A non-inferiority study comparing the ultrasound-guided parasacral with a novel greater ischiatic notch plane approach in canine cadavers

ObjectiveTo describe the gross and ultrasound anatomy of the parasacral region and an ultrasound-guided greater ischiatic notch (GIN) plane approach aimed at staining the lumbosacral trunk (LST) in canine cadavers. To evaluate if the ultrasound-guided GIN plane approach is non-inferior to the previously described ultrasound-guided parasacral approach at staining the LST.Study designProspective, randomized, non-inferiority experimental anatomic study.AnimalsA total of 17 (23.9 ± 5.2 kg) mesocephalic canine cadavers.MethodsAnatomic and echographic landmarks, and the feasibility of performing a GIN plane technique were evaluated using two canine cadavers. The remaining 15 cadavers had each hemipelvis randomly assigned to be administered either parasacral or GIN plane injection of 0.15 mL kg^–1 dye solution. The parasacral region was dissected after injections to assess the staining of LST, cranial gluteal nerve, pararectal fossa and pelvic cavity. The stained LST were removed and processed for histological evaluation of intraneural injections. A one-sided z-test for non-inferiority (non-inferiority margin –14%) was used to statistically evaluate the success of the GIN plane versus the parasacral approach. Data were considered statistically significant when p < 0.05.ResultsThe GIN plane and parasacral approach stained the LST in 100% and 93.3% of the injections, respectively. The success rate difference between treatments was 6.7% [95% confidence interval, –0.6 to 19.0%; p < 0.001 for non-inferiority]. The GIN plane and parasacral injections stained the LST for 32.7 ± 16.8 mm and 43.1 ± 24.3 mm, respectively (p = 0.18). No evidence of intraneural injection was found.Conclusions and clinical relevanceThe ultrasound-guided GIN plane technique resulted in nerve staining that was non-inferior to the parasacral technique and may be considered an alternative to the parasacral approach to block the LST in dogs.     

半干旱草甸草地不同处理下植被特征与土壤酶活性的变化

不同草地处理措施对植被和土壤会产生重要的影响。为探究不同草地处理措施对草甸草地的影响,以科尔沁草甸草地不同点为研究对象,设置围封（UNM）、围封+刈割（M）、围封+火烧（F）、放牧（G）4种处理,针对生长季土壤脲酶（S-UE）、碱性磷酸酶（S-AKP）、蔗糖酶（S-SC）活性和植被特征等开展研究,以探究草甸草地的最佳处理方式。结果显示：1）土壤酶活性随着土层深度的增加而降低,不同处理间的差异随着土层深度增加逐渐降低。2）放牧较围封处理,不同点植被高度、盖度、地上生物量和酶活性均降低,而丰富度指数增加。3）刈割较围封处理,不同功能群物种的补偿能力不同,禾本科的补偿能力大于菊科。4）火烧较围封处理,不同点植被高度、盖度、地上生物量、丰富度指数和3种水解酶活性均增加。5）多年刈割较放牧处理,植被高度、盖度和地上生物量和蔗糖酶、碱性磷酸酶活性均增加,丰富度指数和土壤脲酶活性均降低。综上所述,控制性火烧是半干旱地区草甸草地的最佳处理方式。     

考虑陀螺效应的动力总成悬置系统分析和优化

应用陀螺力学理论，对传统动力总成悬置系统的无阻尼动力学方程进行修正，引入陀螺矩阵，得到新的动力学方程。对新的动力总成悬置系统动力学模型进行计算分析，研究了陀螺矩阵对频域、时域响应的影响。使用遗传算法分别对修改前后的方程进行优化计算，并进行比较分析。结果表明，对于低转速发动机，曲轴转动的陀螺效应不明显，而对于高转速的发动机，陀螺效应不能忽略，应以考虑陀螺力矩的方程为基础进行设计分析。     

FLUENT软件及其在植保机械方面的应用

FLUENT软件是流体力学中通用性较强的商业软件之一，由于FLUENT软件的应用，节省了大量的人力和物力。对实际应用有重大的指导作用。为此，通过简述FLUENT在植保机械方面的应用实例，提出了FLUENT在植保机械方面的发展前景。     

陆地棉品种间杂种苏杂16棉铃发育动态研究

棉铃发育过程中，苏杂１６单铃子棉主的提高表现为二个方面：一是纤维干重的增加，１９９１～１９９２两年平均增加１０．０％；二是种子重量的提高，两年平均单铃种仁重增加９．４％。单铃纤维干重的增长与棉铃对位叶大小呈正相关关系，与棉铃对位叶中全Ｎ含量呈负相关关系．该杂文组合在棉铃发育过程中表现了较强的“源”“库”生理优势，光合产物积累多，营养物质运转快是该组合获得高产的重要生理基础。     

Numerical Analysis and Optimization of a Small Vehicle Heat Exchanger

This paper analyzes the fluid flow and heat transfer of the heat exchanger, and obtainsd the distribution of fluid field, heat field and pressure field in heat exchanger. According the analysis result, some modify measure is adopted, such as decreasing the number of tube bundle, the size of baffle plate and increasing the diameter of exchange heat tube. In the new heat exchanger, the resistance decreased 32.3%, is 103.2 Pa and the temperature of the exit is 130 K. The new heat exchanger satisfies the requirement of exchanging heat. The study indicates that adopting the numerical simulation method could get temperature, pressure and fluid - velocity of anywhere of the heat exchanger, and understand effecfing of structure parameter on fluid flied and heat flied of the heat exchanger. Therefore, it provides a new method for optimization design of heat exchanger.     

ANALYTIC SOLUTION OF CYLINDRICAL SHELL ROOF UNDER GENERAL TRANSVERSE LOCAL LOADINGS

This paper uses the method of mixed-type series to derive the analyticsolution of cylindrical shell roof,being simply supported transversely,arbitra-rily restrained longitudinally and subjected to gereral transverse local loads.This paper also presents the analytic expressions of the solutions for somekinds of local load.Some examples of this kind of shell roof subjected to ainlined single force near the middle of it with free lorgitudinal edges aregiven.The computation shows that the convergence of the solution is woll     

A NEW METHOD BY USING MASS AND ACCELERATION PARAMETERS FOR BALANCING INERTIAL FORCE OF MECHANISM

This paper presents a new method by using mass and acceleration parameters for balancing inertial force of mechanism. Compared with other balance methods, this one is simple, clear and superior in regularity when the balancing equation of complex mechanism is established, and its solving procedure is also easy. The new methcd is convenient to learn and use as well as convenient to program.     

Vehicle Lateral Stability Control Based on Sliding Model Control

In view of the vehicle cornering or path changing under ultimate handling maneuver, a 3-DOF nonlinear vehicle dynamics model which takes the vehicle lateral velocity, yaw rate and body roll angle as the State variables is presented. Based on the dynamic analysis, the method which using additional yaw moment produced by different longitudinal braking force among each wheels to improving vehicle handling stability in emergency situations is discussed. Considering the sideslip angle as one of the vehicle state variables is difficult to measuring, the sideslip angle estimation based on vehicle dynamic model and kinematics is designed. And then, based on the theory of siding model control, the combining sliding model control system is founded, which taking the vehicle yaw rate and body side-slip angle errors between the estimated and the real as the input variables, and taking the braking torque and the steering angle as control aims. The simulation results indicate that the control method can effectively improve the vehicle lateral handling stability.     

Computation of Three-Dimensional Temperature Distribution and Thermal Analysis to Integrated Circuit Substrates

The exact three di me nsional temperatu re distribution and thermal analysiS to inte-grated circuit substrates have been presen ted by means of numerical method of a fin ite difference.Thismethed.which will overcome the di fficuItv of mathematical deduction mav be consltieredas an analytical way aided by com puters for thermal design of electron ic compon ents.