Imaging features of solid pseudopapillary tumor of the pancreas on multi-detector row computed tomography

AIM： To retrospectively analyze the imaging features of solid-pseudopapillary tumors （SPTs） of the pancreas on multi-detector row computed tomography （MDCT） and define the imaging findings suggestive of malignant potential. METHODS： A total of 24 consecutive cases with surgically and pathologically confirmed SPTs of the pancreas underwent preoperative abdominal MDCT studies in our hospital. All axial CT images, CT angiographic images, and coronally and sagittally reformed images were obtained. The images were retrospectively reviewed at interactive picture archiving and communication system workstations. RESULTS： Of the 24 cases of SPTs, 11 cases （45.8%） occurred in the pancreatic head and seven （29.1%） in the tail. Eighteen were pathologically diagnosed as benign and six as malignant. MDCT diagnosis of SPTs was well correlated with the surgical and pathological results （Kappa = 0.6, P 〈 0.05）. The size of SPTs ranged from 3 to 15 cm （mean, 5.8 cm）. When the size of the tumor was greater than 6 cm （including 6 cm）, the possibilities of vascular （8 vs 1） and capsular invasion （9 vs 0） increased significantly （P 〈 0.05）.Two pathologically benign cases with vascular invasion and disrupted capsule on MDCT presented with local recurrence and hepatic metastases during follow-up about 1 year after the resection of the primary tumors. CONCLUSION： Vascular and capsular invasion with superimposed spread into the adjacent pancreatic parenchyrna and nearby structures in SPTs of the pancreas can be accurately revealed by MDCT preoperatively. These imaging findings are predictive of the malignant potential associated with the aggressive behavior of the tumor, even in the pathologically benign cases.

Multiplanar reformations and minimum intensity projections using multi-detector row CT for assessing anomalies and disorders of the pancreaticobiliary tree

CT scan is regarded as the imaging modality of choice in patients with pancreaticobiliary ductal abnormalities. However, the axial orientation of the CT images provides only limited anatomical view of pancreaticobiliary ductal abnormalities. The technological advances of multi-de-tector row CT and three-dimensional image processing in workstations allows rapid image acquisition and a short postprocessing time. In particular, multiplanar reforma-tions (MPR) and minimum intensity projections (MinIP) offer rapid and accurate images of the anatomy and ab-normalities of the pancreaticobiliary tree. Moreover, MPR and MinIP help determine the relationship between the pancreaticobiliary ductal anatomy and the surrounding structures. This pictorial review illustrates the wide spec-trum of images obtained by the MPR and MinIP of the anomalies and disorders of the pancreaticobiliary tree.

Usefulness of an Anisotropic Diffusion Method in Cerebral CT Perfusion Study Using Multi-Detector Row CT

Purpose: To present an application of the anisotropic diffusion (AD) method to improve the accuracy of the functional images of perfusion parameters such as cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) generated from cerebral CT perfusion studies using multi-detector row CT (MDCT). Materials and Methods: Continuous scans (1 sec/rotation ×60 sec) consisting of four 5-mm-thick contiguous slices were acquired after an intravenous injection of iodinated contrast material in 6 patients with cerebrovascular disease using an MDCT scanner with a tube voltage of 80 kVp and a tube current of 200 mA. New image data were generated by thinning out the above original images at an interval of 2 sec or 3 sec. The thinned-out images were then interpolated by linear interpolation to generate the same number of images as originally acquired. The CBF, CBV and MTT images were generated using deconvolution analysis based on singular value decomposition. Results: When using the AD method, the correlation coefficient between the MTT values obtained from the original and thinned-out images was significantly improved. Furthermore, the coefficients of variation of the CBF, CBV and MTT values in the white matter significantly decreased as compared to not using the AD method. Conclusion: Our results suggest that the AD method is useful for improving the accuracy of the functional images of perfusion parameters and for reducing radiation exposure in cerebral CT perfusion studies using MDCT.

Multi-Detector Row Computed Tomography Urography (MDCTU) in the Evaluation of Microscopic Hematuria in Adults

Multi-detector row computed tomography urography (MDCTU) becomes the imaging modality of choice for evaluation of the kidneys and urinary tract. The aim of this study was to discuss and illustrate the role of MDCTU, on a 32-row CT scanner in the evaluation a variety of entities that were frequently associated with microscopic hematuria in adults. This prospective cohort study was performed in the period of August 2013 to October 2014. Fifty positive participants to microscopic hematuria were examined at the radiology department of Alnilin Diagnostic Medical Center and Antalya Medical Center. Computed tomography urography (CTU) scanning was performed using two powerful performances, high speed multi-detector row on 32-row CT scanners (Siemens Healthcare Global, Somatom Emotion Duo Eco). Statistical analysis was done through the standard Statistical Package for the Social Sciences (SPSS Inc., Chicago, IL, USA) version 15 for windows. MDCTU established the correct cause of microscopic hematuria in (44;88%) of participants. In (6;12%) of participants, no cause of hematuria was identified based on the standard of references. The causes of hematuria in (41;82%) participants were diseases in the upper urinary tract, while urinary bladder neoplasms (2;4%) and diverticulum (1;2%) were the causes of hematuria (3;6%) in the lower urinary tract. Thirty two-row MDCTU scanner demonstrated satisfactory results in the investigation of microscopic hematuria, being able to demonstrate a wide spectrum of diseases affecting the urinary tract is the main advantage of the technique.

Optimization of Contrast Material Dose for Abdominal Multi-Detector Row CT: Predicting Patient Lean Body Weight by Using Preliminary Transverse CT Images

Estimated LBW could be used to determine the contrast material dose and rate during MDCT. The aim of this study is to test the accuracy of a technique for estimation of lean body weight (LBW) from a single multi-detector row computed tomographic (MDCT) abdominal image, using a bioelectrical body composition analyzer scale as the reference standard. CT images of 21 patients with previously measured LBW (mLBW) were processed using computer-assisted, vendor-specific software (Advantage Windows 4.2;GE Healthcare, Inc). For each transverse image, a fat-fraction was automatically measured as the number of fat pixels (-200 to -50 HU) divided by the total number of pixels having an attenuation value ≥-200 HU. Estimated LBW (eLBW) of five single contiguous sections was calculated in each of three abdominal regions (upper abdomen, mid abdomen and pelvis) by multiplying TBW by (1 – fat-fraction). Bland-Altman plot with limits of agreement was used to assess agreement between mLBW and eLBW. The mean mLBW for all patients was 56 kg (range, 39 - 75 kg). Mean differences and limits of agreement between mLBW and eLBW measurements for the upper abdomen, mid abdomen and pelvis reported were -8.9 kg (-25.6 kg, +7.5 kg), -10.6 kg (-27.7 kg, +6.4 kg), and +0.5 kg (-12.8 kg, +13.8 kg) respectively. eLBW deriving directly from a transverse CT image of the pelvis can accurately predict mLBW.

Double contrast-enhanced ultrasonography improves diagnostic accuracy of T staging compared with multi-detector computed tomography in gastric cancer patients

BACKGROUND Gastric cancer(GC)is the most common malignant tumor and ranks third for cancer-related deaths among the worldwide.The disease poses a serious public health problem in China,ranking fifth for incidence and third for mortality.Knowledge of the invasive depth of the tumor is vital to treatment decisions.AIM To evaluate the diagnostic performance of double contrast-enhanced ultrasonography(DCEUS)for preoperative T staging in patients with GC by comparing with multi-detector computed tomography(MDCT).METHODS This single prospective study enrolled patients with GC confirmed by preoperative gastroscopy from July 2021 to March 2023.Patients underwent DCEUS,including ultrasonography(US)and intravenous contrast-enhanced ultrasonography(CEUS),and MDCT examinations for the assessment of preoperative T staging.Features of GC were identified on DCEUS and criteria developed to evaluate T staging according to the 8th edition of AJCC cancer staging manual.The diagnostic performance of DCEUS was evaluated by comparing it with that of MDCT and surgical-pathological findings were considered as the gold standard.RESULTS A total of 229 patients with GC(80 T1,33 T2,59 T3 and 57 T4)were included.Overall accuracies were 86.9%for DCEUS and 61.1%for MDCT(P<0.001).DCEUS was superior to MDCT for T1(92.5%vs 70.0%,P<0.001),T2(72.7%vs 51.5%,P=0.041),T3(86.4%vs 45.8%,P<0.001)and T4(87.7%vs 70.2%,P=0.022)staging of GC.CONCLUSION DCEUS improved the diagnostic accuracy of preoperative T staging in patients with GC compared with MDCT,and constitutes a promising imaging modality for preoperative evaluation of GC to aid individualized treatment decision-making.

Effects of mesoclimate and microclimate variations mediated by high altitude and row orientation on sucrose metabolism and anthocyanin synthesis in grape berries

Climate change and extreme weather pose significant challenges to the traditional viticulture regions.Emerging high-altitude grape-producing regions with diverse orientations have shown great potential in coping with this challenge.Stable,high-quality wine grape production may be achieved by synchronizing the meso-and microclimate.To clarify the role of high altitude and row orientation in meso-and microclimate and the response of berries to it,we evaluated seven years(2012-2018)of climate data,two years of basic grape(Cabernet Sauvignon,Vitis vinifera L.)quality,and one-year microclimate from veraison to harvest.By comparing two locations(Sidon 2047 m,Sinon 2208 m)in Yunnan Province,China,we found that the average temperature has been stable at approximately 15℃ for seven years,with no extreme weather or,noticeable global warming.The light intensity(LI)in the north-south(NS)was more balanced than the east-west(EW)direction,and the east-west to the south(EW-S)canopy side was almost higher than the other sides.High LI was associated with high photosynthetically active radiation(PAR),ultraviolet(UV),and infrared(IR)light and vice versa.The north-south to the east(NS-E)and east-west to the north(EWN)sides were characterized by lower LI and higher UV and IR light,and higher total anthocyanin content.Most anthocyanin synthesis-related genes,for example,VvF3'H and VvF3'5'H,were highly expressed in NS-E from veraison to maturity.Perhaps UV and IR light induced their expression.This study provides new insights on the role of differently orientated rows in controlling grape quality due to varied light quality.The findings are globally significant,particularly in the context of climate change,and offer fresh insights into berry physiological responses and decision-making for the management of existing vineyards.

Inter-Row Spacing of PV Power Plant

When designing a solar power plant, it is much more important to avoid the shadow on the PV Panels. As the shadow falls on the PV Panels;it significantly reduces the generation of required power as planned and designed. This research paper and case study will help a lot to avoid shadow, especially when selecting inter-row spacing between the strings of solar power plants.

Utility of multi-detector row computed tomography angiography versus Doppler in localization of perforators of anterolateral thigh flaps

Aim:Anterolateral thigh(ALT)flap is widely used in reconstruction of various defects.Preoperative imaging facilitates perforator mapping,overcoming intraoperative uncertainty.The purpose of this study was to investigate the utility of multi-detector row computed tomography angiography(MDCTA)and a handheld Doppler in locating ALT perforators.Methods:Twenty patients were randomized into two groups.Group 1 patients received MDCTA and Doppler studies whereas Group 2 received only a Doppler study.The number,location,course,and source of all cutaneous and sizable perforators were compared with intraoperative findings.Surgeons’stress levels during flap harvest and flap harvest time were compared.Results:MDCTA findings correlated well with intraoperative findings for perforator type and segmental distribution with 100%concordance.Doppler alone had a 52%rate of concordance.The sensitivity and specificity for MDCTA in demonstrating the presence of perforators were 85.71%and 97.22%,respectively;whereas for Doppler alone the sensitivity and specificity were 80%and 87.91%,respectively.In demonstrating perforator source,MDCTA showed a sensitivity of 100%and specificity of 91.66%,with 100%accuracy.Sensitivity and specificity for sizable perforators were 90%each,with 88.88%accuracy.Doppler studies were unable to provide this information.Comparison of surgeon stress levels showed no differences between the two groups,although the time for flap harvest was significantly shorter in Group 1.Conclusion:MDCTA compared to Doppler is more sensitive,specific,and accurate with respect to location,course,and source of perforators.

Effects of Spatial Row Arrangement and Time of Planting Intercrops on Performance of Groundnut (Arachis hypogaea L.) under Maize (Zea mays L.)—Groundnut Intercropping System in Ejura

In monoculture, crop failure due to biotic or abiotic causes can result in partial or total output failure. The yield, socio-economic, and environmental effects of intercropping on the farmer and the environment as a whole have not received much attention. There is a dearth of knowledge on the productivity of maize-groundnut intercrops in Ghana regarding the relative timing of planting and spatial arrangement of component crops. Therefore, the objective of the study was to determine the effects of spatial row arrangement and the time of planting intercrops on the productivity of groundnut under maize-groundnut intercropping. The 5 × 3 factorial field experiment was undertaken at the Miminaso community in the Ejura-Sekyedumase municipality of the Ashanti Region of Ghana during the 2020 cropping seasons. Treatments were evaluated in a Randomized Complete Block Design (RCBD) with three replicates. The levels of row arrangement of intercrops were: one row of maize and one row of groundnut (1M1G), one row of maize and two rows of groundnut (1M2G), two rows of maize and one row of groundnut (2M1G), two rows of maize and two rows of groundnut (2M2G), sole maize and sole groundnut (M/G). The levels of time of introducing groundnut included simultaneous planting of intercrops (0 WAP), planting groundnut one week after planting maize (1 WAP) and planting groundnut two weeks after planting maize (2 WAP). There were significant (P 0.05) treatment interactions for pod and seed yields of groundnut throughout the study. The highest groundnut pod yields of 1815.00 kg/ha and 2359.00 kg/ha were recorded by the 0WAP × 1M2G treatment in the major and minor seasons of 2020, respectively, while the highest groundnut seed yields of 741.00 kg/ha and 726.00 kg/ha were recorded in the major and minor rainy seasons of 2020 by 1WAP × G and 0WAP × G treatments, respectively. The highest seed yields of groundnut (404 kg/ha and 637 kg/ha for major and minor rainy seasons, respectively) were produced by 1WAP × 2M2G.

软土地区基坑前排倾斜双排桩支护现场试验及工作机理

基坑倾斜桩支护大幅提高了无支撑支护结构的适用深度,具有造价低、施工便捷、绿色低碳、变形控制好等特点,然而目前研究多集中在单排倾斜桩,对前排倾斜双排桩支护的试验、理论与应用的研究均较少。针对前排倾斜双排桩支护基坑开展了现场试验,同时采用有限元方法分别从前排斜桩、桩顶连梁及桩间土体作用3个方面深入探究了前排倾斜双排桩支护的工作机理,进一步分析了直斜桩长度和排距对前排倾斜双排桩支护结构受力变形性能的影响。结果表明,相比传统竖直双排桩,前排倾斜双排桩支护结构的支护性能显著提升,前排斜桩主要发挥“斜撑”作用,连梁主要起到将直斜桩及冠梁连接成一个空间刚架的作用,桩间土体能够提高桩土摩阻力,进而有效减小前排倾斜双排桩变形。研究成果有助于前排倾斜双排桩的推广和应用。

Coronary Artery Anomalies Detected by Multi-Detector Computed Tomography: A Single Centre Experience

Background: Coronary artery anomalies (CAA) prevalence represents less than 1% of congenital heart diseases. It includes anomalies in origin, course, and termination. Its detection has been easier with advances in imaging techniques using multi-detector computed tomography (MDCT). MDCT helps not only detection of the anomalous origin, but it allows delineation of the course and termination of the arteries, differentiation between benign and malignant courses, and guiding therapeutic interventions. Results: There were consecutive patients with a low-to-intermediate probability of coronary artery disease scanned with 128 MDCT. Each patient underwent a non-contrast prospective gating acquisition for coronary calcium scoring followed by contrast-enhanced helical retrospective gated scans for the detection of coronary artery origin, course, termination, and detection of concomitant atherosclerosis. We scanned 1000 patients with a mean age of 57.5 ± 8.3, and 68% were males. Thirty-two anomalies were noted (3.2%) including;nineteen (1.9%) anomalous origin from the opposite sinus, three (0.3%) anomalous left coronary arteries from the pulmonary artery (ALCAPA), one (0.1%) super dominant left anterior descending artery (LAD) giving origin to the posterior descending artery (PDA), three single coronary arteries (0.3%)in which the left main (LM) and right coronary arteries were originating with a common stem from the right coronary sinus (RCS)and the LM took a pre-pulmonic course. Along with six (0.6%) dual LAD including five (0.5%) patients with type I (short LAD and long diagonal), there was one (0.1%) type 4 with an extra LAD originating from the RCS with a pre-pulmonic course. Conclusions: MDCT allows easy detection of coronary anomalies with high spatial resolution and overcomes limitations in conventional invasive coronary angiography. Based on our study we recommend the use of MDCT as an efficient and feasible modality for the diagnosis of coronary anomalies once this pathology is clinically suspected.

气吸双行错置式玉米密植精量排种器设计与试验

针对大豆-玉米复合密植播种模式下传统气吸式排种器单行种盘高转速作业导致充种时间短、气流稳定性差,难以实现高速精量密植播种的问题,设计了一种气吸双行错置式玉米密植精量排种器,阐述了排种器结构与工作原理,对其工作过程及关键部件进行理论分析,构建充种和投种环节的种子力学模型,确定排种盘内外环型孔排布、投种轮、气室等关键结构参数,并开展单、双气道内负压分布、型孔内气流场特性分析,基于DEM-CFD耦合方法对排种器的排种过程进行仿真分析,以作业速度、气室结构和负压为试验因素,充种合格指数、重充指数和漏充指数为评价指标,优选出最优气室结构。通过台架试验开展不同气吸式排种器排种性能对比试验。试验结果表明,在作业速度为5~10 km/h的高速密植工况下,气吸双行错置式密植精量排种器排种合格指数均大于88.7%,且作业速度为10 km/h时,相较于常用单圆环气吸式排种器合格指数提高5.5个百分点,漏播指数降低5.6个百分点;田间试验结果表明,在作业速度为5 km/h下,播种合格指数为95.7%,重播指数为1.6%,漏播指数为2.8%。提出的气吸双行错置式玉米密植精量排种器在高速作业时拥有良好的排种性能,能够满足大豆-玉米高速精量密植播种要求。

肩关节镜下双排缝合桥技术治疗老年肩袖损伤46例

目的 探讨肩关节镜下双排缝合桥修复手术对老年肩袖损伤病人疼痛、手臂与肩部功能障碍(DASH)评分及再撕裂发生率的影响。方法 回顾性分析2018年8月至2020年2月阜阳市第二人民医院收治的89例老年肩袖损伤病人的临床资料,依照手术方法的不同划分成对照组(肩关节镜下单排铆钉固定)、治疗组(肩关节镜下双排缝合桥修复手术),分别为43例、46例。于术前、术后1年采用视觉模拟评分法(VAS)评定患肩疼痛度,采用手臂与肩部功能障碍(DASH)评分量表评定肩关节功能,测量患肩关节前屈、外展活动度,并统计两组1年内再撕裂发生率。通过logistic回归分析确定病人术后再撕裂发生的影响因素。结果 术后1年两组不同撕裂程度病人VAS、DASH评分及患肩关节前屈、外展活动度与同组术前相比均明显改善(均P<0.05),术后两组轻度撕裂病人上述指标改善情况比较差异无统计学意义(均P>0.05),而治疗组中、重度撕裂病人上述指标改善情况均明显较对照组优(均P<0.05);治疗组再撕裂发生率4.35%明显较对照组的23.26%低(P<0.05);年龄、手术方式是病人术后再撕裂发生的影响因素(均P<0.05)。结论 对老年肩袖损伤病人实施肩关节镜下双排缝合桥修复手术,可有效改善患肩疼痛及功能,显著降低再撕裂发生率。

五部中国当代音乐作品中的音列思维探赜

“音列-特定结构模式的音的横向集合体”是作曲家个性化音高组织的基础性材料之一,“音列思维”是指作曲家在创作中恪守特定结构音列的音高组织思维方法。沈葉的唢呐协奏曲《一枝花》、姚晨的管弦乐曲《造园》、张千一的交响套曲《我的祖国》第四乐章《春到边寨》、秦文琛为管弦乐队而作的舞蹈组曲《伶伦作乐图》、郭文景的六重奏《寒山》,上述作品虽然在创作观念、精神内涵、表现内容、写作技法等方面各具特色,但在音高组织思维,即结构的深层次方面,表现出可供探讨的共性问题——音列思维。

基于四行精密播种的玉米直播机设计与试验

为了解决播种玉米种子精度低的问题,设计了一款基于四行精密播种的玉米直播机,可实现玉米种子快速、精准播种。试验表明:该玉米直播机移动性能好、播种速度快、种植深度和每穴种子数量更加准确,封土情况也大幅改善,符合设计需求,具有较高的可靠性和可行性。

关节镜下单排与双排缝合桥技术治疗肩胛下肌腱损伤的临床研究

目的探究关节镜下采用单排与双排缝合桥固定技术治疗肩胛下肌腱损伤的疗效。方法回顾性分析自2018年1月至2020年6月沧州市中心医院采用全关节镜修复治疗的40例肩胛下肌腱损伤患者资料。其中,男23例,女17例;年龄39~70岁,平均(55.25±6.82)岁。依据术中肩胛下肌腱的固定方式分为双排缝合桥固定组(双排组,20例)和单排缝合固定组(单排组,20例)。记录缝合时间、疼痛视觉模拟评分(visual analogue scale,VAS)、美国肩与肘协会评分系统(American Shoulder and Elbow Scoring System,ASES)、洛杉矶加利福尼亚肩关节分级评分(University of California at Los Angeles,UCLA),评估患者术前及术后1年时肩关节功能情况,并应用改良Sugaya分级法评估术后1年肩胛下肌腱愈合和再撕裂情况。结果所有病例获得随访,随访时间12~53个月,平均19.80个月。双排组患者肩胛下肌腱缝合时间多于单排组,差异有统计学意义(P<0.05)。术后1年双排缝合桥固定组的VAS评分[(1.30±0.57)分]、ASES评分[(70.92±5.65)分]、UCLA评分[(26.52±6.88)分]与术前相比明显改善,差异有统计学意义(P<0.05);术后1年单排缝合固定组VAS评分[(1.55±0.69)分]、ASES评分[(70.14±5.46)分]、UCLA评分[(26.89±7.78)分]与术前相比有明显改善,差异有统计学意义(P<0.05)。但术后1年两组间在VAS评分、ASES评分、UCLA评分方面比较,差异均无统计学意义(P>0.05)。根据改良Sugaya分级法,双排组术后1年核磁检查肌腱愈合良好,有1例再撕裂病例,单排组有2例再撕裂病例,两组术后1年肩胛下肌再撕裂情况比较,差异无统计学意义(P>0.05)。结论关节镜下采用单排和双排缝合桥技术修复肩胛下肌腱损伤均可获得满意的临床疗效和较低的再撕裂率。双排缝合固定肩胛下肌腱需要一定的手术技巧,缝合固定时间多于单排缝合方式。

取秧侧向零偏移的空间轨迹再生稻分插机构设计与试验

为了解决现有空间行星轮系式分插机构在再生稻宽窄行机械化种植取秧过程中出现侧向偏移量和侧向偏转角的技术难题,本文提出一种具有局部平面轨迹特性的空间轨迹不等速行星轮系机构,并开展基于取秧口和机构回转中心位置约束下的宽窄行分插机构综合研究。构建了基于关键位姿点(取秧起始点、取秧结束点、推秧点)的空间轮系机构运动综合模型,利用关键位姿点求解机构杆长参数与空间交错轴信息,并通过优选二杆相对角位移参数实现机构传动比分配。将不完全非圆齿轮副引入空间行星轮系机构,利用间歇机构锁止弧约束行星轴,实现机构取秧过程侧向零偏移量、侧向零偏转角的平面轨迹段。通过仿真分析与机构样机试验验证了机构实际作业性能与理论设计相一致,结果表明:分插机构取秧侧向零偏移量,取秧侧向零偏转角,推秧侧向总偏移量为50.24 mm、取秧角为5.18°、推秧角为71.56°、推秧侧向角为16.26°、插秧穴口宽度为22.43 mm、轨迹高度为289.76 mm,满足预期设计要求。最后通过田间试验验证,分插机构可实现等行距取秧口和既定机构回转中心下宽行(40 cm)与窄行(20 cm)间隔机插,满足再生稻宽窄行种植要求。

大豆垄上三行密植行间除草装置设计与试验

针对大豆垄上三行密植种植模式下,苗带间距较小,现有除草装置行间除草率低、伤苗率高、中耕除草作业困难等问题,设计了一种大豆垄上三行密植行间除草装置,主要由定位圆盘、弹齿固定连杆和弹齿等组成。根据中耕时期大豆苗和杂草的生长状态,确定了定位圆盘和除草装置的安装距离;通过对弹齿除草过程进行动力学分析,建立弹齿入土部分曲线方程,并对弹齿进行运动学分析;以圆周弹齿组数、弹齿入土角和轴向弹齿个数为试验因素,松土率和弹齿平均工作阻力为指标,利用离散元仿真方法进行Box-Behnken多因素试验,得到圆周弹齿组数为10、弹齿入土角为80°、轴向弹齿个数为5,具有最佳效果。以机具前进速度、除草组件转速和入土深度为试验因素,以除草率和伤苗率为评价指标,对除草装置进行单因素田间性能试验,结果表明:当除草深度35mm、机具前进速度2.5km/h时,平均除草率、伤苗率分别为88.24%、2.77%,机具作业性能稳定,未出现堵塞现象,满足大豆行间除草农艺要求。

不同大麦品种籽粒营养成分分析

为发掘更多高营养成分大麦品种和优质亲本,以526份国内外大麦品种为材料,鉴定了其皮裸性、棱型、籽粒颜色等性状,使用近红外光谱法和分光光度法测定其籽粒β-葡聚糖、蛋白质、淀粉、直链淀粉、总黄酮、生物碱、γ-氨基丁酸和抗性淀粉8种营养成分含量。结果表明,基因型对大麦籽粒营养成分含量影响显著(P<0.05)。二棱皮大麦的β-葡聚糖含量显著高于六棱裸麦;二棱黄色大麦蛋白质含量显著高于六棱非黄色大麦,淀粉含量显著低于六棱黄色大麦;裸大麦直链淀粉含量显著高于皮大麦,六棱非黄色裸大麦γ-氨基丁酸、总黄酮含量显著高于二棱黄色皮大麦;六棱非黄色皮大麦生物碱含量显著高于二棱黄色裸大麦;非黄色裸大麦抗性淀粉含量显著高于黄色皮麦。526份大麦品种被聚类为5个类群。8个营养成分最高大麦品种分别为CBSS05Y00293S(高β-葡聚糖)、福贡白青稞(高蛋白质)、云啤21号(高淀粉)、云啤10号(高直链淀粉)、宽颖大麦(高γ-氨基丁酸)、冬青17号(高总黄酮)、碧江大麦-1(高生物碱)和景东米大麦(高抗性淀粉)。