他汀类药物用于非酒精性脂肪性肝病的疗效与安全性的Meta分析及GRADE评价

目的:系统评价他汀类药物用于非酒精性脂肪性肝病(NAFLD)的疗效与安全性,为临床合理用药提供参考。方法:计算机检索PubMed、Embase、the Cochrane Library、MEDLINE、中国生物医学文献数据库、万方数据库、中国知网、维普数据库等,收集他汀类药物治疗NAFLD的随机对照试验(RCT,观察组干预措施为他汀类药物,对照组干预措施为非他汀类药物或安慰剂、生活方式干预),不限他汀类药物的品种、剂量及用药持续时间,检索时限为建库至2022年7月。2名评价员根据纳入与排除标准筛选文献并提取数据,采用RevMan 5.4和GRAED pro3.6软件分析数据。结果:纳入7项RCT(6篇中文,1篇英文),共1121例NAFLD患者。Meta分析结果显示,与对照组干预措施比较,他汀类药物可显著降低NAFLD患者的肝酶水平(丙氨酸转氨酶:WMD=-10.45,95%CI=-15.49~-5.41,P<0.0001;天冬氨酸转氨酶:WMD=-9.59,95%CI=-13.03~-6.15,P<0.00001;γ-谷氨酰转移酶:WMD=-6.37,95%CI=-9.90~-2.84,P=0.0004),改善血脂指标水平(总胆固醇:WMD=-0.80,95%CI=-1.07~-0.53,P<0.00001;三酰甘油:WMD=-0.32,95%CI=-0.41~-0.24,P<0.00001;低密度脂蛋白胆固醇:WMD=-0.59,95%CI=-1.03~-0.15,P=0.009;高密度脂蛋白胆固醇:WMD=0.54,95%CI=0.15~0.93,P=0.007),改善肝脏组织学变化(OR=2.79,95%CI=1.59~4.90,P=0.0004),差异均有统计学意义。安全性方面,两组患者均无严重不良反应发生,两组患者不良反应发生率的差异无统计学意义(OR=1.00,95%CI=0.44~2.27,P>0.05)。敏感性分析中,除低密度脂蛋白胆固醇外,其余指标结果稳健。GRADE证据评估结果显示,三酰甘油为中级证据质量,其余结局指标为低等级或极低等级证据质量。结论:基于本研究的情况,他汀类药物在NAFLD的治疗中可发挥积极作用,可降低肝酶水平,改善血脂指标水平和肝脏脂肪浸润程度,耐受性良好。但本研究纳入研究数量不足且对他汀类药物品种、给药剂量及多种潜在药物相互作用研究不充分,未来有待进一步研究。

Safety Evaluation of Myricetin and Crude Extract from Myrica rubra Leaves on Non-target Organisms

[ Objective] The study aimed to supply important basis for developing environment-friendly pesticides with myricetin and crude extract of Myrica rubra leaves as effective components. [ Method] According to ＂Test guidelines for environmental safety evaluation on chemical pesticides＂, the toxicity of myricetin and crude extract of M. rubra leaves on non-target organisms was determined and the safety evaluation was carried out. [Result] MyriceUn and crude extract of M. rubra leaves had low toxicity on non-target organisms, such as earthworm, silkworm and soil microbes. Myricetin showed low toxicity and the crude extract of M. rubra leaves showed middle toxicity on tadpole. The high-concentration crude extract of M. rubra leaves had some antifeedant effect on silkworm. [ Conclusion] Myricetin and crude extract of M. rubra leaves had low toxicity on non-tar- get organisms in environment and they were relatively safe.

The nonlocal solution of two parallel cracks in functionally graded materials subjected to harmonic anti-plane shear waves

In this paper, the dynamic interaction of two parallel cracks in functionally graded materials （FGMs） is investigated by means of the non-local theory. To make the analysis tractable, the shear modulus and the material density are assumed to vary exponentially with the coordinate vertical to the crack. To reduce mathematical difficulties, a one-dimensional non-local kernel is used instead of a twodimensional one for the dynamic problem to obtain stress fields near the crack tips. By use of the Fourier transform, the problem can be solved with the help of two pairs of dual integral equations, in which the unknown variables are the jumps of displacements across the crack surfaces. To solve the dual integral equations, the jumps of displacements across the crack surfaces are expanded in a series of Jacobi polynomials. Unlike the classical elasticity solutions, it is found that no stress singularity is present at the crack tips. The non-local elastic solutions yield a finite hoop stress at the crack tips. The present result provides theoretical references helpful for evaluating relevant strength and preventing material failure of FGMs with initial cracks. The magnitude of the finite stress field depends on relevant parameters, such as the crack length, the distance between two parallel cracks, the parameter describing the FGMs, the frequency of the incident waves and the lattice parameter of materials.

Free vibration of non-uniform axially functionally graded beams using the asymptotic development method

The asymptotic development method is applied to analyze the free vibration of non-uniform axially functionally graded(AFG) beams, of which the governing equations are differential equations with variable coefficients. By decomposing the variable flexural stiffness and mass per unit length into reference invariant and variant parts, the perturbation theory is introduced to obtain an approximate analytical formula of the natural frequencies of the non-uniform AFG beams with different boundary conditions.Furthermore, assuming polynomial distributions of Young's modulus and the mass density, the numerical results of the AFG beams with various taper ratios are obtained and compared with the published literature results. The discussion results illustrate that the proposed method yields an effective estimate of the first three order natural frequencies for the AFG tapered beams. However, the errors increase with the increase in the mode orders especially for the cases with variable heights. In brief, the asymptotic development method is verified to be simple and efficient to analytically study the free vibration of non-uniform AFG beams, and it could be used to analyze any tapered beams with an arbitrary varying cross width.

Recursive Partitioning Analysis Classification and Graded Prognostic Assessment for Non-Small Cell Lung Cancer Patients with Brain Metastasis:A Retrospective Cohort Study

Objective：To assess prognostic factors and validate the effectiveness of recursive partitioning analysis （RPA） classes and graded prognostic assessment （GPA） in 290 non-small cell lung cancer （NSCLC） patients with brain metastasis （BM）.Methods：From Jan 2008 to Dec 2009,the clinical data of 290 NSCLC cases with BM treated with multiple modalities including brain irradiation,systemic chemotherapy and tyrosine kinase inhibitors （TKIs） in two institutes were analyzed.Survival was estimated by Kaplan-Meier method.The differences of survival rates in subgroups were assayed using log-rank test.Multivariate Cox＇s regression method was used to analyze the impact of prognostic factors on survival.Two prognostic indexes models （RPA and GPA） were validated respectively.Results：All patients were followed up for 1-44 months,the median survival time after brain irradiation and its corresponding 95% confidence interval （95% CI） was 14 （12.3-15.8） months.1-,2-and 3-year survival rates in the whole group were 56.0%,28.3%,and 12.0%,respectively.The survival curves of subgroups,stratified by both RPA and GPA,were significantly different （P0.001）.In the multivariate analysis as RPA and GPA entered Cox＇s regression model,Karnofsky performance status （KPS） ≥ 70,adenocarcinoma subtype,longer administration of TKIs remained their prognostic significance,RPA classes and GPA also appeared in the prognostic model.Conclusion：KPS ≥70,adenocarcinoma subtype,longer treatment of molecular targeted drug,and RPA classes and GPA are the independent prognostic factors affecting the survival rates of NSCLC patients with BM.

Development of top high-grade non-grain-oriented silicon steels at Baosteel

The development, production and application of top high-grade non-grain-oriented （NGO） silicon steels at Baosteel were introduced in this paper. Top high grades refer to the highest grades in the intemational silicon steel product standard and above. B35A230 and B50A250 were developed at Baosteel in 2009 and have been used in inverter compressors for air-conditioners, small transformers and big hydropower generators in the Three Gorges project. Small- batch production of B35A210 and B50A230, which exceed the highest grades listed in the intemational silicon steel product standard,began in 2010. That was a breakthrough in the silicon steel making history in China. Presently,Baosteel＇ s high- grade NGO products have passed the strict qualifications of the three major electric power equipment manufacturers in China and the leading international power equipment suppliers like ALSTOM, GE, SIEMENS, VESTAS, etc. These products are characterized by low iron loss, low anisotropy, good punchability and a high lamination factor. They have been used in the 770 MW hydropower generator at Xiluodu Power Station in the three gorges area, 1 000 MW thermal power generators and 2.5 MW wind power generators.

Low Dose Total Body Irradiation for Relapsed Low Grade Non-Hodgkin’s Lymphoma: Experience of National Cancer Institute, Cairo

Background and Purpose: The relapsed low grade non-Hodgkin’s lymphoma (LG-NHL) is currently?incurable disease and the optimal treatment regimen has not determined yet. Low dose total body irradiation (LTBI) provides an alternative mechanism of action against cancer cells rather than direct cell kill. The mode of action of LTBI is immune-modulatory effect, induction of apoptosis and?hypersensitivity to low radiation doses. The aim of our study is to evaluate the effect of LTBI on relapsed?LG-NHL and reporting our experience at National Cancer Institute, Cairo (NCI, Cairo). Material and Methods: Fifty eight patients with relapsed LG-NHL and received LTBI studied retrospectively.?LTBI dose was 1.6 Gy/8 fractions divided on 2 courses;each course 4 fractions treated over 4 days with 2 weeks rest between the 2 courses. Results: The median age is 54 years;65% of the patients are men. Forty (69%) patients had performance status of 2 or more. Twenty seven patients were stage II/III and 31 patients (53%) had stage IV disease. Twenty six (45%) patients had bulky disease more than 10 cm and 22 (38%) patients had B symptoms at the time of relapse. The?extranodal disease was present in 17 patients (29%) and 78% of the patients received?>3 regimens of chemotherapy before referral to LTBI. Twenty three patients received IFRT (mean dose 32 ± 4 Gy) to initially bulky sites after LTBI. Fourteen patients (24%) achieved complete remission (CR) while 45%, 21% and 10% had partial remission (PR), stable disease (SD) and progressive disease (PD) respectively. The median PFS duration was 14 months and the median OS duration?was 39 months. Stage VI,?>3 regimen of chemotherapy and bad response to LTBI (SD) affected?progression duration adversely (0.03, 0.05 and 0.01 respectively). The response to LTBI is the only factor affected the OS duration significantly. The 3-year PFS was 19% ± 9%, and 3-year OS was 45% ± 8%. Stage IV was the only factor affected the 3-year PFS significantly with p value 0.03. The hematological toxicity was the main side effect of LTBI. Eleven patients developed G3/4 anemia while 8 patients only developed G3/4 thrombocytopenia and 13 patients developed G3/4 leucopenia. Conclusion: The use of LTBI in patients with relapsed low grade NHL is a feasible, effective and tolerable treatment that is worthy of testing in a future with chemotherapy and Rituximab maintenance.

Thermoelastic Analysis of Non-uniform Pressurized Functionally Graded Cylinder with Variable Thickness Using First Order Shear Deformation Theory(FSDT) and Perturbation Method

Recently application of functionally graded materials（FGMs） have attracted a great deal of interest. These materials are composed of various materials with different micro-structures which can vary spatially in FGMs. Such composites with varying thickness and non-uniform pressure can be used in the aerospace engineering. Therefore, analysis of such composite is of high importance in engineering problems. Thermoelastic analysis of functionally graded cylinder with variable thickness under non-uniform pressure is considered. First order shear deformation theory and total potential energy approach is applied to obtain the governing equations of non-homogeneous cylinder. Considering the inner and outer solutions, perturbation series are applied to solve the governing equations. Outer solution for out of boundaries and more sensitive variable in inner solution at the boundaries are considered. Combining of inner and outer solution for near and far points from boundaries leads to high accurate displacement field distribution. The main aim of this paper is to show the capability of matched asymptotic solution for different non-homogeneous cylinders with different shapes and different non-uniform pressures. The results can be used to design the optimum thickness of the cylinder and also some properties such as high temperature residence by applying non-homogeneous material.

Maligned non-steroidal anti-inflammatory drugs:Misunderstanding of their safety profile in patients with renal insufficiency

Non-steroidal anti-inflammatory drugs have a fundamental and pivotal position in management of many of the disorders managed by rheumatologists.Promulgation of a false perspective of their toxicity has compromised our ability to advise our patients and participate in the management of their disorders. The literature sources, from which the false perspective derives, do not accurately reflect safety and fail to address the value of appropriate drug use monitoring.We, as rheumatologists, must stand up and proactively address engrained misconceptions-if we are to be able to continue to provide safe, effective care for our patients.

Thermo-electromechanical behavior of functionally graded piezoelectric hollow cylinder under non-axisymmetric loads

This paper presents an analytical solution of a thick walled cylinder composed of a functionally graded piezoelectric material （FGPM） and subjected to a uniform electric field and non-axisymmetric thermo-mechanical loads. All material properties, except Poisson＇s ratio that is assumed to be constant, obey the same power law. An exact solution for the resulting Navier equations is developed by the separation of variables and complex Fourier series. Stress and strain distributions and a displacement field through the cylinder are obtained by this technique. To examine the analytical approach, different examples are solved by this method, and the results are discussed.

Failure Mode and Effects Analysis Based on Z-Numbers and the Graded Mean Integration Representation

Failuremode and effects analysis(FMEA)is a widely used safety assessmentmethod inmany fields.Z-number was previously applied in FMEA since it can take both possibility and reliability of information into consideration.However,the use of fuzzy weighted mean to integrate Z-valuations may have some drawbacks and is not suitable for some situations.In this paper,an improved method is proposed based on Z-numbers and the graded mean integration representation(GMIR)to deal with the uncertain information in FMEA.First,Z-numbers are constructed based on the evaluations of risk factors O,S,D for each failure mode by different experts.Second,weights of the three risk factors and experts are determined.Third,the integration representations of Z-numbers are obtained by a newmethod based on the GMIRmethod.Finally,risk priorities of the failure modes are derived considering the weights of experts and risk factors.Two examples and a case study are given to show the use of the proposed method and comparison with other methods.The results show that the proposed method is more reasonable,universal and simple in calculation.

Low-Dose Involved-Field Radiotherapy in Relapsed Low-Grade Non-Hodgkin's Lymphoma in Elderly Patients (Mansoura University Experience)

Purpose: To assess the response rate, duration of response and prognostic factors affecting response after low-dose involved-field radiotherapy in patients with relapsed low-grade B-cell non-Hodgkin lymphoma. Patients and Methods: Forty-four patients were included. Patients were treated with a total dose of 4 Gy (2 × 2 Gy) using 6 - 15 Mv photon or electron beam. Results: most patients were above age of 60 years (59%) with male predominance. Follicular lymphoma was the most common pathological type;bulky disease (>5 cm) was presented in 61.4%. Patients who received only 2 regimens were 63.7% and 31.8% had >2 involved sites. No treatment related toxicity was observed. The overall response rate was 88.7%;complete response was reached in 59.1% and stable disease in 6.8%, progressive disease in 4.5%. Median time to local progression was 33 months (95% CI 23.70 - 42.29);2-year local progression free survival was 78%. Response rate was found to be dependent on age, number of involved sites and lymph node size but independent on sex, pathological type, number of prior regimens, LDH level and time since diagnosis. Conclusion: Short-course-low dose palliative radiotherapy (2 × 2 Gy) affords an attractive option for treatment of relapsed low-grade non-Hodgkin’s lymphoma due to high response rates. However, these results had to be confirmed in a larger number of patients.

Investigation of third-grade non-Newtonian blood flow in arteries under periodic body acceleration using multi-step differential transformation method

In this paper, a non-Newtonian third-grade blood in coronary and femoral arteries is simulated analytically and numerically. The blood is considered as the third- grade non-Newtonian fluid under the periodic body acceleration motion and the pulsatile pressure gradient. The hybrid multi-step differential transformation method （Hybrid-Ms- DTM） and the Crank-Nicholson method （CNM） are used to solve the partial differential equation （PDE）, and a good agreement between them is observed in the results. The effects of the some physical parameters such as the amplitude, the lead angle, and the body acceleration frequency on the velocity and shear stress profiles are considered. The results show that increasing the amplitude, Ag, and reducing the lead angle of body acceleration, 9, make higher velocity profiles on the center line of both arteries. Also, the maximum wall shear stress increases when Ag increases.

草莓悬挂输送无损分级系统的设计与试验

为解决目前鲜食草莓人工分级效率低,自动化分级易损伤的问题,设计一套草莓悬挂输送无损分级系统。在要求草莓留梗采摘的基础上,设计果梗夹持机构;根据分级功能需求,设计转移上料机构、双链循环输送机构、缓存下料机构,以实现草莓的无损输送。再配合内、外观品质检测模块,即可实现草莓品质分级。以直径30~50 mm,质量20~50 g的草莓为研究对象,根据内、外品质检测结果,将其划分为7个等级,并分别下料包装。草莓外部品质检测采用机器视觉,提取草莓大小、颜色、形状等外观信息;内部品质检测采用近红外光谱,检测可溶性固形物含量;根据分级结果,将其分别输送至对应下料机构进行下料包装。研究为草莓类柔嫩果皮果实的无损分级装备开发提供新的解决方案。

Occupational Health and Safety Hazards Experienced by Healthcare Workers at Two Hospitals in Suyani, Bono Region, Ghana

INTRODUCTION Occupational safety and health (OSH) is generally the anticipation, recognition, evaluation, and control of hazards arising in or from the workplace. The study sought to assess and evaluate occupational health and safety hazards experienced among health workers in the Bono region of Ghana. METHODOLOGY The study was descriptive cross-sectional quantitative study. Data was from two hundred (200) health workers and was analyzed using the binary logistic regression analysis. RESULTS The findings from the study show that risk factors associated with biological hazards were clinical staff [OR = 2.487 (1.146 - 5.397), p = 0.021], poor maintenance of hospital items [OR = 0.446 (0.240 - 0.831), p = 0.011], assault (verbal) abuse [OR = 2.581 (1.317 - 5.059), p = 0.006] and extreme pressure from work [OR = 2.975 (1.519 - 5.829), p = 0.001]. Non-biological hazards were associated with being single [OR = 0.499 (0.263 - 0.947), p = 0.034], being verbally assaulted [OR = 3.581 (1.865 - 6.876), p CONCLUSION Risk factors related with biological hazards include poor maintenance of hospital items and extreme pressure from work whereas non-biological hazards were associated with being single, being verbally assaulted. Clinical healthcare providers are more vulnerable to occupational health and safety hazards. The study recommends the provision of strategic policies to promote and protect the workers’ health based on the development of the epidemiological profile of health, needs to be readjusted and strengthened.

ALK突变晚期非小细胞肺癌靶向治疗耐药后帕博利珠单抗治疗的新探索

目的探索间变性淋巴瘤激酶(ALK)突变晚期非小细胞肺癌(NSCLC)靶向治疗耐药后帕博利珠单抗治疗的效果。方法本方案采用前瞻性、对照、单中心、随机、单盲临床研究方法设计。选择2020年3月至2022年7月在西安高新医院就诊的95例ALK突变晚期NSCLC靶向治疗耐药后患者,以随机数字表法分为对照组和试验组。对照组入组47例,脱落2例,最终45例纳入分析;试验组入组48例,脱落2例,最终46例纳入分析。对照组男29例,女16例;年龄(56.85±8.67)岁;ⅢB期12例,Ⅳ期33例;鳞癌12例,腺癌33例。试验组男26例,女20例;年龄(55.02±8.23)岁;ⅢB期15例,Ⅳ期31例;鳞癌10例,腺癌36例。对照组接受阿来替尼治疗,试验组在对照组基础上接受帕博利珠单抗治疗。21 d为1个治疗周期,两组均治疗3个周期。比较两组治疗前后基质金属蛋白酶-9(MMP-9)、血清细胞角蛋白19片段抗原21-1(CYFRA21-1)、神经元特异性烯醇化酶(NSE)、糖类抗原9(CA9)、内皮抑素(ES)、血管内皮生长因子(VEGF)、自然杀伤(NK)细胞、CD8^(+)、CD4^(+)水平,临床疗效,药物不良反应;记录两组患者生存情况。采用独立样本t检验、配对t检验、χ^(2)检验。结果治疗后,两组CYFRA21-1、NSE、CA9、MMP-9、VEGF、CD8^(+)水平均低于治疗前(均P<0.05),且试验组均低于对照组(均P<0.05);两组ES、CD4^(+)、NK水平均高于治疗前(均P<0.05),且试验组均高于对照组(均P<0.05)。试验组总有效率高于对照组[78.26%(36/46)比57.78%(26/45)](χ^(2)=4.396,P=0.036)。两组药物不良反应总发生率比较差异无统计学意义(χ^(2)=0.385,P=0.535)。随访1年,试验组失访1例,对照组失访2例,随访率为97.70%。试验组的1年总生存率为55.56%(25/45),对照组的1年总生存率为34.88%(15/43)。两组患者总生存期(OS)曲线比较差异有统计学意义(Log-rankχ^(2)=7.805,P=0.005)。结论帕博利珠单抗治疗ALK突变晚期NSCLC靶向治疗耐药后患者疗效显著,可改善免疫功能,降低肿瘤标志物水平,提高生存率,改善血管生成调节因子水平,且不会明显增加药物不良反应的发生率。

非均匀格网下的耕地集中连片等级划分方法

耕地细碎化导致农业生产成本高、效率低,为了提高耕地利用效率,需实现耕地集中式管理。针对均匀网格在对耕地面积进行表达时数据量冗余和格网尺度选择问题,本文提出了根据斑块平均面积和面积表达误差确定格网最适宜起始和终止尺度的方法,构建基于四叉树的非均匀格网,建立了耕地集中连片分析规则、评价指标体系和技术流程,实现非均匀格网下的耕地集中连片等级划分。以江苏省徐州市为试验区开展耕地集中连片分析。结果表明:①与均匀网格相比,非均匀格网减少了43.8%数据冗余,实现了耕地面积最小误差表达,适用性更强。②徐州耕地连片区域占耕地总面积88.6%,其中50%耕地集中连片等级处于中等偏上水平。③连片区域中有21.4%耕地集中连片等级处于中等以下水平,应将其作为提高区域整体连片等级优先优化的耕地。

风化矿选矿技术现状与进展

矿石风化后其理化性质发生了复杂变化,导致后续选矿难度大、分选效率低。详述了风化金属矿和风化非金属矿选矿技术现状,归纳总结了风化矿分选的主要方法。针对含泥量高、粒度细、嵌布复杂的风化金属矿,可采用预处理强化以及加强分级选矿等方法进行多段选别,提高选矿效果。针对风化非金属矿氧化程度高、杂质含量多的特点,利用辅助手段剥去矿物表面氧化层,联合浮选工艺以及分级选矿的方法可获得较高品位的精矿。通过对风化后的矿物进行工艺矿物学研究,可掌握目的矿物和伴生矿物风化后的矿物特征,为制定分选工艺、选择分选设备、确定选矿药剂提供技术指导。进行矿石工艺矿物学研究是风化矿分选的前提,开发先进分选工艺设备、研制高效选矿药剂是风化矿选矿未来研究的重点。

基于VACCP·TACCP的HACCP体系建立与实施研究

[目的]探究如何在脆弱性评估和关键控制点(VACCP)与威胁评估和关键控制点(TACCP)的基础上,建立和实施一套完善的能解决包括故意污染和蓄意破坏从农田到餐桌的食品生产全过程危害分析与关键控制点体系(HACCP)。[方法]选取20家不同类别的食品生产企业进行对比试验,每家企业建立4种食品安全管理体系,分别为单一HACCP体系,基于VACCP的HACCP体系,基于TACCP的HACCP体系,基于VACCP、TACCP的HACCP体系。针对这4种食品安全管理体系,采用头脑风暴法确定体系评价指标及其权重,采用专家打分和企业管理人员打分的方法,对体系评价指标进行评价,并利用权重计算方法计算每个企业每个体系的评价分数,最后计算平均数。[结果]单一的HACCP体系以预防控制为主,难以解决非传统食品安全问题,打分最低;基于VACCP的HACCP体系可以解决经济利益驱动下的故意污染,基于TACCP的HACCP体系可以解决意识驱动型的蓄意破坏,两者相对于单一HACCP体系都有补充,但是都不全面,打分均高于单一HACCP体系,两者比较,基于VACCP的HACCP体系分数更高一些;基于VACCP、TACCP的HACCP体系打分最高,可以解决全链条的非传统食品安全问题和食品安全问题。[结论]建立与实施基于VACCP和TACCP的HACCP体系可使食品安全管理体系更加完善和有效。

级配与拦挡位置对滑坡碎屑流运动影响研究

为了研究不同级配的高位滑坡碎屑流经多级偏转后冲击不同拦挡结构的运动特性以及致灾效应,结合自然地形构建固定坡度和偏转角度均为45°的离散元模型,并利用DEM软件进行数值模拟分析不同拦挡工况和不同级配对碎屑流颗粒运动过程中能量耗散、最终堆积形态,以及碎屑流冲击挡板的作用高度的影响,进而建立相关冲击力学模型。研究结果显示:(1)上下均设置挡板的工况能有效减缓碎屑流颗粒的平均动能和势能,且能有效降低颗粒流翻越挡板的数量,并降低颗粒流的最大运动距离从而减小致灾范围;随着颗粒组级配的增大,势能时程曲线分散点出现的时间越晚,颗粒流最终堆积面积中细颗粒组最大,粗颗粒组最小。(2)当滑槽底部反作用力位置取2/3静止堆积体长度时,计算所得碎屑流最大冲击作用高度与模拟试验结果相接近,力学模型计算的冲击作用高度在0.017~0.138 m。在实际工程中,可按研究相似比对此范围进行加强抗冲击防护。(3)由于侧板的切向力和“颗粒分选效应”,大颗粒会主要冲击挡板的中上部,小颗粒主要冲击挡板的下部,并受偏转角影响集中在一侧,因此工程设计可根据实际情况避免在沟道偏转方向的反向建设工程。研究结果可为高位滑坡碎屑流灾害的治理防护提供参考。