高级氧化和可见光照射协同作用下Bi_(2)WO_(6)对有机污染物降解的催化活性增强

随着工业化社会的不断发展,环境问题日益严重。尤其是工业废水问题一直是催化降解领域的研究热点。光催化与高级氧化工艺(AOPs)耦合技术因为具有高效、无选择性、处理条件温和等特点,被认为是一种高效的有机污染物降解技术。本文以十六烷基三甲基溴化铵(CTAB)表面活性剂作为模板,采用简单的水热法制备了钨酸铋(Bi_(2)WO_(6))纳米花。通过X射线衍射(XRD)、傅里叶红外光谱(FTIR)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线光电子能谱(XPS)和紫外-可见漫反射光谱(DRS)技术对其微观形貌、晶相、表面化学元素状态和光学性质进行了表征。为了研究钨酸铋(Bi_(2)WO_(6))纳米花的催化性能,在不同催化体系下降解有机污染物罗丹明B(Rh B),实验发现,于vis/过硫酸盐(PMS)/Bi_(2)WO_(6)体系下,40 min内对Rh B的去除率高达96.39%,明显优于PMS/Bi_(2)WO_(6)(40 min内去除率为38.77%)和vis/Bi_(2)WO_(6)(40 min内去除率为31.82%)体系,表明可见光照射和PMS的协同作用加速了Bi_(2)WO_(6)对Rh B降解的催化活性。此外,还研究了催化剂剂量、PMS浓度、pH值和离子浓度等环境参数对催化体系催化性能的影响。结果表明,环境参数对vis/PMS/Bi_(2)WO_(6)系统中Rh B的去除率影响不大,Rh B的去除率也高达90%。相反,环境参数对vis/PMS/Bi_(2)WO_(6)体系下催化降解率(K)有明显影响,K值会随着催化剂剂量和PMS浓度的增加而增大。在pH不同环境下,K值会随着催化体系中pH值的升高,先增大后减小。当催化体系中的pH=7时,催化降解率达到最大值(0.1502 min^(-1))。有趣的是,体系中Cl^(-)的存在有利于提高催化降解效率。相反,体系中CO_(3)^(2-)的存在会明显抑制催化降解效率。循环实验的结果也验证了催化剂在降解有机染料方面具有良好的稳定性。此外,淬灭实验和EPR测试结果表明,超氧自由基(·O_(2)^(-))和单线态氧(^(1)O_(2))对有机污染物的降解起着重要作用。Bi_(2)WO_(6)在vis/PMS协同催化体系中的优异催化活性得益于其显著的可见光响应下光催化活性和铋离子对PMS的超强活化能力。

On the complete weight distributions of quantum error-correcting codes

In a recent paper, Hu et al. defined the complete weight distributions of quantum codes and proved the Mac Williams identities, and as applications they showed how such weight distributions may be used to obtain the singleton-type and hamming-type bounds for asymmetric quantum codes. In this paper we extend their study much further and obtain several new results concerning the complete weight distributions of quantum codes and applications. In particular, we provide a new proof of the Mac Williams identities of the complete weight distributions of quantum codes. We obtain new information about the weight distributions of quantum MDS codes and the double weight distribution of asymmetric quantum MDS codes. We get new identities involving the complete weight distributions of two different quantum codes. We estimate the complete weight distributions of quantum codes under special conditions and show that quantum BCH codes by the Hermitian construction from primitive, narrow-sense BCH codes satisfy these conditions and hence these estimate applies.

Diagnostic value of elevated serum carbohydrate antigen 199 level in acute cholangitis secondary to choledocholithiasis

AIM To investigate the diagnostic value of abnormal serum carbohydrate antigen 199(CA199) level in acute cholangitis secondary to choledocholithiasis.METHODS In this retrospective cohort study, the clinical data of 727 patients with choledocholithiasis admitted to the Third Affiliated Hospital of Zunyi Medical College from June 2011 to June 2017 were collected. Among these patients, 258 patients had secondary acute cholangitis and served as observation group, and the remaining 569 choledocholithiasis patients served as the control group. Serum liver function indexes and tumor markers were detected in both groups, and the receiver operating characteristic(ROC) curves were constructed for markers showing statistical significances. The cutoff value, sensitivity, and specificity of each marker were calculated according to the ROC curves. RESULTS The results of liver function tests showed no significant differences between the two groups(P > 0.05). Tumor markers including serum CA125, CA153, carcinoembryonic antigen, and alpha fetoprotein levels were also not significantly different(P > 0.05); however, the serum CA199 level was significantly higher in the observation group than in the control group(P < 0.05). The ROC curve analysis showed that the area under the curve was 0.885(95%CI: 0.841-0.929) for CA199, and the cutoff value of 52.5 kU/L had the highest diagnostic accuracy, with a sensitivity of 86.8% and a specificity of 81.6%.CONCLUSION Abnormally elevated serum CA199 level has an important value in the diagnosis of acute cholangitis secondary to choledocholithiasis. It may be a specific inflammatory marker for acute cholangitis.

Combination of serum gamma-glutamyltransferase and alkaline phosphatase in predicting the diagnosis of asymptomatic choledocholithiasis secondary to cholecystolithiasis

BACKGROUND Gamma-glutamyltransferase(GGT) is one of the most important laboratory tests for the evaluation of liver damage. Through a long-term clinical observation of patients with secondary asymptomatic choledocholithiasis, we found that most patients had abnormal GGT serum levels.AIM To investigate the combination of serum GGT and alkaline phosphatase(ALP) in predicting the diagnosis of asymptomatic choledocholithiasis secondary to cholecystolithiasis.METHODS In this retrospective cohort study, the clinical data of 829 patients with cholecystolithiasis admitted to the Third Affiliated Hospital of Zunyi Medical College from August 2014 to August 2017 were collected. Among these patients,151 patients had secondary asymptomatic choledocholithiasis and served as the observation group, and the remaining 678 cholecystolithiasis patients served as the control group. Serum liver function indexes were detected in both groups,and the receiver operating characteristic(commonly known as ROC) curves were constructed for markers showing statistical significances. The cutoff value,sensitivity, and specificity of each marker were calculated according to the ROC curves.RESULTS The overall incidence of asymptomatic choledocholithiasis secondary to cholecystolithiasis was 18.2%. The results of liver function indexes including serum aspartate aminotransferase, alanine aminotransferase, direct bilirubin and total bilirubin levels showed no significant differences between the two groups(P> 0.05). However, the serum GGT and ALP levels were significantly higher in the observation group than in the control group(P < 0.05). The ROC curve analysis showed that the area under the curve was 0.881(95%CI: 0.830-0.932), 0.647(95%CI: 0.583-0.711) and 0.923(0.892-0.953) for GGT, ALP, and GGT + ALP,respectively. The corresponding cut-off values of GGT and ALP were 95.5 U/L and 151.5 U/L, sensitivity were 90.8% and 65.1%, and specificity were 83.6% and59.8%, respectively. The sensitivity and specificity of GGT + ALP were 93.5% and85.1%, respectively.CONCLUSION An abnormally elevated serum GGT level has an important value in the diagnosis of asymptomatic choledocholithiasis secondary to cholecystolithiasis.The combination of serum GGT and ALP has better diagnostic performance. As a convenient, rapid and inexpensive test, it should be applied in secondary asymptomatic choledocholithiasis routine screening.

里岔黑猪饲养技术要点

里岔黑猪是我国地方特色品种猪,素有“南太湖,北里岔”之称,是青岛市里岔当地养殖户长期择优纯繁、继代选育形成特色的地方品种,被誉为“国宝”。其养殖历史悠久,具有腰身长,形体高,毛色全黑,瘦肉率50%左右,繁殖率高的特点。1985年被原农业部列为重点推广的优良地方猪种,现已被列为国家一类畜种资源重点保护。因此,对里岔黑猪的饲养需要多方面进行把控,利用科学合理地饲养管理措施养殖里岔黑猪,使里岔黑猪更舒适、更健康地生活,更好地发挥其生产潜能,为广大消费者提供更安全、更优质的产品。

Gliomatosis Cerebri

Gliomatosis Cerebri(GC)is a rare tumor of the central nervous system.It is defined as a diffuse glial tumor that extensively infiltrates the brain,involving more than two lobes.And it is listed as a subtype of astrocytic tumors according to the newest 2007(4th edition)WHO classification of tumors of the Central Nervous System.GC can be subdivided into TypeⅠand TypeⅡ.Clinical findings for patients with GC are usually subtle and nonspecific.The lesions of GC generally show hypo,or isodensity on CT;a poorly defined diffuse hypo- or isointense signal on T1-weighted images,and a scattered diffuse hyperintense signal on T2-weighted images.Histological examination of GC reveals widespread infiltration of neoplastic glial cells with minimal destruction of pre-existing structures. Diagnosis of GC can be ascertained on the basis of a combination of clinical,radiological and pathological data.The treatment of GC includes radiotherapy and chemotherapy;however,the optimal therapeutic strategy is still not well established and prognosis of GC remains poor.This report reviews in detail the aspects of GC mentioned above,and three controversial issues are also discussed in the report.

随钻四极子声波技术在南海西部深水区钻探中的应用分析

在南海西部深水区的钻探阶段,钻井工程与地层评价主要面临着如何在强噪音、深水疏松地层中实时获得高品质的全波列信息,以及应用实时随钻声波数据提高层位与压力预测精度这两个挑战。利用最新一代的随钻四极子声波技术能够获取高质量的实时全波列数据,对初始的岩石力学模型进行刻度从而进行实时压力监测与井眼稳定性分析。本文对在南海西部陵水区块服务的新一代随钻四极子声波数据质量、影响实时数据质量的钻井环境及计算方法进行了分析,结果表明,随钻四极子声波技术的应用提高了钻井作业的安全系数,优化了经济效益,在油田勘探中具有较强的应用价值。

A Review of Nonlinear Kalman Filter Appling to Sensorless Control for AC Motor Drives

Sensorless control of AC motor drives,which takes the advantages of cost saving,higher reliability,and less hardware,has been developed for several decades.Among the existing speed sensorless control methods,nonlinear Kalman filter-based one has attached widespread attention due to its superb estimation accuracy and inherent resistibility to noise.However,the determination of noise covariance matrix and robustness of model uncertainties are still open issues in practice.A great number of studies try to solve these problems in resent years.This paper reviews the application of extended Kalman filter(EKF),unscented Kalman filter(UKF),and cubature Kalman filter(CKF)in speed sensorless control for AC motor drives.As an iterative algorithm,EKF has advantages in processor implementation.However,EKF suffers from the linearization error and model uncertainties when applying to sensorless control system.This paper presents the predominant improvements of EKF which is also applicative in UKF and CKF mostly.

Q Versatile Seismic Imager (QVSI) Successfully Predicts Target Depth and Pore-Pressure in HPHT Environment

Drilling in any environment is challenging as it poses a challenge to drill reservoir targets without losses and minimum casing strings and is even challenging in HPHT (high pressure high temperature) environment. Seismic is the fundamental for pre-drill prognosis and completion design. The target depth prognosis is achieved through depth transformation by using seismic velocities or available velocity logs in the nearby field or block and often has varying degree of uncertainty in target depths depending upon the suitable of the velocity function used. The velocity function used could be affected due to available seismic bandwidth or structure. These uncertainties in target depths often lead to increased well costs as a result of wellbore stability issues & undesired casing strings. Most common issue faced by drillers is the target confirmation & distance to these targets ahead of bit. Vertical seismic profile (VSP) look-ahead at intermediate depths is one of the approaches to mitigate these uncertainties and drill wells safely. VSP help confirm the presence of drilling targets & also predict the depth to top of these targets. Additionally, the predicted interval velocity is used to predict the pre-pressure for next section drilling. In South China Sea, oil & gas operators face a significant risk while drilling over-pressured formations. It is therefore imperative to know the depth to top of these high pressured formations to avoid drilling directly into it and risking the well. It is also important to know the pore-pressure and mud weight for the next section to be drilled for safe drilling & with minimum casing strings [1] [2] [3]. It is more difficult to get this information in the HPHT environment due to the lack of high temperature tools [4]. Schlumberger’s proprietary QVSI*—High pressure, high temperature VSI* (Versatile Seismic Imager) has been successfully used to predict the target depth for casing landing and pore-pressure prediction in HPHT environment. QVSI is the latest generation of VSI* Versatile Seismic Imager tools developed by Schlumberger to acquire high quality tri-axial borehole seismic data in extreme environment wells. The QVSI* tool uses the Q-Technology* singlesensor hardware and software and advanced wireline telemetry for fast digital seismic data transmission from borehole to surface. QVSI is a high-temperature, high-pressure array tool design that focuses on tri-axial vector fidelity and efficient data acquisition, extending the limits in a 4-tool configuration to 500&deg;F (260℃) and 30 kpsi (207 MPa). In this paper, a case study is presented for Well-XX for CNOOC from South China Sea. The well-xx is located in Yanyan Sag, Qiongdongnan Basin and the downhole temperature was 204℃. The main target layer is Lingshui III sandstone, which is controlled by Northwest fault. It is a gas well and critical for the client to land the casing at right depth and know the drilling parameters for the next section ahead. QVSI* predicted the target depth within ±2 m for decision on casing point. The predicted pore pressure was within ±0.1 ppg.

The short and long-term effect of polystyrene nanoplastics on nitrifying sludge at high nitrite concentrations

The effect of nanoplastics(NPs)on nitrite oxidation bacteria(NOB)community in treating high-strength wastewater remains unclear,which seriously affects the stability of nitrogen removal process.In this study,highly active nitrifying sludge was enriched and exposed to 50nm polystyrene NPs(PS-NPs)for short-term(1,100,500,and 1000 mg/L,1.5 hr)and long-term(1,10,100 mg/L,40 days)at high nitrite concentration.In contrast to previous studies,our results showed that the exposures to PS-NPs had little effect on nitrifying performances.After long-term exposure,the protein/polysaccharide ratios in extracellular polymeric substances(EPS)were positively correlated with PS-NPs concentrations(0.78–0.99).The produced reactive oxygen species(ROS)were gradually removed,and PS-NPs higher than 10 mg/L caused damage to membrane integrity.Long-term exposure for 40 days increased the community diversity and caused significant differences between the control and exposed communities.The control group were dominated by Nitrobacter and Exiguobacterium,while the exposure group was dominated by Bacillus,Mycobacterium,and Nitrospira.A noticeable shift in the NOB community from Nitrobacter(26.5%to 3.4%)to Nitrospira(1.61%to 14.27%)was observed.A KEGG analysis indicated a decrease in cell growth and death,cell motility and energy metabolism.It appeared that NOB could adapt to PS-NPs stress through enhanced secretion and removal of oxidative damage.Overall,this study provided new insights into the response mechanism of NOB to PS-NPs exposure.

凝结芽孢杆菌耐热β-N-乙酰氨基葡萄糖苷酶在大肠杆菌的分泌表达及其在制备Glc NAc中的应用

β-N-乙酰氨基葡萄糖苷酶体,可作用于几丁质或壳聚糖等天然底物,从末端水解产生N-乙酰-β-D氨基葡萄糖(GlcNAc)单体,其在医药和农业领域有较广泛的用途。文中克隆了耐热菌凝结芽孢杆菌Bacillus coagulans DMS1的β-N-乙酰氨基葡萄糖苷酶基因(BcNagZ),并成功在大肠杆菌Escherichia coli BL21(DE3)进行了分泌表达,蛋白表达量达到0.76 mg/mL。纯化后的BcNagZ分子量为61.3 kDa,测得的比活力为5.918 U/mg;进一步对该酶进行表征,结果显示酶的最适反应pH为5.5,最适反应温度为75℃,在65℃处理30 min后还有85%的残余酶活力,表明该酶具有良好的热稳定性。该酶的米氏常数Km为0.23 mmol/L,Vmax为0.0431 mmol/(L·min)。重组BcNagZ可以水解胶体几丁质得到微量的GlcNAc,可以将二糖水解为单糖;偶联已报道的外切几丁质酶AMcase,可以有效地将胶体几丁质水解为GlcNAc,得率达到86.93%。

Transmission Cost Allocation by Power Tracing Based Equivalent Bilateral Exchanges

The allocation of transmission cost provides important references and signals for system expansions and investments.This paper proposes a power tracing based equivalent bilateral exchange(PTEBX)method in which network users are responsible for not only their induced power flows,but also power flows induced by whom they have equivalent bilateral exchanges with.The equivalent bilateral exchanges are recognized based on the power tracing.To evaluate the performance of different methods of allocating transmission cost,seven criteria are put forward that take into consideration characteristics of power systems.Theoretical analysis is then conducted to certify whether the methods satisfy the criteria.The results indicate that only the PTEBX method is able to satisfy all the seven criteria.Numerical examples based on the IEEE-30 system are presented to further demonstrate the applicability of the proposed method.

A Mechanism of Intraday Market Design for Promoting Wind Power Integration

Wind power generation has been developing rapidly in recent years.Therefore,the mechanism for promoting wind power integration becomes increasingly important.In this paper,a novel mechanism of intraday market is proposed,which can utilize updating information of wind power and effectively exploit the shiftable load.The mechanism is compatible with the existing market framework,and promotes wind power producers(WPPs)to be more competitive in the market.Thus,the WPPs could make decisions for multiple market transactions in various trading timescales according to the market price.Moreover,the WPPs can optimize their decisions continuously in the intraday market at different time points in the model.The case study on IEEE-RTS verifies the proposed method is valid and feasible.It can support wind power integration and increase the benefit of the whole system as well.

正念防复吸干预对苯丙胺类戒毒人员戒治成效的影响

当代医学界认为,成瘾是一种慢性复发的脑疾病。而在吸毒成瘾者中,药物滥用以及对高危情境与负性情绪的错误觉察是深陷复吸泥潭的重要原因之一。正念防复吸干预是近年来针对物质成瘾较为有效的干预手段,其对物质成瘾有效的原因在于非批判性地接纳负性的想法和情绪,而非通过滥用药物来压抑不良的体验,从而降低渴求和复吸之间的自动联系。通过随机对照临床试验,利用脑电脑功能连接探索正念防复吸干预对苯丙胺类戒毒人员的作用机制,探索正念防复吸干预于戒毒场所的使用推广路径,以期进一步丰富戒毒康复的方式与方法。