保定市一亩泉河河流中COD的变化及污染源分析     

班西雨  杜忠文  王世杰  王建伟  田祖光 《绿色科技》2020,(4):27-29

针对保定市城区水系管理委员会2017年3月公布的黑臭水体河流中的一亩泉河7.23km的黑臭水体段为参考进行了勘查、取样与COD实验工作,从2019年4月12日到2019年5月29日进行了为期一个半月的时间。研究结果表明:保定市一亩泉河河流不同位置COD大小不同、污染原因不同。通过周围景观的变化、对采样点附近居民进行的走访和COD浓度的测定,对一亩泉河的水质状况和污染源进行了全面系统地分析。并为此提出了切实可行、经济有效、便于管理的控制方案。  相似文献   

Effects of apple pomace proportion levels on the fermentation quality of total mixed ration silage and its digestibility,preference and ruminal fermentation in beef cows          下载免费PDF全文

Jiachen Fang  Yang Cao  Masatoshi Matsuzaki  Hiroyuki Suzuki 《Animal Science Journal》2016,87(2):217-223

Four Japanese black beef cows were used in a 4 × 4 Latin square to evaluate the fermentation quality, digestibility, ruminal fermentation and preference of total mixed ration (TMR) silages prepared with differing proportions of apple pomace (AP). Experimental treatments were the control (no AP added, CAP), 5% (low, LAP), 10% (medium, MAP) and 20% (high, HAP) of TMR dry matter (DM) as AP. All TMR silages were well preserved. Ethanol was produced in silages containing AP and the amount increased with the proportion of AP (P < 0.05). Nutrient digestibility with LAP, MAP and HAP treatment was lower than that with CAP treatment (P < 0.05). The ruminal molar proportion of acetic acid increased (P < 0.05), but the ruminal ammonia‐N concentration decreased (P < 0.05) as the proportion of AP increased. The preference of the animals was highest for HAP, followed by MAP, CAP and LAP. This study demonstrates that decrease in nutrient digestibility might be related to the ethanol produced naturally from AP. Therefore, the proportion of AP in TMR silages should be less than 5% of dietary DM.  相似文献   

Effects of apple pomace‐mixed silage on growth performance and meat quality in finishing pigs          下载免费PDF全文

Jiachen Fang  Yang Cao  Masatoshi Matsuzaki  Hiroyuki Suzuki  Hirofumi Kimura 《Animal Science Journal》2016,87(12):1516-1521

We measured the growth performance and meat quality of 10 crossbred (Yorkshire × Duroc × Landrace) neutered male pigs to evaluate the effects of apple pomace‐mixed silage (APMS). The pigs were divided into two groups and were respectively fed the control feed and the AMPS ad libitum during the experiment. No difference was found in the finished body weight, average daily gain, carcass weight, back fat thickness or dressing ratio between the control and the AMPS treatments, but average dairy feed intake (dry matter) was significantly lower and feed efficiency was significantly higher using the APMS treatment (P < 0.05). With regard to meat quality, the APMS increased the moisture content but decreased the water holding capacity (P < 0.05) compared with the control treatment. Furthermore, the APMS affected the fatty acid composition of the back fat by increasing linoleic acid (C18:2n6), linolenic acid (C18:3) and arachidic acid (C20:0) levels, while decreasing palmitic acid (C16:0), palmitoleic acid (C16:1) and heptadecenoic acid (C17:1) levels, compared with the control treatment. These results indicate that feeding fermented apple pomace to finishing pigs increases the feed efficiency and affects the meat quality and fatty acid composition of back fat.  相似文献   

基于PCA-GA-SVM的甘蔗收获机运行状态识别     

陈远玲  覃东东  孙英杰  高骁卿  班成周  梁云祥 《中国农机化学报》2020,(2):135-140

由于甘蔗收获机在收获过程中智能化水平较低,依靠人工操作很容易对甘蔗收获机的运行状态产生误判,从而造成物流通道堵塞、能源浪费、收割效率低。针对这些问题,提出一种基于主成分分析(PCA)、遗传算法(GA)和支持向量机(SVM)状态识别模型。首先,通过实地采集甘蔗收获机刀盘轴、行走轴、切段轴和风机轴扭矩和行驶速度特征信息,然后通过PCA进行数据降维,最后利用GA优化参数C、γ,使用每个特性信息来训练SVM,对甘蔗收获机运行状态进行分类。结果表明:PCA-GA-SVM状态识别模型对甘蔗收获机运行状态的识别准确率为93.75%,建模时间为3.688 s,与SVM(81.25%,9.487 s)、PCA-SVM(87.5%,5.817 s)和GA-SVM(90%,8.969 s)进行对比,该模型具有最高准确识别率和最快建模速度,具有较大的应用价值。  相似文献   

Suppurative meningoencephalitis and perineuritis caused by Streptococcus gallolyticus in a Japanese Black calf     

Mikuya IWANAGA  Naoto IMAI  Ayaka KAMIKAWA  Kaho SHIMADA  Masatoshi OKURA  Daisuke TAKAMATSU  Daijiro UEDA  Mizuki NAKAYAMA  Tomoyuki SHIBAHARA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2022,84(1):53

A 179-day-old calf, which was weak and stunted, showed neurological signs and was euthanized. Postmortem examination revealed extensive and severe cloudy area in the meninges, and pleural pneumonia. Gram-positive cocci were isolated from systemic organs. Biochemical and 16S rRNA gene sequence analyses identified the isolate as Streptococcus gallolyticus, and its subspecies was suggested to be gallolyticus (SGG). The isolate was classified as a novel sequence type (ST115) by the multilocus sequence typing scheme for SGG and showed susceptibility to penicillin, ampicillin, amoxicillin, florfenicol, sulfamethoxazole-trimethoprim, and chloramphenicol. Histopathologically, suppurative meningoencephalitis and perineuritis were detected. As SGG has been isolated solely from a cow with mastitis in Japan, this is the first SGG infection in a calf with suppurative meningoencephalitis and perineuritis in this country.  相似文献   

Comparison of flower color with anthocyanin composition patterns in evergreen azalea   总被引：2，自引：0，他引：2  

Daiki Mizuta  Takuya Ban  Ikuo Miyajima  Akira Nakatsuka  Nobuo Kobayashi   《Scientia Horticulturae》2009,122(4):594-602

In evergreen azaleas, major anthocyanins were detected from petals of wild species and cultivars by HPLC analysis. Depending on flower color, all samples were divided into three groups: red, purple or white, using the Japan color standard for horticultural plants. The chromatic components a* and b* values of red group samples showed a convergent distribution, whereas those of purple group samples showed a wider distribution. According to the HPLC analysis, red group samples had two to four major anthocyanins, and those of the purple group had two to six major ones. In contrast, no anthocyanins were detected in the white group petals, although anthocyanidins were detected. These results suggest that the anthocyanin constitution of the purple group flowers is more varied than that of the red group flowers, and this wider variety among purple flowers contributes to extending the diversity of flower color in evergreen azalea.  相似文献   

高精度气动比例压力阀设计与特性分析   总被引：3，自引：1，他引：2  

路波  陶国良  袁月峰  刘昊  班伟 《农业机械学报》2009,40(10):181-187

设计了一种两级阀芯活塞式结构的以比例电磁铁为控制元件,采用电反馈闭环控制的高精度气动比例压力阀。该阀输出压力在0.6MPa内连续可调,且稳态精度可达0.25 kPa。建立了比例阀完整的非线性动态模型,分析了主要物理和几何参数对系统动态特性和控制性能的影响;构建了输出因子调整的模糊自适应比例加积分控制器,并利用ATmega16单片机实现了压力在设定范围内的快速高精度控制。实验结果表明,该阀在设计压力范围内具有良好的压力和流量特性;和传统PI算法相比,输出因子调整的模糊自适应算法在改善系统响应和控制稳定性的同时,显著提高了稳态控制精度,具有较高的效率和鲁棒性。  相似文献   

秦巴山区耕层土壤微量元素空间特征及影响因子——以镇巴县为例   总被引：2，自引：0，他引：2  

姜悦  常庆瑞  赵业婷  班松涛 《中国水土保持科学》2013,(6):50-57

为充分了解与掌握秦巴山区耕层土壤微量元素现状、空间分布规律及其影响因素,为区域土壤微量元素的科学管理及土壤微肥应用提供理论依据和实践指导,以镇巴县为例,基于2010年陕西省耕地地力调查与质量评价项目数据,采用地统计学和GIS相结合的方法,研究秦巴山区耕层土壤有效态Fe、有效态Mn、有效态Cu和有效态Zn的空间特征及其影响因素.结果表明：1）镇巴县耕层土壤有效态Fe、Mn和Cu均属中等变异强度,变异系数介于81.38％～97.57％之间,有效态Zn属强变异强度,变异系数为117.09％;2）空间特征上,根据块金系数值,4种微量元素均表现为中等强度的空间相关性,县域质量分数的空间分布呈南部高、西部低格局,空间变异性是由自然因素（土壤理化性质、地形地貌和常年降水量等）和人为因素（作物熟制和村距等）共同作用而引起的;3）镇巴县耕层土壤整体有效态Cu和Fe质量分数丰富,Zn质量分数适宜,19.14％ Mn缺乏（＜5 mg/kg）,需结合不同的耕作制度、土壤类型及其质量分数丰缺水平进行分区培肥与管理.  相似文献   

帽儿山林场樟子松人工林光辐射分布的研究   总被引：1，自引：0，他引：1  

班宏娜  刘兆刚 《森林工程》2010,26(2):20-23

以东北林业大学帽儿山实验林场老山施业区内的樟子松人工林为研究对象,运用WinSCANOPY2006a冠层分析仪采集数据,并结合实地调查,实测5种林龄的樟子松人工林群落内光辐射特征及冠层参数。结果表明：立地条件基本一致的情况下,樟子松人工林内光辐射随林龄增大呈下降趋势,变化范围为8．8－12．32mol·m^-2·d^-1,平均占冠层顶部总辐射的21．21％。对光的吸收能力逐渐增强且树龄为30a以后趋于稳定。林分开阔度的变化范围为10．78％～21．66％,不同林龄群落之间差异显著,随林龄增大而下降。叶面积指数变化范围为2．29～3．47,不同林龄群落之间差异不显著。消光系数（＆）的变化范围为0．47～0．63,消光能力随林龄增大而增强,冠层结构随林龄的变化对消光能力的变化有一定得影响．  相似文献   

The crystal structure of a mammalian fatty acid synthase     

Maier T  Leibundgut M  Ban N 《Science (New York, N.Y.)》2008,321(5894):1315-1322

Mammalian fatty acid synthase is a large multienzyme that catalyzes all steps of fatty acid synthesis. We have determined its crystal structure at 3.2 angstrom resolution covering five catalytic domains, whereas the flexibly tethered terminal acyl carrier protein and thioesterase domains remain unresolved. The structure reveals a complex architecture of alternating linkers and enzymatic domains. Substrate shuttling is facilitated by flexible tethering of the acyl carrier protein domain and by the limited contact between the condensing and modifying portions of the multienzyme, which are mainly connected by linkers rather than direct interaction. The structure identifies two additional nonenzymatic domains: (i) a pseudo-ketoreductase and (ii) a peripheral pseudo-methyltransferase that is probably a remnant of an ancestral methyltransferase domain maintained in some related polyketide synthases. The structural comparison of mammalian fatty acid synthase with modular polyketide synthases shows how their segmental construction allows the variation of domain composition to achieve diverse product synthesis.  相似文献