Carbon biomass,carbon-to-chlorophyll a ratio and the growth rate of phytoplankton in Jiaozhou Bay,China

Carbon biomass,carbon-to-chlorophyll a ratio(C꞉Chl a),and the growth rate of phytoplankton cells were studied during four seasonal cruises in 2017 and 2018 in Jiaozhou Bay,China.Water samples were collected from 12 stations,and phytoplankton carbon biomass(phyto-C)was estimated from microscope-measured cell volumes.The phyto-C ranged from 5.05 to 78.52μg C/L in the bay,and it constituted a mean of 38.16% of the total particulate organic carbon in the bay.High phyto-C values appeared mostly in the northern or northeastern bay.Diatom carbon was predominant during all four cruises.Dinoflagellate carbon contributed much less(<30%)to the total phyto-C,and high values appeared often in the outer bay.The C꞉Chl a of phytoplankton cells varied from 11.50 to 61.45(mean 31.66),and high values appeared in the outer bay during all four seasons.The phyto-C was also used to calculate the intrinsic growth rates of phytoplankton cells in the bay,and phytoplankton growth rates ranged from 0.56 to 1.96/d;the rate was highest in summer(mean 1.79/d),followed by that in fall(mean 1.24/d)and spring(mean 1.17/d),and the rate was lowest in winter(mean 0.77/d).Temperature and silicate concentration were found to be the determining factors of phytoplankton growth rates in the bay.To our knowledge,this study is the first report on phytoplankton carbon biomass and C꞉Chl a based on water samples in Jiaozhou Bay,and it will provide useful information for studies on carbon-based food web calculations and carbon-based ecosystem models in the bay.

血清CAR及ELR与AECOPD合并肺部感染患者预后的相关性研究

目的探讨血清C反应蛋白/白蛋白比值(CAR)及嗜酸性粒细胞/淋巴细胞比值(ELR)与慢性阻塞性肺疾病急性加重(AECOPD)合并肺部感染患者预后的相关性。方法2019年1月-2022年6月募集180例AECOPD患者,依据是否合并肺部感染将180例AECOPD患者分为感染组(105例)和非感染组(75例),105例感染组患者依据入院治疗后预后情况,分为预后良好组(62例)和预后不良组(43例)。检测所有受试者的血清CAR和ELR水平,Logistic回归模型分析影响AECOPD合并肺部感染患者预后的危险因素,绘制ROC曲线分析CAR、ELR单独和联合检测对AECOPD合并肺部感染患者预后的影响。结果与非感染组相比,感染组患者血清CAR(t=45.25,P<0.001)、ELR(t=20.11,P<0.001)水平升高。与预后良好组相比,预后不良组患者血清CAR、ELR水平升高(均P<0.05),且患者年龄较大、病程较长、合并肺心病比例、无创呼吸机治疗比例高,FEV1、FEV1/FVC、FVC水平低(P<0.05)。Logistic结果显示,病程、无创呼吸机治疗、CAR、ELR是影响AECOPD合并肺部感染患者预后不良的独立危险因素。ROC结果显示,血清CAR、ELR单独预测AECOPD合并肺部感染患者预后的AUC为0.778、0.787,二者联合预测的AUC为0.875,二者联合检测的AUC显著大于CAR、ELR单独检测(Z=2.128,3.236,P<0.05)。结论AECOPD合并肺部感染患者血清CAR、ELR水平升高,二者联合检测能提高对AECOPD合并肺部感染患者预后评估的水平。

外周血CAR、血清IL-17水平与MPP患儿病情严重程度及预后的关系

目的研究外周血C反应蛋白(C-reactive protein,CRP)、白蛋白(Albumin,ALB)比值(CRP to ALB ratio,CAR)、血清白介素-17(Interleukin-17,IL-17)水平与肺炎支原体肺炎(Mycoplasma pneumoniae pneumonia,MPP)患儿病情严重程度及预后的关系。方法以2022年1月-2023年12月于中国人民解放军空军军医大学第一附属医院西京医院儿科就诊并治疗的118例MPP患儿为研究对象,以同期体检的120名健康儿童为对照组。于入院当天采集患者空腹外周血,检测血清CRP、ALB和IL-17水平,计算CRP与ALB比值(CRP to ALB ratio,CAR)。对所有患儿的病情严重程度进行评估,治疗后评估患儿预后。结果与对照组比较,病例组外周血CAR和IL-17水平均升高,差异有统计学意义(P<0.05)。MPP患儿外周血CAR和IL-17水平呈显著正相关关系(r=0.374,P=0.006)。118例MPP患儿中,重症患儿51例,轻症患儿67例。与轻症组比较,重症组患儿外周血CAR和IL-17水平上升,差异有统计学意义(P<0.05)。外周血CAR诊断不同严重程度MPP的曲线下面积(AUC)为0.756(0.667~0.845),灵敏度和特异度分别为62.7%和85.1%;外周血IL-17水平诊断不同严重程度MPP的AUC为0.745(0.654~0.835),灵敏度和特异度分别为51.0%和99.1%;外周血CAR联合IL-17水平诊断不同严重程度MPP的AUC为0.913(0.862~0.964),灵敏度和特异度分别为84.3%和80.6%。51例重症MPP患儿中,14例预后不良,37例预后良好。与预后良好组比较,预后不良组外周血CAR和IL-17水平上升,差异有统计学意义(P<0.05)。外周血CAR预测重症MPP患儿不同预后的AUC为0.685(0.512~0.859),灵敏度和特异度分别为57.1%和75.4%;外周血IL-17水平预测重症MPP患儿不同预后的AUC为0.722(0.548~0.896),灵敏度和特异度分别为78.6%和78.4%;外周血CAR联合IL-17水平预测重症MPP患儿不同预后的AUC为0.764(0.620~0.909),灵敏度和特异度分别为78.6%和70.3%。结论外周血CAR、IL-17水平与MPP患儿严重程度及预后有关,且对MPP患儿不同严重程度的诊断具有一定价值。

莲子在光下萌发过程中类囊体膜垛叠和Chl a/b值的变化

莲(Nelumbo nucifera Gaertn.)子在光下萌发过程中,其胚芽内叶绿体的类囊体膜垛叠和叶绿素a/b(Ch1 a/b)值的动态变化是:莲子萌发前,胚芽叶绿体类囊体膜呈现巨基粒型,Ch1 a/b值为0.9。莲子萌发2天,巨基粒类囊体膜松散成非垛叠以至解垛叠型,Ch1 a/b值为1.06。莲子萌发4天,叶绿体内新出现的基粒类囊体膜比萌发前的巨基粒类囊体膜短,约3—5倍,基粒垛数明显有所减少,Ch1 a/b值为1.42。莲子萌发6天,基粒类囊体膜垛叠变得更有序,基质类囊体膜很少,Ch1 a/b值为2.16。莲子萌发8天,基粒数目增多,但其垛内的类囊体膜数目减少,基质类囊体膜增多,Ch1 a/b值为2.77。莲子萌发10天,基粒和基质类囊体膜发育正常,只是类囊体膜的垛叠程度减低,Ch1 a/b值为2.80。

CAR模型在油田含水率预测中的应用

为了预测油田动态产量,研究油田含水率随油田的开发时间变化的模型。通过分析油田含水上升变化规律,建立带控制项的自回归(CAR)预测模型。该模型可以全程预测油田开发过程的含水率,并且计算方法简单、预测精度较高、适用于不同油区,可为制定油田开发方案提供可靠的科学依据。该模型应用于某油区实际问题的预测,可获得较为满意的预测结果。

基于Adams/Car汽车转向系统力矩波动优化分析

详细阐述转向系统力矩波动的基本原理,并基于Adams/Car悬架系统模型进行DOE分析,找到对转向传动比波动影响最关键的因素;然后结合实际车辆,优化得到转向传动比波动最小时的相位角最佳值.在实车上对优化方案进行验证.

A hybrid algorithm based on tabu search and large neighbourhood search for car sequencing problem

The car sequencing problem(CSP)concerns a production sequence of different types of cars in the mixed-model assembly line.A hybrid algorithm is proposed to find an assembly sequence of CSP with minimum violations.Firstly,the hybrid algorithm is based on the tabu search and large neighborhood search(TLNS),servicing as the framework.Moreover,two components are incorporated into the hybrid algorithm.One is the parallel constructive heuristic(PCH)that is used to construct a set of initial solutions and find some high quality solutions,and the other is the small neighborhood search(SNS)which is designed to improve the new constructed solutions.The computational results show that the proposed hybrid algorithm(PCH+TLNS+SNS)obtains100best known values out of109public instances,among these89instances get their best known values with100%success rate.By comparing with the well-known related algorithms,computational results demonstrate the effectiveness,efficiency and robustness of the proposed algorithm.

基于PNI、SII、CAR的列线图模型对肝移植术后腹腔感染的预测价值

目的探讨原位肝移植术后发生腹腔感染的危险因素。方法回顾性分析284例原位肝移植受者的临床资料,根据术后是否发生腹腔感染分为感染组(51例)和非感染组(233例)。采用单因素和多因素logistic回归分析腹腔感染的危险因素,构建列线图预测模型并评估模型预测效果,分析连续性变量对腹腔感染的预测价值。结果284例受者中,51例发生腹腔感染,发生率为18.0%。术前有糖尿病[比值比(OR)2.66,95%可信区间(CI)1.13~6.14,P=0.013]、手术时间长(OR 1.98,95%CI 1.03~3.57,P=0.038)、预后营养指数(PNI)低(OR 2.18,95%CI 1.06~4.44,P=0.023)、全身免疫炎症指数(SII)高(OR 2.21,95%CI 1.06~4.78,P=0.012)、C-反应蛋白/白蛋白比值(CAR)高(OR 1.90,95%CI 1.05~3.49,P=0.029)是肝移植术后腹腔感染的独立危险因素。列线图模型预测肝移植术后腹腔感染的曲线下面积(AUC)为0.761,且模型标准,一致性较好。CAR、PNI、SII均为肝移植术后腹腔感染的预测因子(均为P<0.05),AUC分别为0.648、0.611和0.648,临界值分别为2.75、43.15和564.50。结论CAR、SII、PNI是肝移植术后腹腔感染的预测因子,基于PNI、SII、CAR构建的列线图模型可有效预测肝移植术后腹腔感染的发生。

The Clinical Value of NLR, D-D and CRP/ALB Ratio in the Diagnosis of Pulmonary Thromboembolism

Objective: To evaluate the clinical diagnostic value of C-reactive protein/albumin ratio (CAR), neutrophil/lymphocyte ratio (NLR) and D-dimer (D-D) in patients with pulmonary thromboembolism (PTE). Methods: We conducted a retrospective analysis comparing hematology and coagulation in 362 PTCA-confirmed PTE patients with the control group and analyzing their relationships with CAR, NLR, and D-D. Receiver operating characteristic curve (ROC) was used to analyze the diagnostic threshold, area under the curve (AUC), diagnostic sensitivity and specificity of CAR, NLR and D-D for PTE. Results: 1) CAR, NLR and D-D levels in PTE patients were 2.13 ± 2.08, 8.96 ± 1.94 and 9.69 ± 8.61 respectively, significantly higher than those in control group (CAR = 0.03 ± 0.01, t = 20.7736, P < 0.01;NLR = 1.76 ± 0.53, t = 2.4281, P < 0.05 and PTE = 0.20 ± 0.11, t = 3.0066, P < 0.01 respectively). 2) NLR was positively correlated with CAR (r = 0.2111, t = 4.0971, P < 0.01) and D-D (r = 0.1065, t = 2.0481, P < 0.05), but CAR was not correlated with D-D (r = 0.0975, P > 0.05). 3) The levels of HB, LY, PLT and AT in PTE patients were significantly lower than those in control group, while WBC, NE and FB were significantly higher than those in control group. 4) CAR was negatively correlated with Hb and AT (P all < 0.01), but positively correlated with WBC, NE, MO and FB (P all < 0.01). NLR was negatively correlated with LY and AT (P all < 0.01), but positively correlated with WBC, NE and FB (P all < 0.01). DD was negatively correlated with Hb and PLT (P all < 0.05), but positively correlated with WBC, NE and MO (P all < 0.01). Conclusion: The levels of Hb, LY, PLT and AT were significantly decreased in PTE patients, while WBC, NE and FB were significantly increased. CAR, NLR and D-D were highly expressed in PTE patients, and were closely correlated with Hb, AT and FB. Combined detection of CAR, NLR and D-D can improve the diagnostic value of PTE.

Design, Development and Testing of an Air Damper to Control the Resonant Response of a SDOF Quarter-Car Suspension System

An air damper possesses the advantages that there are no long term changes in the damping properties, there is no dependence on working temperature and additionally, it has less manufacturing and maintenance costs. As such, an air damper has been designed and developed based on the Maxwell type model concept in the approach of Nishihara and Asami [1]. The cylinder-piston and air-tank type damper characteristics such as air damping ratio and air spring rate have been studied by changing the length and diameter of the capillary pipe between the air cylinder and the air tank, operating air pressure and the air tank volume. A SDOF quarter-car vehicle suspension system using the developed air enclosed cylinder-piston and air-tank type damper has been analyzed for its motion transmissibility characteristics. Optimal values of the air damping ratio at various values of air spring rate have been determined for minimum motion transmissibility of the sprung mass. An experimental setup has been developed for SDOF quarter-car suspension system model using the developed air enclosed cylinder-piston and air-tank type damper to determine the motion transmissibility characteristics of the sprung mass. An attendant air pressure control system has been designed to vary air damping in the developed air damper. The results of the theoretical analysis have been compared with the experimental analysis.

基于CarSim的FSAE赛车传动系统主减速比选择策略

车辆动力学虚拟仿真在汽车设计中具有重要的意义,文章从传统汽车动力学理论出发,结合CarSim汽车动力学仿真软件,提出了一种大学生方程式汽车大赛(FSAE)传动系统主减速比的选择策略。综合大学生方程式大赛规则中各动态赛项目成绩的计算方法,制定了目标分数评价指标,并根据西安交通大学毅行方程式车队2019、2020赛季的实车实验,验证了该传动系统主减速比选择策略的优势。研究结果对FSAE参赛车队传动系统主减速比的设计提供了一定的指导作用。

网约车实时订单在线选择策略设计与竞争分析

针对现实中网约车司机追求自身利益最大化而产生的频繁“拒单”现象,为优化乘客满意度、网约车平台调度效率和司机个人收益,提出派单模式下网约车司机实时订单决策问题,并采用在线策略设计与竞争分析展开研究。本文讨论了订单行驶距离小于返空距离的情形,即订单不收取车辆返空费。研究了一般网络上网约车实时在线调度的竞争比下界,并设计了最优调度策略——阈值策略(PT策略),分析了策略的竞争性能。最后,通过算例分析证明,PT策略能有效帮助网约车司机提高工作期间实时订单的总收益,从而降低司机“拒单”行为,在实际生活中具有很强的实用性,对网约车司机、网约车平台和政府具有一定管理启示。

A new vegetation index combination for leaf carotenoid-tochlorophyll ratio: minimizing the effect of their correlation

The ratio of leaf carotenoid to chlorophyll(Car/Chl)is an indicator of vegetation photosynthesis,development and responses to stress.However,the correlation between Car and Chl,and their overlapping absorption in the visible spectral domain pose a challenge for optical remote sensing of their ratio.This study aims to investigate combinations of vegetation indices(VIs)to minimize the influence of Car-Chl correlation,thus being more sensitive to the variability in the ratio across vegetation species and sites.VIs sensitive to Car and Chl variability were combined into four candidates of combinations,using a simulated dataset from the PROSPECT model.The VI combinations were then tested using six simulated datasets with different Car-Chl correlations,and evaluated against four independent datasets.The ratio of the carotenoid triangle ratio index(CTRI)with the red-edge chlorophyll index(CIred-edge)was found least influenced by the Car-Chl correlation and demonstrated a superior ability for estimating Car/Chl variability.Compared with published VIs and two machine learning algorithms,CTRI/CIred-edge also showed the optimal performance in the fourfield datasets.This new VI combination could be useful to provide insights in spatiotemporal variability in the leaf Car/Chl ratio,applicable for assessing vegetation physiology,phenology,and response to environmental stress.

汽车尾翼对汽车稳定性的影响

为了研究汽车尾翼对气动性能的影响,借鉴某经典车型,建立了该三厢车的汽车模型,为其设计了3种不同的尾翼,并对3种不同翼型的汽车进行三维空气动力学数值计算。采用雷诺时均方程和RNG k-ε湍流模型进行模拟计算,并用SIMPLEC算法进行压力和速度耦合。最后利用经典计算理论进行对比分析,得出不同尾翼对汽车性能的影响以及产生其影响的原因,尾缘下翼面增厚能够提供较大的升力系数使轿车产生更大的行驶稳定性,尾缘上翼面增厚对升力系数影响尤为明显,尖尾缘翼型具有较大的升阻比,可以达到稳定性和燃油经济性兼顾的目的。

军用汽车底盘转向系统结构原理及维修方法

军用汽车的主动式转向系统,具有更高的机动性和灵活性,克服了既往军用汽车转向比固定不变的缺点,能够在更好适应复杂多变战场环境的同时,还可以改善车辆在转向过程中的反应,降低轮胎在转向极限时的压力。在功能上为驾驶者提供行驶舒适性的同时,也满足了汽车行驶安全性的要求。基于此,本文将以某军用车为例,对其转向系统原理进行分析,并针对当前该车型较为常见的三种故障进行维修方法方面的阐述。

用冠层高光谱反射估测玉米植株色素时的采样点和指标选择

初步分析了11个玉米品种在7个生育期的植株叶绿素含量、类胡萝卜素含量和叶绿素/类胡萝卜素比值在不同层位(上层、中层和下层)的变化特点及其与15个高光谱参量间的关系,结果发现1)玉米叶片叶绿素/类胡萝卜素比值较明显表现出随形态学高度的下降而升高;2)绝大多数的高光谱参量与叶绿素含量(m g.g-1FW)间达到了显著或极显著相关,但相关性不强(最大r=0.56,n=77);3)高光谱参量与叶绿素/类胡萝卜素比值间相关性,明显强于与叶绿素含量或类胡萝卜素含量间的相关性(最大r=0.75,n=77),并表现出明显的层间差异,下层明显强于中层和上层。研究表明,在用高光谱反射分析玉米的色素状况时,用叶绿素/类胡萝卜素比值代替叶绿素含量作为色素指标可提高分析精度。

聚合硫酸铁除磷效果及藻类的生理生态响应

通过添加聚合硫酸铁(PSFe)降低水体中的活性磷,对水体中磷浓度、藻类生物量、碱性磷酸酶活性(APA)、类胡萝卜素/叶绿素a(Car/Chl.a)等指标随时间变化的情况进行了研究.结果表明,添加PSFe后,活性磷(RSP)迅速下降,藻类生物量和Car/Chl.a在短期内并没有显著变化.总碱性磷酸酶活性(TAPA)则随着RSP的下降而迅速升高,溶解性碱性磷酸酶活性(DAPA)上升幅度较小.结果表明,PSFe是一种优良高效的除磷剂,水体中TAPA、DAPA对RSP变化敏感,能在一定程度上指示水体中磷的变化.

不同光质对黄瓜叶片光合特性的影响

将黄瓜（ Ｃｕｃｕｍｉｓｓａｔｉｖｕｓ Ｌ．） 幼苗培养在相同辐照度（２０ μｍｏｌ·ｍ － ２·ｓ－１） 的白光、红光和蓝光下，研究了光质对黄瓜叶片的光合作用特性的影响。实验结果表明，生长在白光下的叶片，其叶绿素（Ｃｈｌ）含量分别比红光和蓝光下高７ ％ 和２２４％ ，在蓝光下的含量最低。生长在红光下的黄瓜叶片有较低的Ｃｈｌａ／ｂ 比值和较高的Ｃｈｌ ｂ 含量。低温（７７ Ｋ）荧光发射光谱和Ｃｈｌａ 荧光动力学诱导的实验结果表明，红光下的叶片具有较高的光系统Ⅱ（ＰＳⅡ） 活性和较低的光系统Ⅰ（ＰＳⅠ）活性，蓝光下的叶片具有较低的ＰＳⅡ活性和较高的ＰＳⅠ活性。红光下叶片的放Ｏ２ 速率比白光下叶片的放Ｏ２ 速率高４４９％ ，而蓝光下的叶片放Ｏ２ 速率略低于白光下的。表明光质对调节黄瓜叶片ＰＳⅠ和ＰＳⅡ的发育和光合活性以及光合放Ｏ２ 速率具有重要作用。

塘西河颗粒有机碳浓度季节变化及其来源分析

基于2014年塘西河下游水体中颗粒有机碳（POC）、叶绿素a为期1年的野外调查,结合颗粒有机物C/N比值、POC浓度与叶绿素a浓度比值（POC/Chl a）及降雨量等数据,分析了塘西河下游水体中POC浓度的季节变化规律、影响因素及其主要来源。结果表明,塘西河下游水体中POC浓度夏季最高,冬季最低,呈现出夏季〉春季〉秋季〉冬季的变化趋势;POC浓度与叶绿素a浓度呈现基本一致的变化趋势,说明两者具有共同的来源,但陆源输入对POC浓度变化产生一定的影响;水体中颗粒有机物C/N比值在5.11~8.15之间,年平均值6.12,POC/Chl a比值在16.24~32.18之间,年平均值为21.47,说明塘西河下游水体中POC主要来源于内源。通过计算,内源对水体中POC的贡献率在40.4%~80.07%之间,年平均值为62.55%,春、夏、秋、冬季内源贡献率分别是59.95%、70.24%、59.84%和58.48%。

生态足迹分析法在生态持续发展定量研究中的应用——以南京市1998年的生态足迹计算为例

利用生态足迹分析方法计算了南京市 1998年的生态足迹和生态承载力。认为南京市生态足迹需求对本地生态系统持续发展不构成威胁 ,但对全国或全球可持续发展造成负面影响。