‐amino‐1,1′‐azobenzene‐3,4′‐disulfonic acid monosodium salt (AZO) and poly(diallyldimethylammonium chloride) (PDDA) coated on a membrane with tens of nanometer‐size pores. The ionic current change through the pore channels as a function of pore size variation is then measured. The tran–cis isomerism of AZO–PDDA during light irradiation and the operation mechanism of photomechanical ion channel sensor are discussed and analyzed using UV–vis spectroscopy and atomic force microscopy analysis. It presents the discriminative current levels to the different light wavelengths. The response time of the photoreceptor is about 0.2 s and it consumes very low operating power (≈15 nW) at 0.1 V bias. In addition, it is found that the change of the pore diameter during the light irradiation is due to the photomechanical effect, which is capable of distinguishing light intensity and wavelength.     

Effects of feeding rumen-protected methionine pre- and postpartum on reproductive outcomes of multiparous Holstein cows

Our primary objective was to evaluate the effect of feeding rumen-protected Met (RPM) in the pre- and postpartum total mixed ration (TMR) on pregnancy per artificial insemination (AI) and pregnancy loss in multiparous Holstein cows. We also evaluated multiple secondary reproductive physiological outcomes before and after AI, including uterine health, ovarian cyclicity, response to synchronization of ovulation, and markers of embryo development and size. A total of 470 multiparous Holstein cows [235 at the University of Wisconsin (UW) and 235 at Cornell University (CU)] were used for this experiment. Experimental treatment diets were applied at the pen level (2 and 4 close-up pens at CU and UW, respectively, and 12 and 6 postfresh pens at CU and UW, respectively); thus, pen was the experimental unit, and cow was the observational unit. Cows were enrolled and randomly assigned to be fed the experimental treatment diets at approximately 4 wk before parturition until 67 d of gestation [147 d in milk (DIM)] after their first service. Close-up dry cow and replicated lactation pens were randomly assigned to treatment diets: RPM, prepartum = 2.83% (UW) and 2.85% (CU), postpartum = 2.58% (UW) and 2.65% (CU); and control (CON), prepartum = 2.30% (UW) and 2.22% (CU), postpartum = 2.09% (UW) and 2.19% (CU; Met as percentage of metabolizable protein). Vaginal discharge and uterine cytology (percentage of polymorphonuclear leucocytes) were evaluated at 35 ± 3 DIM. Cows received timed AI (TAI) at 80 ± 3 DIM after synchronization of ovulation with the Double-Ovsynch protocol. Ovarian cyclicity status, response to synchronization of ovulation, and luteal function were determined by measuring circulating concentrations of progesterone at 35 and 49 ± 3 DIM, 48 and 24 h before TAI, and 8, 18, 22, 25, and 29 d after TAI. Interferon-stimulated gene expression in white blood cells were compared on 18 d after TAI (CU only) and pregnancy-specific protein B concentrations at 22, 25, 29, 32, and 67 d after TAI. Pregnancy status was determined using pregnancy-specific protein B at 25 and 29 d after TAI, and by transrectal ultrasonography at 32, 39, and 67 d after TAI. Embryo and amniotic vesicle size were determined at 32 and 39 d after TAI. Pregnancy per AI (25 d: 64.7 vs. 64.0%, 32 d: 54.3 vs. 55.1% for CON and RPM, respectively) and pregnancy loss (25 to 67 d: 22.6 vs. 19.2% for CON and RPM, respectively) for synchronized cows did not differ. The proportion of cows with purulent vaginal discharge (CON = 7.7 vs. RPM = 4.6%) and cytological endometritis (CON = 20.8 vs. RPM = 23.6%) did not differ. Cyclicity status, ovarian responses to the synchronization protocol, and synchronization rate also did not differ. In addition, fold change for interferon-stimulated genes, concentrations of pregnancy-specific protein B, and embryo size were not affected by treatments. In conclusion, feeding RPM in the pre- and postpartum TMR at the amounts used in this experiment did not affect uterine health, cyclicity, embryo development, or reproductive efficiency in dairy cows.     

Sex ratio and reproduction of invasive red devil, (Amphilophus labiatus: Cichlidae) in Lake Sentani,Indonesia

The Red Devil Cichlid Amphilophus labiatus (Günther 1864), native to Lake Nicaragua and Lake Managua in Central America, is widely cultivated as an attractive, yet aggressive, aquarium fish that has been introduced to several freshwater locations around the world. It was recently introduced into Lake Sentani in Indonesian New Guinea, a naturally rich aquatic habitat home exhibiting a diverse fauna with high endemism. To better understand the invasive potential and impacts of A. labiatus, the present study was undertaken to describe the sex ratio and reproductive potential of A. labiatus in Lake Sentani through determination of its gonad maturation stages, gonado‐somatic index and fecundity. The fish were collected using floating gill nets at six locations around the lake between June and August 2019. Sex identification, gonads type, gonad stage and weight, fecundity were observed in the laboratory. Of the total 542 of A. labiatus collected during the survey, 345 individuals were sampled for sex ratio and reproduction. The overall male:female ratio was skewed towards males in a ratio of 3.28:1. The males were generally found to be in the gonad maturation stage I, while the females were commonly found in gonad maturation stages III and IV for all sampling locations during the study period. The highest male mean GSI value was found for the Yakonde site (0.24 ± 0.21) and at the Ayapo site (1.11 ± 1.01) for the females, with a fecundity of 191–2,720 eggs. The fish have spread to most parts of the lake, being conditioned to potentially spawn at any location, thereby providing an explanation for the observed rapid increase of the A. labiatus population over the last ten years. The results of the present study suggest a high invasive potential for this species in this and other similar lake habitats, warning that their careful management should be undertaken to restrict their further spread in Indonesia and elsewhere.     

色外观匹配的多光谱图像再现

针对多光谱图像再现过程中由于观察条件变化引起再现图像与源图像色外观不一致的问题,提出一种基于色外观匹配的多光谱图像再现算法.首先,在源端引入色外观变换,得到源光谱反射率图像在源观察条件下的色外观描述;然后,建立逆向模型,估计目的观察条件下的高维光谱,使得估计光谱与源光谱在观察条件改变时达到色外观匹配;最后,为同时提高再现多光谱图像的光谱精度,以源光谱为标准,采用同色异谱校正方法对估计光谱进行校正,得到变观察条件下与源多光谱图像色外观相匹配、光谱逼近的再现图像.试验结果表明,在源与目的观察条件不同的情况下,再现图像与源图像间的感知色差及光谱误差均较小,在保持源多光谱图像光谱信息的基础上,实现了等观感再现.     

多光谱技术在印刷中的应用

针对现今印刷复制技术与色彩管理技术的主要缺陷,综述了多光谱颜色复制技术的崭新途径,认为多光谱颜色复制技术为高保真印刷和跨媒体出版奠定了基础,并对该技术的基本原理、优越性作了较为全面的阐述,分析了多光谱技术在印刷中的具体应用及其发展趋势。     

当代印刷发展的核心技术

阐述了当代印刷传媒的全新内涵为出版及创意设计,颜色复制科技和媒介资源管理,由此提出当代印刷实现跨越式发展的四大核心技术,即印刷传媒跨媒体化的理论与方法、泛网络化的数字生产技术、印刷数字资产管理技术和基于光谱的印刷颜色复制技术.当代印刷唯有在四大核心技术支撑下,才能真正实现跨媒体图文传播与高保真印刷复制的美好诉求.     

Effect of stillbirths on dam survival and reproduction performance in Holstein dairy cows

The objectives of this study were to evaluate the effect of stillbirth on survival and reproductive performance of lactating dairy cows. Data were collected from 2 different regions of the US calving-ease scores (CES) were recorded by farm personnel on a scale of 1 (no problem) to 5 (extreme difficulty). Stillbirths were recorded by farm personnel. The final analysis included 13,608 calvings of which 93.4% were live calves and 6.6% stillbirths. An increasing or decreasing trend in the incidence of stillbirth by parity and by CES was analyzed by Cochran-Armitage trend tests. A significant decreasing trend in the incidence of stillbirth by parity group was detected. The incidence of stillbirth increased as the CES increased. The incidence of stillbirths was 3.6, 11.2, 25.9, and 60.1% for CES score 1, 2, 3, and 4, respectively. Dam survival in the herd and reproductive performance were analyzed by the Cox proportional hazards model. Variables that decreased dam survival time were stillbirths, primiparity, and CES of 3 and 4. The variables that reduced reproductive performance were stillbirths, multiparity, male calves, and CES of 3 and 4. Cows that had stillbirths had significantly increased risk of culling/death throughout the lactation and increased median days open by 88 d compared with cows that had live calves. In conclusion, losses from stillbirths are far greater than just the value of the calf.